All-vanadium redox flow battery test system

Abstract

The utility model discloses an all-vanadium redox flow battery testing system which comprises a main control unit, an electric pile, a positive electrode electrolyte circulating assembly and a negative electrode electrolyte circulating assembly, a first liquid inlet of the electric pile is communicated with a liquid outlet end of the positive electrode electrolyte circulating assembly, a first liquid outlet of the electric pile is communicated with a liquid inlet end of the positive electrode electrolyte circulating assembly, and a second liquid inlet of the electric pile is communicated with a liquid outlet end of the negative electrode electrolyte circulating assembly; a second liquid outlet of the electric pile is communicated with a liquid inlet end of the negative electrode electrolyte circulating assembly; the main control unit comprises a charging and discharging tester and an upper computer, the charging and discharging tester is electrically connected with the electric pile, and the charging and discharging tester is connected with the upper computer through a communication interface. According to the utility model, comprehensive electrochemical performance test can be realized, the electrolyte can quickly return to the liquid storage tank from the galvanic pile after the performance test is completed, and the influence on the test result caused by the oxidation of the cathode electrolyte is reduced, so that the reliability of the test result can be improved.

Description

Technical Field

[0001] This utility model relates to the field of vanadium redox flow battery technology, and in particular to a vanadium redox flow battery testing system. Background Technology

[0002] The global energy structure is undergoing revolutionary changes, and my country's energy structure is also constantly being adjusted. The combination of energy storage and new energy sources is an inevitable trend in the development of power systems. Against this backdrop, flow batteries, as an energy storage technology with advantages such as safety, life-cycle capacity recovery, cycle life, system integration and scalability, overload capacity, and deep discharge capability, are gradually being promoted and used in the industry.

[0003] Vanadium redox flow batteries are battery devices based on the redox reaction principle of vanadium metals in different valence states, achieving charging and discharging through electrochemical reactions. During the research and development of vanadium redox flow batteries, appropriate experimental methods are frequently used to test battery performance, thereby obtaining high-precision data on the relationship between various influencing factors and battery performance. This provides a strong basis for further battery research and material selection, thus shortening the research and development cycle and reducing costs. Therefore, providing a convenient testing system for vanadium redox flow batteries is a crucial step in the industrialization stage of vanadium redox flow batteries.

[0004] Before a vanadium redox flow battery leaves the factory or is used, the stack needs to be tested to ensure stability. Existing technologies include testing methods for vanadium redox flow batteries, such as a testing method and system for vanadium redox flow batteries (202410510201.X). This document discloses a testing system including: a testing host, a low-temperature chamber, a high-temperature chamber, temperature and humidity sensors, a parameter detection device, and a timing device. The testing host, connected to the temperature and humidity sensors, acquires, displays, and saves the ambient temperature and humidity information. The testing host, connected to the parameter detection device, acquires, displays, and saves the charging voltage, charging current, cutoff voltage, discharging voltage, discharging current, and maximum operating voltage of the stack during the test. The timing device is used to time the test process and emits an audible alert when a preset time point is reached. The low-temperature chamber is used to perform the low-temperature test process, and the high-temperature chamber is used to perform the high-temperature test process. However, in practical use, it has been found that the data obtained using the above system is relatively coarse, lacks safety monitoring strategies, and the testing time is lengthy. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this utility model is to provide a vanadium redox flow battery testing system that can achieve comprehensive electrochemical performance testing and solve the problem of rapid return of electrolyte from the stack to the storage tank after the performance test is completed, thereby reducing the impact of oxidation of the negative electrode electrolyte on the test results and improving the reliability of the test results.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] According to an embodiment of this disclosure, a vanadium redox flow battery testing system is provided, including a main control unit, a battery stack, a positive electrolyte circulation assembly, and a negative electrolyte circulation assembly.

[0008] The first liquid inlet of the fuel cell stack is connected to the liquid outlet of the positive electrode electrolyte circulation assembly, and the first liquid outlet of the fuel cell stack is connected to the liquid inlet of the positive electrode electrolyte circulation assembly.

[0009] The second liquid inlet of the fuel cell stack is connected to the liquid outlet of the negative electrode electrolyte circulation assembly, and the second liquid outlet of the fuel cell stack is connected to the liquid inlet of the negative electrode electrolyte circulation assembly.

[0010] The main control unit includes a charge-discharge tester and a host computer. The charge-discharge tester is electrically connected to the fuel cell stack and is connected to the host computer through a communication interface.

[0011] In a preferred embodiment, the positive electrode electrolyte circulation assembly includes a positive electrode storage tank, a positive electrode circulation pump, and a positive electrode heat exchanger; the positive electrode storage tank is connected in sequence to the positive electrode circulation pump, the positive electrode heat exchanger, and the first inlet of the fuel cell stack via a positive electrode inlet pipeline; the first outlet of the fuel cell stack is connected to the positive electrode storage tank via a positive electrode return pipeline.

[0012] As a preferred embodiment, the positive electrode storage tank is provided with a positive electrode return port, the outlet of the positive electrode return pipeline is connected to the positive electrode return port, and the outlet of the positive electrode return pipeline is located above the positive electrode return port; wherein, a positive electrode vacuum breaking valve is provided on the positive electrode return pipeline.

[0013] As a preferred embodiment, a positive electrode return liquid flow meter, a positive electrode return liquid pressure sensor, and a positive electrode return liquid temperature sensor are installed on the positive electrode return liquid pipeline; a positive electrode storage tank radar level gauge is installed on the positive electrode storage tank.

[0014] In a preferred embodiment, the negative electrode electrolyte circulation assembly includes a negative electrode storage tank, a negative electrode circulation pump, and a negative electrode heat exchanger; the negative electrode storage tank is connected in sequence to the negative electrode circulation pump, the negative electrode heat exchanger, and the second inlet of the fuel cell stack via a negative electrode inlet pipeline; the second outlet of the fuel cell stack is connected to the negative electrode storage tank via a negative electrode return pipeline.

[0015] As a preferred embodiment, the negative electrode storage tank is provided with a negative electrode return port, the outlet of the negative electrode return pipeline is connected to the negative electrode return port, and the outlet of the negative electrode return pipeline is located above the negative electrode return port; wherein, a negative electrode vacuum breaking valve is provided on the negative electrode return pipeline.

[0016] In a preferred embodiment, the negative electrode storage tank is filled with electrolyte, and a mineral oil layer is arranged on the surface of the electrolyte.

[0017] As a preferred embodiment, a hydrogen concentration sensor is provided on the top of the negative electrode storage tank.

[0018] As a preferred embodiment, a negative electrode return liquid flow meter, a negative electrode return liquid pressure sensor, and a negative electrode return liquid temperature sensor are installed on the negative electrode return liquid pipeline; a negative electrode storage tank radar level gauge is installed on the negative electrode storage tank.

[0019] In summary, compared with the prior art, this utility model has the following beneficial effects:

[0020] 1. The positive and negative electrolyte circulation components of this application are configured identically, which effectively avoids the influence of the resistance of different circulation components on the electrolyte flow and pipeline pressure, thereby changing the test results and improving the data accuracy;

[0021] 2. The positive and negative electrolyte circulation components of this application are equipped with heat exchangers, which can effectively control the temperature of the electrolyte when it enters the stack reaction, prevent the electrolyte in the circulation pipeline from precipitating crystals due to temperature, and ensure test accuracy.

[0022] 3. This application uses a charge-discharge tester to charge and discharge the fuel cell stack, which enables precise and controllable testing conditions such as voltage, current and power of the fuel cell stack. This not only improves the testing accuracy, but also uploads the performance data to the host computer and saves the records. The results are clear, and the system automatically alarms and shuts down in case of abnormality, which effectively ensures the safety of the test.

[0023] 4. The surface of the electrolyte in the negative electrode storage tank of this application is covered with mineral oil, which can effectively prevent the negative electrode electrolyte from contacting air and being oxidized, thus ensuring the accuracy of the test.

[0024] 5. After the test is completed, the vacuum rupture valve at the top is opened, and the remaining electrolyte in the fuel cell stack quickly returns to the electrolyte storage tank. This can effectively recover the electrolyte, reduce the workload of handling the electrolyte when disassembling the fuel cell stack, and improve the testing efficiency of the fuel cell stack. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the connection structure of the all-vanadium redox flow battery testing system of this utility model;

[0026] Figure 2 This is a flowchart of the all-vanadium redox flow battery testing system of this utility model;

[0027] The numbers and letters in the figure represent the corresponding component names:

[0028] 1. Main control unit; 11. Charge / discharge tester; 12. Host computer;

[0029] 2. Fuel cell stack; 21. Fuel cell stack testing platform;

[0030] 3. Positive electrode electrolyte circulation assembly; 31. Positive electrode storage tank; 311. Positive electrode storage tank radar level gauge; 32. Positive electrode circulation pump; 33. Positive electrode heat exchanger; 34. Positive electrode inlet pipeline; 35. Positive electrode return pipeline; 351. Positive electrode vacuum breaker valve; 352. Positive electrode return pipeline flow meter; 353. Positive electrode return pipeline pressure sensor; 354. Positive electrode return pipeline temperature sensor

[0031] 4. Negative electrode electrolyte circulation assembly; 41. Negative electrode storage tank; 411. Hydrogen concentration sensor; 412. Radar level gauge for negative electrode storage tank; 42. Negative electrode circulation pump; 43. Negative electrode heat exchanger; 44. Negative electrode inlet pipeline; 45. Negative electrode return pipeline; 451. Negative electrode vacuum breaker valve; 452. Negative electrode return pipeline flow meter; 453. Negative electrode return pipeline pressure sensor; 454. Negative electrode return pipeline temperature sensor. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Example: Figures 1 to 2 As shown, a vanadium redox flow battery testing system includes a main control unit 1, a battery stack 2, a positive electrolyte circulation assembly 3, and a negative electrolyte circulation assembly 4.

[0034] The first liquid inlet of the fuel cell stack 2 is connected to the liquid outlet of the positive electrode electrolyte circulation assembly 3, and the first liquid outlet of the fuel cell stack 2 is connected to the liquid inlet of the positive electrode electrolyte circulation assembly 3.

[0035] The second liquid inlet of the fuel cell stack 2 is connected to the liquid outlet of the negative electrode electrolyte circulation assembly 4, and the second liquid outlet of the fuel cell stack 2 is connected to the liquid inlet of the negative electrode electrolyte circulation assembly 4.

[0036] The main control unit 1 includes a charge-discharge tester 11 and a host computer 12. The charge-discharge tester 11 is electrically connected to the fuel cell stack 2, and the charge-discharge tester 11 is connected to the host computer 12 through a communication interface.

[0037] It should be noted that the fuel cell stack 2 is composed of several vanadium redox flow cells connected in series. The fuel cell stack 2 is set on the fuel cell stack test platform 21, which is higher than the height of the positive electrode storage tank 31 and the negative electrode storage tank 41.

[0038] In practice, the charge / discharge tester 11 is configured to simultaneously charge and discharge the vanadium redox flow battery stack and perform energy tests on the positive and negative terminals of the stack. The data results and charge / discharge configuration information are transmitted to a host computer via a communication interface. Furthermore, the charge / discharge tester 11 can also have constant power and constant current charging / discharging modes. Therefore, the constant power and constant current modes can be switched to charge and discharge the stack according to experimental requirements, meeting different experimental needs and comprehensively testing battery performance and electrolyte utilization.

[0039] It should be noted that the electrical performance indicators of the fuel cell stack include: battery charge / discharge ampere-hours (Ah), watt-hours (Wh), charge / discharge efficiency, energy density, etc. The definitions and calculation formulas of these electrical performance indicators are all in the prior art, and will not be repeated in this embodiment of the present invention.

[0040] During implementation, the host computer 12 is configured to calculate the electrical performance indicators of the fuel cell stack based on the test data and charge / discharge information sent by the charge / discharge tester.

[0041] It should be noted that, in this application, the data for electrical energy testing includes the voltage across the vanadium redox flow battery stack, the charging / discharging current, the pipeline pressure, the electrolyte flow rate, and the temperature; the charging / discharging configuration information includes the output voltage, output current, and output power of the charging / discharging tester.

[0042] During implementation, the host computer 12 and the charged experimental components (fuel pile 2, charge / discharge tester 11, and positive and negative electrolyte circulation components) are located in different spaces, which can avoid the possibility of injury to personnel due to abnormal emergencies during the experiment. In addition, the charge / discharge configuration information during the experiment can be set remotely, and personnel can obtain the electrical performance test report locally on the host computer 12 without having to approach the experimental site.

[0043] In this application, the vanadium redox flow battery stack is charged and discharged using a charge-discharge tester, with precise and controllable current and an anti-reverse current device, making maintenance convenient. In addition, during the test, the operator only needs to execute the test process through the host computer, which effectively avoids injury to personnel caused by emergencies and improves safety.

[0044] Specifically, the positive electrode electrolyte circulation assembly 3 includes a positive electrode storage tank 31, a positive electrode circulation pump 32, and a positive electrode heat exchanger 33; the positive electrode storage tank 31 is connected to the positive electrode circulation pump 32, the positive electrode heat exchanger 33, and the first inlet of the fuel cell stack 2 in sequence through the positive electrode inlet pipe 34; the first outlet of the fuel cell stack 2 is connected to the positive electrode storage tank 31 through the positive electrode return pipe 35.

[0045] In this application, the positive electrode circulation pump draws the positive electrode electrolyte from the positive electrode storage tank and enters the stack through the positive electrode inlet pipeline. The remaining positive electrode electrolyte returns to the positive electrode storage tank through the positive electrode return pipeline.

[0046] In this application, the heat exchanger allows researchers to adjust the temperature of the electrolyte in the pipeline according to different testing needs, ensuring the consistency of the electrolyte temperature throughout the system. This guarantees that the test results are not affected by temperature changes and improves the accuracy of the results. It should be noted that the coolant in the heat exchanger is antifreeze.

[0047] Specifically, the positive electrode storage tank 31 is provided with a positive electrode return port, the outlet of the positive electrode return pipeline 35 is connected to the positive electrode return port, and the outlet of the positive electrode return pipeline 35 is located above the positive electrode return port; wherein, a positive electrode vacuum breaker valve 351 is provided on the positive electrode return pipeline 35.

[0048] Specifically, a positive electrode return liquid flow meter 352, a positive electrode return liquid pressure sensor 353, and a positive electrode return liquid temperature sensor 354 are installed on the positive electrode return liquid pipeline 35; and a positive electrode storage tank radar level gauge 311 is installed on the positive electrode storage tank 31.

[0049] Specifically, the negative electrode electrolyte circulation assembly 4 includes a negative electrode storage tank 41, a negative electrode circulation pump 42, and a negative electrode heat exchanger 43; the negative electrode storage tank 41 is connected in sequence to the negative electrode circulation pump 42, the negative electrode heat exchanger 43, and the second inlet of the fuel cell stack 2 through a negative electrode inlet pipe 44; the second outlet of the fuel cell stack 2 is connected to the negative electrode storage tank 41 through a negative electrode return pipe 45.

[0050] In this application, the negative electrode circulation pump draws the negative electrode electrolyte from the negative electrode storage tank and enters the fuel cell stack through the negative electrode inlet pipeline. The remaining negative electrode electrolyte returns to the negative electrode storage tank through the negative electrode return pipeline.

[0051] Specifically, the negative electrode storage tank 41 is provided with a negative electrode return port, the outlet of the negative electrode return pipeline 45 is connected to the negative electrode return port, and the outlet of the negative electrode return pipeline 45 is located above the negative electrode return port; wherein, a negative electrode vacuum breaker valve 451 is provided on the negative electrode return pipeline 45.

[0052] In this application, opening the vacuum rupture valve allows the electrolyte to be quickly separated from the fuel cell stack using gravity.

[0053] Specifically, the negative electrode storage tank 41 is filled with electrolyte, and a mineral oil layer is arranged on the surface of the electrolyte.

[0054] During implementation, the mineral oil layer is formed by adding mineral oil to the surface of the electrolyte in the negative electrode storage tank 41. The mineral oil is an organic compound containing hydroxyl or carboxyl groups, with a carbon number greater than 5 and a thickness of 0.1-4 mm. Its function is to prevent ink damage and to guide the return liquid to below the liquid surface.

[0055] Specifically, a hydrogen concentration sensor 411 is installed on the top of the negative electrode storage tank 41.

[0056] This allows for monitoring of the amount of hydrogen generated during the hydrogen evolution reaction in the experiment.

[0057] Specifically, a negative electrode return liquid flow meter 452, a negative electrode return liquid pressure sensor 453, and a negative electrode return liquid temperature sensor 454 are installed on the negative electrode return liquid pipeline 45; and a negative electrode storage tank radar level gauge 412 is installed on the negative electrode storage tank 41.

[0058] In this way, pressure and temperature sensors are used to measure the pressure and temperature of the electrolyte after it passes through the heat exchanger, and flow meters are used to measure the electrolyte flow rate.

[0059] In practice, all pipelines in this application are transparent flexible tubes, and the positive electrode storage tank 31 and the negative electrode storage tank 41 can be transparent sealed liquid tanks with volume scales on the tank body. Correspondingly, the top is equipped with a radar level gauge 311 for the positive electrode storage tank and a radar level gauge 412 for the negative electrode storage tank. In this way, the liquid level changes can be observed intuitively during the experiment.

[0060] In practice, the positive circulation pump 32 and the negative circulation pump 42 are magnetic pumps.

[0061] During implementation, the water distributor is positioned below the electrolyte level. This ensures that electrolytes in different valence states within the storage tank are mixed evenly.

[0062] In this application, the testing system also includes sensors, a data acquisition unit, and an execution unit;

[0063] Sensors: used to measure real-time parameters of the fuel cell stack during charging and discharging;

[0064] Data acquisition unit: used to receive real-time parameters from sensors and convert them into digital signals to send to the main control unit;

[0065] Main control unit: Exchanges information with the measurement and control unit, acquires real-time data and issues commands to achieve control and regulation;

[0066] Execution unit: Receives digital signals from the main control unit and is used to drive the positive and negative circulation pumps.

[0067] The data acquisition unit includes an analog-to-digital conversion module connected to multiple sensors.

[0068] The main controller unit includes a computer (PC) as the host computer and a programmable logic controller (PLC) as the slave computer, which are connected by a dedicated cable.

[0069] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of this utility model, and all of these fall within the protection scope of this utility model.

Claims

1. A testing system for an all-vanadium redox flow battery, characterized in that, It includes a main control unit, a fuel cell stack, a positive electrolyte circulation assembly, and a negative electrolyte circulation assembly; The first liquid inlet of the fuel cell stack is connected to the liquid outlet of the positive electrode electrolyte circulation assembly, and the first liquid outlet of the fuel cell stack is connected to the liquid inlet of the positive electrode electrolyte circulation assembly. The second liquid inlet of the fuel cell stack is connected to the liquid outlet of the negative electrode electrolyte circulation assembly, and the second liquid outlet of the fuel cell stack is connected to the liquid inlet of the negative electrode electrolyte circulation assembly. The main control unit includes a charge-discharge tester and a host computer. The charge-discharge tester is electrically connected to the fuel cell stack and is connected to the host computer through a communication interface.

2. The all-vanadium redox flow battery testing system according to claim 1, characterized in that, The positive electrode electrolyte circulation assembly includes a positive electrode storage tank, a positive electrode circulation pump, and a positive electrode heat exchanger. The positive electrode storage tank is connected in sequence to the positive electrode circulation pump, the positive electrode heat exchanger, and the first inlet of the fuel cell stack via a positive electrode inlet pipeline. The first outlet of the fuel cell stack is connected to the positive electrode storage tank via a positive electrode return pipeline.

3. The all-vanadium redox flow battery testing system according to claim 2, characterized in that, The positive electrode storage tank is provided with a positive electrode return port, and the outlet of the positive electrode return pipeline is connected to the positive electrode return port, and the outlet of the positive electrode return pipeline is located above the positive electrode return port; wherein, a positive electrode vacuum breaking valve is provided on the positive electrode return pipeline.

4. The all-vanadium redox flow battery testing system according to claim 2, characterized in that, A positive electrode return liquid flow meter, a positive electrode return liquid pressure sensor, and a positive electrode return liquid temperature sensor are installed on the positive electrode return liquid pipeline; a positive electrode storage tank radar level gauge is installed on the positive electrode storage tank.

5. The all-vanadium redox flow battery testing system according to claim 1, characterized in that, The negative electrode electrolyte circulation assembly includes a negative electrode storage tank, a negative electrode circulation pump, and a negative electrode heat exchanger. The negative electrode storage tank is connected in sequence to the negative electrode circulation pump, the negative electrode heat exchanger, and the second inlet of the fuel cell stack via a negative electrode inlet pipeline. The second outlet of the fuel cell stack is connected to the negative electrode storage tank via a negative electrode return pipeline.

6. The all-vanadium redox flow battery testing system according to claim 5, characterized in that, The negative electrode storage tank is provided with a negative electrode return port, and the outlet of the negative electrode return pipeline is connected to the negative electrode return port, and the outlet of the negative electrode return pipeline is located above the negative electrode return port; wherein, a negative electrode vacuum breaking valve is provided on the negative electrode return pipeline.

7. The all-vanadium redox flow battery testing system according to claim 5, characterized in that, The negative electrode storage tank is filled with electrolyte, and a mineral oil layer is arranged on the surface of the electrolyte.

8. The all-vanadium redox flow battery testing system according to claim 5, characterized in that, A hydrogen concentration sensor is installed on the top of the negative electrode storage tank.

9. The all-vanadium redox flow battery testing system according to claim 5, characterized in that, A negative electrode return liquid flow meter, a negative electrode return liquid pressure sensor, and a negative electrode return liquid temperature sensor are installed on the negative electrode return liquid pipeline; a negative electrode storage tank radar level gauge is installed on the negative electrode storage tank.

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