Energy storage method of all-vanadium liquid flow energy storage equipment

Abstract

The invention relates to an energy storage method of all-vanadium liquid flow energy storage equipment, and belongs to the technical field of all-vanadium liquid flow energy storage. Comprising the following steps: S1, selecting a cell stack; s2, selecting an electrolyte storage tank with a proper size; s3, preparing an electrolyte; s4, arranging a circulating flow pipeline; s5, arranging a heat exchanger; s6, current is connected for energy storage; and S7, control and monitoring are conducted, specifically, opening and closing of the all-vanadium liquid flow energy storage equipment are controlled through a control system. The invention provides an energy storage method of all-vanadium redox flow energy storage equipment, which comprises the following steps: selecting a battery stack, selecting an electrolyte storage tank with a proper size, preparing an electrolyte with a proper concentration, arranging a circulating flow pipeline, arranging a heat exchanger, introducing current to store energy, and controlling and monitoring to realize the storage and release of electric energy. The all-vanadium liquid flow energy storage equipment has the advantages of being long in service life, high in safety, environmentally friendly and suitable for large-scale energy storage, and a new choice is provided for storage and utilization of renewable energy sources.

Description

Technical Field

[0001] The present invention relates to a energy storage method for a all-vanadium redox flow energy storage device, belonging to the technical field of all-vanadium redox flow energy storage. Background Technique

[0002] The all-vanadium redox flow energy storage device is an advanced electrochemical energy storage system. Its core lies in realizing the storage and release of energy through the cyclic redox reaction of the electrolyte solution. The electrical energy of the vanadium battery is stored in the sulfuric acid electrolyte of vanadium ions in different valence states in the form of chemical energy. The electrolyte is pumped into the battery stack body through an external pump. Under the action of mechanical power, it circulates in the closed loop of different liquid storage tanks and half-cells. A proton exchange membrane is used as the diaphragm of the battery pack. The electrolyte solution flows parallel to the electrode surface and undergoes an electrochemical reaction. The current is collected and conducted through the bipolar plate, so that the chemical energy stored in the solution is converted into electrical energy.

[0003] The existing energy storage methods of all-vanadium redox flow energy storage devices can basically meet the normal use requirements. However, compared with other mature energy storage technologies, all-vanadium redox flow batteries still have room for improvement in terms of equipment service life, safety performance, environmental friendliness, and large-scale energy storage. Based on this, the present invention provides a energy storage method for an all-vanadium redox flow energy storage device. Summary of the Invention

[0004] In view of this, the present invention provides a energy storage method for an all-vanadium redox flow energy storage device. The all-vanadium redox flow energy storage device has the advantages of long life, high safety, environmental friendliness, and suitability for large-scale energy storage, providing a new choice for the storage and utilization of renewable energy.

[0005] The present invention provides a energy storage method for an all-vanadium redox flow energy storage device. The proposed technical solution includes the following steps:

[0006] S1: Select a battery stack: The battery stack includes a positive electrode, a negative electrode, and a diaphragm; the positive electrode electrolyte is composed of a pentavalent vanadium ion solution and a tetravalent vanadium ion solution, and the negative electrode electrolyte is composed of a trivalent vanadium ion solution and a divalent vanadium ion solution;

[0007] S2: Select an electrolyte liquid storage tank of appropriate size: The size of the electrolyte liquid storage tank limits the energy storage capacity of the energy storage system. The electrolyte liquid storage tank includes a negative electrode liquid storage tank and a positive electrode liquid storage tank. The positive electrode liquid storage tank is used to store the positive electrode electrolyte, and the negative electrode liquid storage tank is used to store the negative electrode electrolyte;

[0008] S3: Prepare the electrolyte: By adjusting the concentration of the electrolyte, the energy storage capacity of the energy storage system can be further adjusted;

[0009] S4: Lay out the circulating pipeline: The circulating pipeline includes a liquid inlet pipe connecting the electrolyte storage tank and the battery stack: used to transport the electrolyte in the positive electrolyte storage tank to the positive electrode of the battery stack, and to transport the electrolyte in the negative electrolyte storage tank to the negative electrode of the battery stack; a liquid return pipe: used to reversely return the electrolyte flowing out from the positive electrode of the battery stack to the positive electrolyte storage tank, and to reversely return the electrolyte flowing out from the negative electrode of the battery stack to the negative electrolyte storage tank; a circulating pump arranged on the liquid inlet pipe;

[0010] S5: Lay out the heat exchanger: Connect the heat exchanger in series in the circulating pipeline to transfer the generated heat or absorb heat to maintain the stable operation of the energy storage system;

[0011] S6: Store energy by passing current: During the circulation of the electrolyte solution, vanadium ions undergo redox reactions in the stack, enabling electrical energy to be stored in the electrolyte solution in the form of chemical energy, thereby realizing the charging and discharging of electrical energy;

[0012] S7: Control and monitoring: Control the opening and closing of the all-vanadium redox flow energy storage device through the control system, and install various sensors to monitor various parameters during the energy storage process in real time.

[0013] Further, in step S1, the diaphragm adopts a proton exchange membrane, which is used to inhibit the cross-mixing of vanadium ions with different valence states in the positive and negative electrolyte solutions, and does not hinder the passage of hydrogen ions through the diaphragm to transfer charges, which is a key step to ensure charge balance and electrochemical reactions.

[0014] Further, in step S2, the larger electrolyte storage tank can accommodate more electrolyte solution, thereby storing more electrical energy.

[0015] Further, in step S3, the higher electrolyte concentration means that more vanadium ions participate in the electrochemical reaction, thereby being able to store more electrical energy.

[0016] Further, in step S4, the electrolyte circulates between the electrolyte storage tank and the battery under the action of the circulating pump, which is used to enable the electrolyte to continuously participate in the electrochemical reaction, thereby realizing the continuous storage and release of electrical energy.

[0017] Further, in step S5, the electrolyte storage tank is made of stainless steel or carbon steel. The electrolyte storage tank is of a cylindrical structure, and heat dissipation fins are provided on the outer wall of the cylindrical electrolyte storage tank to cool the electrolyte in the electrolyte storage tank. It is of great significance to cooperate with the heat exchanger to prevent the battery from overheating, improve the energy storage efficiency and extend the service life of the equipment.

[0018] Further, in step S6, during the charging process, vanadium(IV) ions in the positive electrolyte are oxidized to vanadium(V) ions and lose one electron. At the same time, vanadium(III) ions in the negative electrolyte gain one electron and are reduced to vanadium(II) ions. During the discharging process, these reactions proceed in the reverse direction, that is, vanadium(V) ions in the positive electrolyte gain one electron and are reduced to vanadium(IV) ions, and vanadium(II) ions in the negative electrolyte lose one electron and are oxidized to vanadium(III) ions.

[0019] Further, in step S7, the control system includes a battery management system BMS and an electrolyte management system LEMS. The battery management system BMS includes data acquisition: collecting and summarizing data through various sensors connected to the battery compartment; data processing: calibrating, smoothing, and filtering key data to ensure the accuracy and reliability of the data; status monitoring: real-time monitoring of the battery status to ensure that the battery operates within appropriate parameter ranges; abnormal alarm: once an abnormal situation is detected, immediately alarm and take measures such as shutting down the system and halting operation. The electrolyte management system LEMS includes flow control: precisely controlling the flow rate of the electrolyte to ensure the stability and efficiency of the charge and discharge processes; status monitoring: monitoring the liquid level, pressure, and temperature parameters of the electrolyte to ensure the normal operation of the system; abnormal alarm: immediately alarm and take measures once an abnormal situation is detected.

[0020] Further, in step S7, the sensors include temperature sensors, pressure sensors, liquid leakage sensors, voltage sensors, current sensors, flow sensors, and humidity sensors.

[0021] Advantages of the present invention:

[0022] The present invention provides a method for storing energy in a vanadium redox flow energy storage device. By selecting a battery stack, selecting an electrolyte storage tank of appropriate size, preparing an electrolyte of appropriate concentration, laying out a circulating pipeline, laying out a heat exchanger, passing an electric current for energy storage, and controlling and monitoring, the storage and release of electrical energy are realized, making the vanadium redox flow energy storage device have the advantages of long life, high safety, environmental friendliness, and suitability for large-scale energy storage, providing a new option for the storage and utilization of renewable energy. Specific embodiments

[0023] The preferred embodiments of the present invention will be described in detail below.

[0024] The present invention provides a method for storing energy in a vanadium redox flow energy storage device, which includes the following steps:

[0025] S1: Select a battery stack: The battery stack includes a positive electrode, a negative electrode, and a separator; the positive electrode electrolyte is composed of a solution of vanadium pentoxide ions and a solution of vanadium tetraoxide ions, and the negative electrode electrolyte is composed of a solution of vanadium trioxide ions and a solution of vanadium dioxide ions; the separator uses a proton exchange membrane, which is used to inhibit the cross-mixing of vanadium ions with different valence states in the positive and negative electrode electrolytes, and does not prevent hydrogen ions from passing through the separator to transfer charges, which is used to ensure the key steps of achieving charge balance and electrochemical reactions;

[0026] S2: Select an electrolyte storage tank of appropriate size: The size of the electrolyte storage tank limits the energy storage capacity of the energy storage system. A larger electrolyte storage tank can hold more electrolyte solution, thus storing more electrical energy. By adjusting the size of the storage tank, the energy storage capacity of the energy storage system can be flexibly changed. The electrolyte storage tank includes a negative electrode storage tank and a positive electrode storage tank. The positive electrode storage tank is used to store the positive electrode electrolyte, and the negative electrode storage tank is used to store the negative electrode electrolyte;

[0027] S3: Prepare the electrolyte: By adjusting the concentration of the electrolyte, a higher electrolyte concentration means that more vanadium ions participate in the electrochemical reaction, thus enabling more electrical energy to be stored, and the energy storage capacity of the energy storage system can be further adjusted;

[0028] S4: Arrange the circulating pipeline: The circulating pipeline includes an inlet pipe connecting the electrolyte storage tank and the battery stack: used to transport the electrolyte in the positive electrode storage tank to the positive electrode of the battery stack, and to transport the electrolyte in the negative electrode storage tank to the negative electrode of the battery stack, a return pipe: used to reverse the flow of the electrolyte flowing out of the positive electrode of the battery stack back into the positive electrode storage tank, and to reverse the flow of the electrolyte flowing out of the negative electrode of the battery stack back into the negative electrode storage tank, and a circulating pump installed on the inlet pipe. The electrolyte circulates between the electrolyte storage tank and the battery under the action of the circulating pump, which is used to enable the electrolyte to continuously participate in the electrochemical reaction, thereby realizing the continuous storage and release of electrical energy;

[0029] S5: Arrange a heat exchanger: Connect the heat exchanger in series in the circulating pipeline to transfer the generated heat or absorb heat to maintain the stable operation of the energy storage system. The electrolyte storage tank is made of stainless steel or carbon steel. The electrolyte storage tank has a cylindrical structure, and heat dissipation fins are provided on the outer wall of the cylindrical electrolyte storage tank to cool the electrolyte in the electrolyte storage tank. Cooperating with the heat exchanger is of great significance for preventing the battery from overheating, improving the energy storage efficiency, and extending the equipment life;

[0030] S6: Storing energy by passing current: During the circulation of the electrolyte solution, redox reactions occur to vanadium ions within the stack, enabling electrical energy to be stored in the electrolyte solution in the form of chemical energy, thereby achieving charge and discharge of electrical energy. During the charging process, tetravalent vanadium ions in the positive electrolyte are oxidized to pentavalent vanadium ions and lose one electron. Meanwhile, trivalent vanadium ions in the negative electrolyte gain one electron and are reduced to divalent vanadium ions. During the discharging process, these reactions proceed in reverse, i.e., pentavalent vanadium ions in the positive electrolyte gain one electron and are reduced to tetravalent vanadium ions, and divalent vanadium ions in the negative electrolyte lose one electron and are oxidized to trivalent vanadium ions.

[0031] S7: Control and monitoring: The opening and closing of the all-vanadium redox flow energy storage device are controlled by a control system. Various sensors are installed to monitor various parameters during the energy storage process in real time. The sensors include temperature sensors, pressure sensors, leak sensors, voltage sensors, current sensors, flow sensors, and humidity sensors. The control system includes a battery management system BMS and an electrolyte management system LEMS. The battery management system BMS includes data acquisition: collecting and summarizing data through various sensors connected to the battery compartment; data processing: calibrating, smoothing, and filtering key data to ensure the accuracy and reliability of the data; state monitoring: monitoring the state of the battery in real time to ensure that the battery operates within appropriate parameter ranges; abnormal alarm: once an abnormal situation is detected, immediately alarm and take measures such as shutting down the system and halting the machine. The electrolyte management system LEMS includes flow control: precisely controlling the flow rate of the electrolyte to ensure the stability and efficiency of the charge and discharge process; state monitoring: monitoring the liquid level, pressure, and temperature parameters of the electrolyte to ensure the normal operation of the system; abnormal alarm: once an abnormal situation is detected, such as abnormal flow or too high temperature, immediately alarm and take measures.

[0032] In summary, the all-vanadium redox flow energy storage device stores and releases electrical energy by selecting a battery stack, selecting an electrolyte storage tank of appropriate size, preparing an electrolyte of appropriate concentration, arranging a circulating pipeline, arranging a heat exchanger, storing energy by passing current, and performing control and monitoring. This makes the all-vanadium redox flow energy storage device have the advantages of long life, high safety, environmental friendliness, and suitability for large-scale energy storage, providing a new option for the storage and utilization of renewable energy.

[0033] The above describes the present invention and its implementation manners. This description is not restrictive, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of the present invention, design similar structural manners and embodiments to this technical solution without creative efforts, they should all fall within the protection scope of the present invention.

Claims

1. A energy storage method for a all-vanadium redox flow energy storage device, characterized in that: It includes the following steps: S1: Select a battery stack: The battery stack includes a positive electrode, a negative electrode, and a separator; the positive electrode electrolyte is composed of a pentavalent vanadium ion solution and a tetravalent vanadium ion solution, and the negative electrode electrolyte is composed of a trivalent vanadium ion solution and a divalent vanadium ion solution; S2: Select an electrolyte storage tank of appropriate size: The size of the electrolyte storage tank limits the energy storage capacity of the energy storage system. The electrolyte storage tank includes a negative electrode storage tank and a positive electrode storage tank. The positive electrode storage tank is used to store the positive electrode electrolyte, and the negative electrode storage tank is used to store the negative electrode electrolyte; S3: Prepare the electrolyte: By adjusting the concentration of the electrolyte, the energy storage capacity of the energy storage system can be further adjusted; S4: Lay out the circulating pipeline: The circulating pipeline includes an inlet pipe connecting the electrolyte storage tank and the battery stack: used to transport the electrolyte in the positive electrode storage tank to the positive electrode of the battery stack, used to transport the electrolyte in the negative electrode storage tank to the negative electrode of the battery stack, a return pipe: used to reversely return the electrolyte flowing out of the positive electrode of the battery stack to the positive electrode storage tank, used to reversely return the electrolyte flowing out of the negative electrode of the battery stack to the negative electrode storage tank, and a circulating delivery pump arranged on the inlet pipe; S5: Lay out a heat exchanger: Connect the heat exchanger in series in the circulating pipeline to transfer the generated heat or absorb heat to maintain the stable operation of the energy storage system; S6: Store energy by passing an electric current: During the circulation of the electrolyte solution, redox reactions occur to vanadium ions in the stack, enabling electrical energy to be stored in the electrolyte solution in the form of chemical energy, thereby realizing the charge and discharge of electrical energy; S7: Control and monitoring: Control the opening and closing of the all-vanadium redox flow energy storage device through a control system, and install various sensors to monitor various parameters during the energy storage process in real time.

2. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, characterized in that: In step S1, the separator uses a proton exchange membrane, which is used to inhibit the cross-mixing of vanadium ions in different valence states in the positive and negative electrode electrolytes, and does not prevent hydrogen ions from passing through the separator to transfer charges, which is a key step to ensure charge balance and electrochemical reactions.

3. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, wherein: In step S2, the larger electrolyte storage tank can hold more electrolyte solution, thereby storing more electrical energy.

4. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, characterized in that: In step S3, the higher electrolyte concentration means that more vanadium ions participate in the electrochemical reaction, thereby being able to store more electrical energy.

5. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, characterized in that: In step S4, the electrolyte circulates between the electrolyte storage tank and the battery under the action of the circulating delivery pump, enabling the electrolyte to continuously participate in the electrochemical reaction, thereby realizing the continuous storage and release of electrical energy.

6. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, characterized in that: In step S5, the electrolyte storage tank is made of stainless steel or carbon steel. The electrolyte storage tank is of a cylindrical structure, and heat dissipation fins are provided on the outer wall of the cylindrical electrolyte storage tank to cool the electrolyte in the electrolyte storage tank, which is of great significance for preventing the battery from overheating, improving the energy storage efficiency, and extending the service life of the equipment in cooperation with the heat exchanger.

7. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, wherein: In step S6, during the charging process, the tetravalent vanadium ions in the positive electrolyte are oxidized to pentavalent vanadium ions and lose one electron. At the same time, the trivalent vanadium ions in the negative electrolyte gain one electron and are reduced to divalent vanadium ions. During the discharging process, these reactions proceed in the reverse direction, that is, the pentavalent vanadium ions in the positive electrolyte gain one electron and are reduced to tetravalent vanadium ions, and the divalent vanadium ions in the negative electrolyte lose one electron and are oxidized to trivalent vanadium ions.

8. The energy storage method of a full vanadium redox flow energy storage device according to claim 1, characterized in that: In step S7, the control system includes a battery management system BMS and an electrolyte management system LEMS. The battery management system BMS includes data acquisition: collecting and summarizing data through various sensors connected to the battery compartment; data processing: calibrating, smoothing, and filtering key data to ensure the accuracy and reliability of the data; status monitoring: real-time monitoring of the battery status to ensure that the battery operates within appropriate parameter ranges; abnormal alarm: once an abnormal situation is detected, immediately alarm and take measures such as shutting down the system and halting operation. The electrolyte management system LEMS includes flow control: precisely controlling the flow rate of the electrolyte to ensure the stability and efficiency of the charge and discharge processes; status monitoring: monitoring the liquid level, pressure, and temperature parameters of the electrolyte to ensure the normal operation of the system; abnormal alarm: once an abnormal situation is detected, immediately alarm and take measures.

9. The energy storage method of a all-vanadium redox flow energy storage device according to claim 1, characterized in that: In step S7, the sensors include temperature sensors, pressure sensors, leak sensors, voltage sensors, current sensors, flow sensors, and humidity sensors.