Liquid storage tank for flow battery

Abstract

The liquid storage tank comprises a tank body, the outer wall of the tank body adopts a stepped thickness structure from top to bottom, a liquid level pipe unit is arranged on the outer side of the tank body, and the liquid level pipe unit comprises a transparent PVC (polyvinyl chloride) pipe, a graduated scale, a top interface and a bottom interface, a liquid mixing main pipe is arranged at the top of the tank body, the liquid mixing main pipe is of a closed annular structure and is downwards connected with a plurality of liquid mixing branch pipes, each liquid mixing branch pipe is provided with a middle liquid outlet and a bottom liquid outlet, the liquid mixing main pipe is provided with a vent hole, and a manhole flange is arranged at the top of the tank body. The manhole flange is of a bolt pre-tightening sealing structure, and a liquid return flange is further arranged at the top of the tank body and communicated with the liquid mixing main pipe. According to the utility model, the high-efficiency electrolyte mixing is realized through the structural design, the inert atmosphere is accurately controlled, and the cost optimization, the high reliability and the operation safety are realized by adopting the non-contact sensing and modular design.

Description

Technical Field

[0001] This utility model belongs to the field of flow battery technology, and in particular relates to a liquid storage tank for flow batteries. Background Technology

[0002] As an emerging energy storage technology, the research and development of flow batteries can be traced back to the 1970s. Vanadium redox flow batteries (VRFBs), in particular, have gradually become a research hotspot in the field of large-scale energy storage due to their advantages such as long lifespan, high efficiency, and deep discharge capability. With the increasing demand for renewable energy storage, liquid storage tank technology, as one of the key components, has also undergone significant development. From early basic designs to today's high-performance, multi-functional designs, liquid storage tank technology has made significant progress in corrosion resistance, sealing, and intelligent monitoring.

[0003] Currently, the design of flow battery storage tanks primarily focuses on improving the cycle efficiency, safety, and lifespan of the battery system. Particularly in material selection, storage tanks need excellent corrosion resistance to cope with highly oxidizing environments, especially for different types of electrolytes (such as acidic or alkaline). Furthermore, to ensure a uniform distribution of electrolyte valence states and prevent stratification during charging, the storage tank also needs to integrate an effective mixing mechanism. In terms of safety, the storage tank must be able to withstand high pressure and be equipped with an efficient sealing system to prevent leakage. Existing mainstream solutions mainly include mechanical circulation mixing and gas bubbling mixing. Mechanical circulation mixing uses a pumping system to extract the electrolyte from the bottom of the tank and transport it through pipelines to the top for re-injection, thus creating forced convection and promoting the uniform distribution of vanadium ions with different valence states. However, this method typically only achieves surface flow of the electrolyte, and "dead zones" easily form inside the tank (especially in corners or the bottom area), leading to insufficient mixing and affecting battery consistency and cycle life. Gas bubbling involves introducing inert gas into the tank, utilizing the disturbance generated by the rising bubbles to achieve electrolyte mixing. Although this method is simple in structure and easy to maintain, it is difficult to achieve uniform mixing throughout the entire tank in large storage tanks due to the limited range of gas disturbance, especially in tank structures with high aspect ratios, thus limiting its application in large-scale energy storage systems. Furthermore, both mechanical circulation and gas bubbling increase system energy consumption, affecting overall energy efficiency. Therefore, further optimization of mixing strategies is needed to improve mixing efficiency while reducing auxiliary energy consumption. Meanwhile, in large-scale flow battery systems, mature technical specifications for tank layout design have not yet been established. How to rationally arrange tank locations, optimize pipeline connections, and improve space utilization while ensuring mixing effectiveness remains a key research focus and challenge. Summary of the Invention

[0004] The purpose of this utility model embodiment is to provide a liquid storage tank for flow batteries to solve the problems of uneven electrolyte mixing and high energy consumption, while optimizing the layout design of large storage tanks to ensure efficient and stable energy storage operation of flow batteries.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is a liquid storage tank for flow batteries, including a tank body, wherein the outer wall of the tank body adopts a stepped thickness structure from top to bottom.

[0006] The tank body is equipped with a liquid level pipe unit on the outside, including a vertically arranged transparent PVC pipe, a scale, and a top interface and a bottom interface connected to the tank body. Both the top interface and the bottom interface are equipped with shut-off valves.

[0007] The top of the tank is equipped with a main mixing pipe, which has a closed ring structure and is connected downward to multiple mixing branch pipes. Each mixing branch pipe has a middle outlet and a bottom outlet. The main mixing pipe is equipped with a vent.

[0008] The top of the tank is equipped with a manhole flange, which adopts a bolt pre-tightening sealing structure.

[0009] The top of the tank is also equipped with a return flange, which is connected to the mixing main pipe.

[0010] Furthermore, the surface of the scale is coated with a corrosion-resistant protective coating, which is a polytetrafluoroethylene coating.

[0011] Furthermore, the top of the tank is equipped with a radar level sensor, a pressure sensor, a temperature sensor, and an electromagnetic switch valve temperature sensor, and each sensor is connected to the inside of the tank in a non-contact manner.

[0012] Furthermore, the scale has an arc-shaped groove in the middle, and the transparent PVC pipe is embedded in the arc-shaped groove to form a snap-fit ​​structure.

[0013] Furthermore, the top and bottom interfaces are connected to the tank body via flange joints; the transparent PVC pipe is connected to the bottom and top interfaces via flange joints, and the transparent PVC pipe is fixed to the flange joints by clamps.

[0014] Furthermore, the main mixing pipe has an octagonal closed ring structure, with the midpoint of each side vertically connected to a mixing branch pipe, and the outlet direction of the mixing branch pipe is consistent with the direction of the main mixing pipe.

[0015] Furthermore, the tank sidewall is equipped with a fully enclosed ladder railing, and the top edge of the tank is also equipped with a continuous steel railing.

[0016] Compared with existing technologies, the beneficial effects of this utility model are as follows: The tank body of the liquid storage tank for the flow battery of this utility model adopts PPH material and spiral extrusion winding molding process, combined with the stepped thickness design of the outer wall, which reduces material consumption while ensuring structural strength, and achieves lightweighting and optimized manufacturing costs. The liquid level tube unit uses a transparent PVC pipe and a scale for mechanical liquid level display, providing a redundant verification means for electronic sensors and enhancing system reliability; the corrosion-resistant coating and arc-shaped groove design on the scale surface improve corrosion resistance and mechanical stability. The standardized flange interface, clamp fixing structure and shut-off valve configuration of the liquid level tube unit support plug-and-play quick replacement and can isolate system pressure during maintenance to avoid the risk of liquid leakage. This utility model uses an octagonal closed-loop mixing main pipe and a combination of multiple branch pipes, combined with the directional flow guidance of the middle and bottom outlets, to form a ring vortex, eliminate the mixing "dead zone" and improve the homogenization efficiency of the electrolyte. The mixing main vent is linked to an inert gas supply system, introducing inert gas only when the electrolyte supply stops. This maintains the system's inert environment and avoids the continuous gas consumption of traditional bubbling methods, reducing operating energy consumption. The radar level sensor and pressure sensor in this invention employ non-contact installation to prevent electrolyte corrosion and extend sensor lifespan. The fully enclosed structure design of the ladder railing and top steel railing enhances safety protection for high-altitude operations. Components such as the level pipe and flange interfaces adopt standardized designs to adapt to different specifications of storage tanks, supporting flexible system expansion and rapid maintenance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the liquid storage tank in this embodiment;

[0019] Figure 2 This is a cross-sectional view of the liquid storage tank in this embodiment;

[0020] Figure 3 This is a cross-sectional view of the top of the storage tank in this embodiment;

[0021] Figure 4 This is a schematic diagram of the liquid level tube in this embodiment;

[0022] In the diagram: 1. Tank body; 2. Liquid level pipe unit; 3. Manhole flange; 4. Radar liquid level sensor; 5. Pressure sensor; 6. Return flange; 7. Temperature sensor; 8. Electromagnetic switch valve; 9. Ladder railing; 10. Mixing branch pipe; 11. Mixing main pipe; 12. Vent; 13. Transparent PVC pipe; 14. Clamp; 15. Bottom interface; 16. Top interface; 17. Shut-off valve; 18. Ruler. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] like Figures 1-4 This embodiment provides a liquid storage tank for a flow battery, including a tank body 1. The tank body 1 is made of PPH (Polypropylene Homopolymer) material and adopts large-scale spiral extrusion winding technology. The outer wall of the tank body 1 adopts a stepped thickness design from top to bottom, which can effectively reduce material consumption while meeting structural strength requirements, thereby achieving cost optimization.

[0025] In some specific embodiments, a level tube is configured on the outside of the tank body 1. The level tube unit 2 includes a vertically installed transparent PVC pipe 13, on which a scale 18 is correspondingly set, which can be used to monitor the dynamic changes in the electrolyte level in real time. When the electronic detection equipment fails, it can provide level information as a backup observation method. At the same time, it can also be used to verify the reading accuracy of the electronic measuring equipment, which helps to accurately grasp the trend of electrolyte storage changes and improve the decision-making efficiency and system reliability of operation and maintenance management.

[0026] In some possible implementations, the scale 18 is coated with polytetrafluoroethylene or other corrosion-resistant protective coatings to enhance its corrosion resistance, achieving liquid level measurement while also ensuring compatibility with the buffer structure. The scale 18 has an arc-shaped groove in the center, into which a transparent PVC tube 13 is embedded. This effectively resists the impact of turbulent flow inside the storage tank and accidental external mechanical collisions, ensuring the structural stability and operational reliability of the measurement system, thereby extending the overall service life of the equipment.

[0027] In some possible implementations, the level tube unit 2 further includes a top interface 16 and a bottom interface 15, which are connected to the tank 1 via flange joints. A transparent PVC pipe 13 is connected to both the bottom interface 15 and the top interface 16 via flange joints, and the transparent PVC pipe 13 is fixed to the flange joints by clamps 14. Both the top interface 16 and the bottom interface 15 are equipped with shut-off valves 17. When the transparent PVC pipe 13 ages or other components need replacement, the shut-off valves 17 can be closed to effectively isolate the system pressure. This allows for pre-cutting of the tank 1's passage before equipment inspection and maintenance, releasing the pressure accumulated inside the component to be replaced. This effectively prevents the risk of liquid splashing and leakage caused by residual pressure inside the tank, improves the operational safety and stability of the system under high temperature and high load conditions, ensures operator safety, and expands the system's safety boundaries. In this embodiment, both the flange and the clamp 14 adopt a standardized interface design to form a plug-in component structure, which can achieve quick maintenance or replacement without relying on professional tools, significantly shortening equipment downtime. At the same time, it has good versatility and can be adapted to various specifications of liquid storage tanks to meet the needs of flexible system expansion.

[0028] In some specific embodiments, the top of the tank 1 is provided with a manhole flange 3, which facilitates operators to enter the container for inspection, maintenance, or cleaning. This manhole flange 3 uses a bolted connection structure, and achieves sealing performance through pre-tightening force, effectively preventing media leakage and blocking the intrusion of external contaminants, ensuring the safety and reliability of the system operation.

[0029] In some specific embodiments, a radar level sensor 4, a pressure sensor 5, a temperature sensor 7, and an electromagnetic switch valve 8 are integrated and installed on the top of the tank 1. Each sensor has no direct contact with the electrolyte, thus effectively avoiding corrosion risks and improving the stability and service life of the system. The radar level sensor 4, pressure sensor 5, temperature sensor 7, and electromagnetic switch valve 8 are connected via a wireless signal transmission module (such as Bluetooth, LoRa, etc.). The radar level sensor 4 is used to monitor the liquid level inside the tank in real time; the pressure sensor 5 is used to detect pressure changes inside the tank to ensure that the pressure is within a safe range; the temperature sensor 7 is used to collect real-time temperature data of the electrolyte; and the electromagnetic switch valve 8 opens to release air when the air pressure inside the tank exceeds a set threshold, ensuring the safe operation of the tank.

[0030] In some specific embodiments, the side wall of the tank body 1 is provided with a ladder railing 9, which is set as a fully enclosed structure according to the height of the liquid storage tank to improve the safety protection level of working at height; a continuous steel railing is set at the top edge of the tank body 1 to ensure the operational safety of maintenance personnel during high-altitude operations, prevent the risk of falling, and improve the safety and standardization of the overall operation and maintenance process.

[0031] In some specific embodiments, a return flange 6 is provided at the top of the tank body 1, and a mixing main pipe 11 is provided at the top inside the tank body 1. The mixing main pipe 11 is connected downward to multiple mixing branch pipes 10. Specifically, the mixing main pipe 11 adopts an octagonal closed ring structure, with a mixing branch pipe 10 vertically connected downward at the midpoint of each side. The electrolyte enters the mixing main pipe 11 inside the tank through the return flange 6 and is transported to the inside of the storage tank through the mixing branch pipes 10. Each mixing branch pipe 10 is provided with a middle outlet and a bottom outlet, and the direction of the outlet is consistent with the direction of the mixing main pipe 11, thereby forming a ring vortex inside the storage tank, realizing efficient turbulent mixing of the electrolyte at different scales. This not only overcomes the "dead zone" problem existing in traditional methods, but also improves the liquid homogenization effect and system mass transfer efficiency.

[0032] In this embodiment, each mixing branch pipe 10 is provided with a middle outlet and a bottom outlet to ensure that the electrolyte can enter the storage tank from multiple directions, further enhancing the mixing effect and making the distribution of electrolyte in the storage tank more uniform, thus avoiding the local unevenness that may occur in traditional methods.

[0033] In some specific embodiments, the mixing main pipe 11 is equipped with a vent 12. When the electrolyte stops entering the storage tank, the vent 12 introduces inert gas from inside the storage tank into the entire system, thereby maintaining an inert atmosphere and effectively preventing oxidation or other adverse chemical reactions. This embodiment not only ensures the stability and safety of the system's internal environment but also significantly reduces energy consumption compared to traditional gas bubbling and stirring methods. Traditional gas bubbling methods often result in high energy consumption and potential safety hazards due to the need for a continuous supply of inert gas to generate sufficient stirring. This embodiment, by precisely controlling the timing and amount of inert gas introduction, ensures necessary protective effects while improving operational safety and energy efficiency. Furthermore, this embodiment reduces unnecessary mechanical stress and noise pollution caused by gas bubbling, further enhancing the overall reliability and operational stability of the system.

[0034] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. A liquid storage tank for a flow battery, comprising a tank body (1), characterized in that, The outer wall of the tank (1) adopts a stepped thickness structure from top to bottom; The tank body (1) is provided with a liquid level pipe unit (2) on the outside, including a vertically arranged transparent PVC pipe (13), a scale (18), and a top interface (16) and a bottom interface (15) connected to the tank body (1). Both the top interface (16) and the bottom interface (15) are equipped with shut-off valves (17). The tank body (1) is provided with a mixing main pipe (11) at the top. The mixing main pipe (11) has a closed ring structure and is connected to multiple mixing branch pipes (10) downwards. Each mixing branch pipe (10) is provided with a middle outlet and a bottom outlet. The mixing main pipe (11) is provided with a vent hole (12). The top of the tank body (1) is provided with a manhole flange (3), and the manhole flange (3) adopts a bolt pre-tightening sealing structure; The tank body (1) is also provided with a return flange (6) at the top, which is connected to the mixing pipe (11).

2. The liquid storage tank for a flow battery according to claim 1, characterized in that, The scale (18) is coated with a corrosion-resistant protective coating, which is a polytetrafluoroethylene coating.

3. The liquid storage tank for a flow battery according to claim 1, characterized in that, The top of the tank (1) is equipped with a radar level sensor (4), a pressure sensor (5), a temperature sensor (7), and an electromagnetic switch valve (8). The temperature sensor (7) is connected to the inside of the tank (1) in a non-contact manner.

4. The liquid storage tank for a flow battery according to claim 1, characterized in that, The scale (18) has an arc-shaped groove in the middle, and the transparent PVC pipe (13) is embedded in the arc-shaped groove to form a snap-fit ​​structure.

5. The liquid storage tank for a flow battery according to claim 1, characterized in that, The top interface (16) and bottom interface (15) are connected to the tank body (1) through flange joints; the transparent PVC pipe (13) is connected to the bottom interface (15) and the top interface (16) through flange joints, and the transparent PVC pipe (13) is fixed to the flange joints by clamps (14).

6. The liquid storage tank for a flow battery according to claim 1, characterized in that, The main mixing pipe (11) is an octagonal closed ring structure, with the midpoint of each side vertically connected to the mixing branch pipe (10). The outlet direction of the mixing branch pipe (10) is consistent with the direction of the main mixing pipe (11).

7. The liquid storage tank for a flow battery according to claim 1, characterized in that, The tank (1) has a fully enclosed ladder fence (9) on its side wall, and a continuous steel fence is provided on the top edge of the tank (1).

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