All-vanadium redox flow battery stack crystallization elimination device
Patent Information
- Application Number
- CN202522138924.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-10
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2035-10-10
AI Technical Summary
[0002]全钒液流电池长期运行中，正负极电解液在碳毡电极表面沉积钒结晶，导致电池容量衰减，降低电极有效反应面积，且结晶易在管路和流道中聚集，导致电解液流动阻力增大
本申请在对全钒液流电池管路和流道中结晶进行清洗时，通过正极液冲刷负极系统，溶解低价态钒结晶，利用负极液冲刷正极系统，溶解高价态钒结晶，无需化学清洗剂，也无需拆卸电堆，只需通过管道上的阀门切换即可实现自循环清洗，显著降低人工成本；清洗后电解液还可直接回流储液罐再次利用，从而有效减少废水排放。
Smart Images
Figure CN224745706U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of vanadium redox flow batteries, specifically relating to a device for eliminating crystallization in a vanadium redox flow battery stack. Background Technology
[0002] During long-term operation of vanadium redox flow batteries, vanadium crystals deposit on the surface of the carbon felt electrodes in both the positive and negative electrode electrolytes. This leads to capacity decay, reduces the effective reaction area of the electrodes, and the crystals tend to accumulate in pipes and flow channels, increasing electrolyte flow resistance. Existing cleaning methods rely on chemical agents and disassembly, resulting in high battery maintenance costs, environmental pollution, and resource waste. Utility Model Content
[0003] To address the shortcomings of existing technologies, this utility model aims to provide a crystallization removal device for vanadium redox flow battery stacks. This device eliminates the need for chemical cleaning agents and disassembly of the stack, achieving self-circulation cleaning by switching relevant valves, thereby reducing labor costs and significantly improving the efficiency of stack crystallization removal.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A crystallization elimination device for a vanadium redox flow battery stack includes a positive electrode tank and a negative electrode tank storing positive and negative electrode electrolytes, respectively. The outlet of the positive electrode tank is connected to the inlet of a first pump. The outlet of the first pump is connected to one end of a first valve and a second valve via pipelines. The other end of the first valve is connected to the positive electrode inlet of the flow battery stack and one end of a fourth valve via pipelines. The outlet of the negative electrode tank is connected to the inlet of a second pump. The outlet of the second pump is connected to one end of a third valve and the other end of a fourth valve via pipelines. The other end of the third valve is connected to the negative electrode inlet of the flow battery stack and the other end of the second valve via pipelines. The outlet of the positive electrode of the flow battery stack is connected to the inlet of the positive electrode tank and the inlet of the negative electrode tank via pipelines through a fifth valve and a sixth valve, respectively. The outlet of the negative electrode of the flow battery stack is connected to the inlet of the negative electrode tank and the inlet of the positive electrode tank via pipelines through a seventh valve and an eighth valve, respectively.
[0005] Preferably, the flow battery includes multiple stacks, and the positive / negative liquid inlets / outlets of each stack are connected in parallel to the corresponding positive / negative electrode pipelines.
[0006] Preferably, the eight valves are solenoid valves.
[0007] The beneficial effects of this utility model are as follows: This application cleans the crystals in the pipelines and channels of a vanadium redox flow battery by flushing the negative electrode system with the positive electrode liquid to dissolve low-valence vanadium crystals, and by flushing the positive electrode system with the negative electrode liquid to dissolve high-valence vanadium crystals. No chemical cleaning agents are needed, and the battery stack does not need to be disassembled. Self-circulation cleaning can be achieved simply by switching valves on the pipeline, which significantly reduces labor costs. After cleaning, the electrolyte can be directly returned to the storage tank for reuse, thereby effectively reducing wastewater discharge. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation
[0009] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of application of this utility model.
[0010] like Figure 1 As shown, this utility model proposes a crystallization elimination device for a vanadium redox flow battery stack, including a positive electrode storage tank 2 and a negative electrode storage tank 1 storing positive and negative electrode electrolytes. The outlet of the positive electrode storage tank 2 is connected to the inlet of a first pump 3. The outlet of the first pump 3 is connected to one end of a first valve A1 and one end of a second valve A2 via corresponding pipelines. The other end of the first valve A1 is connected to one end of a fourth valve B2 via corresponding pipelines and is connected in parallel to the positive electrode liquid inlet 52 of each stack 5 of the flow battery. The outlet of the negative electrode storage tank 1 is connected to the inlet of a second pump 4. The outlet of the second pump 4 is connected to one end of a third valve B1 and the other end of a fourth valve B2 via corresponding pipelines. The other end of the third valve B1 is connected to the other end of the second valve A2 via corresponding pipelines and is connected in parallel to the negative electrode liquid inlet 51 of each stack 5 of the flow battery. The positive electrode liquid outlet 53 of the flow battery stack 5 is connected to the liquid inlet of the positive electrode storage tank 2 and the liquid inlet of the negative electrode storage tank 1 via corresponding pipelines through valves C1 and C2, respectively. The negative electrode liquid outlet 54 of the flow battery stack 5 is connected to the liquid inlet of the negative electrode storage tank 1 and the liquid inlet of the positive electrode storage tank 2 via corresponding pipelines through valves D1 and C2, respectively. In specific implementation, all the valves mentioned above in this application adopt a solenoid valve structure.
[0011] When the vanadium redox flow battery of this utility model is working, the positive electrode electrolyte flows in the positive electrode pipeline: the first valve A1 is opened, the second valve A2 is closed, the fifth valve C1 is opened, and the sixth valve C2 is closed; under the action of the first pump 3, the positive electrode electrolyte in the positive electrode storage tank 2 flows into the stack 5 through the corresponding positive electrode pipeline, and then flows back into the positive electrode storage tank 2. The negative electrode electrolyte flows in the negative electrode pipeline: open the third valve B1, close the fourth valve B2, open the seventh valve D1, and close the eighth valve D2; under the action of the second pump 4, the negative electrode electrolyte in the negative electrode storage tank 1 flows into the fuel cell stack 5 through the corresponding negative electrode pipeline and then flows back into the negative electrode storage tank 1.
[0012] The working principle of this invention for eliminating crystallization is as follows: When crystals in fuel cell stack 5 need to be removed, the corresponding valves are controlled to allow the positive electrolyte to flow through the negative electrode pipeline and fuel cell stack 5, and the negative electrolyte to flow through the positive electrode pipeline and fuel cell stack 5. The strong oxidizing properties of the positive electrolyte and the strong reducing properties of the negative electrolyte are used to dissolve the crystals. The specific implementation is as follows: ① Close the first valve A1 and open the second valve A2. With the first pump 3 activated, the positive electrolyte in the positive electrode storage tank 2 flows into the fuel cell stack 5 through the corresponding negative electrode pipeline. ② Close the third valve B1 and open the fourth valve B2. With the second pump 4 activated, the negative electrode electrolyte in the negative electrode storage tank 1 flows into the fuel cell stack 5 through the corresponding positive electrode pipeline. ③ Close the fifth valve C1 and open the sixth valve C2 to allow the cleaned negative electrode electrolyte in the positive electrode pipeline to flow back to the negative electrode storage tank 1; ④ Close the seventh valve D1 and open the eighth valve D2 to allow the cleaned positive electrolyte in the negative electrode pipeline to flow back to the positive electrode storage tank 2.
[0013] In this application, when cleaning the crystals in the pipelines and channels of a vanadium redox flow battery, the low-valence vanadium crystals are dissolved by flushing the negative electrode system with the positive electrode liquid, and the high-valence vanadium crystals are dissolved by flushing the positive electrode system with the negative electrode liquid. No chemical cleaning agent is required, nor is it necessary to disassemble the stack 5. Self-circulation cleaning can be achieved simply by switching valves on the pipeline, which significantly reduces labor costs. After cleaning, the electrolyte can be directly returned to the storage tank for reuse, thereby effectively reducing wastewater discharge.
[0014] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.
Claims
1. A crystallization elimination device for a vanadium redox flow battery stack, comprising a positive electrode storage tank and a negative electrode storage tank storing positive electrode electrolyte and negative electrode electrolyte, characterized in that: The outlet of the positive electrode storage tank is connected to the inlet of the first pump. The outlet of the first pump is connected to one end of the first valve and one end of the second valve via pipelines. The other end of the first valve is connected to the positive electrode liquid inlet of the flow battery stack and one end of the fourth valve via pipelines. The outlet of the negative electrode storage tank is connected to the inlet of the second pump. The outlet of the second pump is connected to one end of the third valve and the other end of the fourth valve via pipelines. The other end of the third valve is connected to the negative electrode liquid inlet of the flow battery stack and the other end of the second valve via pipelines. The positive electrode liquid outlet of the flow battery stack is connected to the inlet of the positive electrode storage tank and the inlet of the negative electrode storage tank via pipelines through the fifth valve and the sixth valve. The negative electrode liquid outlet of the flow battery stack is connected to the inlet of the negative electrode storage tank and the inlet of the positive electrode storage tank via pipelines through the seventh valve and the eighth valve.
2. The vanadium redox flow battery stack crystallization elimination device according to claim 1, characterized in that: The flow battery comprises multiple stacks, with the positive and negative liquid inlets / outlets of each stack connected in parallel to the corresponding positive / negative electrode pipelines.
3. The crystallization elimination device for a vanadium redox flow battery stack according to claim 1, characterized in that: The eight valves are solenoid valves.