Static mixer for balancing electrolyte concentration of flow battery

Abstract

The utility model belongs to the technical field of flow batteries, and discloses a static mixer for balancing the electrolyte concentration of a flow battery, which realizes zero energy consumption, high mixing efficiency and flexible adaptability through the design of a multi-section annular mixing structure, an anti-blocking runner and a modular mixing structure. The mixer does not need external power, the electrolyte concentration difference can be controlled within + / -5%, and the mixer supports rapid disassembly, assembly and maintenance and is suitable for a large-scale flow battery energy storage system.

Description

Technical Field

[0001] This utility model relates to the field of flow battery technology, specifically to a static mixer for balancing the electrolyte concentration in a flow battery. Background Technology

[0002] The uniformity of electrolyte concentration in flow batteries is a key factor affecting energy conversion efficiency and cycle life. In existing technologies, dynamic mixers (such as mechanical stirring and pump circulation systems) rely on external power input, resulting in problems such as high energy consumption, easy wear and clogging of mechanical parts; while traditional static mixers (such as simple pipe structures) are difficult to eliminate concentration gradients due to insufficient turbulence disturbance.

[0003] Currently, flow battery electrolyte mixing technology is mainly divided into the following two categories:

[0004] Dynamic mixing technology: This technology uses mechanical stirrers, circulating pumps, or dynamic mixing devices to forcibly mix the electrolyte. This type of technology relies on external power input, and its energy consumption accounts for 15%-20% of the total system energy consumption. Major drawbacks include easy wear and clogging of mechanical parts, high maintenance costs, and reduced system efficiency due to complex circuit switching.

[0005] Static mixing technology utilizes fixed structures within the pipe (such as spiral vanes or baffles) to generate turbulent disturbances. However, traditional static mixers, due to their simple structure, struggle to eliminate concentration gradients at low flow rates (concentration differences typically exceed ±20%), and improper flow channel design can easily lead to sedimentation and blockage. Key drawbacks include low mixing efficiency, inability to adapt to high-viscosity electrolyte requirements, and a lack of modular structural expansion capabilities.

[0006] The main bottlenecks of existing technologies are: ① contradiction between energy consumption and efficiency: dynamic mixing requires continuous energy input, while static mixing is not efficient enough; ② frequent flow channel blockage: impurities in the electrolyte are prone to deposit in narrow flow channels or dead corners of the structure; ③ poor scalability: the internal structure of existing mixers is mostly of fixed size, making it difficult to adapt to different battery systems. Summary of the Invention

[0007] This utility model aims to provide a static mixer with "zero energy consumption, anti-clogging, and modular structure expansion", which achieves breakthroughs through the following technical means: ① Static powerless design: using the own flow inertia of the electrolyte to drive mixing, with no additional energy consumption; ② Anti-clogging optimization: suppressing precipitation and adhesion through optimized flow channel structure and corrosion-resistant material coating; ③ Modular and flexible configuration: supporting the replacement of internal flow guiding structure to adapt to different systems.

[0008] This application provides a static mixer for equalizing the electrolyte concentration in a flow battery, comprising a mixing chamber, an upper cover, a lower cover, and a support frame. The upper cover has multiple inlet channels, and the lower cover has multiple outlet channels. Electrolytes of different concentrations flow into the mixing chamber through the inlet channels and flow out through the outlet channels. Inside the mixing chamber, at least five annular mixing structures are spaced apart along the liquid flow direction. A fixed annular mixing structure with a larger inner diameter is connected to the inner wall of the mixing chamber and fixed to it via slots welded to the inner wall. The number of slots can be adjusted according to actual needs. A floating annular mixing structure with a smaller inner diameter is connected via a support rod and can slide within the length of the support rod. The fixed and floating annular mixing structures have different radial cross-sectional shapes and dimensions to generate alternating disturbances to the electrolyte. The support frame is welded to the mixing chamber to fix the static mixer. The mixer as a whole is a static mixing structure, requiring no external power input, and achieving concentration equalization through the inertia of electrolyte flow.

[0009] By adopting the above technical solution, the fluid mixing effect in the static mixer can be enhanced, and the difference in electrolyte concentration can be reduced.

[0010] Furthermore, at least five annular structures are spaced apart along the axial direction of the mixing cavity. The radial cross-sectional shapes of adjacent structures can all be circular, or they can be differentiated (e.g., alternating arrangements of circles, hexagons, or circles and waves). The radial cross-sectional areas of adjacent structures are staggered, with the uppermost layer being a fixed annular mixing structure with the same inner diameter as the mixing cavity. The second layer is a floating annular mixing structure with an inner diameter smaller than the mixing cavity's inner diameter. The diameter of the circular floating annular mixing structure is 70%-80% of the mixing cavity's inner diameter; the diameter of the inscribed circle of the hexagonal floating annular mixing structure is 60%-70% of the mixing cavity's inner diameter; the wave-shaped floating annular mixing structure has a peak spacing of 10-15 mm and a wave height of 3-5 mm. The axial height between adjacent structures is 15%-25% of the mixing cavity's diameter, ensuring a balance between disturbance intensity and pressure drop.

[0011] By adopting the above technical solution, fluid disturbance can be increased by changing the flow cross-sectional area, making the electrolyte mix more uniform.

[0012] Furthermore, the mixing chamber is a cylindrical cavity with its inner wall surface coated with polytetrafluoroethylene (PTFE) or silicon carbide ceramic composite material, with a surface roughness ≤0.1μm, which significantly reduces frictional resistance and electrolyte adhesion.

[0013] By adopting the above technical solution, the adhesion of impurities in the electrolyte to the mixing chamber can be reduced, thereby reducing the risk of flow channel blockage.

[0014] Furthermore, the fixed annular hybrid structure consists of a circular annular plate and guide vanes, with the guide vanes welded to the annular plate. The guide vanes have a certain tilt angle, with the angle between the vanes and the horizontal plane being 5-10°. All vanes rotate in the same direction, either clockwise or counterclockwise. The inner diameter of the annular plate is half the outer diameter.

[0015] By adopting the above technical solution, the swirling intensity in the mixing chamber can be enhanced, the dead zone of the flow can be reduced, and the mixing efficiency can be improved.

[0016] Furthermore, the upper part of the floating mixing structure is provided with a flow guide protrusion, the rotation direction of the flow guide protrusion is consistent with the rotation direction of the flow guide blade, and the support rod is embedded between the two fixed annular mixing structures through a fixing groove.

[0017] By adopting the above technical solution, the combination of the guide protrusions and guide blades increases the circumferential swirling flow in the mixing chamber, thereby achieving the effect of static stirring.

[0018] Furthermore, the spacing between the fixed annular mixing structure and the floating annular mixing structure is dynamically designed based on the electrolyte viscosity, with the difference between adjacent spacings being 10%-20% of the mixing chamber diameter.

[0019] By adopting the above technical solutions, the possibility of high-concentration electrolyte accumulating in the flow dead zone is reduced, the anti-blocking function and the mixing function are reasonably balanced, and the mixer structure is optimized.

[0020] Furthermore, the mixer adopts a modular design, allowing for the free disassembly and replacement of different fixed ring mixing structures and floating ring mixing structures via slots to adapt to flow battery systems of different capacities.

[0021] By adopting the above technical solution, the mixing structure inside the mixing chamber can be adjusted and replaced, making it easier to adapt the optimal mixing structure to electrolytes with different parameters.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. Employing a static mixing structure, no additional power is required. Flow velocity is increased through guide vanes and guide protrusions, enhancing mixing efficiency within the mixing chamber.

[0024] 2. The mixing chamber employs an internal coating and a variable cross-section flow channel to enhance the mixer's anti-clogging performance. The wall coating inhibits sediment adhesion, while the variable cross-section flow channel increases turbulence and reduces flow dead zones.

[0025] 3. The internal structure of the mixing chamber adopts a modular form, and the replaceable flow guide structure can be adapted to flow battery systems of different capacities and forms. Attached Figure Description

[0026] Figure 1This is a three-dimensional structural diagram of an embodiment of this application.

[0027] Figure 2 This is a cross-sectional view of an embodiment of this application.

[0028] Figure 3 This is a partial view of positions A and B in the embodiments of this application.

[0029] Explanation of reference numerals in the attached drawings: 1. Mixing chamber; 101. Fixed annular mixing structure; 1011. Circular plate; 1012. Guide vane; 102. Floating annular mixing structure; 1021. Guide protrusion; 103. Slot; 104. Support rod; 105. Fixing groove; 2. Upper cover; 201. Liquid inlet; 3. Lower cover; 301. Liquid outlet; 4. Support frame. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1-3 The present application will be further described in detail with reference to the embodiments.

[0031] This application discloses a static mixer for balancing the electrolyte concentration in a flow battery. (Reference) Figure 1 The mixing chamber 1 is cylindrical with an outer diameter of 500 mm and a wall thickness of 10 mm. A support frame 4 is welded to each of the left and right sides of the mixer for fixing it. The upper end of the mixing chamber 1 is connected to an upper cover 2, and the lower end is connected to a lower cover 3. The upper cover 2 has four liquid inlet ports 201, evenly distributed along its circumference. The lower cover 3 has four liquid outlet ports 301, evenly distributed along its circumference, staggered with the liquid inlet ports 201. The outer diameter of both the liquid inlet ports 201 and the liquid outlet ports 301 is 32 mm.

[0032] refer to Figure 2Within the mixing chamber 1, fixed annular mixing structures 101 and floating annular mixing structures 102 are arranged alternately. The fixed annular mixing structures 101 are fixed by slots 103, and the floating annular mixing structures 102 are connected to the fixed annular mixing structures 101 via support rods 104. The uppermost and lowermost ends of the mixing chamber 1 are occupied by fixed annular mixing structures 101, with floating annular mixing structures 102 interspersed in between. The axial distance between the fixed annular mixing structures 101 and the floating annular mixing structures 102 is 150 mm. The fixed annular mixing structures 101 are in contact with the inner wall of the mixing chamber 1, and the diameter of the floating annular mixing structures 102 is 70% of the inner diameter of the mixing chamber 1. Six to eight support rods 104 are distributed circumferentially along the mixing chamber 1. The upper and lower ends of the support rods 104 are fixed in fixing grooves 105 on the fixed annular mixing structures 101 and the floating annular mixing structures 102, respectively. The fixing grooves 105 are 5 mm deep, and the thicknesses of the fixed annular mixing structures 101 and the floating annular mixing structures 102 are 20 mm. Multiple slots 103 are distributed along the axial direction of the mixing chamber 1, with a total number of not less than 5 layers. Each layer has at least 4 slots 103 evenly distributed in the circumferential direction. The fixed annular mixing structure 101 is fixed by the slots 103.

[0033] refer to Figure 2 , Figure 3 The fixed annular hybrid structure 101 consists of an annular plate 1011 and guide vanes 1012. The inner diameter of the annular plate 1011 is half the diameter of the outer diameter. The guide vanes 1012 have an inclination angle of 5° with the horizontal plane. Six guide vanes 1012 are distributed circumferentially along the inner ring of the annular plate 1011. The guide vanes 1012 have a rotation direction; clockwise rotation is defined as the height of the guide vanes 1012 decreasing in a clockwise direction, and counterclockwise rotation is defined as the height of the guide vanes 1012 decreasing in a counterclockwise direction. In this embodiment, clockwise rotation is used, but both rotation directions can be used in practice.

[0034] refer to Figure 2 , Figure 3 The floating annular hybrid structure 102 includes a flow-guiding protrusion 1021, which is spiral-shaped. In this embodiment, it rotates clockwise. The rotation directions of the flow-guiding blade 1012 and the flow-guiding protrusion 1021 must be consistent. The flow-guiding protrusion 1021 is 2mm wide and 5mm high.

[0035] The implementation principle of a static mixer for a balanced flow battery electrolyte provided in this application embodiment is as follows: Electrolytes of different concentrations converge into the mixer through multiple inlet channels. Through the mixing action of the guide vanes on the fixed annular mixing structure, the electrolytes generate a certain tangential velocity and rotate around the center of the mixing chamber, enhancing the mixing effect of electrolytes of different concentrations. After the fixed annular mixing structure, the guide protrusions of the floating annular mixing structure further increase the tangential velocity of the electrolyte. After several layers of alternating circulation of fixed and floating annular mixing structures, the electrolyte concentration difference is balanced.

[0036] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A static mixer for equalizing the concentration of electrolyte in a flow battery, characterized by, The application relates to a static mixer for electrolyte, which comprises a mixing cavity (1), an upper cover (2), a lower cover (3) and a support frame (4). The upper cover (2) is provided with a plurality of liquid inlet flow channel openings (201), and the lower cover (3) is provided with a plurality of liquid outlet flow channel openings (301). At least five annular mixing structures are arranged in the mixing cavity (1) along the liquid flow direction. A fixed annular mixing structure (101) with a large inner diameter is connected with the inner wall of the mixing cavity (1) and is fixed on the inner wall of the mixing cavity (1) through clamping grooves (103) which are welded on the inner wall of the mixing cavity (1). The number of the clamping grooves (103) can be adjusted according to actual conditions. A floating annular mixing structure (102) with a small inner diameter is connected through support rods (104) and can slide within the length range of the support rods (104). The radial section shape and size of the fixed annular mixing structure (101) and the floating annular mixing structure (102) are different, and the fixed annular mixing structure (101) and the floating annular mixing structure (102) are used for alternately disturbing electrolyte. The support frame (4) is welded on the mixing cavity (1) and is used for fixing the static mixer. The whole mixer is a static structure, does not need external power input, and realizes concentration balance through electrolyte flow inertia.

2. The static mixer of claim 1, wherein, The radial section shape of the fixed annular mixing structure (101) and the floating annular mixing structure (102) includes any one of a circle and a wave shape.

3. The static mixer of claim 1, wherein, The surface of the mixing cavity (1) is coated with a corrosion-resistant material layer, and the surface roughness is less than or equal to 0.1 mu m. The corrosion-resistant material is polytetrafluoroethylene or silicon carbide ceramic composite material.

4. The static mixer of claim 1, wherein, The fixed annular mixing structure (101) is composed of a circular ring plate (1011) and guide vanes (1012), and the guide vanes (1012) are welded on the circular ring plate (1011). The guide vanes have a certain inclination angle, the included angle between the vanes and the horizontal plane is 5-10 DEG, all the vanes rotate in the same direction and rotate clockwise or counterclockwise. The inner diameter of the circular ring plate is 1 / 2 of the outer diameter.

5. The static mixer of claim 1, wherein, The floating annular mixing structure (102) is provided with guide protrusions (1021) on the upper portion, the rotating direction of the guide protrusions (1021) is consistent with the rotating direction of the guide vanes (1012), and the support rods (104) are embedded between the two fixed annular mixing structures (101) through fixed grooves (105).

6. The static mixer of claim 1, wherein, The interval between the fixed annular mixing structure (101) and the floating annular mixing structure (102) is dynamically designed according to the viscosity of electrolyte, and the difference between the adjacent intervals is 10%-20% of the diameter of the mixing cavity (1).

7. The static mixer of claim 1, wherein, The mixer adopts modular design, and different fixed annular mixing structures (101) and floating annular mixing structures (102) can be freely disassembled, replaced and used to adapt to liquid flow battery systems with different capacities through the clamping grooves (103).

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