Flow battery degassing device, method and system, and storage medium

Abstract

A flow battery degassing device, method and system, and a storage medium. A flow battery comprises a liquid tank. The flow battery degassing device comprises: a degassing tank, a degassing pump, a liquid outlet pipe, and a liquid inlet pipe; the liquid outlet pipe is configured such that electrolyte in the liquid tank flows into the degassing tank; the liquid inlet pipe is configured such that the electrolyte in the degassing tank flows into the liquid tank; and the degassing pump is arranged on the liquid inlet pipe and is configured such that a vacuum environment is formed in the degassing tank.

Description

Liquid flow battery degassing device, degassing method, system and storage medium Technical Field

[0001] This article relates to, but is not limited to, the field of electrochemical energy storage, and in particular to a flow battery degassing device, degassing method, system, and storage medium. Background Art

[0002] With the development of society and the economy, the demand for new energy sources continues to grow, driving the development of the energy storage industry. Flow batteries achieve the mutual conversion of electrical energy and chemical energy through reversible redox reactions (i.e., reversible changes in valence states) between the active substances in the positive and negative electrolytes. Due to their excellent stability and safety, flow batteries have become a mainstream technology solution in the energy storage field.

[0003] The inventors of the present application have discovered through research that the gas content in the electrolyte of a flow battery has a significant impact on the operation of the flow battery. However, it is currently difficult to degas the electrolyte.

[0004] Summary of the Invention

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] The embodiments of the present application provide a flow battery degassing device, degassing method, system and storage medium, which can solve the problem of difficult degassing of electrolyte.

[0007] In a first aspect, an embodiment of the present application provides a liquid flow battery degassing device, wherein the liquid flow battery includes a liquid tank, and the liquid flow battery degassing device includes: a degassing tank, a degassing pump, a liquid outlet pipe and a liquid inlet pipe, wherein the liquid outlet pipe is configured to allow the electrolyte in the liquid tank to flow into the degassing tank, and the liquid inlet pipe is configured to allow the electrolyte in the degassing tank to flow into the liquid tank; the degassing pump is arranged on the liquid inlet pipe and is configured to form a vacuum environment in the degassing tank.

[0008] In an exemplary embodiment, the liquid flow battery degassing device further includes a switch device, which includes a check valve arranged on the liquid inlet pipe. The check valve is located downstream of the degassing pump along the electrolyte flow direction and is configured to prevent the degassed electrolyte from flowing back into the degassing tank.

[0009] In an exemplary embodiment, the switch device further comprises a first switch disposed on the liquid outlet pipe, configured to control the electrolyte to enter the degassing tank.

[0010] In an exemplary embodiment, the liquid flow battery degassing device further includes a control device, which is configured to receive a gas content value of the electrolyte in the liquid flow battery, and control the degassing pump and the switching device to operate to degas the electrolyte when the gas content value is greater than or equal to a first threshold.

[0011] In an exemplary embodiment, the liquid flow battery degassing device further includes a gas detection device configured to detect the gas content of the electrolyte in the liquid flow battery and send the detected gas content value to the control device.

[0012] In an exemplary embodiment, the liquid flow battery degassing device further includes a flow detection device, which is configured to detect the flow of electrolyte entering the degassing tank and send the detected electrolyte flow value to the control device; the control device is also configured to control the first switch to close after the electrolyte flow value is greater than or equal to a first set value.

[0013] In an exemplary embodiment, the liquid flow battery degassing device further includes a heat exchange device; the heat exchange device includes a heat exchanger and a refrigerant machine, the heat exchanger is configured to cool the electrolyte, and the refrigerant machine is configured to provide refrigerant to the heat exchanger.

[0014] In an exemplary embodiment, the heat exchanger is disposed inside the degassing tank. After the electrolyte enters the degassing tank, it passes through the heat exchanger and flows to the bottom of the degassing tank.

[0015] In an exemplary embodiment, a plurality of heat exchange tubes are provided in the heat exchanger, the heat exchange tubes are connected to the refrigerant machine, and the refrigerant flows in the heat exchange tubes; a spray pipe is provided at the bottom of the heat exchanger, and the electrolyte enters the heat exchanger from one end of the spray pipe, and the spray pipe is configured to allow the electrolyte to contact the heat exchange tubes.

[0016] In an exemplary embodiment, the plurality of heat exchange tubes are arranged in layers from bottom to top in the heat exchanger.

[0017] In an exemplary embodiment, the control device is further configured to receive a temperature value of the electrolyte in the flow battery, and when the temperature value is greater than or equal to a second threshold, control the heat exchange device to operate and cool the electrolyte.

[0018] In an exemplary embodiment, the liquid flow battery degassing device further includes a temperature detection device configured to detect the temperature of the electrolyte in the liquid flow battery and send the detected temperature value to the control device.

[0019] In a second aspect, an embodiment of the present application further provides a liquid flow battery degassing system, comprising a liquid flow battery and the liquid flow battery degassing device as described above.

[0020] In a third aspect, an embodiment of the present application also provides a degassing method for a liquid flow battery, wherein the liquid flow battery includes a liquid tank, and the method includes: using a degassing pump to form a vacuum environment in the degassing tank; controlling the electrolyte in the liquid tank to flow into the degassing tank along a liquid outlet pipe; controlling the degassed electrolyte to flow back to the liquid tank along a liquid inlet pipe; and the degassing pump is arranged on the liquid inlet pipe.

[0021] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the liquid flow battery degassing method as described above.

[0022] The liquid flow battery degassing device provided in the embodiment of the present application utilizes a degassing pump to create a vacuum environment in the degassing tank. The electrolyte in the liquid flow battery tank can enter the degassing tank and return to the tank after degassing in a vacuum environment, so that the gas in the electrolyte will not be adsorbed on the battery stack unit, thereby ensuring the flow rate of the electrolyte and the reaction efficiency of charging and discharging, so that the battery stack unit is always at a relatively high operating efficiency, and ensuring the operational reliability of the battery stack unit. The liquid flow battery degassing device provided in the embodiment of the present application can perform degassing on the basis of the normal operation of the liquid flow battery, and can ensure the working efficiency of the liquid flow battery. It solves the problem of difficulty in degassing the electrolyte.

[0023] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings.

[0024] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0026] FIG1 is a schematic diagram of a flow battery;

[0027] FIG2 is a schematic diagram of a degassing device for a flow battery in an exemplary embodiment;

[0028] FIG3 is a schematic diagram of some components of the flow battery degassing device in FIG2 ;

[0029] FIG4 is a schematic diagram of a degassing tank and a heat exchanger in an exemplary embodiment;

[0030] FIG5 is a schematic diagram of a method for degassing and cooling using a flow battery degassing device in an exemplary embodiment. DETAILED DESCRIPTION

[0031] This application describes multiple embodiments, but this description is exemplary rather than restrictive, and it will be apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described herein. Although many possible feature combinations are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0032] The embodiments of the present application include and contemplate combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the appended claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the appended claims.

[0033] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be understood by those skilled in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can readily understand that these orders can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0034] A flow battery is a high-performance storage battery that separates and circulates the positive and negative electrolytes. The electrolyte contains active substances, which flow through the positive and negative electrolytes and undergo reversible redox reactions, enabling the flow battery to complete the charging and discharging process. Depending on the active substances contained in the electrolyte, flow batteries can be divided into: all-vanadium flow batteries, iron-chromium flow batteries, zinc-bromine flow batteries, sodium polysulfide / bromine flow batteries, and zinc / nickel flow batteries. As an electrochemical energy storage technology, flow batteries are characterized by high capacity, wide application range, and long cycle life.

[0035] Figure 1 is a schematic diagram of a flow battery. As shown in Figure 1 , the flow battery includes a cathode liquid tank 100, a cathode liquid tank 200, and a stack unit 300. The cathode liquid tank 100 contains a cathode electrolyte, which circulates between the cathode liquid tank 100 and the stack unit 300 via a cathode pipe 101. The cathode liquid tank 100, cathode pipe 101, and stack unit 300 form a circulation loop for the cathode electrolyte. The direction of flow of the cathode electrolyte within the circulation loop can be indicated by the arrow on the cathode pipe 101 in Figure 1 . The negative electrode liquid tank 200 contains a negative electrode electrolyte, which circulates between the negative electrode liquid tank 200 and the stack unit 300 via the negative electrode pipe 201. The negative electrode liquid tank 200, the negative electrode pipe 201 and the stack unit 300 form a circulation loop of the negative electrode electrolyte. The flow direction of the negative electrode electrolyte in the circulation loop can be as shown by the arrow direction of the negative electrode pipe 201 in Figure 1. A separator 301 can be provided in the stack unit 300 to prevent the positive electrode electrolyte and the negative electrode electrolyte from mixing. The stack unit 300 has a positive electrode (+) and a negative electrode (-), which can be connected to an external power source or load to achieve charging and discharging. The electrolyte will undergo oxidation or reduction reactions in the process of flowing through the stack unit 300. During the charging process of the flow battery, the positive electrode electrolyte undergoes an oxidation reaction to increase the valence of the active material, and the negative electrode electrolyte undergoes a reduction reaction to reduce the valence of the active material. The discharge process is the opposite. Flow batteries achieve spatial separation between the electrochemical reaction site (the stack unit) and the active energy storage material, allowing for relatively independent battery power and capacity designs. Compared to other energy storage methods such as lithium batteries, pumped hydro, and compressed air storage, flow batteries offer superior performance in terms of charge capacity, long-term discharge capability, and durability, making them suitable for large-scale energy storage systems such as wind and photovoltaic power generation.

[0036] When the liquid flow battery is first operated, it is necessary to control the continuous flow of the electrolyte in its respective circulation loops to expel the air accumulated in the pipes and the stack unit, and then the liquid flow battery can operate normally. Under normal operation, the circulation loop of the electrolyte needs to maintain a certain vacuum environment. However, in actual applications, it is not easy to completely remove the air accumulated in the pipes and the stack unit, and at the reaction interface between the stack unit and the positive and negative electrolytes, hydrogen evolution and oxygen evolution reactions often occur. Part of the hydrogen and oxygen produced by the reaction will be adsorbed on the solid-liquid interface, and the other part will dissolve in the electrolyte. As the electrolyte continues to circulate, the vacuum environment of the liquid flow battery changes.

[0037] The inventors of this application have found in practice that the gas content in the electrolyte of the flow battery has a great influence on the operation of the flow battery. After the hydrogen evolution reaction occurs, the content of hydrogen ions in the electrolyte will decrease, resulting in the loss of hydrogen ions during the charge and discharge process, causing the capacity of the flow battery to decay; and the hydrogen and oxygen adsorbed on the solid-liquid interface will occupy the reaction area of ​​the electrolyte charge and discharge, resulting in a decrease in the coulomb efficiency and energy efficiency of the battery. For the gas dissolved in the electrolyte, this part of the gas exists in the form of bubbles in the pipeline. When the gas content is too high, it will affect the vacuum degree of the normal operation of the electrolyte and produce cavitation. Cavitation will cause noise and vibration during the operation of the flow battery, resulting in a decrease in the flow rate of the electrolyte and the reaction efficiency of charge and discharge, and causing the metal materials in contact with the electrolyte to rust. In the pipeline where the electrolyte enters the liquid tank from the stack unit, the pressure in the pipeline increases, causing some bubbles to dissolve. After the bubbles condense, they release heat, which is easy to cause chemical corrosion. After entering the tank, some of the gas dissolved in the electrolyte will precipitate from the electrolyte and accumulate above the tank. If too much hydrogen accumulates and the concentration reaches a critical value, it can easily cause a safety accident. However, there is currently a lack of effective means to degas the electrolyte.

[0038] An embodiment of the present application provides a liquid flow battery degassing device, wherein the liquid flow battery includes a liquid tank, and the liquid flow battery degassing device includes: a degassing tank, a degassing pump, a liquid outlet pipe and a liquid inlet pipe, wherein the liquid outlet pipe is configured to allow the electrolyte in the liquid tank to flow into the degassing tank, and the liquid inlet pipe is configured to allow the electrolyte in the degassing tank to flow into the liquid tank; the degassing pump is arranged on the liquid inlet pipe and is configured to form a vacuum environment in the degassing tank.

[0039] The flow battery degassing device provided in the embodiment of the present application utilizes a degassing pump to create a vacuum environment in the degassing tank. The electrolyte in the flow battery tank can enter the degassing tank and return to the tank after degassing in the vacuum environment. This prevents the gas in the electrolyte from being adsorbed on the battery stack unit, thereby ensuring the flow rate of the electrolyte and the reaction efficiency of charge and discharge, so that the battery stack unit is always at a relatively high operating efficiency and the operational reliability of the battery stack unit. The flow battery degassing device provided in the embodiment of the present application can perform degassing on the basis of the normal operation of the flow battery, thereby ensuring the working efficiency of the flow battery.

[0040] In an exemplary embodiment, the liquid flow battery degassing device further includes a switch device, which includes a check valve arranged on the liquid inlet pipe. The check valve is located downstream of the degassing pump along the electrolyte flow direction and is configured to prevent the degassed electrolyte from flowing back into the degassing tank.

[0041] In an exemplary embodiment, the switch device further comprises a first switch disposed on the liquid outlet pipe, configured to control the electrolyte to enter the degassing tank.

[0042] In an exemplary embodiment, the liquid flow battery degassing device further includes a control device, which is configured to receive a gas content value of the electrolyte in the liquid flow battery, and control the degassing pump and the switching device to operate to degas the electrolyte when the gas content value is greater than or equal to a first threshold.

[0043] In an exemplary embodiment, the liquid flow battery degassing device further includes a gas detection device configured to detect the gas content of the electrolyte in the liquid flow battery and send the detected gas content value to the control device.

[0044] In an exemplary embodiment, the liquid flow battery degassing device further includes a flow detection device, which is configured to detect the flow of electrolyte entering the degassing tank and send the detected electrolyte flow value to the control device; the control device is also configured to control the first switch to close after the electrolyte flow value is greater than or equal to a first set value.

[0045] In an exemplary embodiment, the liquid flow battery degassing device further includes a heat exchange device; the heat exchange device includes a heat exchanger and a refrigerant machine, the heat exchanger is configured to cool the electrolyte, and the refrigerant machine is configured to provide refrigerant to the heat exchanger.

[0046] In an exemplary embodiment, the heat exchanger is disposed inside the degassing tank. After the electrolyte enters the degassing tank, it passes through the heat exchanger and flows to the bottom of the degassing tank.

[0047] In an exemplary embodiment, a plurality of heat exchange tubes are provided in the heat exchanger, the heat exchange tubes are connected to the refrigerant machine, and the refrigerant flows in the heat exchange tubes; a spray pipe is provided at the bottom of the heat exchanger, and the electrolyte enters the heat exchanger from one end of the spray pipe, and the spray pipe is configured to allow the electrolyte to contact the heat exchange tubes.

[0048] In an exemplary embodiment, the plurality of heat exchange tubes are arranged in layers from bottom to top in the heat exchanger.

[0049] In an exemplary embodiment, the control device is further configured to receive a temperature value of the electrolyte in the flow battery, and when the temperature value is greater than or equal to a second threshold, control the heat exchange device to operate and cool the electrolyte.

[0050] In an exemplary embodiment, the liquid flow battery degassing device further includes a temperature detection device configured to detect the temperature of the electrolyte in the liquid flow battery and send the detected temperature value to the control device.

[0051] Figure 2 is a schematic diagram of a flow battery degassing device in an exemplary embodiment, providing a simplified schematic diagram of the flow battery. Figure 3 is a schematic diagram of some components of the flow battery degassing device in Figure 2. As shown in Figures 2 and 3, the flow battery includes a liquid tank 7, which can be a positive electrode liquid tank or a negative electrode liquid tank. The liquid tank 7 has a first outlet and a first inlet. The first outlet can be located at the bottom of the liquid tank 7, and the first inlet can be located at the top of the liquid tank 7. The flow battery degassing device includes a degassing tank 4, which has a second outlet and a second inlet. The second outlet can be located at the bottom of the degassing tank 4, and the second inlet can be located above the second outlet. The flow battery degassing device includes a liquid outlet pipe 31 and a liquid inlet pipe 32. The liquid outlet pipe 31 connects the first outlet of the liquid tank 7 and the second inlet of the degassing tank 4, allowing the electrolyte to flow out of the liquid tank 7. The liquid inlet pipe 32 connects the first inlet of the liquid tank 7 and the second outlet of the degassing tank 4, allowing the electrolyte to flow into the liquid tank 7. A degassing pump 11 is provided on the liquid inlet pipe 31. The degassing pump 11 can create a vacuum environment in the degassing tank 4 to facilitate degassing of the electrolyte. The liquid tank 7, the liquid outlet pipe 31, the degassing tank 4, and the liquid inlet pipe 32 form a circulation loop. Under the action of the degassing pump 11, the electrolyte 1 can be returned to the liquid tank 7 after being degassed from the degassing tank 4. In an exemplary embodiment, the liquid flow battery degassing device can be turned on to degas the electrolyte 1 when the gas content in the electrolyte 1 is greater than or equal to a pre-set first threshold value. The degassed electrolyte 1 can be returned to the liquid tank 7 in a timely manner without affecting the normal operation of the liquid flow battery. That is, the liquid flow battery degassing device provided in this application can degas the electrolyte without affecting the normal operation of the liquid flow battery, helping to ensure the operating efficiency of the liquid flow battery.

[0052] In an exemplary embodiment, a single liquid tank 7 may be provided with at least one liquid flow battery degassing device to improve the degassing efficiency, which is not limited in the present application.

[0053] In an exemplary embodiment, the degassing pump 11 can control the vacuum level in the degassing tank 4 , and can be equipped with a frequency converter, for example.

[0054] In an exemplary embodiment, the degassing pump 11 may also be configured to transport the degassed electrolyte 1 back to the liquid tank 7. In other embodiments, other structures may be provided on the liquid inlet pipe 32 to transport the degassed electrolyte 1 back to the liquid tank 7, and this application is not limited thereto.

[0055] In an exemplary embodiment, the flow battery degassing device includes a switch device configured to control the flow of electrolyte and the exhaust of gas within the flow battery degassing device.

[0056] In an exemplary embodiment, the switch device includes a first switch 3, which is provided on the liquid outlet pipe and configured to control the electrolyte 1 to enter the degassing tank 4. The first switch may be, for example, an electric valve, which is not limited in this application.

[0057] In an exemplary embodiment, the flow battery degassing device includes a flow detection device configured to detect the flow rate of the electrolyte entering the degassing tank 4. The present application does not limit the type of the flow detection device.

[0058] In an exemplary embodiment, the switch device further includes an outlet valve 2, which is disposed near the liquid tank 7 on the outlet pipe 31 to prevent the electrolyte 1 from flowing out of the liquid tank 7. In the flow direction of the electrolyte 1, the outlet valve 2 may be located upstream of the first switch 3.

[0059] In an exemplary embodiment, the switch device further includes a return valve 6 , which is disposed at a position of the liquid inlet pipe 32 close to the liquid tank 7 to prevent the electrolyte 1 from flowing out of the liquid tank 7 .

[0060] In an exemplary embodiment, the switch device further includes a check valve 5 disposed on the liquid inlet pipe. A return valve 6 may be located downstream of the check valve 5 in the flow direction of the electrolyte 1 to prevent the degassed electrolyte 1 from flowing back into the degassing tank 4. If the electrolyte 1 breaks through the return valve 6, the check valve 5 prevents the electrolyte 1 from flowing into the degassing tank 4.

[0061] In an exemplary embodiment, the check valve 5 may be located downstream of the degassing pump 11 in the flow direction of the electrolyte 1 .

[0062] In an exemplary embodiment, the switching device further includes an exhaust valve 12, which is disposed above the mouth of the degassing tank 4. The electrolyte 1 enters the degassing tank 4 from the second inlet and flows to the bottom of the degassing tank 4. Under the action of the vacuum negative pressure, the gas dissolved in the electrolyte 1 will precipitate and gather above the mouth of the degassing tank 4. The precipitated gas can be discharged to the outside of the degassing tank 4 through the exhaust valve 12, and the degassed electrolyte 1 can flow back to the liquid tank 7 from the second outlet.

[0063] In an exemplary embodiment, the flow battery degassing apparatus may include a control device configured to receive a gas content value of an electrolyte in the flow battery and compare it with a preset first threshold value. When the gas content value of the electrolyte is greater than or equal to the first threshold value, the control device controls the degassing pump 11 and the switch device to operate to degas the electrolyte. The first threshold value may be set as desired and is not limited in this application.

[0064] In an exemplary embodiment, a flow battery degassing device may include a gas detection device configured to detect the gas content of the electrolyte within the flow battery and transmit the detected gas content value to a control device. In this exemplary embodiment, the gas detection device may be a non-contact measuring instrument such as an ultrasonic sensor, a capacitive sensor, or a laser sensor, which can measure the gas content without contacting the electrolyte. Alternatively, a contact measuring instrument may be used to detect the gas content of the electrolyte, and this application is not limited thereto. In other embodiments, the flow battery degassing device may not include a gas detection device and may only receive the gas content value of the electrolyte detected by the gas detection device, and this application is not limited thereto.

[0065] In an exemplary embodiment, the flow detection device can transmit the detected electrolyte flow rate value to the control device. The control device is further configured to control the first switch 3 to close when the electrolyte flow rate value is greater than or equal to a first set value, thereby controlling the electrolyte flow rate during a single degassing operation. The first set value can be set as needed and is not limited in this application. By setting the first set value, the electrolyte flow rate entering the degassing tank 4 for a single degassing operation can be controlled, helping to ensure effective degassing without affecting the normal operation of the flow battery.

[0066] In the exemplary embodiment, the gas detection device is further configured to detect the gas content within the degassing tank 4 and transmit the information to the control device. If the control device determines that the gas content within the degassing tank 4 is greater than or equal to the exhaust threshold, it controls the exhaust valve 12 to open, thereby exhausting the separated gas outside the degassing tank 4. The gas detection device can be configured to determine the gas content within the degassing tank 4 based on parameters such as the pressure value and gas composition within the degassing tank 4, which is not limited in this application. The exhaust threshold can be set as needed, which is not limited in this application.

[0067] In an exemplary embodiment, the gas detection device for detecting the gas content in the degassing tank 4 and the gas detection device for detecting the gas content of the electrolyte in the liquid flow battery can also be different gas detection devices. For example, a first gas detection device can be set to detect the gas content of the electrolyte in the liquid flow battery, and a second gas detection device can be set to detect the gas content in the degassing tank 4. This application does not impose any restrictions on this.

[0068] The inventors of this application have also found in practice that the electrolyte of the flow battery will generate heat during the charging and discharging process, causing the temperature of the electrolyte to rise. When the temperature of the electrolyte exceeds the critical temperature, the active material in the electrolyte will crystallize and precipitate from the electrolyte, thereby reducing the capacity of the flow battery system and causing performance degradation. The critical temperature at which the active material precipitates from the electrolyte may vary with different operating environments. For example, when the temperature is between 40°C and 45°C, the active material can precipitate. In addition, if the temperature of the electrolyte is too high, the diffusion rate of the active material in the positive and negative electrolytes will increase, resulting in an imbalance in the concentration of the active material in the positive and negative electrolytes, which will also reduce the system capacity. The diffusion of the active material is often in the form of hydrates, which will cause the liquid level of the positive and negative electrolytes to differ. The higher the temperature, the faster the liquid level differentiation rate. Therefore, it is necessary to cool the electrolyte in time, otherwise it will affect the operating efficiency of the flow battery.

[0069] In an exemplary embodiment, as shown in Figures 2 and 3, the flow battery degassing device further includes a heat exchange device, which may include a heat exchanger 9 and a refrigerant 10. The heat exchanger 9 can cool the electrolyte, and the refrigerant 10 can provide a refrigerant with a set temperature and flow rate to the heat exchanger 9. The refrigerant can be, for example, a cooling medium such as water, and the refrigerant 10 can be a chiller. The heat exchanger 9 can be positioned along the electrolyte flow path to cool the electrolyte 1 flowing therethrough. For example, the heat exchanger 9 can be positioned in at least one of the liquid outlet pipe 31, the degassing tank 4, and the liquid inlet pipe 32. This application does not limit the location and number of heat exchangers, nor the specific type of refrigerant.

[0070] In an exemplary embodiment, the refrigerant machine 10 may include an inverter to control the temperature and flow rate of the refrigerant.

[0071] In an exemplary embodiment, the heat exchanger 9 can be disposed inside the degassing tank 4. The electrolyte 1 enters the degassing tank 4 through the second inlet, flows to the bottom of the degassing tank 4 after passing through the heat exchanger 9, and the refrigerant 10 can be disposed outside the degassing tank 4. The electrolyte 1 can be degassed and cooled inside the degassing tank 4, saving the operation and maintenance time and cost of the flow battery and improving its operating efficiency.

[0072] Figure 4 is a schematic diagram of a degassing tank and heat exchanger in an exemplary embodiment. As shown in Figure 4 , the heat exchanger 9 is internally provided with a plurality of heat exchange tubes 22, which can be arranged in layers from bottom to top within the heat exchanger 9. A refrigerant transmission pipe 23 can be provided on the side of the heat exchanger 9. The refrigerant transmission pipe 23 is configured to connect the heat exchange tubes 22 and the refrigerant machine 10, allowing refrigerant to flow between the heat exchange tubes 22 and the refrigerant machine 10, thereby providing refrigerant at a set temperature to the heat exchange tubes 22. A spray pipe 21 is provided at the bottom of the heat exchanger 9. One end of the spray pipe 21 can be connected to the second inlet. At least one nozzle can be provided at the top of the spray pipe 21. The plurality of heat exchange tubes 22 can be positioned above the spray pipe 21. After entering the spray pipe 21, the electrolyte 1 can be sprayed onto the plurality of heat exchange tubes 22 via the nozzle, thereby cooling the electrolyte 1.

[0073] In an exemplary embodiment, the plurality of heat exchange tubes 22 in each layer may be distributed in a mesh shape to increase the contact area between the heat exchange tubes 22 and the electrolyte.

[0074] In an exemplary embodiment, the heat exchange tube 22 may be a capillary tube to increase the contact area between the heat exchange tube 22 and the electrolyte.

[0075] In the exemplary embodiment, at least one leakage hole is provided at the bottom of the heat exchanger 9 to allow electrolyte to flow out of the heat exchanger 9. Since the spray pipe 21 is located at the bottom of the heat exchanger 9, under normal circumstances, the electrolyte flows upward through the multiple heat exchange tubes 22 before flowing out of the top of the heat exchanger 9. However, if the electrolyte level is lower than the height of the heat exchanger 9, the electrolyte will accumulate in the heat exchanger 9. This accumulated electrolyte can be returned to the liquid tank along with the next batch of electrolyte entering the heat exchanger 9 for cooling. In this embodiment, by providing a leakage hole at the bottom of the heat exchanger 9, the electrolyte accumulated in the heat exchanger 9 can flow through the leakage hole to the bottom of the degassing tank 4. Since the electrolyte at the bottom of the degassing tank 4 has already completed heat exchange, the electrolyte flowing out of the leakage hole does not significantly affect the cooling effect of the electrolyte. The size of the leakage hole can be set to be smaller so that more electrolyte can complete the cooling and heat exchange process. However, a leakage hole that is too small may cause the accumulated electrolyte to take a longer time to flow to the bottom of the degassing tank 4, increasing the electrolyte cooling treatment time. In practical applications, the size of the leakage hole can be set according to actual needs to balance the relationship between the cooling effect and the cooling treatment time. This application does not impose any restrictions on this.

[0076] In an exemplary embodiment, the size range of the leakage hole can be set to be greater than or equal to 4 mm and less than or equal to 12.5 mm, for example, it can be set to be greater than or equal to 5 mm and less than or equal to 10 mm, and this application does not impose any limitation on this.

[0077] In an exemplary embodiment, the control device is also configured to receive the temperature value of the electrolyte in the flow battery and compare it with a pre-set second threshold value. When the temperature value of the electrolyte is greater than or equal to the second threshold value, the heat exchange device is controlled to cool the electrolyte.

[0078] In an exemplary embodiment, the flow battery degassing device may include a temperature detection device configured to detect the temperature of the electrolyte within the flow battery and transmit the detected temperature value to a control device. This application does not limit the specific temperature measurement method. In other embodiments, the flow battery degassing device may not include a temperature detection device and may only receive the temperature value detected by the temperature detection device. This application does not limit this.

[0079] In an exemplary embodiment, the control device is configured to control the operation of the degassing pump 11 , the switch device, and the heat exchange device according to the received gas content and temperature values ​​of the electrolyte.

[0080] In an exemplary embodiment, the control device is configured to use a PID algorithm to control the operation of the degassing pump 11, the switching device, and the heat exchange device. For example, the target gas content value of the electrolyte can be set in advance as a first threshold value, and the target temperature value of the electrolyte can be set as a second threshold value. The target gas content value and target temperature value can be recorded as u(t), and the error between the gas content value and temperature value received by the control device and the corresponding target value can be recorded as e(t). The degassing pump 11, the switching device, and the heat exchange device are actuators. The proportion (Proportion), integral (Integral), and differential (Differential) of the error can be linearly combined to form a control variable, which is used to control the actuator. The control device can use Formula 1 to control the actuator:

[0081] Among them, Kp is the proportional gain, Ki is the integral gain, Kd is the differential gain, Kp, Ki and Kd are all adaptive parameters and can be set according to actual needs; error e is the difference between the target value and the received value; t represents the current time.

[0082] The liquid flow battery degassing device provided in the embodiment of the present application can make the electrolyte of the liquid flow battery operate without gas and at an ideal temperature, which can ensure the highest charging and discharging efficiency of the liquid flow battery, and the electrolyte will not have adverse phenomena such as crystallization and precipitation. A single device can realize both degassing and cooling functions, reducing the operation and maintenance time and cost of the liquid flow battery. The control device can receive the gas content and temperature value of the electrolyte, and control the operation of the degassing pump, the switching device and the heat exchange device accordingly, avoiding defects such as cavitation, excessive vibration and excessive noise of the electrolyte circulation pump, and the gas will not be adsorbed on the reaction interface of the stack unit, and will not reduce the available area of ​​the reaction interface, so that the stack is always at a relatively high efficiency and the operational reliability of the stack unit is guaranteed.

[0083] FIG5 is a schematic diagram of a method for degassing and cooling using a flow battery degassing device in an exemplary embodiment. As shown in FIG5 ,

[0084] S1. Start the degassing pump to create a vacuum environment in the degassing tank;

[0085] In the initial state, the outlet valve 2 and the first switch 3 are closed by default. After the degassing pump 11 is activated, the degassing tank 4 is in a negative pressure state, which can form a predetermined vacuum environment. The vacuum level within the degassing tank 4 can be adjusted as needed, and this application does not limit this. The degassing pump 11 can be activated by a control device or manually, and this application does not limit this.

[0086] S2. Control the operation of the degassing pump, switch device and heat exchange device according to the gas content and temperature of the electrolyte;

[0087] In an exemplary embodiment, the control device can control the degassing pump and the switch device to operate when the gas content of the liquid flow battery electrolyte is greater than or equal to the first threshold. For example, the control device can control the outlet valve 2 and the first switch 3 to open, and the electrolyte in the liquid tank 7 enters the degassing tank 4 under the influence of negative pressure. In an exemplary embodiment, the control device can close the first switch 3 after the electrolyte volume entering the degassing tank 4 reaches the first set value. By controlling the electrolyte flow rate of a single degassing, the degassing effect can be ensured and the operation of the liquid flow battery can be avoided. The size of the first set value can be set according to actual needs, and this application does not impose any restrictions on this. The outlet valve 2 and other switch devices can also be manually controlled, and this application does not impose any restrictions on this.

[0088] In an exemplary embodiment, the control device can control the heat exchange device to operate when the temperature value of the flow battery electrolyte is greater than or equal to the second threshold value. In an exemplary embodiment, the control device can control the refrigerant machine 10 to provide refrigerants of different temperatures and flow rates according to the size of the received temperature value, and the refrigerant temperature and flow rate can be controlled by controlling the operating power of the refrigerant machine 10. For example, the control device can calculate the first difference between the temperature value and the second threshold value, and when the first difference is less than or equal to 10% of the second threshold value, the refrigerant temperature is controlled to be the first temperature and the refrigerant flow rate is the first flow rate. When the first difference is greater than or equal to 10% of the second threshold value and less than or equal to 30% of the second threshold value, the refrigerant temperature is controlled to be the second temperature and the refrigerant flow rate is the second flow rate. By analogy, the higher the temperature value of the electrolyte, the lower the refrigerant temperature and the faster the flow rate can be set to improve the cooling effect. The correspondence between the temperature value and the refrigerant temperature and flow rate can be set as needed. For example, the temperature value can be the independent variable, the refrigerant temperature and flow rate can be the dependent variables, and the dependent variable and the independent variable can have different functional relationships or piecewise functions. This application does not impose any restrictions on this.

[0089] S3. Open the exhaust valve to discharge the precipitated gas to the outside of the degassing tank;

[0090] As shown in Figure 4, after the electrolyte enters the degassing tank 4, it can be sprayed onto the heat exchange tube 22 through the nozzle on the top of the spray pipe 21. The electrolyte moves upward from the bottom of the heat exchanger 9 and contacts the heat exchange tube 22 during the movement. The refrigerant flowing in the heat exchange tube 22 can take away the heat of the electrolyte. The electrolyte flows out from the top of the heat exchanger 9 and flows to the bottom of the degassing tank 4. Under the action of the liquid level pressure difference and the vacuum negative pressure, the gas in the electrolyte is precipitated. The control device controls the exhaust valve 12 to open and discharge the precipitated gas to the outside of the degassing tank 4.

[0091] In an exemplary embodiment, the control device can control the opening of the exhaust valve 12 based on the operating time. For example, after detecting the first time that the electrolyte enters the degassing tank 4, the exhaust and temperature reduction are considered complete, and the exhaust valve 12 is controlled to open. Alternatively, the gas detection device is further configured to detect the gas content within the degassing tank 4 and transmit the information to the control device. If the control device determines that the gas content within the degassing tank 4 is greater than or equal to the exhaust threshold, the exhaust valve 12 is controlled to open. Alternatively, the exhaust valve 12 can automatically open when the gas content within the gas tank 4 is greater than or equal to the exhaust threshold. This application does not limit the conditions for controlling the opening of the exhaust valve or the opening method.

[0092] S4. Start the degassing pump to send the degassed and heat-exchanged electrolyte into the liquid tank.

[0093] After the exhaust valve 12 is opened, the vacuum degree in the degassing tank 4 is reduced. By opening the degassing pump 11, the degassed electrolyte can be sent back to the liquid tank 7 from the second outlet. The check valve 5 can prevent the degassed electrolyte from flowing back.

[0094] After completing step S4, the degassing and cooling treatment of the electrolyte is completed, and then the process can jump back to step S1. The control device continues to receive the gas content and temperature value of the electrolyte to determine whether the next degassing and cooling treatment is required. The liquid flow battery degassing device of the embodiment of the present application can achieve closed-loop control.

[0095] An embodiment of the present application further provides a liquid flow battery degassing system, comprising a liquid flow battery and the liquid flow battery degassing device described in the above embodiment.

[0096] An embodiment of the present application also provides a liquid flow battery degassing method, wherein the liquid flow battery includes a liquid tank, and the method includes: using a degassing pump to form a vacuum environment in the degassing tank; controlling the electrolyte in the liquid tank to flow into the degassing tank along a liquid outlet pipe; controlling the degassed electrolyte to flow back to the liquid tank along a liquid inlet pipe; the degassing pump is arranged on the liquid inlet pipe.

[0097] The flow battery degassing method provided in the embodiment of the present application utilizes a degassing pump to create a vacuum environment in the degassing tank. The electrolyte in the flow battery tank can enter the degassing tank and return to the tank after degassing in the vacuum environment. This prevents the gas in the electrolyte from being adsorbed on the stack unit, thereby ensuring the flow rate of the electrolyte and the reaction efficiency of charge and discharge, so that the stack unit is always at a relatively high operating efficiency and the operational reliability of the stack unit. The flow battery degassing method provided in the embodiment of the present application can perform degassing on the basis of the normal operation of the flow battery, thereby ensuring the working efficiency of the flow battery.

[0098] The liquid flow battery degassing method of the embodiment of the present application is applied to the liquid flow battery degassing device described in the above embodiment. For specific steps and effects, please refer to the description of the above liquid flow battery degassing device, which will not be repeated here.

[0099] An embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the liquid flow battery degassing method as described above.

[0100] Although the embodiments disclosed herein are as described above, the contents described herein are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art to which the present invention pertains may make any modifications and variations in the form and details of the embodiments without departing from the spirit and scope of the present invention.

Claims

1. A liquid flow battery degassing device, the liquid flow battery comprising a liquid tank, characterized in that: The liquid flow battery degassing device comprises: a degassing tank, a degassing pump, a liquid outlet pipe and a liquid inlet pipe, wherein the liquid outlet pipe is configured to allow the electrolyte in the liquid tank to flow into the degassing tank, and the liquid inlet pipe is configured to allow the electrolyte in the degassing tank to flow into the liquid tank; The degassing pump is arranged on the liquid inlet pipe and is configured to form a vacuum environment in the degassing tank.

2. The liquid flow battery degassing device according to claim 1, characterized in that: The liquid flow battery degassing device also includes a switch device, which includes a check valve arranged on the liquid inlet pipe. The check valve is located downstream of the degassing pump along the electrolyte flow direction and is configured to prevent the degassed electrolyte from flowing back to the degassing tank.

3. The liquid flow battery degassing device according to claim 2, characterized in that: The switch device also includes a first switch arranged on the liquid outlet pipe, which is configured to control the electrolyte to enter the degassing tank.

4. The liquid flow battery degassing device according to claim 3, characterized in that: The liquid flow battery degassing device also includes a control device, which is configured to receive a gas content value of an electrolyte in the liquid flow battery, and control the degassing pump and the switch device to operate to degas the electrolyte when the gas content value is greater than or equal to a first threshold.

5. The liquid flow battery degassing device according to claim 4, characterized in that: The liquid flow battery degassing device also includes a gas detection device, which is configured to detect the gas content of the electrolyte in the liquid flow battery and send the detected gas content value to the control device.

6. The liquid flow battery degassing device according to claim 4, characterized in that: The flow battery degassing device further comprises a flow detection device, which is configured to detect the flow rate of the electrolyte entering the degassing tank and send the detected electrolyte flow rate value to the control device; The control device is also configured to control the first switch to close after the electrolyte flow value is greater than or equal to a first set value.

7. The liquid flow battery degassing device according to claim 4, characterized in that: The liquid flow battery degassing device also includes a heat exchange device; the heat exchange device includes a heat exchanger and a refrigerant machine, the heat exchanger is configured to cool the electrolyte, and the refrigerant machine is configured to provide refrigerant to the heat exchanger.

8. The liquid flow battery degassing device according to claim 7, characterized in that: The heat exchanger is arranged inside the degassing tank. After the electrolyte enters the degassing tank, it flows to the bottom of the degassing tank through the heat exchanger.

9. The liquid flow battery degassing device according to claim 7, characterized in that: A plurality of heat exchange tubes are arranged in the heat exchanger, the heat exchange tubes are connected to the refrigerant machine, and the refrigerant flows in the heat exchange tubes; a spray pipe is arranged at the bottom of the heat exchanger, and the electrolyte enters the heat exchanger from one end of the spray pipe, and the spray pipe is arranged to make the electrolyte contact with the heat exchange tubes.

10. The liquid flow battery degassing device according to claim 9, characterized in that: The plurality of heat exchange tubes are arranged in layers from bottom to top in the heat exchanger.

11. The liquid flow battery degassing device according to claim 7, characterized in that: The control device is also configured to receive a temperature value of the electrolyte in the flow battery, and when the temperature value is greater than or equal to a second threshold, control the heat exchange device to operate and cool the electrolyte.

12. The liquid flow battery degassing device according to claim 11, characterized in that: The liquid flow battery degassing device also includes a temperature detection device, which is configured to detect the temperature of the electrolyte in the liquid flow battery and send the detected temperature value to the control device.

13. A liquid flow battery degassing system, characterized in that: The invention comprises a liquid flow battery and the liquid flow battery degassing device according to any one of claims 1 to 12.

14. A method for degassing a liquid flow battery, the liquid flow battery comprising a liquid tank, characterized in that: The method comprises: using a degassing pump to form a vacuum environment in a degassing tank; controlling the electrolyte in the liquid tank to flow into the degassing tank along a liquid outlet pipe; controlling the degassed electrolyte to flow back to the liquid tank along a liquid inlet pipe; and the degassing pump is arranged on the liquid inlet pipe. 15 . A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the liquid flow battery degassing method according to claim 14 .

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