Flow battery system and gas circuit early warning method thereof

Abstract

The invention relates to the technical field of flow batteries, and discloses a flow battery system and a gas circuit early warning method thereof, and the gas circuit early warning method comprises the following steps: S1, in the charging process of a flow battery, hydrogen separated out from an electrolyte flows along with the electrolyte and is accumulated to the top of a liquid tank; s2, hydrogen enters an exhaust device at the top of the liquid tank and then enters a hydrogen metering device; s3, the hydrogen metering device monitors the hydrogen evolution amount in real time, and when the hydrogen evolution amount reaches a certain concentration, a prompt is sent to the system; s4, the system automatically calculates whether a single battery is close to the potential of 1.18 V or not; s5, if the single battery is not close to the potential of 1.18 V, the flow battery system operates normally, if the single battery is close to the potential of 1.18 V, the flow battery system controls the automatic charging and discharging device to reduce the charging current, and if the single battery exceeds the potential of 1.18 V, the flow battery system controls the automatic charging and discharging device to stop charging; according to the invention, early warning can be carried out through the gas circuit, and the safety performance of the flow battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flow batteries, and specifically to a flow battery system and an air circuit early warning method thereof. Background Art

[0002] With the continuous growth of the world economy, people's demand for energy is increasing day by day, and the energy shortage is becoming more and more serious; the extensive consumption of traditional fossil energy has led to increasing environmental problems. Therefore, renewable energy has been widely used. However, the power generation of renewable energy such as wind energy and solar energy has the characteristics of instability and discontinuity, which restricts the further development of renewable energy; therefore, large-scale energy storage technologies, especially long-term energy storage technologies, are extremely needed to improve the power quality and reliability of renewable energy power generation; flow batteries have the advantages of high safety, long cycle life, recyclable electrolyte, high cost performance in the life cycle, environmental friendliness, etc., and are considered to be one of the preferred technologies for large-scale energy storage technologies, with broad application prospects; among them, comprehensively measured by indicators such as energy density, efficiency, scale, cycle life and cost, the best technology to match the new generation of power grid is the flow energy storage battery technology in electrochemical energy storage, whose energy storage density reaches 10 - 30 Wh / kg, and the efficiency is between 60% - 85%. Moreover, the power and capacity can be designed separately and independently, the charge and discharge reaction is rapid, and the applicable range is wide; it can not only be used for peak shaving and valley filling, but also as a backup power supply or emergency power supply, and can also be used to improve the power quality, voltage regulation and frequency modulation, etc.

[0003] As a key component of the iron-chromium flow battery, the electrolyte largely determines the efficiency and stability of the battery. In the actual application process, the hydrogen evolution reaction on the negative electrode side of the iron-chromium flow battery is serious. In order to better monitor the system operation and make the best reaction strategy, it is necessary to measure the amount of hydrogen; since the iron-chromium flow battery needs to maintain the best operation efficiency during operation, the operation temperature is generally 50 - 60 °C, and the electrolyte contains many elements, so the characteristics of the evolved gas are high temperature and wet. The components of the evolved gas are complex, and some of the evolved gases are flammable; at present, the air circuit of the flow battery has no early warning function and the safety performance is not high. Summary of the Invention

[0004] (I) Technical Problems to be Solved Aiming at the deficiencies of the prior art, the present invention provides a flow battery system and an air circuit early warning method thereof, which have the advantages of being able to automatically give early warnings and having high safety performance, and solve the problems that the air circuit of the flow battery system cannot give early warnings and the safety performance is low.

[0005] (II) Technical Solutions To achieve the above object of being able to automatically give early warnings and improve the safety of the flow battery, the present invention provides the following technical solutions: a flow battery system and its gas path early warning method. The flow battery system includes a stack chamber and a liquid tank. A number of stacks and harmful gas monitoring devices are arranged in the stack chamber. A voltage and current detection device, a stack liquid leakage monitoring device, and an automatic charge and discharge device are connected to the stack. The stack is connected to the liquid tank through a pipeline. An electrolyte flow rate adjustment device, a flow rate monitoring device, a pressure detection device, and an automatic pipeline valve opening and closing device are successively installed on the connection pipeline between the stack and the liquid tank. An exhaust device for drying and filtering the hydrogen gas precipitated in the liquid tank is installed at the top of the liquid tank. The exhaust device is connected to a hydrogen gas metering device for monitoring the hydrogen evolution situation in the liquid tank; The gas path early warning method includes the following steps: Step S1: During the charging process of the flow battery, the hydrogen gas precipitated from the electrolyte flows with the electrolyte and finally accumulates at the top of the liquid tank; Step S2: The hydrogen gas enters the exhaust device at the top of the liquid tank and enters the hydrogen gas metering device after being dried by the exhaust device; Step S3: The hydrogen gas metering device monitors the hydrogen evolution amount in real time. When the hydrogen evolution amount reaches a certain concentration, the hydrogen gas metering device gives a reminder to the system; Step S4: The system automatically calculates whether a single battery is approaching a potential of 1.18V according to the series-parallel relationship of the battery strings; Step S5: If a single battery is not approaching a potential of 1.18V, the flow battery system operates normally. If a single battery is approaching a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to reduce the charging current. If a single battery exceeds a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to stop charging.

[0006] Preferably, the gas path early warning method further includes the following steps: Step 1: When the stack is operating, harmful gases such as hydrogen gas are generated inside the electrolyte or when the stack leaks liquid, the leaked electrolyte contacts the air and undergoes a chemical reaction to generate harmful gases; Step 2: The harmful gas monitoring device in the stack chamber will give an early warning when it detects harmful gases and transmit it to the system; Step 3: The system makes a comprehensive judgment in combination with the data fed back by the stack liquid leakage monitoring device in the stack chamber. If the harmful gas value reaches the preset value, the automatic charge and discharge device stops charging and discharging; Step 4: The electrolyte flow rate adjustment device quickly reduces the pump speed step by step until the electrolyte delivery stops; Step 5: The automatic pipeline valve opening and closing device automatically closes the valve to prevent the electrolyte from flowing from the liquid tank into the stack and leaking to generate harmful gases.

[0007] Preferably, the voltage and current monitoring device is connected to the stack, and the current and voltage of the stack can be monitored in real time regardless of whether the stack is operating or not.

[0008] Preferably, a liquid tank leakage monitoring device for monitoring whether the liquid tank leaks and a liquid level detection device for real-time monitoring of the liquid level height in the liquid tank are further installed in the liquid tank.

[0009] Preferably, the electrolyte flow rate adjusting device is installed between the liquid tank of the energy storage system and the stack pipeline for adjusting the electrolyte flow rate in the pipeline.

[0010] Preferably, the flow rate monitoring device is installed between the liquid tank of the energy storage system and the stack pipeline for real-time monitoring of the electrolyte flow rate in the pipeline.

[0011] Preferably, the pressure detection device is installed between the liquid tank of the energy storage system and the stack pipeline for real-time monitoring of the pressure in the pipeline.

[0012] Preferably, the pipeline valve automatic opening and closing device is installed at the liquid inlet and outlet of the liquid tank of the energy storage system for remotely operating the pipeline valve to open and close.

[0013] Preferably, the harmful gas monitoring device is installed in the stack compartment of the energy storage system for real-time monitoring of harmful gases in the air in the stack compartment. When the harmful gas value reaches a preset value, a warning can be issued.

[0014] Preferably, the stack leakage monitoring device is installed in the stack compartment of the energy storage system to monitor whether there is leakage in the stack compartment in real time; the liquid tank leakage monitoring device is also installed in the liquid tank of the energy storage system to monitor whether there is leakage in the liquid tank in real time.

[0015] (III) Beneficial effects Compared with the prior art, the present invention provides a flow battery system and its gas path warning method, having the following beneficial effects: 1. The flow battery system and its gas path warning method. During the charging process of the flow battery system, the hydrogen generated will flow with the electrolyte and finally accumulate at the top of the liquid tank. In the present invention, an exhaust device is provided at the top of the positive and negative liquid tanks. The exhaust device connects the hydrogen gas separated after drying to a hydrogen gas metering device. When the system is running, the hydrogen gas metering device monitors the amount of hydrogen evolution in real time. When the hydrogen gas metering device detects a large amount of hydrogen evolution, first, the hydrogen gas metering device will remind the system to automatically calculate whether a single battery is approaching a potential of 1.18V according to the series and parallel relationship of the battery strings. If a single battery is not approaching a potential of 1.18V, the flow battery system operates normally. If a single battery is approaching a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to reduce the charging current. If a single battery exceeds a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to stop charging. Through the warning of the gas path, faults can be prevented, the service life of the flow battery system can be extended, the battery capacity can be increased, the operating state of the flow battery can be optimized, and the safety performance of the flow battery can be improved.

[0016] 2. The flow battery system and its gas path warning method. The harmful gas monitoring device monitors the above-mentioned harmful gases in the air in real time. When harmful gases are detected, an alarm is issued and handed over to the system. The system comprehensively judges by combining the feedback data of the liquid leakage monitoring device in the stack compartment. The automatic charge and discharge device stops charging and discharging, and the electrolyte flow rate adjustment device quickly reduces the pump speed step by step until the electrolyte delivery stops. The pipeline valve automatic opening and closing device automatically closes the valve to prevent the electrolyte from leaking into the stack from the liquid tank and generating harmful gases. Further improve the safety performance of the flow battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the structural framework diagram of the flow battery system of the present invention; Figure 2 is the framework diagram of the steps of the gas path warning method in the liquid tank of the flow battery system of the present invention; Figure 3 is the framework diagram of the steps of the gas path warning method in the stack compartment of the flow battery system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. 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.

[0019] Such as Figure 1 and Figure 2As shown, a flow battery system and its gas path early warning method. The flow battery system includes a stack bin and a liquid tank. Inside the stack bin, there are several stacks and harmful gas monitoring devices. On the stack, there are voltage and current detection devices, stack liquid leakage monitoring devices, and automatic charge and discharge devices connected. The stack is connected to the liquid tank through a pipeline. On the connection pipeline between the stack and the liquid tank, an electrolyte flow rate adjustment device, a flow monitoring device, a pressure detection device, and a pipeline valve automatic opening and closing device are installed in sequence. At the top of the liquid tank, an exhaust device for drying and filtering the hydrogen evolved in the liquid tank is installed. The exhaust device is connected to a hydrogen gas metering device for monitoring the hydrogen evolution situation in the liquid tank; The gas path early warning method includes the following steps: Step S1: During the charging process of the flow battery, the hydrogen evolved from the electrolyte flows with the electrolyte and finally accumulates at the top of the liquid tank; Step S2: The hydrogen enters the exhaust device at the top of the liquid tank and enters the hydrogen gas metering device after being dried by the exhaust device; Step S3: The hydrogen gas metering device monitors the hydrogen evolution amount in real time. When the hydrogen evolution amount reaches a certain concentration, the hydrogen gas metering device issues a reminder to the system; Step S4: The system automatically calculates whether a single battery is approaching a potential of 1.18V according to the battery series and parallel relationship; Step S5: If a single battery is not approaching a potential of 1.18V, the flow battery system operates normally. If a single battery is approaching a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to reduce the charging current. If a single battery exceeds a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to stop charging.

[0020] The Cr2+ / Cr3+ electrode couple at the negative electrode of the iron-chromium flow battery has relatively poor reaction activity compared to the Fe2+ / Fe3+ electrode couple at the positive electrode, which is one of the main reasons affecting the battery performance. In addition, due to the isomerization of Cr3+ ions in aqueous solution, the molecular formula of the newly prepared CrCl3 aqueous solution at room temperature will change to Cr(H2O)6Cl3 as the storage time prolongs, resulting in a further reduction in its activity, thereby affecting the charge-discharge efficiency and cycle life of the iron-chromium flow battery. The redox potential of Cr2+ / Cr3+ in the iron-chromium flow battery is -0.41V, which is quite close to the overpotential required for hydrogen evolution on the surface of the carbon electrode by water. Coupled with the obvious polarization loss caused by the poor reaction activity, at room temperature, hydrogen evolution will occur at the negative electrode of the iron-chromium flow battery at the end of charging, reducing the Coulomb efficiency of the battery system; the hydrogen generated during the charging process of the energy storage system will flow with the electrolyte and will eventually accumulate at the top of the liquid tank. In the present invention, an exhaust device is provided at the top of the positive and negative liquid tanks, and the hydrogen evolved is connected to a hydrogen metering device after drying. During system operation, the hydrogen metering device monitors the hydrogen evolution amount in real time. When the hydrogen metering device detects a large amount of hydrogen evolution, first, the hydrogen metering device will remind the system to automatically calculate whether a single cell is approaching a potential of 1.18V according to the series-parallel relationship of the battery string. If a single cell is not approaching a potential of 1.18V, the flow battery system operates normally. If a single cell is approaching a potential of 1.18V, the flow battery system controls the automatic charge-discharge device to reduce the charging current. If a single cell exceeds a potential of 1.18V, the flow battery system controls the automatic charge-discharge device to stop charging; through the early warning of the gas path, faults can be prevented, the service life of the flow battery system can be extended, the battery capacity can be increased, the operating state of the flow battery can be optimized, and the safety performance of the flow battery can be improved.

[0021] As Figure 3 shown, in this embodiment, the gas path early warning method further includes the following steps: Step 1: When the stack is operating, harmful gases such as hydrogen are generated inside the electrolyte, or when the stack leaks liquid, the leaked electrolyte contacts the air and undergoes a chemical reaction to generate harmful gases; Step 2: The harmful gas monitoring device in the stack compartment monitors the harmful gas, issues an early warning, and transmits it to the system; Step 3: The system comprehensively judges in combination with the data fed back by the stack liquid leakage monitoring device in the stack compartment. If the harmful gas value reaches the preset value, the automatic charge-discharge device stops charging and discharging; Step 4: The electrolyte flow rate adjustment device quickly and gradually reduces the pump speed until the electrolyte delivery stops; Step 5: The pipeline valve automatic opening and closing device automatically closes the valve to prevent the electrolyte from leaking into the stack from the liquid tank and generating harmful gases.

[0022] During the operation of the flow battery system, the electrochemical reaction between the positive and negative electrodes inside the stack generates an electric current, thereby achieving energy conversion and output. However, during the operation of the stack, it needs to withstand the liquid pressure brought by the electrolyte flow, the temperature change of the electrolyte during operation, and the corrosiveness of the electrolyte itself. Moreover, the seals are prone to aging over time. Considering all the above situations, there is a risk of liquid leakage. When the stack leaks, a large amount of electrolyte gushes out and contacts the air. For flow battery electrolytes with different formulations, various harmful gases may be generated during chemical reactions, such as hydrogen, ammonia, chlorine, hydrogen chloride gas and other harmful gases. In the stack chamber of the present invention, there is a harmful gas monitoring device, which monitors the above-mentioned harmful gases in the air in real time. When harmful gases are detected, an alarm is issued and handed over to the system. The system comprehensively judges by combining the feedback data of the liquid leakage monitoring device in the stack chamber. The automatic charge and discharge device stops charging and discharging, and the pump speed is rapidly reduced step by step through the electrolyte flow rate adjustment device until the electrolyte delivery stops. The pipeline valve automatic opening and closing device automatically closes the valve to prevent the electrolyte from leaking into the stack from the liquid tank and generating harmful gases.

[0023] In this embodiment, the voltage and current monitoring device is connected to the stack, and the current and voltage of the stack can be monitored in real time whether the stack is operating or not.

[0024] In this embodiment, a liquid tank liquid leakage monitoring device for monitoring whether the liquid tank leaks and a liquid level detection device for real-time monitoring of the liquid level height in the liquid tank are also installed in the liquid tank.

[0025] In this embodiment, the electrolyte flow rate adjustment device is installed between the energy storage system liquid tank and the stack pipeline, and is used to adjust the electrolyte flow rate in the pipeline; ensuring the stability and efficiency of the electrolyte flow inside the battery.

[0026] In this embodiment, the flow rate monitoring device is installed between the energy storage system liquid tank and the stack pipeline, and is used to monitor the electrolyte flow rate in the pipeline in real time; ensuring the stable supply of the electrolyte and the normal operation of the battery.

[0027] In this embodiment, the pressure detection device is installed between the energy storage system liquid tank and the stack pipeline, and is used to monitor the pressure in the pipeline in real time; it can provide data support for the maintenance and servicing of the battery.

[0028] In this embodiment, the pipeline valve automatic opening and closing device is installed at the liquid inlet and outlet of the energy storage system liquid tank, and is used to remotely operate the pipeline valve to open and close, realizing the automatic circulation and stop of the electrolyte inside the battery, improving the operation efficiency, safety and automation level of the flow battery.

[0029] In this embodiment, the harmful gas monitoring device is installed in the stack chamber of the energy storage system, and is used to monitor the harmful gases in the air in the stack chamber in real time. When the harmful gas value reaches the preset value, an alarm can be issued to ensure the safe and stable operation of the flow battery.

[0030] In this embodiment, the stack leakage monitoring device is installed in the stack chamber of the energy storage system, and can monitor in real time whether there is leakage in the stack chamber, further ensuring the safe and stable operation of the flow battery. The liquid tank leakage monitoring device is also installed in the liquid tank of the energy storage system, and can monitor in real time whether there is leakage in the liquid tank, further ensuring the safe and stable operation of the flow battery.

[0031] Working principle: The hydrogen generated during the charging process of the energy storage system will flow with the electrolyte and will eventually accumulate at the top of the liquid tank. In the present invention, an exhaust device is provided at the top of the positive and negative liquid tanks, and the hydrogen evolved is connected to a hydrogen metering device after drying. When the system is running, the hydrogen metering device monitors the hydrogen evolution amount in real time. When the hydrogen metering device detects a large amount of hydrogen evolution, first, the hydrogen metering device will remind the system to automatically calculate whether a single cell is approaching the potential of 1.18 V according to the series-parallel relationship of the battery strings. If a single cell is not approaching the potential of 1.18 V, the flow battery system operates normally. If a single cell is approaching the potential of 1.18 V, the flow battery system controls the automatic charge and discharge device to reduce the charging current. If a single cell exceeds the potential of 1.18 V, the flow battery system controls the automatic charge and discharge device to stop charging. The early warning through the gas path can prevent failures, extend the service life of the flow battery system, increase the battery capacity, optimize the operating state of the flow battery, and improve the safety performance of the flow battery. In the stack chamber of the present invention, a harmful gas monitoring device is arranged. The harmful gas monitoring device monitors the above-mentioned harmful gases in the air in real time. When harmful gases are detected, an alarm is issued and handed over to the system. The system combines the feedback data of the leakage monitoring device in the stack chamber for comprehensive judgment. The automatic charge and discharge device stops charging and discharging, and the pump speed is quickly reduced step by step until the electrolyte delivery stops through the electrolyte flow rate adjustment device. The pipeline valve automatic opening and closing device automatically closes the valve to prevent the electrolyte from flowing from the liquid tank into the stack and leaking to generate harmful gases.

[0032] In summary, for the flow battery system and its gas path warning method, the hydrogen generated during the charging process of the flow battery system will flow with the electrolyte and eventually accumulate at the top of the liquid tank. In the present invention, an exhaust device is provided at the top of the positive and negative liquid tanks, and the hydrogen evolved is connected to a hydrogen metering device after drying. During system operation, the hydrogen metering device monitors the hydrogen evolution amount in real time. When the hydrogen metering device detects a large amount of hydrogen evolution, first, the hydrogen metering device will remind the system to automatically calculate whether a single cell is approaching a potential of 1.18 V according to the series-parallel relationship of the battery string. Second, the system will also make a comprehensive judgment based on the data feedback by the voltage and current detection device. If a single cell is not approaching a potential of 1.18 V, the flow battery system operates normally. If approaching the potential, the system will automatically reduce the charging current through the automatic charge and discharge device. As the charging current decreases, the system voltage will also decrease, which will significantly improve the hydrogen evolution situation during charging. If a single cell exceeds a potential of 1.18 V, the flow battery system controls the automatic charge and discharge device to stop charging; through the warning of the gas path, faults can be prevented, the service life of the flow battery system can be extended, the operating state of the flow battery can be optimized, and the safety performance of the flow battery can be improved.

[0033] For the flow battery system and its gas path warning method, the above-mentioned harmful gases in the air are monitored in real time by a harmful gas monitoring device. When harmful gases are detected, an alarm is issued and handed over to the system. The system makes a comprehensive judgment by combining the data feedback by the liquid leakage monitoring device in the stack bin. The automatic charge and discharge device stops charging and discharging, and the pump speed is quickly reduced step by step until the electrolyte transportation stops through the electrolyte flow rate adjustment device. The pipeline valve is automatically opened and closed by the automatic opening and closing device of the pipeline valve to prevent the electrolyte from leaking into the stack from the liquid tank and generating harmful gases; the safety performance of the flow battery is further improved.

[0034] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flow battery system and its gas path warning method, characterized in that: The flow battery system includes a stack chamber and a liquid tank. Inside the stack chamber, there are several stacks and a harmful gas monitoring device. A voltage and current detection device, a stack liquid leakage monitoring device, and an automatic charge and discharge device are connected to the stack. The stack is connected to the liquid tank through a pipeline. An electrolyte flow rate adjustment device, a flow rate monitoring device, a pressure detection device, and a pipeline valve automatic opening and closing device are sequentially installed on the connection pipeline between the stack and the liquid tank. An exhaust device for drying and filtering the hydrogen gas precipitated in the liquid tank is installed at the top of the liquid tank. The exhaust device is connected to a hydrogen gas metering device for monitoring the hydrogen evolution situation in the liquid tank; The gas path warning method includes the following steps: Step S1: During the charging process of the flow battery, the hydrogen gas precipitated from the electrolyte flows with the electrolyte and finally accumulates at the top of the liquid tank; Step S2: The hydrogen gas enters the exhaust device at the top of the liquid tank and enters the hydrogen gas metering device after being dried by the exhaust device; Step S3: The hydrogen gas metering device monitors the hydrogen evolution amount in real time. When the hydrogen evolution amount reaches a certain concentration, the hydrogen gas metering device sends a reminder to the system; Step S4: The system automatically calculates whether a single battery is approaching a potential of 1.18V according to the series and parallel relationship of the battery strings; Step S5: If a single battery is not approaching a potential of 1.18V, the flow battery system operates normally. If a single battery is approaching a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to reduce the charging current. If a single battery exceeds a potential of 1.18V, the flow battery system controls the automatic charge and discharge device to stop charging.

2. The flow battery system and its gas path warning method according to claim 1, characterized in that: The gas path warning method further includes the following steps: Step 1: When the stack is operating, harmful gases such as hydrogen gas are generated inside the electrolyte or when the stack leaks liquid, the leaked electrolyte contacts the air and undergoes a chemical reaction to generate harmful gases; Step 2: The harmful gas monitoring device in the stack chamber monitors the harmful gas, issues a warning, and transmits it to the system; Step 3: The system comprehensively judges by combining the data fed back by the stack liquid leakage monitoring device in the stack chamber. If the harmful gas value reaches the preset value, the automatic charge and discharge device stops charging and discharging; Step 4: The electrolyte flow rate adjustment device quickly reduces the pump speed step by step until the electrolyte delivery stops; Step 5: The pipeline valve automatic opening and closing device automatically closes the valve to prevent the electrolyte from flowing from the liquid tank into the stack and leaking to generate harmful gases.

3. The flow battery system and its gas path early warning method according to claim 1, characterized in that: The voltage and current monitoring device is connected to the stack and can monitor the current and voltage of the stack in real time whether the stack is operating or not.

4. A flow battery system and its gas path early warning method according to claim 1, characterized in that: A liquid tank liquid leakage monitoring device for monitoring whether the liquid tank leaks and a liquid level detection device for real-time monitoring of the liquid level height in the liquid tank are also installed in the liquid tank.

5. A flow battery system and its gas path warning method according to claim 1, characterized in that: The electrolyte flow rate adjustment device is installed between the liquid tank of the energy storage system and the stack pipeline for adjusting the electrolyte flow rate in the pipeline.

6. The flow battery system and its gas path early warning method according to claim 1, characterized in that: The flow rate monitoring device is installed between the liquid tank of the energy storage system and the stack pipeline for real-time monitoring of the electrolyte flow rate in the pipeline.

7. A flow battery system and its gas path warning method according to claim 1, characterized in that: The pressure detection device is installed between the liquid tank of the energy storage system and the stack pipeline for real-time monitoring of the pressure in the pipeline.

8. A flow battery system and its gas path warning method according to claim 1, characterized in that: The pipeline valve automatic opening and closing device is installed at the liquid inlet and outlet of the energy storage system liquid tank for remotely operating the pipeline valve to open and close.

9. A flow battery system and its gas path warning method according to claim 1, characterized in that: The harmful gas monitoring device is installed in the stack compartment of the energy storage system, and is used to monitor the harmful gases in the air of the stack compartment in real time. When the harmful gas value reaches the preset value, an early warning can be issued.

10. A flow battery system and its gas path early warning method according to claim 1, characterized in that: The stack leakage monitoring device is installed in the stack compartment of the energy storage system and can monitor in real time whether there is leakage in the stack compartment; the liquid tank leakage monitoring device is also installed in the liquid tank of the energy storage system and can monitor in real time whether there is leakage in the liquid tank.

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