Off-grid starting device of liquid flow energy storage system
By designing the positive and negative electrolyte circulation systems of the flow battery system and using gravity to make the electrolyte flow into the battery stack, the problem of starting the flow battery system after a long shutdown is solved, reliable off-grid startup is achieved, the use of external UPS is avoided, the system reliability is improved and the cost is reduced.
Patent Information
- Application Number
- CN202422512171.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-17
AI Technical Summary
After a flow battery system has been shut down for a long time, the electrolyte in the stack will self-discharge, requiring an external UPS for startup, which increases costs and reduces system reliability.
Using gravity, through the positive and negative electrolyte circulation system design, and taking advantage of the height difference between the positive and negative auxiliary liquid storage tanks, the electrolyte flows into the fuel cell stack under the action of gravity to provide starting power without the need for an external UPS.
It achieves reliable off-grid startup after a long shutdown, avoids the use of external UPS, improves system reliability and reduces costs.
Smart Images
Figure CN223347794U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of liquid flow batteries, in particular to an off-grid starting device for a liquid flow energy storage system. Background Art
[0002] After a liquid flow battery system has been shut down for an extended period, the electrolyte in the stack will self-discharge through the battery, consuming all the energy and leaving the battery system uncharged. Starting the liquid flow energy storage system requires pumping charged electrolyte into the stack. The mainstream solution for powering the electrolyte pump during off-grid startup is to use an external, independent UPS. This UPS drives the pump, pumping electrolyte into the stack, charging the battery system, and then starting the system. This approach requires a separate UPS, increasing costs. Prolonged periods of uncharging the UPS can also cause the internal batteries to self-discharge, consuming significant energy and preventing startup, reducing system reliability. Utility Model Content
[0003] In response to the deficiencies in the existing technology, the utility model provides an off-grid starting device for a liquid flow energy storage system, which can start the liquid flow energy storage system through gravity, solving the problem of requiring an external power supply for off-grid starting.
[0004] The present application provides an off-grid starting device for a liquid flow energy storage system using the following technical solutions:
[0005] A liquid flow energy storage system off-grid starting device, including a liquid flow stack, a positive electrode electrolyte circulation system and a negative electrode electrolyte circulation system connected to the liquid flow stack; the positive electrode electrolyte circulation system includes a positive electrode main liquid storage tank, a positive electrode auxiliary liquid storage tank and a pump, and the positive electrode main liquid storage tank, the positive electrode auxiliary liquid storage tank, the pump and the liquid flow stack form a closed loop; the negative electrode electrolyte circulation system includes a negative electrode main liquid storage tank, a negative electrode auxiliary liquid storage tank and a pump, and the negative electrode main liquid storage tank, the negative electrode auxiliary liquid storage tank, the pump and the liquid flow stack form a closed loop ; The positive electrode electrolyte circulation system and the negative electrode electrolyte circulation system have the same structure; the positive electrode auxiliary liquid storage tank includes a bottom interface opened at the bottom, a high-level interface opened on the side and a top interface set at the top; the top interface and the bottom interface are connected to the liquid flow stack through pipelines, and the high-level interface is connected to the positive electrode main liquid storage tank through pipelines. A valve is provided between the bottom interface and the liquid flow stack, and a closed loop is formed between the positive electrode storage tank, the positive electrode auxiliary liquid storage tank and the liquid flow stack; the bottom interface is higher than the liquid flow stack.
[0006] Optionally, the height difference between the bottom interface and the liquid flow stack is 30-50 cm.
[0007] Optionally, the height difference between the high-position interface and the bottom of the positive electrode auxiliary liquid storage tank is 1 / 2 of the height of the positive electrode auxiliary liquid storage tank.
[0008] Optionally, the positive electrode electrolyte circulation system further includes a check valve disposed between the liquid flow stack and the positive electrode main liquid storage tank.
[0009] Optionally, a control system electrically connected to the liquid flow stack and the pump is also included.
[0010] Optionally, the control system includes an inverter electrically connected to the liquid flow battery stack and a battery management system electrically connected to the inverter; the battery management system is electrically connected to two pumps in the positive electrode electrolyte circulation system and the negative electrode electrolyte circulation system respectively.
[0011] Optionally, the positive electrode electrolyte circulation system further includes a placement rack for placing the positive electrode auxiliary liquid storage tank.
[0012] Optionally, the placement rack includes a placement table for contacting the positive electrode auxiliary liquid storage tank and a cylinder for driving the placement table to move up and down.
[0013] In summary, this application includes at least one of the following beneficial technical effects:
[0014] 1. Because the positive and negative electrode auxiliary liquid storage tanks are installed at high positions, the electrolyte flows into the liquid flow stack under the action of gravity, providing starting power for the battery management system, converter, and pump, without the need for additional auxiliary power supplies such as UPS. It can still reliably start off-grid after a long shutdown;
[0015] 2. This application is provided with a placement table for placing the positive electrode negative liquid storage tank and the negative electrode negative liquid storage tank. The height of the placement table can be adjusted, and the height difference between the positive electrode negative liquid storage tank and the negative electrode negative liquid storage tank and the liquid flow battery stack can be reasonably adjusted according to the on-site working scene. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application. DETAILED DESCRIPTION
[0017] The following is combined with Figure 1 This application is described in further detail.
[0018] The embodiment of the present application discloses an off-grid starting device for a liquid flow energy storage system. Figure 1 A liquid flow energy storage system off-grid starting device includes a liquid flow battery stack, a positive electrode electrolyte circulation system, a negative electrode electrolyte circulation system and a control system.
[0019] refer to Figure 1 The positive electrode electrolyte circulation system and the negative electrode electrolyte circulation system have the same structure, and the two are symmetrically arranged about the liquid flow stack.
[0020] refer to Figure 1The positive electrode electrolyte circulation system includes a positive electrode main liquid storage tank, a positive electrode auxiliary liquid storage tank and a positive electrode electrolyte pump. The positive electrode main liquid storage tank and the positive electrode negative liquid storage tank are both cylindrical. The positive electrode auxiliary liquid storage tank includes a bottom interface opened at the bottom, a high-position interface opened at the side and a top interface set at the top. The outlet of the positive electrode main liquid storage tank is connected to the inlet of the positive electrode electrolyte pump, the outlet of the positive electrode electrolyte pump is connected to the positive electrode inlet of the stack, the bottom interface of the positive electrode auxiliary liquid storage tank is connected to the positive electrode electrolyte inlet of the stack, the positive electrode outlet of the stack is connected to the top interface of the positive electrode auxiliary liquid storage tank, the high-position interface of the auxiliary liquid storage tank is connected to the top inlet of the positive electrode main liquid storage tank, a valve is set on the pipeline between the bottom interface of the positive electrode auxiliary liquid storage tank and the positive electrode electrolyte inlet of the stack, and a check valve is set on the pipeline between the positive electrode electrolyte pump and the positive electrode electrolyte inlet of the stack.
[0021] refer to Figure 1 The high-level interface is located in the middle of the positive electrode auxiliary liquid storage tank, so that the height difference between the high-level interface and the bottom of the positive electrode auxiliary liquid storage tank is equal to half the height of the entire tank body. The positive electrode electrolyte circulation also includes a placement rack for placing the positive electrode auxiliary liquid storage tank. The placement rack includes a placement table for contacting the positive electrode auxiliary liquid storage tank and a cylinder that drives the placement table up and down. The lowest point of the placement table is higher than the highest point of the liquid flow stack, and the maximum distance the placement table can move up and down is 50cm.
[0022] refer to Figure 1 The negative electrode electrolyte circulation system includes a negative electrode main liquid storage tank, a negative electrode auxiliary liquid storage tank and a negative electrode electrolyte pump. The negative electrode main liquid storage tank and the negative electrode negative liquid storage tank are both cylindrical. The negative electrode auxiliary liquid storage tank includes a bottom interface opened at the bottom, a high-position interface opened at the side and a top interface set at the top. The outlet of the negative electrode main liquid storage tank is connected to the inlet of the negative electrode electrolyte pump, the outlet of the negative electrode electrolyte pump is connected to the negative electrode inlet of the stack, the bottom interface of the negative electrode auxiliary liquid storage tank is connected to the negative electrode electrolyte inlet of the stack, the negative electrode outlet of the stack is connected to the top interface of the negative electrode auxiliary liquid storage tank, the high-position interface of the auxiliary liquid storage tank is connected to the top inlet of the negative electrode main liquid storage tank, a valve is set on the pipeline between the bottom interface of the negative electrode auxiliary liquid storage tank and the negative electrode electrolyte inlet of the stack, and a check valve is set on the pipeline between the negative electrode electrolyte pump and the negative electrode electrolyte inlet of the stack.
[0023] refer to Figure 1 The high-level interface is located in the middle of the negative electrode auxiliary liquid storage tank, so that the height difference between the high-level interface and the bottom of the negative electrode auxiliary liquid storage tank is equal to half the height of the entire tank body. The negative electrode electrolyte circulation also includes a placement rack for placing the negative electrode auxiliary liquid storage tank. The placement rack includes a placement table for contacting the negative electrode auxiliary liquid storage tank and a cylinder that drives the placement table up and down. The lowest point of the placement table is higher than the highest point of the liquid flow stack, and the maximum distance the placement table can move up and down is 50cm.
[0024] The control system includes the converter and battery management system. The positive and negative electrodes of the flow cell stack are electrically connected to the converter's positive and negative electrodes. The battery management system also has electrical and communication connections to the converter, the battery management system to the power-consuming equipment, and the battery management system to the positive and negative electrolyte pumps. The valve control is connected to the battery management system and can be operated manually or through the battery management system.
[0025] The battery management system transmits information to the energy storage converter. It monitors the stack voltage and temperature, assesses the battery's state of charge, and controls valve and pump operation. The battery management system manages incoming power to consumers and controls the converter's output power.
[0026] The implementation principle of an off-grid starting device for a liquid flow energy storage system in the embodiment of the present application is as follows:
[0027] When off-grid startup is required, manually open the valve connecting the bottom interface of the positive electrode auxiliary liquid reservoir to the battery stack, and at the same time, manually open the valve connecting the bottom interface of the negative electrode auxiliary liquid reservoir to the battery stack, allowing the positive and negative electrolytes to enter the battery stack by gravity. When the voltage of a single battery stack is greater than 150V, the self-starting voltage of the inverter and battery management system is met, and the inverter and battery management system are started at this time. When the voltage of a single battery stack is greater than 180V, the battery management system detects the battery stack voltage, temperature signal, and evaluates the battery's state of charge to ensure that all conditions are met. Close the valve connecting the bottom interface of the positive electrode auxiliary liquid reservoir and the positive electrolyte inlet of the battery stack, start the positive electrolyte pump, and at the same time close the valve connecting the bottom interface of the negative electrode auxiliary liquid reservoir and the negative electrolyte inlet of the battery stack, and start the negative electrolyte pump. After a delay of more than 3 minutes, if there are no errors in the battery management system and the inverter, the power-consuming equipment is put into operation and the startup is complete.
[0028] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.
Claims
1. An off-grid starting device for a liquid flow energy storage system, characterized by: The invention comprises a liquid flow stack, a positive electrode electrolyte circulation system and a negative electrode electrolyte circulation system connected to the liquid flow stack; the positive electrode electrolyte circulation system comprises a positive electrode main liquid storage tank, a positive electrode auxiliary liquid storage tank and a pump, and the positive electrode main liquid storage tank, the positive electrode auxiliary liquid storage tank, the pump and the liquid flow stack form a closed loop; the negative electrode electrolyte circulation system comprises a negative electrode main liquid storage tank, a negative electrode auxiliary liquid storage tank and a pump, and the negative electrode main liquid storage tank, the negative electrode auxiliary liquid storage tank, the pump and the liquid flow stack form a closed loop; the positive electrode electrolyte circulation system and the negative electrode The structure of the cathode electrolyte circulation system is the same; the positive electrode auxiliary liquid storage tank includes a bottom interface opened at the bottom, a high-level interface opened at the side and a top interface set at the top; the top interface and the bottom interface are connected to the liquid flow stack through pipelines, and the high-level interface is connected to the positive electrode main liquid storage tank through pipelines. A valve is provided between the bottom interface and the liquid flow stack, and a closed loop is formed between the positive electrode main liquid storage tank, the positive electrode auxiliary liquid storage tank and the liquid flow stack; the bottom interface is higher than the liquid flow stack.
2. The off-grid starting device for a liquid flow energy storage system according to claim 1, characterized in that: The height difference between the bottom interface and the liquid flow stack is 30-50 cm.
3. The off-grid starting device for a liquid flow energy storage system according to claim 2, characterized in that: The height difference between the high-position interface and the bottom of the positive electrode auxiliary liquid storage tank is 1 / 2 of the height of the positive electrode auxiliary liquid storage tank.
4. The off-grid starting device for a liquid flow energy storage system according to claim 3, characterized in that: The positive electrode electrolyte circulation system further includes a check valve arranged between the liquid flow stack and the positive electrode main liquid storage tank.
5. The off-grid starting device for a liquid flow energy storage system according to claim 4, characterized in that: Also included is a control system electrically connected to the flow stack and the pump.
6. The off-grid starting device for a liquid flow energy storage system according to claim 5, characterized in that: The control system includes a converter electrically connected to the liquid flow battery stack and a battery management system electrically connected to the converter; the battery management system is electrically connected to two pumps in the positive electrode electrolyte circulation system and the negative electrode electrolyte circulation system respectively.
7. The off-grid starting device for a liquid flow energy storage system according to claim 6, characterized in that: The positive electrode electrolyte circulation system further includes a placement rack for placing the positive electrode auxiliary liquid storage tank.
8. The off-grid starting device for a liquid flow energy storage system according to claim 7, characterized in that: The placement rack includes a placement platform for contacting the positive electrode auxiliary liquid storage tank and a cylinder for driving the placement platform to move up and down.