Hydrogen discharging method and device of flow battery system

Abstract

The invention discloses a hydrogen discharging method and device of a flow battery system. The method comprises the following steps: in response to an external input instruction, determining a preset working mode of the flow battery system, and controlling a hydrogen discharge strategy entering the preset working mode; acquiring the hydrogen concentration in the preset working mode; and according to the hydrogen concentration and a preset hydrogen concentration threshold value, controlling the running states of a hydrogen discharge fan in a hydrogen circulation loop of the flow battery system and the flow battery system. The hydrogen discharging strategy is formulated and implemented in advance according to different preset working modes, the risk that the hydrogen concentration is abnormally increased is reduced, and by monitoring the relation between the hydrogen concentration and the preset hydrogen concentration threshold value, the reaction can be made in advance in the process that the hydrogen concentration tends to be increased and approaches the preset hydrogen concentration threshold value, so that the hydrogen discharging effect is improved. And the running state of the hydrogen discharge fan or the running state of the flow battery system is adjusted, so that the safety risk caused by overhigh hydrogen concentration can be effectively avoided, and the unnecessary power consumption of the hydrogen discharge fan can be reduced on the premise of safety.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery systems, and in particular to a hydrogen discharge method and device for a liquid flow battery system. Background Art

[0002] Zinc-based flow batteries will produce different amounts of hydrogen under different working conditions due to their own electrochemical mechanism.

[0003] The hydrogen exhaust function of existing liquid flow battery systems is relatively simple. Either the hydrogen exhaust fan is kept in operation, resulting in high power consumption; or it only responds in real time based on the feedback data from the hydrogen concentration sensor. However, due to the lag in sensor detection, the hydrogen exhaust fan cannot respond in advance, and there is still a risk of exceeding the hydrogen concentration limit. Summary of the invention

[0004] The present invention provides a hydrogen discharge method and device for a liquid flow battery system, so as to solve the problems in the prior art that the hydrogen discharge fan cannot respond in advance due to high power consumption caused by continuous operation of the hydrogen discharge fan and the hysteresis of sensor detection.

[0005] According to one aspect of the present invention, a method for discharging hydrogen from a liquid flow battery system is provided, comprising:

[0006] In response to an external input command, determine a preset operating mode of the liquid flow battery system, and control a hydrogen discharge strategy under the preset operating mode;

[0007] Obtaining the hydrogen concentration under the preset working mode;

[0008] According to the hydrogen concentration and a preset hydrogen concentration threshold, the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system are controlled.

[0009] Optionally, in response to an external input instruction, determining a preset working mode of the liquid flow battery system, and controlling the hydrogen discharge strategy to enter the preset working mode includes:

[0010] In response to an external input command, determining that a preset operating mode of the flow battery system is a safety mode;

[0011] In the safety mode, the hydrogen exhaust blower in the hydrogen circulation loop of the liquid flow battery system is controlled to operate based on a first preset frequency.

[0012] Optionally, in response to an external input instruction, determining a preset working mode of the liquid flow battery system and controlling the hydrogen discharge strategy to enter the preset working mode further includes:

[0013] In response to an external input command, determining that a preset operating mode of the flow battery system is a shutdown heating mode;

[0014] In the shutdown heating mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a second preset frequency every first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

[0015] Optionally, in response to an external input instruction, determining a preset working mode of the liquid flow battery system and controlling the hydrogen discharge strategy to enter the preset working mode further includes:

[0016] In response to an external input command, determining that a preset operating mode of the flow battery system is a normal charging mode;

[0017] In the normal charging mode, controlling a circulation pump in a hydrogen circulation loop of the liquid flow battery system to start and run for a third preset time based on a third preset frequency;

[0018] Obtain the single cell voltage of the battery stack in the flow battery system;

[0019] When the single cell voltage is less than the first preset voltage, controlling the circulation pump to operate based on a second preset frequency;

[0020] When the single cell voltage is greater than or equal to the first preset voltage, the circulation pump is controlled to operate based on the third preset frequency; the first preset frequency < the second preset frequency < the third preset frequency; the first preset time > the third preset time > the second preset time.

[0021] Optionally, in response to an external input instruction, determining a preset working mode of the liquid flow battery system and controlling the hydrogen discharge strategy to enter the preset working mode further includes:

[0022] In response to an external input command, determining that a preset operating mode of the flow battery system is a normal discharge mode;

[0023] In the normal discharge mode, controlling a circulation pump in a hydrogen circulation loop of the liquid flow battery system to start and run for a third preset time based on a third preset frequency;

[0024] The circulation pump is controlled to operate based on the first preset frequency for a second preset time at intervals of the first preset time, and to operate based on the first preset frequency when the second preset time is greater than the second preset time and less than the first preset time.

[0025] Optionally, in response to an external input instruction, determining a preset working mode of the liquid flow battery system and controlling the hydrogen discharge strategy to enter the preset working mode further includes:

[0026] In response to an external input command, determining that a preset operating mode of the flow battery system is a maintenance mode;

[0027] In the maintenance mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a third preset frequency every first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

[0028] Optionally, the preset hydrogen concentration threshold includes a first preset hydrogen concentration threshold, a second preset hydrogen concentration threshold and a third preset hydrogen concentration threshold;

[0029] The controlling of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the operating state of the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises:

[0030] When the hydrogen concentration is greater than or equal to the first preset hydrogen concentration threshold and less than the second preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be normally open, and the speed of the hydrogen exhaust fan is controlled according to the hydrogen concentration; the hydrogen concentration is positively correlated with the speed of the hydrogen exhaust fan.

[0031] Optionally, controlling the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises:

[0032] When the hydrogen concentration is greater than or equal to the second preset hydrogen concentration threshold and less than the third preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be always on, and the liquid flow battery system is controlled to operate at limited power.

[0033] Optionally, controlling the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises:

[0034] When the hydrogen concentration is greater than or equal to the third preset hydrogen concentration threshold, the liquid flow battery system is controlled to shut down.

[0035] According to another aspect of the present invention, a hydrogen discharge device for a liquid flow battery system is provided, which is used to perform the hydrogen discharge method for a liquid flow battery system according to any embodiment of the present invention. The hydrogen discharge device for the liquid flow battery system comprises:

[0036] A determination module, the determination module is used to determine a preset working mode of the liquid flow battery system in response to an external input instruction, and control a hydrogen discharge strategy when entering the preset working mode;

[0037] An acquisition module, the acquisition module is used to acquire the hydrogen concentration under the preset working mode;

[0038] A control module is used to control the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system according to the hydrogen concentration and a preset hydrogen concentration threshold.

[0039] The embodiment of the present invention provides a method and device for discharging hydrogen from a liquid flow battery system. The method includes: determining a preset working mode of the liquid flow battery system in response to an external input instruction, and controlling a hydrogen discharging strategy in the preset working mode; obtaining a hydrogen concentration in the preset working mode; and controlling a hydrogen discharging fan in a hydrogen circulation loop of the liquid flow battery system and an operating state of the liquid flow battery system according to the hydrogen concentration and a preset hydrogen concentration threshold. The technical solution provided by the embodiment of the present invention can prepare for possible hydrogen concentration problems before the system is operated by formulating and implementing hydrogen discharge strategies in advance according to different preset working modes, thereby reducing the risk of abnormal increase in hydrogen concentration from the source, and having the beneficial effect of early prevention; by obtaining the hydrogen concentration under the preset working mode, the operating state of the hydrogen discharge fan and the liquid flow battery system in the hydrogen circulation loop of the liquid flow battery system is controlled according to the hydrogen concentration and the preset hydrogen concentration threshold, that is, the system can monitor the relationship between the hydrogen concentration and the preset hydrogen concentration threshold, and can respond in advance when the hydrogen concentration has an upward trend and approaches the preset hydrogen concentration threshold, and adjust the operating state of the hydrogen discharge fan or the operating state of the liquid flow battery system to prevent the hydrogen concentration from further rising to a dangerous level; it is achieved that the safety risks caused by excessively high hydrogen concentration can be effectively avoided, and unnecessary power consumption of the hydrogen discharge fan can be reduced under the premise of safety.

[0040] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A flow chart of a hydrogen discharge method for a liquid flow battery system provided in an embodiment of the present invention;

[0043] Figure 2 A schematic structural diagram of a hydrogen discharge device for a liquid flow battery system provided in an embodiment of the present invention;

[0044] Figure 3 A schematic structural diagram of an electronic device for a hydrogen discharge method for a liquid flow battery system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] Figure 1 This is a flow chart of a hydrogen discharge method for a liquid flow battery system provided by an embodiment of the present invention. The method can be performed by a hydrogen discharge device for the liquid flow battery system. Figure 1 , the method comprising:

[0048] S110, in response to an external input instruction, determining a preset working mode of the liquid flow battery system, and controlling a hydrogen discharge strategy under the preset working mode.

[0049] Among them, the external input instruction refers to a signal or command from outside the liquid flow battery system and used to indicate or change the working state of the liquid flow battery system. The external input instruction can be input from the user through a physical button or touch screen, or it can be sent from the central control unit of the liquid flow battery system or other related systems to the liquid flow battery system from the remote control center through a network communication protocol; the preset working mode can be pre-set according to different application scenarios and working requirements. For example, the preset working mode can be one of the following modes: safety mode, manual mode, shutdown heating mode, shutdown heating internal circulation mode, shutdown heating external circulation mode, normal charging mode, normal discharge mode, activation mode, energy optimization mode, and maintenance mode. Under different preset working modes, the liquid flow battery system will produce different amounts of hydrogen, so a corresponding hydrogen discharge strategy is required to ensure the safe and stable operation of the liquid flow battery system.

[0050] Specifically, the liquid flow battery system will determine and switch to the corresponding preset working mode according to the external input instructions, and adopt the corresponding hydrogen discharge strategy according to the needs of this mode to ensure the safe and efficient operation of the liquid flow battery system. This mechanism enables the liquid flow battery system to flexibly adjust its working state according to the actual situation, so as to meet different operating needs and safety requirements. For example, when the grid load is low and the liquid flow battery needs to be charged to store more electricity, the staff inputs the corresponding instructions, and the system will determine to enter the normal charging mode. In the normal charging mode, a more conventional strategy of timing detection of the single cell voltage and starting the circulation pump according to a certain threshold can be adopted.

[0051] S120, obtaining the hydrogen concentration in the preset working mode.

[0052] Specifically, when the liquid flow battery system is in a pre-set specific working mode, the hydrogen concentration in the liquid flow battery system is measured and obtained by a hydrogen concentration sensor.

[0053] S130. According to the hydrogen concentration and the preset hydrogen concentration threshold, the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system are controlled.

[0054] The preset hydrogen concentration threshold can be preset according to factors such as safety standards and performance requirements of the flow battery system. The preset hydrogen concentration threshold can be divided into a primary threshold, a secondary threshold and a tertiary threshold.

[0055] Specifically, when the hydrogen concentration detected by the hydrogen concentration sensor reaches or exceeds the first-level threshold and is less than or equal to the second-level threshold, the system will issue a command to start the hydrogen exhaust fan. The hydrogen exhaust fan starts working and discharges the gas containing hydrogen out of the system through the hydrogen circulation loop, reducing the hydrogen concentration in the system to prevent hydrogen from accumulating to a dangerous level and ensuring system safety. In this process, the system will adjust the speed of the hydrogen exhaust fan according to the hydrogen concentration. The higher the hydrogen concentration, the higher the speed of the hydrogen exhaust fan. When the hydrogen concentration drops below the preset hydrogen concentration lower limit threshold and is at a stable level, meeting the system safety requirements, the system will instruct the hydrogen exhaust fan to stop running to save energy and reduce power consumption. When the hydrogen concentration reaches or exceeds the second-level threshold and is less than or equal to the third-level threshold, it means that the chemical reaction or operating state inside the liquid flow battery system is abnormal. In addition to starting the hydrogen exhaust fan, the system will also adjust the operating parameters of the liquid flow battery system according to the relationship between the hydrogen concentration and the preset hydrogen concentration threshold. For example, the operating power of the system can be appropriately reduced to slow down the chemical reaction rate inside the battery, thereby reducing the amount of hydrogen produced; when the hydrogen concentration reaches or exceeds the third-level threshold, it means that the system will have serious accident hazards. In order to avoid safety accidents, the system will take shutdown operations, stop the main operating processes such as charging and discharging of the liquid flow battery system, and continue to operate safety equipment such as hydrogen exhaust fans until the hydrogen concentration returns to normal, and then restart the system after inspection and maintenance.

[0056] The technical solution provided by the embodiment of the present invention can prepare for possible hydrogen concentration problems before the system is operated by formulating and implementing hydrogen discharge strategies in advance according to different preset working modes, thereby reducing the risk of abnormal increase in hydrogen concentration from the source, and having the beneficial effect of early prevention; by obtaining the hydrogen concentration under the preset working mode, the operating state of the hydrogen discharge fan and the liquid flow battery system in the hydrogen circulation loop of the liquid flow battery system is controlled according to the hydrogen concentration and the preset hydrogen concentration threshold, that is, the system can monitor the relationship between the hydrogen concentration and the preset hydrogen concentration threshold, and can respond in advance when the hydrogen concentration has an upward trend and approaches the preset hydrogen concentration threshold, and adjust the operating state of the hydrogen discharge fan or the operating state of the liquid flow battery system to prevent the hydrogen concentration from further rising to a dangerous level; it is achieved that the safety risks caused by excessively high hydrogen concentration can be effectively avoided, and unnecessary power consumption of the hydrogen discharge fan can be reduced under the premise of safety.

[0057] Optionally, in one embodiment, step S110 includes:

[0058] S111a, in response to an external input instruction, determining that the preset operating mode of the liquid flow battery system is a safety mode.

[0059] Among them, the safety mode is a special preset working mode that is activated under specific conditions to ensure the safety of the system and related equipment and personnel. Its main purpose is to ensure the safety of the flow battery system.

[0060] S111b. In the safety mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate based on a first preset frequency.

[0061] The first preset frequency is the minimum operating frequency of the hydrogen exhaust fan and / or circulation pump, which is preset according to various factors such as the hydrogen generation rate and safety standards of the liquid flow battery system in the safety mode. For example, if the rated operating frequency of the hydrogen exhaust fan is 50 Hz, then the minimum operating frequency is one tenth of the rated operating frequency, that is, 5 Hz.

[0062] Specifically, in the safety mode, the hydrogen exhaust fan is allowed to operate based on the first preset frequency, which means that the hydrogen exhaust fan will continue to operate at this specific frequency and perform hydrogen exhaust operations with stable power and air volume. On the one hand, it can ensure that in the safety mode, no matter how other parameters of the liquid flow battery system change, as long as it is in the safety mode, the hydrogen exhaust fan can work at a relatively fixed, safe and effective frequency, and discharge hydrogen in time to prevent the hydrogen concentration from rising to a dangerous level. On the other hand, in the safety mode, the control method of allowing the hydrogen exhaust fan to operate based on the first preset frequency is repeatable and stable, which is convenient for system monitoring and management. The staff can judge whether the working status of the hydrogen exhaust fan is normal based on the first preset frequency, which is also conducive to the system to maintain a consistent hydrogen exhaust strategy in different safety mode scenarios, thereby improving the reliability and safety of the system.

[0063] Optionally, in one embodiment, step S110 further includes:

[0064] S112a, in response to an external input instruction, determining that the preset operating mode of the liquid flow battery system is a shutdown heating mode.

[0065] Among them, "shutdown" in the shutdown heating mode does not mean that the entire liquid flow battery system is completely cut off from power and stops all functions. Instead, it means that the liquid flow battery system stops the normal main work processes such as charging and discharging, and no longer performs the storage and release of electrical energy. However, some auxiliary equipment and control circuits of the system are still powered on at this time to perform specific tasks, such as the control and monitoring of the heating function. The performance and life of liquid flow batteries are sensitive to temperature. In a low temperature environment, the chemical reaction rate inside the battery will slow down and the conductivity of the electrolyte will decrease, which may lead to a decrease in the battery's charging and discharging efficiency, a decrease in capacity, and even irreversible damage to the battery. Therefore, entering the heating mode is to increase the temperature of the liquid flow battery and its related components through a heating device to keep it within a more suitable temperature range to protect the battery performance and life. The shutdown heating mode is usually used when the liquid flow battery system is not in use but the ambient temperature is low, such as on a cold night or in a low-temperature storage environment, to ensure that the battery can quickly return to normal working condition when it is used next time, thereby improving the reliability and service life of the battery.

[0066] S112b. In the shutdown heating mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a second preset frequency every first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

[0067] Among them, the first preset time is a pre-set time interval, such as 10 minutes, which means that the hydrogen exhaust fan is not running continuously, but is started once every period of time. The reason for this is that in the shutdown heating mode, the hydrogen generation rate is relatively slow, and the fan does not need to run continuously to exhaust hydrogen. The hydrogen exhaust demand can be met through intermittent operation, while also saving energy and reducing the wear of the fan. The second preset frequency is the medium operating frequency of the hydrogen exhaust fan pre-set according to multiple factors such as the hydrogen generation rate and safety standards of the liquid flow battery system in the shutdown heating mode. For example, if the rated operating frequency of the hydrogen exhaust fan is 50Hz, then the medium operating frequency is half of the rated operating frequency, that is, 25Hz. The second preset time refers to the length of time that the hydrogen exhaust fan continues to run after each start, for example, it may be 1 minute. During this 1 minute, the hydrogen exhaust fan runs at the second preset frequency to discharge the hydrogen accumulated during this period of time from the system to ensure that the hydrogen concentration remains within a safe range.

[0068] Specifically, after the hydrogen exhaust fan completes a work of running at a second preset frequency for a second preset time, there is a special time interval between the time period when it is restarted after the first preset time, that is, a stage greater than the second preset time and less than the first preset time. During this special time period, the hydrogen exhaust fan runs at the first preset frequency. Exemplarily, in the shutdown heating mode, the hydrogen exhaust fan is controlled to run at a medium frequency for 1 minute every 10 minutes, and during the time period when it is restarted after the next 10-minute interval, it runs based on the lowest operating frequency of the hydrogen exhaust fan. This hydrogen exhaust strategy can flexibly adjust the operating frequency and time of the hydrogen exhaust fan according to the characteristics of hydrogen generation in the liquid flow battery system under the shutdown heating mode, which not only ensures the safety of the system, but also realizes the rational use of energy and the effective operation of equipment.

[0069] Optionally, in one embodiment, step S110 further includes:

[0070] S113a, in response to an external input instruction, determining that the preset operating mode of the liquid flow battery system is a normal charging mode.

[0071] Among them, the normal charging mode is a working state in which the flow battery system performs charging operations under normal circumstances. In this mode, the system will store the electrical energy of the external power supply into the battery in a relatively stable and conventional manner.

[0072] S113b. In a normal charging mode, control a circulation pump in a hydrogen circulation loop of the liquid flow battery system to start, and operate the circulation pump for a third preset time based on a third preset frequency.

[0073] Among them, the third preset frequency is the high operating frequency of the hydrogen exhaust fan that is pre-set based on multiple factors such as the hydrogen production rate and safety standards of the liquid flow battery system in normal charging mode. For example, if the rated operating frequency of the hydrogen exhaust fan is 50Hz, then the high operating frequency is the rated operating frequency. The third preset time refers to the length of time that the circulation pump continues to run after each start, for example, it may be 3 minutes. During these 3 minutes, the circulation pump runs at the third preset frequency to discharge the hydrogen accumulated during this period out of the system to ensure that the hydrogen concentration remains within a safe range.

[0074] Specifically, during the normal charging process of the flow battery, electrochemical reactions will occur on the electrodes, and hydrogen will inevitably be produced. These hydrogen gases need to be processed and circulated in a timely and effective manner to maintain the pressure balance inside the system, ensure the normal progress of the reaction, and prevent the accumulation of hydrogen gas from bringing safety risks. The circulation pumps of the cathode and anode of the battery are controlled to be turned on and run for a third preset time based on a third preset frequency. Exemplarily, in the normal charging mode, the circulation pumps of the cathode and anode of the battery are controlled to be turned on and rotated at a high frequency for 3 minutes.

[0075] S113c, obtaining the single-cell voltage of the battery stack in the liquid flow battery system.

[0076] Among them, the single cell voltage, also known as the monomer battery voltage, refers to the potential difference across a single battery unit (single cell) in a liquid flow battery system or other battery system consisting of multiple batteries connected in series or in parallel.

[0077] Specifically, the single-cell voltage of the battery stack in the liquid flow battery system is obtained through the battery management system of the liquid flow battery system.

[0078] S113d. When the single cell voltage is less than the first preset voltage, control the circulation pump to operate based on the second preset frequency.

[0079] The first preset voltage is preset based on multiple factors such as battery characteristics, system operation requirements, safety factors, etc. The embodiment of the present invention takes 2V as an example.

[0080] Specifically, during the operation of the flow battery, when the potential on the electrode surface reaches a certain level, water electrolysis may occur to produce hydrogen and oxygen. For a single cell, when the voltage of the single cell is too high, especially when it exceeds its normal operating voltage range and is higher than a certain value (this specific value may be close to or is the reference threshold of the first preset voltage in hydrogen evolution), favorable conditions will be created for the hydrogen evolution reaction. Because higher voltages accelerate the electron transfer process on the electrode, making the water electrolysis reaction more likely to occur, resulting in the production of hydrogen. If the single cell voltage is less than the first preset voltage, it means that the battery may be at the end of normal discharge or there are other performance problems, but at this time the electrochemical reaction inside the battery is usually still within the normal design range, and the hydrogen evolution reaction is not the main problem, and the possibility of producing hydrogen is relatively low. The system controls the circulation pump to operate based on the second preset frequency, that is, the medium frequency. Exemplarily, when the single cell voltage is <2V, the circulation pump is controlled to rotate at the medium frequency.

[0081] S113e: When the single cell voltage is greater than or equal to the first preset voltage, control the circulation pump to operate based on a third preset frequency.

[0082] The magnitude relationship among the first preset frequency, the second preset frequency and the third preset frequency can be customized, and the first preset time, the third preset time and the second preset time can also be customized, which is not limited in the present invention. The embodiment of the present invention is illustrated by taking the first preset frequency < the second preset frequency < the third preset frequency; the first preset time > the third preset time > the second preset time as an example.

[0083] Specifically, when the single cell voltage is greater than or equal to the first preset voltage, the situation is different. If the single cell voltage is only slightly higher than the first preset voltage, you may need to pay attention to the operating status of the battery, because this may be a normal fluctuation when the battery is close to full or charging, but there is also a risk of hydrogen evolution reaction starting to occur. If the single cell voltage is much higher than the first preset voltage, the possibility of hydrogen evolution reaction occurring is greatly increased, and a large amount of hydrogen may have been produced inside the battery. At this time, the system will control the circulation pump to run based on the third preset frequency, that is, high frequency. Exemplarily, when the single cell voltage is ≥2V, the circulation pump is controlled to rotate at high frequency.

[0084] The technical solution provided by the embodiment of the present invention can formulate a corresponding hydrogen discharge control strategy for the liquid flow battery system based on the comparison result between the single cell voltage and the first preset voltage. When the single cell voltage is less than the first preset voltage, the circulating pump is controlled to operate based on the second preset frequency; when the single cell voltage is greater than or equal to the first preset voltage, the circulating pump is controlled to operate based on the third preset frequency. Through this hydrogen discharge strategy, based on the comparison between the single cell voltage and the first preset voltage, effective control of the hydrogen discharge operation in the liquid flow battery system is achieved to ensure the safety and stability of the system.

[0085] Optionally, in one embodiment, step S110 further includes:

[0086] S114a, in response to an external input instruction, determining that the preset operating mode of the liquid flow battery system is a normal discharge mode.

[0087] Among them, the normal discharge mode is a working state in which the liquid flow battery system converts the stored chemical energy into electrical energy and outputs it to the outside. In this mode, the system will provide electrical energy to the external load in a stable manner according to the designed discharge strategy.

[0088] S114b, in the normal discharge mode, controlling the circulation pump in the hydrogen circulation loop of the liquid flow battery system to start, and running the circulation pump for a third preset time based on a third preset frequency.

[0089] Specifically, in the normal discharge mode of the liquid flow battery system, the positive and negative electrodes undergo redox reactions, converting chemical energy into electrical energy and outputting it to the external load. In this process, some side reactions may be involved or specific conditions may be required to ensure battery performance and stability. For example, hydrogen will be produced in some liquid flow batteries, which needs to be processed through a hydrogen circulation loop to maintain the pressure balance inside the system, ensure the normal progress of the reaction, and prevent hydrogen accumulation from causing safety risks. The circulation pumps of the battery cathode and anode are controlled to be turned on and run for a third preset time based on a third preset frequency. For example, in the normal discharge mode, the circulation pumps of the battery cathode and anode are controlled to be turned on and rotated at a high frequency for 3 minutes.

[0090] S114c, controlling the circulating pump to operate based on the first preset frequency for a second preset time at intervals of the first preset time, and operating based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

[0091] Specifically, after the circulating pump in the hydrogen circulation loop of the control liquid flow battery system is turned on and runs for a third preset time based on the third preset frequency, it runs for a second preset time based on the first preset frequency at intervals of the first preset time, and runs based on the first preset frequency when it is greater than the second preset time and less than the first preset time. Exemplarily, the circulating pumps of the cathode and anode of the control battery are turned on, and after high-frequency rotation for 3 minutes, they are rotated at a low frequency for 1 minute at intervals of 10 minutes, and during the next time they are restarted at an interval of 10 minutes, they are operated based on the lowest operating frequency. The hydrogen discharge strategy provided in the embodiment of the present invention can ensure the stable and efficient operation of the liquid flow battery system, ensure that hydrogen is properly handled, and improve the performance and safety of the battery.

[0092] Optionally, in one embodiment, step S110 further includes:

[0093] S115a, in response to an external input instruction, determining that the preset operating mode of the liquid flow battery system is a maintenance mode.

[0094] Among them, the maintenance mode is mainly for inspection, maintenance, repair and troubleshooting of the liquid flow battery system to ensure that the system can maintain good performance and operating status, extend the service life of the system, and improve the reliability and safety of the system.

[0095] S115b. In the maintenance mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a third preset frequency at intervals of a first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

[0096] For example, in the maintenance mode, the hydrogen exhaust fan is controlled to run at a high frequency for 1 minute every 10 minutes, and in the next 10-minute interval, it is started again and runs at the lowest operating frequency of the hydrogen exhaust fan. This hydrogen exhaust strategy can flexibly and effectively manage the hydrogen emission and gas state in the hydrogen circulation loop according to the actual situation of the liquid flow battery system during the maintenance process, ensure the safety and stability of the system during the maintenance period, and achieve the purpose of energy saving and equipment protection.

[0097] Optionally, the preset hydrogen concentration threshold includes a first preset hydrogen concentration threshold, a second preset hydrogen concentration threshold and a third preset hydrogen concentration threshold; in one embodiment, step S130 includes:

[0098] S131. When the hydrogen concentration is greater than or equal to a first preset hydrogen concentration threshold and less than a second preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be always on, and the speed of the hydrogen exhaust fan is controlled according to the hydrogen concentration; the hydrogen concentration is positively correlated with the speed of the hydrogen exhaust fan.

[0099] The first preset hydrogen concentration threshold, the second preset hydrogen concentration threshold and the third preset hydrogen concentration threshold are used to further distinguish different dangerous levels of hydrogen concentration or different levels of control strategies, corresponding to the first level threshold, the second level threshold and the third level threshold respectively.

[0100] Specifically, when the hydrogen concentration is in the interval of being greater than or equal to the first preset hydrogen concentration threshold and less than the second preset hydrogen concentration threshold, it means that the hydrogen concentration in the system is already in a state that requires attention and processing, but has not yet reached a very dangerous height. At this time, the hydrogen exhaust fan is set to be normally open in order to continuously discharge hydrogen, avoid further accumulation of hydrogen, and control the hydrogen concentration within a relatively safe range to ensure the normal operation and safety of the liquid flow battery system. Controlling the speed of the hydrogen exhaust fan according to the hydrogen concentration means that the speed of the hydrogen exhaust fan is determined by the level of hydrogen concentration. For example, if the hydrogen concentration is close to the first preset hydrogen concentration threshold, the hydrogen exhaust fan may run at a relatively low basic speed, such as 1000 rpm, to maintain the basic hydrogen discharge volume and ensure that the hydrogen concentration does not continue to rise. As the hydrogen concentration gradually increases and approaches the second preset hydrogen concentration threshold, the speed of the hydrogen exhaust fan will increase accordingly, possibly reaching 2000 rpm or even higher, to speed up the hydrogen discharge rate and reduce the hydrogen concentration to a safe level as soon as possible.

[0101] The technical solution provided by the embodiment of the present invention can flexibly and effectively control the operation of the hydrogen exhaust fan according to the actual situation of the hydrogen concentration in the liquid flow battery system, thereby ensuring that hydrogen can be discharged in a timely and sufficient manner when the hydrogen concentration is high, and avoiding unnecessary high-load operation of the hydrogen exhaust fan when the hydrogen concentration is low, thereby achieving a balance between system safety and energy utilization efficiency.

[0102] Optionally, in one embodiment, step S130 further includes:

[0103] S132. When the hydrogen concentration is greater than or equal to the second preset hydrogen concentration threshold and less than the third preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be always on, and the liquid flow battery system is controlled to operate at limited power.

[0104] The second preset hydrogen concentration threshold indicates that the hydrogen concentration has reached a relatively high dangerous level. Exceeding this threshold indicates that the accumulation of hydrogen in the system is already serious and may pose a greater threat to the safety of the system. The third preset hydrogen concentration threshold is a higher danger limit. If the hydrogen concentration reaches or exceeds this value, it may cause more serious safety problems, such as hydrogen explosion.

[0105] Specifically, when the hydrogen concentration is in a range greater than or equal to the second preset hydrogen concentration threshold and less than the third preset hydrogen concentration threshold, the accumulation of hydrogen in the system may affect the normal operation and safety of the liquid flow battery system. Power-limited operation is a protective measure designed to reduce the operating power of the system, thereby reducing factors that may lead to an accelerated rate of hydrogen production. By limiting the operating power of the system, the chemical reaction rate in the liquid flow battery system can be slowed down to a certain extent, the amount of hydrogen generated can be reduced, and the problem of hydrogen accumulation can be alleviated from the source. Power-limited operation also helps the system remain relatively stable and safe in a high hydrogen concentration environment, avoids the aggravation of hydrogen production and accumulation due to continued high-power operation, and further improves the safety of the system. For example, if the liquid flow battery system is originally operating at full power, power-limited operation may reduce its power to 50% of the rated power or other set safety ratios to ensure that the hydrogen concentration in the system does not continue to rise rapidly while the hydrogen exhaust fan continues to exhaust hydrogen.

[0106] The technical solution provided in the embodiment of the present invention, when the hydrogen concentration is in the interval greater than or equal to the second preset hydrogen concentration threshold and less than the third preset hydrogen concentration threshold, takes the dual measures of controlling the hydrogen exhaust fan to be normally open and operating at limited power, thereby strengthening the emission of hydrogen on the one hand and reducing the generation of hydrogen on the other hand, aiming to ensure the safe operation of the liquid flow battery system and avoid serious safety accidents caused by hydrogen accumulation.

[0107] Optionally, in one embodiment, step S130 further includes:

[0108] S133. When the hydrogen concentration is greater than or equal to a third preset hydrogen concentration threshold, control the liquid flow battery system to shut down.

[0109] Among them, the third preset hydrogen concentration threshold is an extremely critical safety limit, which indicates that the hydrogen concentration in the liquid flow battery system has reached a very dangerous level. Hydrogen is a flammable and explosive gas. When it accumulates to such a high concentration in the system, even a very small energy trigger, such as static electricity, electric sparks, etc., may cause a violent explosion or combustion reaction, which will cause extremely serious damage and harm to the entire liquid flow battery system and surrounding equipment, personnel and environment. Therefore, controlling the shutdown of the liquid flow battery system when the hydrogen concentration is greater than or equal to the third preset hydrogen concentration threshold is a necessary and critical safety measure to ensure the safety of personnel, protect equipment and prevent environmental damage. It is the last important line of defense for the safe operation of the liquid flow battery system.

[0110] In addition, when the hydrogen concentration is less than the first preset hydrogen concentration threshold, it is a normal value of the hydrogen concentration. When the hydrogen concentration is at a normal value, the hydrogen exhaust fan is controlled to continue to operate according to the hydrogen exhaust strategy corresponding to the working mode of the liquid flow battery system when the hydrogen concentration is at a normal value.

[0111] Figure 2 A schematic diagram of the structure of a hydrogen discharge device for a liquid flow battery system provided by an embodiment of the present invention. Figure 2 The device includes: a determination module 210, an acquisition module 220 and a control module 230.

[0112] It can be understood that the determination module 210 is used to determine the preset working mode of the liquid flow battery system in response to an external input instruction, and control the hydrogen discharge strategy under the preset working mode; the specific determination process can be referred to step S110 in the above embodiment. Optionally, the determination module 210 can also be used to execute steps S111a, step S111b, step S112a, step S112b, step S113a, step S113b, step S113c and step S113d, step S113e, step S114a, step S114b, step S114c, step S115a and step S115b in the above embodiment, which will not be repeated here.

[0113] The acquisition module 220 is used to acquire the hydrogen concentration under the preset working mode; the specific acquisition process can refer to step S120 in the above embodiment, which will not be repeated here.

[0114] The control module 230 is used to control the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold. The specific control process can be referred to step S130 in the above embodiment. Optionally, the control module 230 is also used to execute step S131, step S132 and step S133 in the above embodiment, which will not be repeated here.

[0115] A hydrogen discharge device for a liquid flow battery system provided in an embodiment of the present invention can execute a hydrogen discharge method for a liquid flow battery system provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0116] Figure 3 A schematic diagram of the structure of an electronic device for a hydrogen discharge method of a flow battery system provided by an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0117] like Figure 3 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0118] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0119] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a hydrogen discharge method for a liquid flow battery system.

[0120] In some embodiments, a method for discharging hydrogen from a flow battery system may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for discharging hydrogen from a flow battery system described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute a method for discharging hydrogen from a flow battery system in any other appropriate manner (e.g., by means of firmware).

[0121] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0122] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0123] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0124] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0125] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0126] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0127] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0128] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for discharging hydrogen from a liquid flow battery system, characterized in that: include: In response to an external input command, determine a preset operating mode of the liquid flow battery system, and control a hydrogen discharge strategy under the preset operating mode; Obtaining the hydrogen concentration under the preset working mode; According to the hydrogen concentration and a preset hydrogen concentration threshold, the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system are controlled.

2. The hydrogen discharge method according to claim 1, characterized in that: The step of determining a preset working mode of the liquid flow battery system in response to an external input command and controlling the hydrogen discharge strategy under the preset working mode includes: In response to an external input command, determining that a preset operating mode of the flow battery system is a safety mode; In the safety mode, the hydrogen exhaust blower in the hydrogen circulation loop of the liquid flow battery system is controlled to operate based on a first preset frequency.

3. The hydrogen discharge method according to claim 1, characterized in that: The step of determining a preset working mode of the liquid flow battery system in response to an external input command and controlling the hydrogen discharge strategy under the preset working mode further includes: In response to an external input command, determining that a preset operating mode of the flow battery system is a shutdown heating mode; In the shutdown heating mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a second preset frequency every first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

4. The hydrogen discharge method according to claim 1, characterized in that: The step of determining a preset working mode of the liquid flow battery system in response to an external input command and controlling the hydrogen discharge strategy under the preset working mode further includes: In response to an external input command, determining that a preset operating mode of the flow battery system is a normal charging mode; In the normal charging mode, controlling a circulation pump in a hydrogen circulation loop of the liquid flow battery system to start and run for a third preset time based on a third preset frequency; Obtain the single cell voltage of the battery stack in the flow battery system; When the single cell voltage is less than the first preset voltage, controlling the circulation pump to operate based on a second preset frequency; When the single cell voltage is greater than or equal to the first preset voltage, the circulation pump is controlled to operate based on the third preset frequency; the first preset frequency < the second preset frequency < the third preset frequency; the first preset time > the third preset time > the second preset time.

5. The hydrogen discharge method according to claim 1, characterized in that: The step of determining a preset working mode of the liquid flow battery system in response to an external input command and controlling the hydrogen discharge strategy under the preset working mode further includes: In response to an external input command, determining that a preset operating mode of the flow battery system is a normal discharge mode; In the normal discharge mode, controlling a circulation pump in a hydrogen circulation loop of the liquid flow battery system to start and run for a third preset time based on a third preset frequency; The circulation pump is controlled to operate based on the first preset frequency for a second preset time at intervals of the first preset time, and to operate based on the first preset frequency when the second preset time is greater than the second preset time and less than the first preset time.

6. The hydrogen discharge method according to claim 1, characterized in that: The step of determining a preset working mode of the liquid flow battery system in response to an external input command and controlling the hydrogen discharge strategy under the preset working mode further includes: In response to an external input command, determining that a preset operating mode of the flow battery system is a maintenance mode; In the maintenance mode, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to operate for a second preset time based on a third preset frequency every first preset time, and to operate based on the first preset frequency when the time is greater than the second preset time and less than the first preset time.

7. The hydrogen discharge method according to claim 1, characterized in that: The preset hydrogen concentration thresholds include a first preset hydrogen concentration threshold, a second preset hydrogen concentration threshold and a third preset hydrogen concentration threshold; The controlling of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the operating state of the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises: When the hydrogen concentration is greater than or equal to the first preset hydrogen concentration threshold and less than the second preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be normally open, and the speed of the hydrogen exhaust fan is controlled according to the hydrogen concentration; the hydrogen concentration is positively correlated with the speed of the hydrogen exhaust fan.

8. The hydrogen discharge method according to claim 7, characterized in that: The controlling of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the operating state of the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises: When the hydrogen concentration is greater than or equal to the second preset hydrogen concentration threshold and less than the third preset hydrogen concentration threshold, the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system is controlled to be always on, and the liquid flow battery system is controlled to operate at limited power.

9. The hydrogen discharge method according to claim 7, characterized in that: The controlling of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the operating state of the liquid flow battery system according to the hydrogen concentration and the preset hydrogen concentration threshold comprises: When the hydrogen concentration is greater than or equal to the third preset hydrogen concentration threshold, the liquid flow battery system is controlled to shut down.

10. A hydrogen discharge device for a liquid flow battery system, characterized in that: Used to perform the hydrogen discharge method of a liquid flow battery system as claimed in any one of claims 1 to 9, the hydrogen discharge device of the liquid flow battery system comprises: A determination module, the determination module is used to determine a preset working mode of the liquid flow battery system in response to an external input instruction, and control a hydrogen discharge strategy when entering the preset working mode; An acquisition module, the acquisition module is used to acquire the hydrogen concentration under the preset working mode; A control module is used to control the operating state of the hydrogen exhaust fan in the hydrogen circulation loop of the liquid flow battery system and the liquid flow battery system according to the hydrogen concentration and a preset hydrogen concentration threshold.

Images