CN-122025713-A - Flow battery gas self-layering waste gas treatment system

Abstract

The invention belongs to the technical field of energy storage of flow batteries, and particularly relates to a flow battery gas self-layering waste gas treatment system which can realize efficient recovery of useful components and thorough elimination of harmful substances in waste gas on the premise of not damaging electrolyte ion balance, so that the dual problems of battery performance degradation and harmful gas leakage are solved. The invention realizes the efficient recovery and the return of acid radical ions in the waste gas, fundamentally avoids the problem of unbalance of electrolyte ions caused by waste gas treatment, maintains the performance and the service life of the battery, greatly reduces the risk of leakage of toxic and harmful gases to the environment through closed circulation and efficient purification in the system, improves the safety and the environmental friendliness of the system, optimizes the gas-liquid separation and reaction process, and remarkably improves the recovery efficiency and the overall treatment efficiency of useful components in the waste gas.

Inventors

• LIU HAOJI
• MAO HENGSHAN
• LIU XIAOJIE
• HU WEIHAO
• HAN WENJIE
• WANG JIE
• LI WEI
• WANG TAO
• LIU JUN

Assignees

• 中电建新能源集团股份有限公司

Dates

Publication Date

20260512

Application Date

20251231

Claims (10)

1. 1. The flow battery gas self-layering waste gas treatment system is characterized by comprising a gas storage tank, a gas pump and a gas disperser; the inside of the air storage tank is divided into an upper air chamber and a lower air chamber by a partition plate which is horizontally arranged; the upper air chamber is provided with a nitrogen replacement port and an exhaust valve; The lower air chamber is communicated with the upper air chamber through a venturi tube; The inlet end of the air pump is connected to the gas phase space of the positive electrode electrolyte storage tank and/or the negative electrode electrolyte storage tank of the flow battery system through a pipeline, and the outlet end of the air pump is connected to the upper air chamber of the air storage tank; The gas disperser is arranged in a negative electrolyte storage tank of the flow battery system and is communicated with a lower air chamber of the air storage tank through a pipeline.
2. 2. The system of claim 1, wherein the partition is fixedly installed at a middle or upper portion of an inner wall of the air tank for promoting stratification of the mixed exhaust gas entering the air tank in the upper and lower air chambers based on a density difference.
3. 3. The system of claim 1, wherein the venturi has an opening at one end thereof at an upper portion of the lower plenum for extracting the low-density gas accumulated therein and an opening at the other end thereof in communication with the upper plenum for delivering the low-density gas thereto.
4. 4. The system of claim 1, wherein the gas disperser is one of a microporous aerator, a sintered metal disperser, or a porous ceramic disperser.
5. 5. The system of claim 1, further comprising a first valve disposed on a line connecting the gas disperser and the lower plenum.
6. 6. The system of claim 1, further comprising a second valve disposed on a line connecting the upper plenum and the gas phase space of the positive electrolyte tank.
7. 7. The system according to claim 1, wherein the inlet end of the air pump is connected to the gas phase spaces of the positive electrolyte tank and the negative electrolyte tank, respectively, through a three-way valve or two branch pipes connected in parallel.
8. 8. The system of claim 1, wherein the exhaust valve is a solenoid valve or a pneumatic valve and is connected to a controller, and wherein a pressure sensor is further disposed in the upper plenum, and is electrically connected to the controller for controlling the exhaust valve to open and initiate nitrogen replacement when the hydrogen enrichment pressure is detected to reach a set threshold.
9. 9. The system of claim 2, wherein the separator is a circular or square plate, and the edges of the plate are fixed and sealed with the inner wall of the air storage tank by welding or sealing rings.
10. 10. The system of any one of claims 1-9, wherein the flow battery system is an all-vanadium flow battery system.

Description

Flow battery gas self-layering waste gas treatment system Technical Field The invention belongs to the technical field of energy storage of flow batteries, and particularly relates to a flow battery gas self-layering waste gas treatment system. Background In recent years, the energy storage of the flow battery is gradually a new choice for large-scale long-time energy storage, and the characteristics of high intrinsic safety and long cycle life are particularly suitable for large-scale energy storage power stations. However, one problem with flow batteries is that during charging and discharging, gas may inevitably be evolved inside the stack due to local overcharging. Taking a common hydrochloric acid group or a flow battery added with hydrochloric acid as an example, the overcharge can lead to the precipitation of chlorine and hydrogen. Chlorine is a toxic, corrosive gas potentially harmful to personnel and equipment, while hydrogen is a flammable, explosive gas, with the risk of explosion. And is therefore of particular importance for the rational treatment of exhaust gases. The common treatment modes at present are direct exhaust of waste gas, absorption of alkaline liquid, absorption and reuse. The direct exhaust of the waste gas can cause harm to personnel and environment, and absorption and adsorption can lead to loss of chlorine element in the electrolyte, so that the valence state of the electrolyte is unbalanced. The recycling method needs to treat various gases simultaneously and keep the content of acid radical ions in the electrolyte unchanged, which is still a difficult problem and a problem to be solved. Discussion and study of flow battery exhaust treatment is inadequate in the prior art. At present, common waste gas treatment technologies of flow batteries mainly comprise an adsorption method, a direct recovery and reuse method, a chemical absorption method and the like. For example, by using an adsorption purification device with a specific filter material (such as the solution disclosed in CN 218794641U), although exhaust gas can be captured, acid radical ions in the electrolyte can be selectively adsorbed, and long-term operation will destroy the ion balance of the electrolyte, causing attenuation of the battery capacity and increase of side reactions, and eventually accelerating failure of the galvanic pile. Another idea is to directly introduce the exhaust gas into the pile loop for recovery (e.g. CN110858659 a), and introduce the positive exhaust gas into the negative electrolyte through a venturi or other device. Although the method is intended to realize waste gas recycling, bubbles are easy to enter the pile due to limited gas-liquid contact area and incomplete absorption, the performance of the pile is reduced, and the overall purification efficiency is low. In addition, there is also a technology of absorbing the exhaust gas with an alkaline solution (such as sodium hydroxide) (such as CN118983483 a) after the exhaust gas is extracted, and this method can neutralize the acid gas, but the method also causes the electrolyte system to lose acid radical ions, which causes unbalance of electrolyte components, and further affects long-term operation stability and cycle life of the battery. In summary, in the prior art, when waste gas of a flow battery is treated, there is a core contradiction that, on one hand, if the waste gas is discharged or purified externally, the critical components (especially acid radical ions) of the electrolyte are easily lost irreversibly, the chemical balance of the electrolyte is destroyed, the capacity and the service life of the battery are directly affected, and on the other hand, if the waste gas is tried to be recovered in the system, the technical bottlenecks of low gas-liquid mass transfer efficiency, incomplete absorption, bubble risk introduction and the like are faced, and the environment and safety risk of potential leakage of harmful gas cannot be effectively prevented. Therefore, an integrated treatment scheme capable of efficiently and safely realizing the recovery of effective components and the purification of harmful substances in exhaust gas without damaging the ion balance of the electrolyte is needed. Disclosure of Invention In view of the above, the invention provides a gas self-layering waste gas treatment system of a flow battery, which can realize efficient recovery of useful components and complete elimination of harmful substances in waste gas on the premise of not damaging ion balance of electrolyte, thereby solving the dual problems of battery performance degradation and harmful gas leakage. In order to achieve the above purpose, the technical scheme of the invention is as follows: A flow battery gas self-layering waste gas treatment system comprises a gas storage tank, a gas pump and a gas disperser; the inside of the air storage tank is divided into an upper air chamber and a lower air chamber by a partition plate which is hor