Active flow equalizing device of flow battery system

Abstract

The utility model discloses an active flow equalizing device of a flow battery system, which relates to the field of flow batteries and comprises a flow battery module and a flow battery capacity unit, the active flow equalizing device of the flow battery system adopts a standardized design, and one flow battery module is provided with two adjustable distributed circulating pumps. Data are collected through temperature, pressure and flow sensors, a battery management system performs analysis according to a big data algorithm, and independent control of each flow battery module is realized on each module, so that the flow of each electric pile in the module is uniform and controllable; when it is monitored that the galvanic piles in the modules run abnormally and are not controlled, the battery management system can close the control valves of the galvanic piles in time and give an early warning, subsequent fault detection is facilitated, and meanwhile normal running of the other galvanic piles is not affected. According to the utility model, stable output of the circulating pump is realized, and the pile charging and discharging efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to the field of flow battery equipment, and more specifically to an active current sharing device for a flow battery system. Background Art

[0002] The all-vanadium flow battery energy storage system mainly consists of a power unit and a capacity unit, which are connected by a circulation system device such as a pipeline and a circulation pump. Among them, the power unit is composed of multiple stacks connected in series to form a module, and then multiple modules are connected in parallel. During the operation of the battery, the electrolyte enters the main pipeline from the capacity unit through the circulation pump and is transported to each module, and then transported to each stack through the branch in the module to complete the charging and discharging of the battery.

[0003] At present, most flow batteries are in the pilot stage and have not been applied on a large scale. In large-scale applications, due to the complex series and parallel connection of the stacks, the transport distance of the electrolyte from the main pipeline and the branch to each stack is relatively long, and it is difficult to keep the electrolyte flow rate in each stack consistent. Moreover, after the energy storage system operates for a long time, the output of the circulation pump is unstable, and the independent control of the stack flow rate cannot be achieved, resulting in a reduction in the charge and discharge efficiency of some stacks. Summary of the Utility Model

[0004] The purpose of the utility model is to design an active current sharing device for a flow battery system. An adjustable distributed circulation pump is used for pressure compensation in the flow battery module, and at the same time, sensors such as flow rate, temperature, and pressure are equipped for real-time monitoring, and through big data algorithm analysis, each flow battery module can independently control the electrolyte flow rate in its internal stack, improve the charge and discharge efficiency of each stack, and realize the efficient utilization of the electrolyte.

[0005] In order to achieve the above technical effects, the utility model adopts the following technical solutions:

[0006] An active current sharing device for a flow battery system, which includes: the first flow battery module, the flow battery capacity unit, and the nth flow battery module, and the first flow battery module and the nth flow battery module are connected to the flow battery capacity unit through the main electrolyte circulation path.

[0007] As a further description of the above technical solution:

[0008] The first flow battery module and the nth flow battery module include a battery management system, a positive distributed circulation pump, a negative distributed circulation pump, a flow sensor, a temperature sensor, a pressure sensor, a control valve, a frequency converter, an electrolyte circulation branch, a positive stack inlet, a positive stack outlet, a negative stack inlet, a negative stack outlet, a first stack and an nth stack. The battery management system is connected to the sensors and the control valve through cables. The positive distributed circulation pump and the negative distributed circulation pump are located inside the first flow battery module and are connected to the sensors through the electrolyte circulation branch. The flow sensor, the temperature sensor, and the pressure sensor are arranged side by side outside the control valve. The frequency converter is located above the first flow battery module. The positive stack inlet, the positive stack outlet, the negative stack inlet, and the negative stack outlet are located outside the first stack and are connected to the control valve. The first stack and the nth stack are located at the center of the first flow battery module.

[0009] As a further description of the above technical solution:

[0010] The flow battery capacity unit includes a positive liquid storage tank, a negative liquid storage tank, a positive main circulation pump, a negative main circulation pump, and an electrolyte main circulation path. The positive liquid storage tank and the negative liquid storage tank are arranged side by side below the first flow battery module. The positive main circulation pump is located on the side of the positive liquid storage tank, and the negative main circulation pump is located on the side of the negative liquid storage tank.

[0011] As a further description of the above technical solution:

[0012] The first flow battery module is configured with two adjustable distributed circulation pumps to reduce the impact of a single pump failure on the overall performance of the device and improve the reliability and stability of the device.

[0013] As a further description of the above technical solution:

[0014] The battery management system includes a state evaluation module, an equalization management module, and a fault diagnosis and alarm module. The output end of the state evaluation module is connected to the input end of the equalization management module for overall state evaluation of the first flow battery module. The output end of the equalization management module is connected to the input end of the fault diagnosis and alarm module for equalization control of each stack inside the first flow battery module. The fault diagnosis and alarm module is used for fault analysis and outputting the fault analysis result.

[0015] As a further description of the above technical solution:

[0016] The positive liquid storage tank and the negative liquid storage tank are made of corrosion-resistant materials and are both cylindrical in shape.

[0017] As a further description of the above technical solution:

[0018] The flow sensor model is an electromagnetic flow sensor, the temperature sensor model is a platinum resistance temperature sensor, and the pressure sensor model is a differential pressure sensor.

[0019] As a further description of the above technical solution:

[0020] The positive distributed circulation pump and the negative distributed circulation pump are driven by a motor, and the motor is used to adjust the rotational speed and flow rate of the distributed circulation pump.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present utility model are as follows: The active current sharing device of the flow battery system designed by the present utility model adopts a standardized design. A flow battery module is configured with two adjustable distributed circulation pumps. Data is collected through temperature, pressure, and flow sensors. The battery management system analyzes according to big data algorithms to achieve independent control of each flow battery module, making the flow of each stack in the module uniform and controllable. In addition, when it is monitored that the stack in the module operates abnormally and is out of control, the battery management system can timely close the control valve of the stack and give an alarm, which is convenient for subsequent fault detection and does not affect the normal operation of the remaining stacks at the same time. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings, where:

[0023] Figure 1 It is a schematic diagram of the active current sharing device of the flow battery system of the present utility model;

[0024] Figure 2 It is a control logic block diagram of the active current sharing device of the flow battery system of the present utility model;

[0025] Figure 3 It is a schematic diagram of the battery management system of the active current sharing device of the flow battery system of the present utility model;

[0026] Reference numerals in the figure: 1, flow battery module; 2, battery management system (BMS); 3, positive electrolyte storage tank; 4, negative electrolyte storage tank; 5, positive main circulation pump; 6, negative main circulation pump; 7, positive distributed circulation pump; 8, negative distributed circulation pump; 9, flow sensor; 10, temperature sensor; 11, pressure sensor; 12, control valve; 13, frequency converter; 14, electrolyte circulation branch; 15, electrolyte circulation main path; 16, positive electrode inlet of the stack; 17, positive electrode outlet of the stack; 18, negative electrode inlet of the stack; 19, negative electrode outlet of the stack; 20, the first stack; 21, the nth stack; 22, flow battery capacity unit; 23, flow battery module n. Detailed implementation mode

[0027] Next, in combination with the accompanying drawings as shown in Figure 1 - Figure 2 the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] As Figure 1 shown, an active current sharing device for a flow battery system includes:

[0029] The first flow battery module 1, the flow battery capacity unit 22, and the nth flow battery module 23;

[0030] Among them, the first flow battery module 1 and the nth flow battery module 23 include a battery management system 2, a positive distributed circulation pump 7, a negative distributed circulation pump 8, a flow sensor 9, a temperature sensor 10, a pressure sensor 11, a control valve 12, a frequency converter 13, an electrolyte circulation branch 14, a positive electrode inlet of the stack 16, a positive electrode outlet of the stack 17, a negative electrode inlet of the stack 18, a negative electrode outlet of the stack 19, the first stack 20, and the nth stack 21. The battery management system 2 is connected to the sensors and the control valve 12 through cables. The positive distributed circulation pump 7 and the negative distributed circulation pump 8 are located inside the first flow battery module 1 and are connected to the sensors through the electrolyte circulation branch 14. The flow sensor 9, the temperature sensor 10, and the pressure sensor 11 are arranged side by side outside the control valve 12. The frequency converter 13 is located above the first flow battery module 1. The positive electrode inlet of the stack 16, the positive electrode outlet of the stack 17, the negative electrode inlet of the stack 18, and the negative electrode outlet of the stack 19 are located outside the first stack 20 and are connected to the control valve. The first stack 20 and the nth stack 21 are located at the center of the first flow battery module 1, where:

[0031] The battery management system 2 is used to monitor the flow rate, temperature, and pressure of the electrolyte in the electrolyte circulation branch 14 in real time, and adjusts the operating states of the positive distributed circulation pump 7 and the negative distributed circulation pump 8 by controlling the frequency converter 13 to achieve the balanced control of each stack inside the first flow battery module 1;

[0032] The positive distributed circulation pump 7 and the negative distributed circulation pump 8 are used to control the electrolyte flow rate of each stack in the first flow battery module 1;

[0033] The flow sensor 9, the temperature sensor 10, and the pressure sensor 11 are used to monitor the liquid flow rate, temperature, and pressure parameters in the first flow battery module 1;

[0034] The control valve 12 is used to adjust the pressure and flow rate of the electrolyte circulation branch;

[0035] The frequency converter 13 is used to adjust the output of the distributed circulation pump to achieve the flow control of the first stack 20;

[0036] The flow battery capacity unit 22 includes a positive electrolyte storage tank 3, a negative electrolyte storage tank 4, a positive main circulation pump 5, a negative main circulation pump 6, and an electrolyte circulation main path 15. The positive electrolyte storage tank 3 and the negative electrolyte storage tank 4 are arranged side by side below the first flow battery module 1. The positive main circulation pump 5 is located on the side of the positive electrolyte storage tank 3, and the negative main circulation pump 6 is located on the side of the negative electrolyte storage tank 4. Among them:

[0037] The positive electrolyte storage tank 3 and the negative electrolyte storage tank 4 are used to store the electrolyte;

[0038] The positive main circulation pump 5 and the negative main circulation pump 6 are used to transport the electrolyte in the storage tank to each flow battery module through the electrolyte circulation main path 15;

[0039] The first flow battery module 1 and the nth flow battery module 23 are connected to the flow battery capacity unit 22 through the electrolyte circulation main path 15.

[0040] In a specific embodiment, the first flow battery module 1 stores and releases energy by inputting electrolyte liquid into the first stack 20 for reaction. The first stack 20 is the core part of the flow battery system, and its main function is to convert chemical energy into electrical energy or convert electrical energy into chemical energy. During the charging process of the flow battery, electrical energy is converted into chemical energy and stored in the electrolyte. During the discharging process, chemical energy is converted into electrical energy for external loads. In the flow battery system, the first stack 20 is connected to the positive electrode liquid storage tank 3 and the negative electrode liquid storage tank 4 through the electrolyte circulation branch 14 and the electrolyte circulation main path 15 to achieve energy conversion and transmission. The motor speed and output power are controlled by the frequency converter 13 to regulate the positive electrode distributed circulation pump 7, the negative electrode distributed circulation pump 8, and the control valve 12, so as to control the electrolyte flow rate in the first flow battery module 1 to ensure the stability of the pressure, flow rate, and temperature parameters in the entire system, thereby improving the efficiency of the flow battery.

[0041] In a specific embodiment, there are two loops between the first flow battery module 1 and the flow battery capacity unit 22. The first loop is that the electrolyte enters the main electrolyte circulation path 15 from the positive electrode liquid storage tank 3 through the positive electrode main circulation pump 5, passes through the electrolyte circulation branch 14, and is delivered to each stack through the flow sensor 9, temperature sensor 10, pressure sensor 11 and control valve 12. Inside each flow battery module, the positive electrode distributed circulation pump 7 dynamically adjusts its output according to the real-time data monitored by the flow sensor 9 to independently control the flow rate of the first stack 20 in each flow battery module 1. After the electrolyte reacts in each stack, it enters the electrolyte circulation branch 14 from the outlet of the first stack 20 through the control valve 12 and returns to the positive electrode liquid storage tank 3 through the main electrolyte circulation path 15. The second loop is that the electrolyte enters the main electrolyte circulation path 15 from the negative electrode liquid storage tank 4 through the negative electrode main circulation pump 6, passes through the electrolyte circulation branch 14, and is delivered to each stack through the flow sensor 9, temperature sensor 10, pressure sensor 11 and control valve 12. Inside each flow battery module, the negative electrode distributed circulation pump 8 dynamically adjusts its output according to the real-time data monitored by the flow sensor 9. After the electrolyte reacts in each stack, it enters the electrolyte circulation branch 14 from the outlet of the first stack 20 through the control valve 12 and returns to the negative electrode liquid storage tank 3 through the main electrolyte circulation path 15. Since the electrolyte is connected to multiple flow battery modules through complex pipelines from the flow battery capacity unit 22, there will be differences in the pressure, flow rate and temperature parameters of the pipelines inside different flow battery modules. The active flow equalization device of the flow battery system will compare and analyze the parameters between different flow battery modules according to the data collected by the monitoring devices such as the flow sensor 9, temperature sensor 10 and pressure sensor 11, and adjust the output of the corresponding distributed circulation pump through the frequency converter 13 according to the analysis results to achieve flow equalization control of the entire flow battery system. Through the operation of the active flow equalization device, the problem of unbalanced flow rate, temperature and pressure of the electrolyte between different flow battery modules 1 can be effectively avoided, thus ensuring that the flow battery system can work stably and efficiently.

[0042] Furthermore, the first flow battery module 1 is configured with two adjustable distributed circulation pumps to reduce the impact of a single pump failure on the overall performance of the device and improve the reliability and stability of the device.

[0043] In a specific embodiment, by configuring two adjustable distributed circulation pumps for each flow battery module, the system can more precisely control the flow velocity and flow rate of the electrolyte in each flow battery module, thereby achieving a more uniform distribution of the electrolyte, while reducing the impact on the overall performance of the device when one distributed circulation pump fails.

[0044] Further, the battery management system 2 includes a state evaluation module, a balancing management module, and a fault diagnosis and alarm module. The output end of the state evaluation module is connected to the input end of the balancing management module, and is used for overall state evaluation of the first flow battery module 1. The output end of the balancing management module is connected to the input end of the fault diagnosis and alarm module, and is used for balancing control of each stack inside the first flow battery module 1. The fault diagnosis and alarm module is used for fault analysis and outputting the fault analysis result.

[0045] In a specific embodiment, the battery management system 2 adjusts the operating states of the positive distributed circulation pump 7 and the negative distributed circulation pump 8 by controlling the frequency converter 13 to achieve balancing control of each stack inside the first flow battery module 1. The state evaluation module obtains flow rate, temperature, and pressure data information through the flow sensor 9, the temperature sensor 10, and the pressure sensor 11, and performs balancing control on each stack inside the first flow battery module 1 through the balancing management module, and conducts fault analysis based on the control result and outputs the fault analysis result. By using the battery management system 2 to independently control each flow battery module and achieving good coordination and interaction between each module, the performance and stability of the entire system can be effectively improved.

[0046] Further, the positive electrolyte storage tank 3 and the negative electrolyte storage tank 4 are made of corrosion-resistant materials and are both cylindrical in shape.

[0047] In a specific embodiment, the electrolytes stored in the positive electrolyte storage tank 3 and the negative electrolyte storage tank 4 contain active substances that can participate in redox reactions during the operation of the battery and are corrosive. In the present invention, corrosion-resistant stainless steel materials are used, and the tank body is cylindrical in shape, which can provide good structural strength and stability.

[0048] Further, the model of the flow sensor 9 is an electromagnetic flow sensor, the model of the temperature sensor 10 is a platinum resistance temperature sensor, and the model of the pressure sensor 11 is a differential pressure sensor.

[0049] In a specific embodiment, the electromagnetic flow sensor has high measurement accuracy and fast response speed, can accurately control the flow rate of the electrolyte to achieve uniform flow. The platinum resistance temperature sensor has the advantages of high precision, good stability, wide measurement range, and strong corrosion resistance, and can help the battery management system 2 achieve efficient uniform flow control. The differential pressure sensor is suitable for occasions where the pressure difference between two points needs to be measured and can achieve more accurate uniform flow control.

[0050] Further, the positive distributed circulation pump 7 and the negative distributed circulation pump 8 are driven by motors, and the motors are used to adjust the rotational speed and flow rate of the distributed circulation pumps.

[0051] In a specific embodiment, by controlling the rotational speed and output power of the motor, the flow rate and pressure balance between different flow battery modules are adjusted to achieve an equal flow effect.

[0052] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these specific embodiments are merely illustrative. Without departing from the principles and essence of the present invention, those skilled in the art can make various omissions, substitutions, and changes to the details of the above methods and systems. For example, combining the above method steps so as to perform substantially the same function in a substantially the same way to achieve substantially the same result falls within the scope of the present invention. Therefore, the scope of the present invention is only defined by the appended claims.

Claims

1. An active current sharing device for a flow battery system, characterized in that, The device includes: The first flow battery module (1), the flow battery capacity unit (22), and the nth flow battery module (23); Wherein the first flow battery module (1) and the nth flow battery module (23) include a battery management system (2), a positive distributed circulation pump (7), a negative distributed circulation pump (8), a flow sensor (9), a temperature sensor (10), a pressure sensor (11), a control valve (12), a frequency converter (13), an electrolyte circulation branch (14), a stack positive inlet (16), a stack positive outlet (17), a stack negative inlet (18), a stack negative outlet (19), the first stack (20), and the nth stack (21). The battery management system (2) is connected to the sensors and the control valve (12) by cables. The positive distributed circulation pump (7) and the negative distributed circulation pump (8) are located inside the first flow battery module (1) and are connected to the sensors through the electrolyte circulation branch (14). The flow sensor (9), the temperature sensor (10), and the pressure sensor (11) are arranged side by side outside the control valve (12). The frequency converter (13) is located above the first flow battery module (1). The stack positive inlet (16), the stack positive outlet (17), the stack negative inlet (18), and the stack negative outlet (19) are located outside the first stack (20) and are connected to the control valve. The first stack (20) and the nth stack (21) are located at the center of the first flow battery module (1). Among them: The battery management system (2) is used to monitor the flow rate, temperature, and pressure of the electrolyte in the electrolyte circulation branch (14) in real time, and to adjust the operating states of the positive distributed circulation pump (7) and the negative distributed circulation pump (8) by controlling the frequency converter (13), so as to achieve the balanced control of each stack inside the first flow battery module (1); The positive distributed circulation pump (7) and the negative distributed circulation pump (8) are used to control the electrolyte flow rate of each stack in the first flow battery module (1); The flow sensor (9), the temperature sensor (10), and the pressure sensor (11) are used to monitor the liquid flow rate, temperature, and pressure parameters in the first flow battery module (1); The control valve (12) is used to adjust the pressure and flow rate of the electrolyte circulation branch; The frequency converter (13) is used to adjust the output of the distributed circulation pump to achieve the flow control of the first stack (20); The flow battery capacity unit (22) includes a positive electrolyte storage tank (3), a negative electrolyte storage tank (4), a positive main circulation pump (5), a negative main circulation pump (6), and an electrolyte circulation main path (15). The positive electrolyte storage tank (3) and the negative electrolyte storage tank (4) are arranged side by side below the first flow battery module (1). The positive main circulation pump (5) is located on the side of the positive electrolyte storage tank (3), and the negative main circulation pump (6) is located on the side of the negative electrolyte storage tank (4). Among them: The positive electrolyte storage tank (3) and the negative electrolyte storage tank (4) are used to store the electrolyte; The positive main circulation pump (5) and the negative main circulation pump (6) are used to transport the electrolyte in the liquid storage tank to each flow battery module through the main electrolyte circulation path (15). The first flow battery module (1) and the nth flow battery module (23) are connected to the flow battery capacity unit (22) through the main electrolyte circulation path (15).

2. The active current sharing device for a flow battery system according to claim 1, characterized in that: The first flow battery module (1) is configured with two adjustable distributed circulation pumps, which are used to reduce the impact of a single pump failure on the overall performance of the device and improve the reliability and stability of the device.

3. The active current sharing device for a flow battery system according to claim 1, characterized in that: The battery management system (2) includes a state evaluation module, an equalization management module, and a fault diagnosis and alarm module. The output end of the state evaluation module is connected to the input end of the equalization management module, which is used for the overall state evaluation of the first flow battery module (1). The output end of the equalization management module is connected to the input end of the fault diagnosis and alarm module, which is used for the equalization control of each stack inside the first flow battery module (1). The fault diagnosis and alarm module is used for fault analysis and outputting the fault analysis result.

4. The active current sharing device for a flow battery system according to claim 1, characterized in that: The positive liquid storage tank (3) and the negative liquid storage tank (4) are made of corrosion-resistant materials and are both cylindrical in shape.

5. The active current sharing device for a flow battery system according to claim 1, wherein: The model of the flow sensor (9) is an electromagnetic flow sensor, the model of the temperature sensor (10) is a platinum resistance temperature sensor, and the model of the pressure sensor (11) is a differential pressure sensor.

6. The active current sharing device for a flow battery system according to claim 2, characterized in that: The positive distributed circulation pump (7) and the negative distributed circulation pump (8) are driven by a motor, and the motor is used to adjust the rotation speed and flow rate of the distributed circulation pump.

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