A mixed tank for flow battery electrolyte and flow battery

Abstract

The utility model belongs to the technical field of liquid flow battery energy storage system, concretely relates to a kind of mixed storage tank for liquid flow battery electrolyte, including liquid storage tank body, the drive assembly being set on liquid storage tank body, the stirring assembly being connected with drive assembly and the drainage tube being set on liquid storage tank body and extending to the inside of liquid storage tank body, stirring assembly includes stirring shaft and the stirring paddle being connected with stirring shaft, the output end of drainage tube is located the position above stirring paddle.The utility model's mixed storage tank forms axial circulation flow field when rotating by propelling type stirring paddle, and by drainage tube, back liquid is actively sucked and quickly rolled into main flow field, realize global efficient mixing, significantly improve mixing effect, the negative pressure generated by stirring paddle rotation forms suction effect to circulating pipeline, reduce the energy consumption of circulating pump, simple structure and low cost.The utility model further provides a kind of liquid flow battery.

Description

Technical Field

[0001] This utility model relates to the field of flow battery energy storage system technology, specifically to a mixing tank for flow battery electrolyte and a flow battery. Background Technology

[0002] In flow batteries, such as vanadium redox flow batteries, the electrolyte circulates between the storage tank and the battery stack during operation. Maintaining a high degree of uniformity in the concentration and temperature of the electrolyte within the storage tank is crucial, directly affecting the battery's output power, energy efficiency, and lifespan.

[0003] The existing method of electrolyte homogenization is to disperse the return liquid through a distribution pipe. However, this method has problems such as complex distribution pipe structure, high processing precision requirements, and high manufacturing cost. During long-term operation, it is prone to deformation or blockage due to fluid impact, corrosion, or vanadium precipitation, thereby losing the distribution function and forming a mixing dead zone, which is especially unsuitable for large storage tanks.

[0004] Therefore, it is necessary to provide a new type of mixing tank for electrolyte in flow batteries and a flow battery. Utility Model Content

[0005] In view of this, the present invention provides a mixing tank for electrolyte in flow batteries. The mixing tank forms an axial circulating flow field when the propeller-type stirring paddle rotates, and the electrolyte is actively drawn in and quickly drawn into the main flow field through the diversion pipe, achieving efficient mixing throughout the entire area and significantly improving the mixing effect. The negative pressure generated by the rotation of the stirring paddle forms a suction effect on the circulation pipeline, reducing the energy consumption of the circulation pump. The structure is simple and the cost is low.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a mixing tank for electrolyte in flow batteries is provided, including: a storage tank body, a drive assembly disposed on the storage tank body, a stirring assembly connected to the drive assembly, and a drain pipe disposed on the storage tank body and extending into the storage tank body. The stirring assembly includes a stirring shaft and a stirring paddle connected to the stirring shaft. The output end of the drain pipe is located above the stirring paddle.

[0007] Furthermore, the drive assembly includes a drive motor, a reducer connected to the drive motor, and a bearing housing.

[0008] Furthermore, the input shaft of the reducer is coaxially connected to the output shaft of the drive motor, the output shaft of the reducer is coaxially connected to the upper end of the stirring shaft, the housing of the reducer is connected to the bearing seat, and the bearing seat is connected to the liquid storage tank.

[0009] Furthermore, the stirring shaft extends through the shaft hole of the bearing housing into the interior of the liquid storage tank, and the inner ring of the built-in bearing of the bearing housing is fixedly connected to the stirring shaft.

[0010] Furthermore, the upper end of the stirring shaft passes through the bearing seat and is connected to the reducer, the lower end of the stirring shaft extends into the electrolyte inside the storage tank, and the stirring paddle is located at a predetermined liquid level inside the storage tank.

[0011] Furthermore, the stirring impeller is a three-bladed propeller or an airfoil impeller.

[0012] Furthermore, the three blades 221 of the three-bladed propeller are symmetrically distributed at 120° along the central axis, and the blade tilt angle is between 30° and 60°.

[0013] Furthermore, the output end of the drain tube is configured with an oblique cut facing the stirring shaft, and a guide port communicating with the output end of the drain tube and facing the stirring shaft is also provided on the output end.

[0014] To achieve the above objectives, the technical solution adopted by this utility model is: to provide a flow battery, including the mixing tank for the electrolyte of the flow battery provided by any of the above solutions.

[0015] Furthermore, the flow battery also includes a reactor stack, a circulation pipeline, and a delivery pump. The outlet of the storage tank is connected to the inlet of the circulation pipeline, and the inlet of the drain pipe is connected to the return port of the circulation pipeline.

[0016] The beneficial effects of this invention are as follows: The mixing tank for electrolyte in flow batteries uses a propeller-type stirring paddle to form an axial circulating flow field during rotation. Combined with the precise positioning of the outlet end of the drain pipe in the negative pressure zone of the stirring paddle, the electrolyte is actively drawn in and quickly drawn into the mainstream field, achieving efficient mixing across the entire area. This effectively avoids the formation of concentration gradients and dead zones, significantly improving the mixing effect. The negative pressure generated by the rotation of the stirring paddle creates a suction effect on the circulation pipeline, which, in conjunction with the thrust of the delivery pump, reduces the back pressure of the return liquid and reduces the required head of the delivery pump, thereby reducing the power consumption of the main pump, achieving system energy saving, eliminating the need for a complex liquid distribution pipe structure, and using conventional drive components and stirring components, resulting in a simple structure and low cost. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a diagram showing the usage state of the mixing tank according to an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of the mixing tank according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the stirring paddle in an embodiment of the present invention; Figure 4 This is a partially enlarged view of the drainage tube according to an embodiment of the present invention.

[0019] The component names and their numbers in the diagram are as follows: Mixing storage tank 100; Drive assembly 1, drive motor 11, reducer 12, bearing housing 13; Stirring assembly 2, stirring shaft 21, stirring paddle 22, blade 221; Drainage tube 3, output end 31, guide port 311; Storage tank 4; Flow battery 200, reactor 202, circulation pipeline 203, transfer pump 204. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] It should be noted that when a component is referred to as "connected to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 limitations on this utility model.

[0024] Throughout this specification, reference to "an embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in one embodiment," "in some embodiments," or "in some of these embodiments" appear in various places throughout the specification, and not all refer to the same embodiment. Furthermore, in one or more embodiments, a particular feature, structure, or characteristic may be combined in any suitable manner.

[0025] Example 1 This invention provides a mixing tank 100 for electrolyte in a flow battery. The flow battery includes a positive electrode mixing tank, a negative electrode mixing tank, and a reactor stack. The positive electrode electrolyte in the positive electrode mixing tank is output from the positive electrode mixing tank via a positive electrode circulation pipeline and a positive electrode transfer pump, then transported to the reactor stack, and then returned to the positive electrode mixing tank via the positive electrode circulation pipeline, achieving a cyclical transport. The negative electrode electrolyte in the negative electrode mixing tank is output from the negative electrode mixing tank via a negative electrode circulation pipeline and a negative electrode transfer pump, then transported to the reactor stack, and then returned to the negative electrode mixing tank via the negative electrode circulation pipeline, achieving a cyclical transport. The positive and negative electrode electrolytes undergo an electrochemical reaction at the reactor stack to achieve charging and discharging. The mixing tank 100 for electrolyte in a flow battery provided by this invention can be used as a positive electrode mixing tank and / or a negative electrode mixing tank. The electrolyte inside the tank can be uniformly stirred, achieving a high degree of uniformity in the concentration and temperature of the electrolyte within the tank. Since the positive electrode mixing tank, positive electrode circulation pipeline, and positive electrode delivery pump are similarly configured as well as the negative electrode mixing tank, negative electrode circulation pipeline, and negative electrode delivery pump, this description will focus on the mixing tank 100 for flow battery electrolyte provided by this invention, using a single-sided mixing tank, circulation pipeline, and delivery pump as an example. The mixing tank, circulation pipeline, and delivery pump on the other side are not shown in the diagram. Figure 1 As shown, the electrolyte (such as positive electrode electrolyte) in the mixing tank 100 is output from the mixing tank 100 through the circulation pipeline 203 and the transfer pump 204, then transported to the reactor 202, and then returned to the mixing tank 100 through the circulation pipeline 203 to achieve cyclic transport.

[0026] like Figure 1As shown, this embodiment provides a mixing tank 100 for flow battery electrolyte, including a storage tank 4, a drive assembly 1 disposed on the storage tank 4, a stirring assembly 2 connected to the drive assembly 1, and a drain pipe 3 disposed on the storage tank 4 and extending into the storage tank 4. The outlet of the storage tank 4 is connected to the inlet of the circulation pipeline 203. The drive assembly 1 provides a power source for the stirring assembly 2 of the mixing tank 100. The stirring assembly 2 is used to uniformly stir the electrolyte in the storage tank 4 and can generate negative pressure to enhance the stirring effect. The inlet of the drain pipe 3 is connected to the return port of the circulation pipeline 203 for transporting and guiding the refluxed electrolyte after the reaction, thereby reducing flow resistance and directional flow.

[0027] In some of these embodiments, such as Figure 1 and Figure 2 As shown, the storage tank 4 contains electrolyte. The drive assembly 1 includes a drive motor 11, a reducer 12 connected to the drive motor 11, and a bearing housing 13. The stirring assembly 2 includes a stirring shaft 21 and a stirring paddle 22. The drive motor 11 is located on the outside of the storage tank 4. The output shaft of the drive motor 11 is coaxially connected to the input shaft of the reducer 12. The power of the output shaft of the drive motor 11 is transmitted to the reducer 21. The drive motor 11 provides initial power to the entire mixing tank 100, and the drive motor 11 can adjust its speed to adapt to the stirring requirements under different working conditions. At the same time, it works with the reducer 12 to reduce speed and increase torque to meet the torque requirements of electrolyte stirring. The reducer 12 is a transmission reduction mechanism that converts the high speed and low torque of the drive motor 11 into the low speed and high torque required for stirring. A reducer 12 is positioned between the drive motor 11 and the bearing housing 13. The input shaft of the reducer 12 is coaxially connected to the output shaft of the drive motor 11, and the output shaft of the reducer 12 is coaxially connected to the upper end of the stirring shaft 21 of the stirring assembly 2. The housing of the reducer 12 is fixed to the upper end face of the bearing housing 13. The reducer 12 amplifies the torque of the drive motor 11 to meet the torque requirements during electrolyte stirring and prevents the stirring paddle 22 from jamming due to insufficient torque. The bearing housing 13 is positioned below the reducer 12 and fixed to the top cover of the storage tank 4. The bearing housing 13 provides stable radial support for the stirring shaft 21 and restricts its radial displacement. The axis of the shaft hole of the bearing housing 13 coincides with the axis of the output shaft of the reducer 12. The stirring shaft 21 extends through the shaft hole of the bearing housing 13 into the interior of the storage tank 4. The inner ring of the built-in bearing of the bearing housing 13 is fixedly connected to the stirring shaft 21 to achieve radial positioning of the stirring shaft 21. The upper end face of the bearing housing 13 is fixedly connected to the housing of the reducer 12, and the lower end face of the bearing housing 13 is fixed to the top cover of the liquid storage tank 4. The bearing housing 13 can counteract the radial force generated by the high-speed rotation of the stirring shaft 21, prevent the stirring shaft 21 from shaking, ensure that the stirring paddle 22 always rotates in the preset area, and ensure that the stirring paddle 22 generates a uniform flow field.

[0028] In some of these embodiments, such as Figure 1 and Figure 3 As shown, the stirring assembly 2 includes a stirring shaft 21 connected to the reducer 12 and a stirring paddle 22 connected to the stirring shaft 21. The stirring shaft 21 is made of corrosion-resistant material and is a slender cylindrical rod. The length of the stirring shaft 21 matches the preset depth of the storage tank 4, ensuring that the stirring paddle 22 connected to the lower end of the stirring shaft 21 is positioned at the predetermined liquid level of the electrolyte in the storage tank 4. The stirring shaft 21 is distributed along the vertical axis of the storage tank 4. The upper end of the stirring shaft 21 passes through the bearing seat 13 and is connected to the reducer 12. The lower end of the stirring shaft 21 extends into the electrolyte inside the storage tank 4, and most of the shaft of the stirring shaft 21 is located inside the storage tank 4. The upper end of the stirring shaft 21 is coaxially connected to the output shaft of the reducer 12. The upper part of the shaft body of the stirring shaft 21 is fixedly connected to the built-in bearing of the bearing seat 13 to achieve axial positioning. The lower end of the stirring shaft 21 is connected to the center interface of the stirring paddle 22 to ensure that the stirring paddle 22 and the shaft body of the stirring shaft 21 rotate synchronously. The stirring shaft 21 transmits the amplified torque of the reducer 12 to the stirring paddle 22, driving the stirring paddle 22 to rotate to generate a circulating flow field. The stirring paddle 22 is made of corrosion-resistant material. The stirring paddle 22 is fixed to the lower end of the stirring shaft 21 and is completely immersed in the electrolyte in the storage tank 4. The central axis of the stirring paddle 22 coincides with the axis of the stirring shaft 21. The stirring paddle 22 adopts a propulsion axial flow structure. As an example, the stirring paddle 22 adopts a three-bladed propeller or an airfoil propeller. The three blades 221 of the three-bladed propeller are symmetrically distributed at 120° along the central axis, and the inclination angle of the blades 221 is approximately 30°-60°. Because the impeller 22 has a propulsion structure, when the impeller 22 rotates, the blades 221 generate axial thrust on the surrounding electrolyte. The blades push the electrolyte downward in a jet motion. After the electrolyte hits the bottom of the storage tank 4, it diffuses around the inner wall of the storage tank 4 and flows back upward along the inner wall. The backflowing electrolyte is eventually drawn in again by the rotating blades and pushed downward, forming a circulating flow field where the electrolyte is pushed downward, diffused at the bottom of the tank, rises along the inner wall of the tank, and is drawn in again by the blades 221 of the impeller 22. This process covers the area inside the storage tank 4, achieving full-area mixing of the electrolyte. In addition, when the impeller 22 rotates, the back surface of the blades 221, that is, the side where the electrolyte is drawn into the impeller 22, forms a negative pressure zone due to the fluid motion characteristics. During the rotation of the blades, the electrolyte flow velocity in the back surface area increases significantly. According to Bernoulli's principle, the faster the fluid velocity, the lower the pressure. Therefore, a low-pressure negative pressure zone is formed near the back surface of the blades 221.

[0029] In some of these embodiments, see Figure 1 and Figure 2The drain pipe 3 is installed on the liquid storage tank 4 and extends into the interior of the liquid storage tank 4. The drain pipe 3 is made of corrosion-resistant material. The input end of the drain pipe 3 is sealed to the return port of the circulation pipe 203 of the flow battery 200 to receive the electrolyte returning from the reactor stack 202; the output end of the drain pipe 3 extends into the interior of the liquid storage tank 4 and is located above the agitator 22. Figure 4 As shown, the output end 31 of the drain pipe 3 is configured with a bevel, and the bevel of the output end 31 faces the stirring shaft 21. A guide port 311 communicating with the output end 31 of the drain pipe 3 is also provided on the output end 31, and the guide port 311 faces the stirring shaft 21, thus ensuring that both the output end 31 of the drain pipe 3 and the guide port 311 are located within the low-pressure negative pressure zone of the stirring paddle 22. The drain pipe 3 stably transports the reacted electrolyte from the circulation pipeline 203 to the storage tank 4. The bevel of the output end 31 and the guide port 311 reduce the local resistance coefficient when the electrolyte flows out, increase the return flow rate, and ensure that all the return liquid is directly drawn into the negative pressure zone, quickly merging with the circulating flow field of the stirring paddle 22, preventing local accumulation of the return liquid in the tank. As the blades 211 of the agitator 22 rotate, the electrolyte flow rate in the back liquid surface area increases significantly. According to Bernoulli's principle, the faster the fluid flow rate, the lower the pressure. Therefore, a low-pressure negative pressure zone is formed near the back liquid surface of the blades 211. The oblique cut of the output end 31 of the drain pipe 3 and the outlet direction of the guide port 311 are directly facing the negative pressure zone. The electrolyte returning from the fuel cell stack 202 will be quickly drawn into the circulating flow field under the synergistic effect of negative pressure suction and blade 211 propulsion, accelerating the mixing with the original electrolyte in the storage tank 4. Furthermore, since the outlet of the drain pipe 3 is precisely aligned with the negative pressure zone, the electrolyte returning from the fuel cell stack will enter the storage tank 4 more smoothly under the synergistic effect of negative pressure suction. At this time, when the transfer pump delivers the electrolyte, the back pressure of the circulation pipeline 203 on the circulation is significantly reduced due to the assistance of negative pressure suction, which effectively reduces the back pressure of the return pipeline on the transfer pump, reduces the head required by the transfer pump, thereby reducing the power consumption of the transfer pump and reducing the total energy consumption of the system.

[0030] The present invention provides a mixing tank 100 for electrolyte in a flow battery, comprising a storage tank 4, a drive assembly 1 disposed on the storage tank 4, a stirring assembly 2 connected to the drive assembly 1, and a drain pipe 3 disposed on the storage tank 4 and extending into the storage tank 4. The stirring assembly 2 includes a stirring shaft 21 and a stirring paddle 22 connected to the stirring shaft 21. The stirring paddle 22 adopts a propulsion axial flow structure. The output end of the drain pipe 3 is located above the stirring paddle 21, and the output end 31 of the drain pipe 3 is configured as a bevel. The mixing tank 100 for flow battery electrolyte provided by this utility model forms an axial circulating flow field when the propeller-type stirring paddle 22 rotates. Combined with the precise positioning of the output end of the diversion pipe 3 in the negative pressure zone of the stirring paddle 22, the return liquid is actively drawn in and quickly drawn into the mainstream field, achieving efficient mixing throughout the entire area. This effectively avoids the formation of concentration gradients and dead zones, and significantly improves the mixing effect. The negative pressure generated by the rotation of the stirring paddle 22 forms a suction effect on the circulation pipeline, which works in conjunction with the thrust of the delivery pump to reduce the back pressure of the return liquid, reduce the required head of the pump, thereby reducing the power consumption of the main pump and achieving system energy saving. The complex liquid distribution pipe structure is eliminated, and conventional drive components 1 and stirring components 2 are used, resulting in a simple structure and low cost.

[0031] Example 2 This embodiment also provides a flow battery, including the mixing tank 100 for the electrolyte of the flow battery as described in Embodiment 1, a reactor stack, a circulation pipeline, and a delivery pump. Specifically, the flow battery includes a positive electrode mixing tank, a negative electrode mixing tank, and a reactor stack. The positive electrode electrolyte in the positive electrode mixing tank is output from the positive electrode mixing tank through the positive electrode circulation pipeline and the positive electrode delivery pump, then transported to the reactor stack, and then returned to the positive electrode mixing tank through the positive electrode circulation pipeline, thus achieving cyclic transport. The negative electrode electrolyte in the negative electrode mixing tank is output from the negative electrode mixing tank through the negative electrode circulation pipeline and the negative electrode delivery pump, then transported to the reactor stack, and then returned to the negative electrode mixing tank through the negative electrode circulation pipeline, thus achieving cyclic transport. The positive electrode electrolyte and the negative electrode electrolyte undergo an electrochemical reaction at the reactor stack to achieve charging and discharging. The mixing tank 100 for the electrolyte of the flow battery is used as a positive electrode mixing tank and / or a negative electrode mixing tank. Since the setup of the positive electrode mixing tank, positive electrode circulation pipeline, and positive electrode transfer pump is similar to that of the negative electrode mixing tank, negative electrode circulation pipeline, and negative electrode transfer pump, this explanation will focus on a single-sided mixing tank, circulation pipeline, and transfer pump; the other-sided mixing tank, circulation pipeline, and transfer pump are not shown in the diagram. Figure 1As shown, the outlet of the storage tank 100 is connected to the inlet of the circulation pipeline 203; the inlet of the drain pipe 3 is connected to the return port of the circulation pipeline 203. The electrolyte (such as negative electrode electrolyte) in the mixing tank 100 is output from the mixing tank 100 through the circulation pipeline 203 and the transfer pump 204, then transported to the reactor stack 202, and then returned to the mixing tank 100 through the circulation pipeline 203 and the drain pipe 3, realizing the circulation transport. The flow battery provided in this embodiment has the beneficial effects of the mixing tank 100 for the electrolyte of the flow battery provided in Embodiment 1 above, which will not be repeated here.

[0032] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A mixing tank for electrolyte in flow batteries, characterized in that, include: The liquid storage tank, the drive assembly disposed on the liquid storage tank, the stirring assembly connected to the drive assembly, and the drain pipe disposed on the liquid storage tank and extending into the liquid storage tank, wherein the stirring assembly includes a stirring shaft and a stirring paddle connected to the stirring shaft, and the output end of the drain pipe is located above the stirring paddle.

2. The mixing tank for flow battery electrolyte according to claim 1, characterized in that, The drive assembly includes a drive motor, a reducer connected to the drive motor, and a bearing housing.

3. The mixing tank for flow battery electrolyte according to claim 2, characterized in that, The input shaft of the reducer is coaxially connected to the output shaft of the drive motor, the output shaft of the reducer is coaxially connected to the upper end of the stirring shaft, the housing of the reducer is connected to the bearing seat, and the bearing seat is connected to the liquid storage tank.

4. The mixing tank for flow battery electrolyte according to claim 2, characterized in that, The stirring shaft extends through the shaft hole of the bearing housing into the interior of the liquid storage tank, and the inner ring of the built-in bearing of the bearing housing is fixedly connected to the stirring shaft.

5. The mixing tank for flow battery electrolyte according to claim 2, characterized in that, The upper end of the stirring shaft passes through the bearing seat and is connected to the reducer, the lower end of the stirring shaft extends into the electrolyte inside the storage tank, and the stirring paddle is located at a predetermined liquid level inside the storage tank.

6. The mixing tank for flow battery electrolyte according to claim 1, characterized in that, The agitator is a three-bladed propeller or an airfoil propeller.

7. The mixing tank for flow battery electrolyte according to claim 6, characterized in that, The three blades of the three-bladed propeller are symmetrically distributed at 120° along the central axis, and the blade tilt angle is between 30° and 60°.

8. The mixing tank for flow battery electrolyte according to claim 1, characterized in that, The output end of the drain pipe is configured with an oblique cut facing the stirring shaft, and a guide port communicating with the output end of the drain pipe and facing the stirring shaft is also provided on the output end.

9. A flow battery, characterized in that, The flow battery includes a mixing tank for the electrolyte of a flow battery as described in any one of claims 1 to 8.

10. The flow battery according to claim 9, characterized in that, The flow battery also includes a reactor, circulation pipelines, and a delivery pump; The outlet of the storage tank is connected to the inlet of the circulation pipeline; the inlet of the drainage pipe is connected to the return port of the circulation pipeline.

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