A kind of negative liquid storage tank air pressure balancing device of all-vanadium redox flow battery

Abstract

The utility model discloses a kind of negative electrode liquid storage tank air pressure balancing devices of all-vanadium redox flow battery, and it is related to energy storage battery technical field, including negative electrode liquid storage tank and U type liquid seal pipe, both ends of U type liquid seal pipe are open setting, its left end is connected with the gas phase interface of negative electrode liquid storage tank, U type liquid seal pipe has stored liquid seal liquid, further include air bag, gas hose and intermediate joint assembly, the air port of air bag is connected with the one end of gas hose by intermediate joint assembly, the utility model is added air bag and gas hose, air bag can utilize self elastic volume change, substantially enhance the adjusting ability of gas volume in negative electrode liquid storage tank, when the air pressure in negative electrode liquid storage tank fluctuates due to temperature change or electrolyte flow, air bag can be through expansion or shrinkage flexible absorption or release inert gas, cooperate U type liquid seal pipe and jointly act, significantly improve the adjusting efficiency of tank air pressure balance.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage battery technology, specifically relating to a pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery. Background Technology

[0002] Vanadium redox flow batteries, as an energy storage device with high energy density and cycle life, have shown great potential in the field of large-scale energy storage.

[0003] However, this battery faces the challenge of balancing the gas pressure in the positive and negative electrode electrolyte tanks during operation. Specifically, the negative electrode tank plays a crucial role in the vanadium redox flow battery. Because it contains divalent vanadium ions, it typically requires sealing to prevent vanadium oxidation. While this sealing design effectively prevents oxygen intrusion, it introduces a new problem—when the ambient temperature changes or the electrolyte flows, the gas volume inside the tank changes accordingly, leading to a pressure imbalance between the inside and outside of the tank. Meanwhile, the positive electrode tank, which does not require sealing, experiences natural pressure changes with temperature. The pressure difference between the positive and negative electrodes accelerates the migration of vanadium ions, further increasing the electrolyte concentration difference and accelerating the decline in battery capacity.

[0004] Currently, pressure regulation technologies in all-vanadium redox flow battery systems mainly include liquid sealing technology or inert gas sealing technology.

[0005] Liquid sealing devices have limited capacity to regulate gas volume within the storage tank, resulting in limited capacity to regulate gas pressure balance. Furthermore, relying on the U-shaped tube level difference to balance gas pressure, significant pressure fluctuations within the tank due to large temperature differences can lead to insufficient liquid seal height, causing liquid backflow or ejection from the seal tube. This inability to offset the pressure difference can result in seal failure and oxygen intrusion, leading to vanadium divalent oxidation. Additionally, while inert gas sealing technology can prevent oxygen intrusion, its airtightness is insufficient, making it prone to inert gas leakage. Regular replenishment of inert gas is necessary, increasing maintenance costs.

[0006] Therefore, we propose a pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery to solve the above problems. Utility Model Content

[0007] To address the problems of current liquid sealing devices being unable to adapt to large pressure changes and inert gas sealing having insufficient sealing performance, leading to increased operation and maintenance costs, this utility model provides a pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery.

[0008] The solution adopted by this utility model to solve its technical problem is: a pressure balancing device for the negative electrode storage tank of a full vanadium redox flow battery, including a negative electrode storage tank and a U-shaped liquid seal tube. Both ends of the U-shaped liquid seal tube are open. Its left end is connected to the gas phase interface of the negative electrode storage tank. The U-shaped liquid seal tube stores liquid seal liquid. It also includes an air bag, a gas guiding hose and an intermediate connector assembly. The air inlet of the airbag is connected to one end of the air delivery hose via an intermediate connector assembly, and the other end of the air delivery hose is inserted from the right end of the U-shaped liquid seal tube and completely passes through the liquid seal liquid.

[0009] Preferably, the airbag is made of a corrosion-resistant material.

[0010] Preferably, a nut is provided at the air inlet of the airbag, and a nut is provided at the outer end of the air guiding hose.

[0011] Preferably, the intermediate joint assembly includes a retaining ring, and a double-threaded joint is welded and fixed to the inner hole of the retaining ring. Both ends of the double-threaded joint are open, one end of which is threadedly connected to nut one and the other end of which is threadedly connected to nut two. An O-ring seal is provided between the double-threaded joint and nut one, and an O-ring seal is provided between the double-threaded joint and nut two.

[0012] Preferably, it also includes two arc-shaped clamps, which are located at the right end of the U-shaped liquid seal tube and are connected by multiple bolts.

[0013] Preferably, a connecting plate is welded and fixed between the lower arc-shaped clamp and the fixing ring.

[0014] Compared with the prior art, the beneficial effects of this utility model are: 1. By adding an airbag and a gas guiding hose, this utility model can significantly enhance the ability to regulate the gas volume in the negative electrode storage tank by utilizing its own elastic volume change. When the gas pressure in the negative electrode storage tank fluctuates due to temperature changes or electrolyte flow, the airbag can flexibly absorb or release inert gas by expanding or contracting. Together with the U-shaped liquid seal tube, it significantly improves the regulation efficiency of gas pressure balance in the tank.

[0015] 2. This utility model combines a U-shaped liquid seal tube with a gas delivery hose, allowing inert gas to be delivered to the gas bladder through the gas delivery hose while preventing external oxygen from back-entering the negative electrode storage tank. Compared with traditional liquid seal technology, this combined design breaks through the limitation of simply relying on the liquid level difference of the U-shaped tube to regulate gas pressure. Even when the temperature difference is large and the gas pressure inside the tank changes significantly, the pressure fluctuation can be buffered by the elastic deformation of the gas bladder, avoiding liquid backflow or spraying caused by insufficient liquid seal height, and ensuring the reliability of gas pressure balance regulation.

[0016] 3. By using an airbag as the core component for air pressure regulation, this utility model eliminates the need for periodic replenishment of inert gas, reducing consumable consumption caused by gas leakage. Furthermore, the airbag is made of corrosion-resistant materials, and the overall structure is reliably sealed, making it less prone to gas leakage. This significantly reduces the frequency and cost of gas replenishment during operation and maintenance, extends the system's maintenance cycle, and improves the economic efficiency of the vanadium redox flow battery system. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This utility model Figure 1 Enlarged structural diagram at point A in the middle; Figure 3 This is a front view cross-sectional structural diagram of the U-shaped liquid seal pipe of this utility model.

[0018] In the diagram: 1 Negative electrode storage tank, 2 U-shaped liquid seal pipe, 3 Airbag, 31 Nut 1, 41 Arc-shaped clamp, 42 Bolt, 51 Double threaded connector, 52 Fixing ring, 6 Connecting plate, 71 Air guide hose, 72 Nut 2. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Please see Figure 1-3 This utility model provides a technical solution for a pressure balancing device for the negative electrode storage tank 1 of a vanadium redox flow battery: Example 1: according to Figure 1-3 As shown, it includes a negative electrode storage tank 1 and a U-shaped liquid seal tube 2. Both ends of the U-shaped liquid seal tube 2 are open. Its left end is connected to the gas phase interface of the negative electrode storage tank 1. The U-shaped liquid seal tube 2 stores liquid seal liquid to prevent external oxygen from back-entering the negative electrode storage tank 1.

[0021] It also includes an airbag 3, a gas-conducting hose 71, and an intermediate connector 51 assembly. The airbag 3 is made of corrosion-resistant materials, such as silicone rubber or fluororubber. A nut 31 is provided at the air inlet of the airbag 3, and a nut 72 is provided at the outer end of the gas-conducting hose 71. The intermediate connector 51 assembly includes a retaining ring 52, and a double-threaded connector 51 is welded and fixed to the inner hole of the retaining ring 52. Both ends of the double-threaded connector 51 are open. One end is threaded to the nut 31, and the other end is threaded to the nut 72. An O-ring is provided between the double-threaded connector 51 and the nut 31, and an O-ring is provided between the double-threaded connector 51 and the nut 72. The intermediate connector 51 assembly realizes the detachable connection between the airbag 3 and the gas-conducting hose 71 through the threaded connection. With the help of the O-ring and the O-ring, the sealing effect is ensured, while facilitating the replacement and maintenance of the components.

[0022] The other end of the gas guiding hose 71 is inserted from the right end of the U-shaped liquid seal tube 2 and completely passes through the liquid seal liquid. By adding the air bag 3 and the gas guiding hose 71, the air bag 3 can greatly enhance the ability to regulate the gas volume in the negative electrode storage tank 1 by utilizing its own elastic volume change. When the gas pressure in the negative electrode storage tank 1 fluctuates due to temperature changes or electrolyte flow, the air bag 3 can flexibly absorb or release inert gas by expanding or contracting. Together with the U-shaped liquid seal tube 2, it significantly improves the regulation efficiency of the gas pressure balance in the tank.

[0023] It also includes two arc-shaped clamps 41, which are located at the right end of the U-shaped liquid seal tube 2. The two arc-shaped clamps 41 are connected by multiple bolts 42. A connecting plate 6 is welded and fixed between the lower arc-shaped clamp 41 and the fixing ring 52 to fix the position of the fixing ring 52. At the same time, it keeps the relative position of the gas guide hose 71 and the U-shaped liquid seal tube 2 fixed, preventing the gas guide hose 71 from shifting and ensuring the reliability of the gas channel.

[0024] In practical use, the pressure balancing device for the negative electrode storage tank of the vanadium redox flow battery of this utility model first tightens the nut 31 to one end of the double threaded connector 51 and installs the O-ring seal to ensure air tightness. Then tightens the nut 72 to the other end of the double threaded connector 51 and installs the O-ring seal to complete the sealed connection between the airbag 3 and the air guiding hose 71. Next, insert the other end of the gas delivery hose 71 from the right end of the U-shaped liquid seal tube 2 and completely pass through the liquid seal liquid. Then, fix the two arc-shaped clamps 41 to the right end of the U-shaped liquid seal tube 2 with bolts 42 to ensure that the gas delivery hose 71 is stable and avoids displacement or loosening. When the gas pressure inside the negative electrode storage tank 1 increases due to temperature rise or electrolyte flow, excess inert gas enters the air bag 3 through the gas guide hose 71. The air bag 3 expands to absorb the gas and maintain stable pressure inside the tank. When the pressure inside the tank decreases, the air bladder 3 contracts and releases inert gas, which flows back to the liquid storage tank 1 through the air guide hose 71 to compensate for the negative pressure.

Claims

1. A pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery, comprising a negative electrode storage tank and a U-shaped liquid-sealed tube, wherein both ends of the U-shaped liquid-sealed tube are open, and its left end is connected to the gas phase interface of the negative electrode storage tank, and the U-shaped liquid-sealed tube stores a liquid-sealed liquid, characterized in that: It also includes airbags, air hoses, and intermediate connector assemblies; The air inlet of the airbag is connected to one end of the air delivery hose via an intermediate connector assembly, and the other end of the air delivery hose is inserted from the right end of the U-shaped liquid seal tube and completely passes through the liquid seal liquid.

2. The pressure balancing device for the negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: The airbag is made of corrosion-resistant material.

3. The pressure balancing device for the negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: A nut is provided at the air inlet of the airbag, and a nut is provided at the outer end of the air guiding hose.

4. The pressure balancing device for the negative electrode storage tank of the all-vanadium redox flow battery according to claim 3, characterized in that: The intermediate joint assembly includes a retaining ring, and a double-threaded joint is welded and fixed to the inner hole of the retaining ring. Both ends of the double-threaded joint are open. One end is threaded to nut one, and the other end is threaded to nut two. An O-ring seal is provided between the double-threaded joint and nut one, and an O-ring seal is provided between the double-threaded joint and nut two.

5. The pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery according to claim 4, characterized in that: It also includes two arc-shaped clamps, which are located at the right end of the U-shaped liquid seal tube and are connected by multiple bolts.

6. The pressure balancing device for the negative electrode storage tank of a vanadium redox flow battery according to claim 5, characterized in that: A connecting plate is welded and fixed between the lower arc-shaped clamp and the fixing ring.

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