A flow battery soc value balancing device

Abstract

The utility model relates to the technical field of liquid flow battery energy storage, disclose a kind of liquid flow battery SOC value balancing device, including one power unit container and second power unit container, the one power unit container is communicated with second negative electrode liquid storage tank by one negative electrode return liquid pipeline, the second power unit container is communicated with one negative electrode liquid storage tank by second negative electrode return liquid pipeline;The one power unit container is communicated with second positive electrode liquid storage tank by one positive electrode return liquid pipeline, the second power unit container is communicated with one positive electrode liquid storage tank by second positive electrode return liquid pipeline;The utility model, by making the same polarity electrolyte intercommunication, can guarantee the charge status of the same polarity electrolyte of two sets of systems, ion valence state concentration always keep consistent, simple structure, low in cost, strong practicality.

Description

Technical Field

[0001] This utility model relates to the field of flow battery energy storage technology, and in particular to a flow battery SOC value balancing device. Background Technology

[0002] The PCS (Power Conversion System) of a flow battery energy storage power station is one of the core components of an energy storage system, responsible for the energy conversion and control between the battery energy storage unit and the grid or load. It undertakes key functions such as bidirectional energy flow (charging and discharging), power regulation, and grid-connected / off-grid switching, and is a core technology for the efficient and stable operation of the energy storage system. According to current industry standards, a single PCS system has a power output of 500kW, simultaneously controlling two 250kW power unit systems for charging and discharging. This design leads to inconsistencies in the State of Charge (SOC) values ​​of the two systems with increasing charge-discharge cycles. Therefore, a flow battery SOC balancing device is urgently needed to solve this problem. Utility Model Content

[0003] The purpose of this invention is to provide a flow battery SOC balancing device. By connecting the electrolytes of the same electrode, the state of charge and ion valence concentration of the electrolytes of the same electrode in the two systems can be kept consistent. The device has a simple structure, low cost, and strong practicality.

[0004] The present invention adopts the following technical solution:

[0005] A flow battery SOC balancing device includes a first power unit container and a second power unit container. The first power unit container is connected to a first positive electrode storage tank and a first negative electrode storage tank via a circulation pump. The second power unit container is connected to a second positive electrode storage tank and a second negative electrode storage tank via a circulation pump. The first power unit container is connected to the second negative electrode storage tank via a first negative electrode return pipe, and the second power unit container is connected to the first negative electrode storage tank via a second negative electrode return pipe. The first power unit container is connected to the second positive electrode storage tank via a first positive electrode return pipe, and the second power unit container is connected to the first positive electrode storage tank via a second positive electrode return pipe.

[0006] Preferably, the first positive electrode return pipe, the first negative electrode return pipe, the second positive electrode return pipe, and the second negative electrode return pipe are all located at the upper part.

[0007] Preferably, a negative electrode connecting pipe is provided between the first negative electrode storage tank and the second negative electrode storage tank; a positive electrode connecting pipe is provided between the first positive electrode storage tank and the second positive electrode storage tank.

[0008] Preferably, both the negative electrode connecting pipe and the positive electrode connecting pipe are located at the lower part.

[0009] Preferably, four circulation pumps are provided.

[0010] Preferably, all the circulating pumps are located at the bottom.

[0011] Preferably, both the negative electrode connecting pipe and the positive electrode connecting pipe are located at the inlet of the circulating pump.

[0012] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention utilizes a cross-connection design of the positive and negative return liquid pipes between the first and second power unit containers (i.e., the first negative electrode return liquid pipe is connected to the second negative electrode storage tank, and the second negative electrode return liquid pipe is connected to the first negative electrode storage tank; the positive electrode return liquid pipe is similarly cross-connected), enabling the electrolyte of the two power unit systems to form a bidirectional flow path during circulation. When the SOC values ​​of the two systems become inconsistent due to increased charge-discharge cycles, active ions (such as high-valence metal ions) in the electrolyte of the high SOC system can flow into the storage tank of the low SOC system through the return liquid pipe, while the electrolyte of the low SOC system flows back into the high SOC system. This dynamic exchange of ion concentration achieves a balance of SOC values ​​between the two systems, fundamentally solving the technical problem of accumulated SOC deviation in traditional simultaneous charge-discharge designs. Because the consistency of SOC values ​​is guaranteed, the two power unit systems can always maintain synchronous charge-discharge, avoiding capacity decay caused by overcharging or over-discharging of a single system and extending the overall lifespan of the battery pack. Furthermore, this device achieves SOC balance through a hardware structure with cross-connected pipes, eliminating the need for additional complex electrical control modules or algorithm control systems. Compared to software optimization schemes, it has the advantages of simple structure and high reliability. Attached Figure Description

[0013] Figure 1 This is a top view of an embodiment of this application. Detailed Implementation

[0014] The present invention will now be described clearly and completely with reference to the accompanying drawings and embodiments:

[0015] like Figure 1 As shown, the flow battery SOC balancing device of this utility model includes a first power unit container 2 and a second power unit container 10. The PCS (Power Conversion System) 1 charges and discharges the first power unit container 2 and the second power unit container 10. The first power unit container 2 is connected to a first positive electrode storage tank 11 and a first negative electrode storage tank 12 respectively through two circulation pumps 4. The second power unit container 10 is connected to a second positive electrode storage tank 13 and a second negative electrode storage tank 14 through two circulation pumps 4. The circulation pumps 4 are located on one side below the storage tanks.

[0016] The negative electrolyte of power unit container 2 after electrochemical reaction is connected to negative electrode storage tank 14 of the second negative electrode via negative electrode return pipe 5; the negative electrolyte of power unit container 10 after electrochemical reaction is connected to negative electrode storage tank 12 of the first negative electrode via negative electrode return pipe 6; similarly, the positive electrolyte of power unit container 2 after electrochemical reaction is connected to positive electrode storage tank 13 of the second positive electrode via positive electrode return pipe 7, and the positive electrolyte of power unit container 10 after electrochemical reaction is connected to positive electrode storage tank 11 of the first positive electrode via positive electrode return pipe 8. This arrangement enables mutual return of electrolyte storage tanks of the same electrode in the two systems, thereby ensuring that the state of charge and ion valence concentration of the electrolyte of the same electrode in the two systems remain consistent; the dynamic exchange of ion concentration achieves the balance of SOC value between the two systems, fundamentally solving the technical problem of SOC deviation accumulation in traditional simultaneous charge and discharge designs. In addition, the interconnected return pipeline forms an electrolyte sharing mechanism between the two power units. When an abnormal electrolyte concentration occurs in a local storage tank of one system, it can be buffered and adjusted through the electrolyte circulation of the other system, thereby improving the system's fault tolerance to single-point failures.

[0017] In this embodiment, the first positive electrode return pipe 7, the first negative electrode return pipe 5, the second positive electrode return pipe 8, and the second negative electrode return pipe 6 are all located at the top of their respective storage tanks. Furthermore, a negative electrode connecting pipe 3 is provided between the first negative electrode storage tank 12 and the second negative electrode storage tank 14; a positive electrode connecting pipe 9 is provided between the first positive electrode storage tank 11 and the second positive electrode storage tank 13, and both the negative electrode connecting pipe 3 and the positive electrode connecting pipe 9 are located at the bottom of the storage tanks. Preferably, both the negative electrode connecting pipe 3 and the positive electrode connecting pipe 9 are located at the inlet of the circulating pump 4. The negative electrode connecting pipe 3 and the positive electrode connecting pipe 9 ensure that the bottom of the electrolyte storage tanks of the same electrode in both systems is the same, thus maintaining a consistent electrolyte level in both systems' electrolyte storage tanks. This eliminates the need to adjust the opening size of the return valve and the pipe pressure to ensure a consistent level, enhancing practicality.

Claims

1. A flow battery SOC balancing device, comprising a first power unit container and a second power unit container, wherein the first power unit container is connected to a first positive electrode storage tank and a first negative electrode storage tank via a circulation pump, and the second power unit container is connected to a second positive electrode storage tank and a second negative electrode storage tank via a circulation pump; characterized in that: The No. 1 power unit container is connected to the No. 2 negative electrode storage tank via the No. 1 negative electrode return pipe, and the No. 2 power unit container is connected to the No. 1 negative electrode storage tank via the No. 2 negative electrode return pipe; the No. 1 power unit container is connected to the No. 2 positive electrode storage tank via the No. 1 positive electrode return pipe, and the No. 2 power unit container is connected to the No. 1 positive electrode storage tank via the No. 2 positive electrode return pipe.

2. The flow battery SOC balancing device according to claim 1, characterized in that: The first positive electrode return liquid pipe, the first negative electrode return liquid pipe, the second positive electrode return liquid pipe, and the second negative electrode return liquid pipe are all located at the upper part.

3. The flow battery SOC balancing device according to claim 2, characterized in that: A negative electrode connecting pipe is provided between the No. 1 negative electrode storage tank and the No. 2 negative electrode storage tank; a positive electrode connecting pipe is provided between the No. 1 positive electrode storage tank and the No. 2 positive electrode storage tank.

4. The flow battery SOC balancing device according to claim 3, characterized in that: Both the negative electrode connecting pipe and the positive electrode connecting pipe are located at the bottom.

5. The flow battery SOC balancing device according to claim 4, characterized in that: The circulating pump is provided in four parts.

6. The flow battery SOC balancing device according to claim 5, characterized in that: All the circulating pumps are located at the bottom.

7. The flow battery SOC balancing device according to claim 6, characterized in that: Both the negative electrode connecting pipe and the positive electrode connecting pipe are located at the inlet of the circulating pump.

Images