Electrolyte transfer device and flow battery module

Abstract

The utility model relates to the technical field of redox flow batteries, and discloses an electrolyte transmission device and a redox flow battery module, the electrolyte transmission device comprises an interflow liquid storage structure, a cylinder and a cavity surrounded by the cylinder, and the cylinder is provided with a pressure regulating port, an upper liquid inlet and a lower liquid outlet; the intermittent flow liquid storage structure is arranged to be rotatable, is mounted in the cavity, is positioned below the upper liquid inlet and is used for receiving the electrolyte, the intermittent flow liquid storage structure is provided with at least two hoppers which are arranged at an included angle, and when one hopper is in a receiving state, the other hopper is in a dumping state between two adjacent hoppers. The device provided by the utility model has the advantage that the continuous flow of the electrolyte can be realized while no bypass current is ensured.

Description

Technical Field

[0001] This utility model relates to the field of flow battery technology, specifically to an electrolyte transfer device and a flow battery module. Background Technology

[0002] A flow battery stack consists of multiple individual cells connected in series with their electrolytes in parallel, sharing a common flow channel. Due to the potential difference between the individual cells, ions in the electrolyte undergo directional migration as the electrolyte flows through the stack, influenced by this potential difference. For example, in a vanadium redox flow battery, vanadium ions move through the electrolyte channels between the positive and negative electrodes. Since the connecting pipes between the stacks and the common flow channel within the stack have a certain degree of conductivity, these directionally migrating ions create a current in the pipes—a bypass current. This bypass current bypasses the normal load, leading to energy loss and reducing the overall system efficiency of the battery.

[0003] Eliminating shared electrolyte channels or interrupting them are the main approaches to solving the problem. In the prior art, CN213340450U discloses a bubble interruptor for flow batteries, which forms bubbles in the channel to increase the effective resistance of the solution. However, this bubble method can cause irreversible damage to the exchange membrane if gas enters the stack. CN118553975B discloses a coil-heat dissipation integrated inlet / outlet pipe structure for flow battery stacks, employing a coil structure in all-vanadium flow batteries to increase resistance and reduce bypass current loss. However, this technical solution has a low effect on reducing bypass current loss. CN221508245U discloses an electrolyte spacer transmitter and a bypass interruptor for flow batteries. The bypass current interruption device employs a piston structure to isolate the liquid in the inlet and outlet chambers, thereby blocking the conductivity of the liquid in the flow channel. The reciprocating piston structure of this technical solution prevents the fluid from flowing continuously. CN221708748U discloses a dual-flow battery bypass current interruptor that uses a two-stage liquid storage device. Its main interruption principle is to first use a lever principle to intermittently store the liquid in a temporary liquid storage mechanism, and then release the liquid to the lower liquid storage port through a siphon effect. The disadvantages of this technical solution are that the structure is complex and continuous liquid discharge is not possible; the first and second stage siphon tubes have the risk of intermittent flow failure. Utility Model Content

[0004] The purpose of this invention is to overcome the problem that existing electrolyte transfer devices cannot continuously drain electrolyte, and to provide an electrolyte transfer device, a flow battery module, and a flow battery system, which have the advantage of ensuring no bypass current while achieving continuous electrolyte flow.

[0005] To achieve the above objectives, this utility model provides an electrolyte transfer device, which includes:

[0006] The cylindrical body and the cavity formed by the cylindrical body are provided with a pressure regulating port, an upper liquid inlet and a lower liquid outlet;

[0007] An intermittent flow liquid storage structure is rotatably installed in the cavity and located below the upper liquid inlet for receiving electrolyte. The intermittent flow liquid storage structure has at least two hoppers arranged at an angle, such that when one hopper is in the receiving state, the other hopper is in the tilting state between two adjacent hoppers.

[0008] The second aspect of this utility model provides a flow battery module, wherein the electrolyte transfer device described in this utility model is installed on the inlet and outlet lines of the battery stack of the flow battery module.

[0009] Through the above technical solutions, the electrolyte transfer device of this utility model can fundamentally achieve intermittent flow, ensuring continuous electrolyte flow while preventing bypass current, and without generating pulse-like pressure and flow rate changes. Furthermore, the intermediate flow storage structure of the electrolyte transfer device of this utility model is a purely mechanical structure, which reduces the cost and lifespan risk of valve devices. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the electrolyte transfer device according to one embodiment of the present invention;

[0011] Figure 2 This is a schematic diagram of the electrolyte transfer device according to another embodiment of the present invention;

[0012] Figure 3 This is a schematic diagram of the external structure of an electrolyte transfer device according to one embodiment of the present invention;

[0013] Figure 4 yes Figure 2 A schematic diagram of the intermediate flow liquid storage structure;

[0014] Figure 5 This is a schematic diagram of a flow battery system according to one embodiment of the present invention;

[0015] Figure 6 yes Figure 5 The left view.

[0016] Explanation of reference numerals in the attached figures

[0017] 1 Electrolyte transfer device; 2 Flow battery module; 3 Flow battery unit; 4 Main storage tank; 5 Inlet main pipe; 6 Return main pipe; 7 Circulation pump; 10 Upper inlet; 11 Mounting hole; 12 Pressure regulating port; 13 Top cover; 14 Indirect flow storage structure; 15 Cylinder; 16 Lower outlet; 17 Lower cover; 18 Liquid level sensor mounting port; 20 Battery stack; 21 Outlet pipeline; 22 Inlet pipeline; 141 Side baffle; 142 Indirect baffle. Detailed Implementation

[0018] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0019] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right positions shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component; and "top" and "bottom" are generally used to describe the relative positional relationships of the components in relation to the direction shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0020] To address the problem of continuous electrolyte discharge in existing electrolyte transfer devices, this utility model discloses an electrolyte transfer device, such as... Figures 1-4 As shown, the electrolyte transfer device 1 includes:

[0021] The cylinder 15 and the cavity formed around the cylinder 15 are used to store electrolyte. The top of the cylinder 15 has an upper liquid inlet 10 and the bottom has a lower liquid outlet 16. The top of the cylinder 15 has a pressure regulating port 12. The pressure regulating port 12 is connected to an external air source through an air pipe with a pressure regulating device to regulate the liquid level and ensure the continuous flow of electrolyte inside. It can be understood that the liquid level and the flow rate of electrolyte in the flow battery can be adjusted by adjusting the pressure inside the cavity.

[0022] The intermittent flow storage structure 14 is rotatably installed in the cavity and located below the upper liquid inlet 10 for receiving electrolyte. The intermittent flow storage structure 14 has at least two hoppers arranged at an angle, with one hopper in the receiving state and the other hopper in the tilting state between two adjacent hoppers. Thus, when the electrolyte enters the cavity through the upper inlet 10, it is continuously stored in one of the hoppers of the intermittent flow storage structure 14. When the liquid is poured out of the hopper, the other hopper continues to receive the liquid to ensure continuous liquid intake. The liquid is poured to the bottom of the cavity, and a certain liquid level is ensured at the bottom of the cavity (for example, 40% to 60% of the liquid level from bottom to top of the cavity). Pressurized gas (for example, nitrogen gas with a pressure of 80 kPa to 140 kPa) is introduced through the pressure regulating port 12 to transfer the fluid pressure, so that the electrolyte is continuously discharged through the lower outlet 16. The intermittent flow storage structure 14 of this invention can realize the intermittent flow of electrolyte between the flow battery stack and the common flow channel, ensuring that each energy storage flow battery stack and the common flow channel are disconnected at the same time, avoiding the bypass current of the flow battery energy storage system and improving the efficiency of the flow energy storage system.

[0023] The support member can be configured as a radial support rod fixedly connected to the inner wall of the cavity. The intermittent flow storage structure 14 is fitted onto this support rod and can rotate around it. Specifically, the intermittent flow storage structure 14 includes a hopper assembly, which includes two hoppers fixedly connected. The position of the other hopper is determined by rotating it 10–20° from the position where the inlet of one hopper is directly opposite the inlet 10. Thus, the hopper assembly has two hoppers at an angle of 20–40°. Both hoppers have the same shape and structure, being larger at the top and smaller at the bottom, but differ in capacity. The support rod is installed in the upper middle region of the larger capacity hopper. As the electrolyte flows into the hopper, its center of gravity changes, causing it to rotate around the support rod and pour the electrolyte into the cavity. Because the two hoppers are at an angle of 20–40°, when one hopper is in the pouring state, the other is in the receiving state.

[0024] The longitudinal cross-sectional shape of the hopper in this invention can be various, such as semi-circular, semi-elliptical, or... Figure 1 The trapezoid shown is, for example Figure 1 As shown, lifting lugs can be installed on the top of the larger hopper in the hopper group, and the support rod is passed through the lifting lugs. The unloaded center of gravity of the two hoppers in the hopper group is set on both sides of the support rod.

[0025] It should be noted that the intermittent flow storage structure 14 can also be configured as follows: Figure 2 , Figure 4 The structure shown includes multiple outwardly extending baffles 142 arranged at equal intervals around the circumference. Adjacent baffles 142 are connected by side baffles 141 to form hoppers. This inter-flow liquid storage structure 14 is divided into multiple independently sized hoppers, forming a windmill-like structure. The inter-flow liquid storage structure 14 is mounted on a support and configured to rotate around the support. Electrolyte is fed into the hoppers through the upper inlet 10. When the liquid reaches a certain capacity, the resulting eccentric force and the force exerted by the flowing electrolyte on the inter-flow liquid storage structure 14 cause it to rotate in one direction. When the liquid flow below the upper inlet 10 crosses the next baffle 142, the next hopper begins to store liquid, and the electrolyte from the previous hopper is poured into the cavity. Since the storage and drainage cavities are independent at any given time, inter-flow functionality is achieved.

[0026] To facilitate the flow of liquid below the upper inlet 10 across the next baffle 142, a folding section is provided at the end of the baffle 142.

[0027] To ensure the continuous reaction of the electrolyte, the electrolyte needs to circulate, which results in a certain pressure. Therefore, an explosion-proof device (such as an explosion-proof valve) is installed on the cylinder 15. Specifically, an installation hole 11 for installing the explosion-proof valve can be opened on the cylinder 15. When the pressure value exceeds the protection limit, the explosion-proof valve acts as a protection device.

[0028] To facilitate liquid level detection, the electrolyte transfer device is equipped with a liquid level sensor. There are various forms of liquid level sensors, such as a communicating vessel-type liquid level display structure. The liquid level sensor mounting port 18 of this communicating vessel-type liquid level display structure can be opened in, for example... Figures 1-3 The upper and lower parts of the cylindrical body 15 shown.

[0029] To facilitate loading and unloading, the cylinder can be configured as follows: Figures 1-3 The structure shown has open ends at both ends of the cylinder 15, which are detachably connected to the upper cover 13 and the lower cover 17 respectively. The cylinder 15, the upper cover 13 and the lower cover 17 are sealed together to form a sealed cavity by existing sealing methods.

[0030] Based on the foregoing disclosure, this utility model discloses a flow battery module, such as... Figure 5 As shown, the electrolyte transfer device 1 of this utility model is installed on the inlet line 22 and the outlet line 21 of the stack 20 of the flow battery module 2.

[0031] Based on the foregoing disclosure, this utility model discloses a flow battery system, such as... Figures 5-6 As shown, the flow battery system includes the flow battery module 2 of this invention.

[0032] The flow battery system includes a main liquid storage tank 4 and at least one flow battery unit 3. Each flow battery unit 3 is connected to the main liquid storage tank 4 through a common liquid inlet pipe 5 and a common liquid return pipe 6 to form a circulation pipeline. At least one circulation pump 7 (e.g., a magnetic pump) is installed on the circulation pipeline.

[0033] In existing flow battery systems, each flow battery module typically requires an independent electrolyte supply and return path. To maintain fluid flow between these modules, multiple circulation pumps are usually needed to control the electrolyte circulation of each module. This design not only increases energy consumption and cost but also leads to system complexity and reliability issues. This invention introduces a novel electrolyte transfer device that achieves an "inter-flow" function. Simultaneously, the inter-flow device maintains pressure balance among the battery stack modules, ensuring a uniform electrolyte supply. This allows the entire system to be efficiently driven by a single high-power magnetic pump (such as circulation pump 7), avoiding the energy waste caused by coordinated operation in traditional multi-pump systems.

[0034] Each flow battery unit 3 includes at least one flow battery module 2. The inlet line 22 of each flow battery module 2 is connected to the main inlet line 5 through a common inlet branch pipe, and the outlet line 21 of each flow battery module is connected to the return line 6 through a common outlet branch pipe.

[0035] This invention provides an electrolyte transfer device with excellent adaptability and scalability, suitable for flow battery systems of different specifications and scales. Regardless of system size variations, only adjustments to the transfer device configuration are needed to meet requirements. This design allows for more flexible system expansion, easily increasing or decreasing the number of battery modules.

[0036] In the flow battery system using the electrolyte transfer device of this utility model, the number of flow battery modules 2 is 20 to 30, and the entire system's liquid circulation can be driven by only one 5.5KW magnetic pump. When adding modules, only the number of branch pipes needs to be adjusted, without changing the number of pumps. The power of the pump can be selected according to the requirements.

[0037] like Figures 5-6 The flow battery system shown consists of a battery cluster formed by 28 battery stacks. Each flow battery module 2 includes a battery stack 20, and every four flow battery modules 2 form a flow battery unit 3. Seven flow battery units 3 are connected in parallel on the circulation pipeline, enabling complete charging and discharging of the system. The circuits are connected in series, while the liquid circuits are connected in parallel. Each battery stack 20 has an electrolyte transfer device 1 and an inlet tank installed on its inlet pipeline 22, and an electrolyte transfer device 1 and an outlet tank installed on its outlet pipeline 21. The circulation pump 7 simultaneously fills all 28 inlet tanks with liquid. The incoming liquid compresses the air in the tanks. When the pressure of the compressed air exceeds the flow resistance of the battery stack, the liquid flows into the battery stack, then out to the outlet tank, and then into the main storage tank 4, where it is circulated again by the circulation pump 7. This disconnects the electrical connection between the main storage tank and the battery stack, and also saves power by using a large pump.

[0038] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An electrolyte transfer device, characterized in that, The electrolyte transfer device (1) includes: The cylinder (15) and the cavity formed by the cylinder (15) are provided with a pressure regulating port (12), an upper liquid inlet (10) and a lower liquid outlet (16); The inter-flow liquid storage structure (14) is rotatable, installed in the cavity and located below the upper liquid inlet (10) for receiving electrolyte. The inter-flow liquid storage structure (14) has at least two hoppers arranged at an angle. Between two adjacent hoppers, when one hopper is in the receiving state, the other hopper is in the tilting state.

2. The electrolyte transfer device according to claim 1, characterized in that, A support member is fixedly arranged in the cavity. The interflow liquid storage structure (14) is installed on the support member and can rotate around the support member. The interflow liquid storage structure (14) includes a hopper group. The hopper group includes two hoppers with different capacities that are fixedly connected at an angle of 20 to 40°. The longitudinal section of the hopper is set to be larger at the top and smaller at the bottom, and the support member is installed in the upper middle area of ​​the hopper with larger capacity.

3. The electrolyte transfer device according to claim 2, characterized in that, The larger hopper in the hopper group is equipped with a lifting lug at its top. The lifting lug is rotatably fitted onto the support member. The unloaded center of gravity of the two hoppers in the hopper group is respectively located on both sides of the support member.

4. The electrolyte transfer device according to claim 2 or 3, characterized in that, The longitudinal cross-section of the hoppers in the hopper group is set as semi-circular, semi-elliptical, or trapezoidal.

5. The electrolyte transfer device according to claim 1, characterized in that, A support member is fixedly arranged in the cavity. The interflow liquid storage structure (14) is installed on the support member and can rotate around the support member. The interflow liquid storage structure (14) includes a plurality of outwardly extending inter-baffles (142) arranged circumferentially at equal intervals. Two adjacent inter-baffles (142) are connected by side baffles (141) to form the hopper.

6. The electrolyte transfer device according to claim 5, characterized in that, The end of the baffle (142) is provided with a folding section.

7. The electrolyte transfer device according to claim 1, characterized in that, An explosion-proof device is installed on the cylinder (15).

8. The electrolyte transfer device according to claim 1, characterized in that, The electrolyte transfer device is equipped with a liquid level sensor.

9. The electrolyte transfer device according to claim 1, characterized in that, The two ends of the cylinder (15) are set as open ends and each is detachably connected to an upper cover (13) and a lower cover (17).

10. A flow battery module, characterized in that, The inlet line (22) and outlet line (21) of the stack (20) of the flow battery module (2) are each equipped with an electrolyte transfer device (1) as described in any one of claims 1-9.

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