Liquid mixing control method and device, flow battery system and storage medium

Abstract

The invention relates to the technical field of flow batteries, and provides a liquid mixing control method and device, a flow battery system and a storage medium. The liquid mixing control method is applied to a controller connected with the flow battery, the flow battery comprises a positive electrode electrolyte circulating pipeline, a negative electrode electrolyte circulating pipeline, an electric pile, an electrolyte storage tank and a partition plate, and the electrolyte storage tank comprises a positive electrode electrolyte storage area and a negative electrode electrolyte storage area. The positive electrode electrolyte storage area and the negative electrode electrolyte storage area are separated by a partition plate. The liquid mixing control method comprises the following steps: determining an ion concentration difference between a positive electrode electrolyte and a negative electrode electrolyte; determining a liquid mixing control strategy according to the liquid mixing period and the ion concentration difference; and the separator is controlled to move according to the liquid mixing control strategy for liquid mixing, so that ions in the positive and negative electrolyte rapidly recover balance, the activity of the electrolyte is improved, the effective active couple concentration in the electrolyte is increased, the battery capacity is recovered, and the charging and discharging efficiency is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of liquid flow batteries, and in particular to a liquid mixing control method and device, a liquid flow battery system, and a storage medium. Background Art

[0002] Liquid flow batteries, with their inherent safety, long cycle life, and environmental friendliness, are an important large-scale energy storage technology, having been demonstrated in numerous fields, including renewable energy power generation and measurement, and grid transmission and distribution. A liquid flow battery primarily consists of a stack, a reservoir (for storing the positive and negative electrolytes), and a circulation pump. The stack comprises an ion exchange membrane, bipolar plates, and electrodes. The positive and negative reservoirs contain vanadium ion solutions of varying valence states. During operation, the positive and negative electrolytes are introduced into the stack via a circulation pump, where redox reactions occur at the electrodes. The positive and negative electrodes are separated by an ion exchange membrane.

[0003] In related technologies, during the charge and discharge process, ions in the positive and negative electrolytes (such as vanadium ions and hydrogen ions) carry different amounts of water molecules through the ion exchange membrane to the other electrode, resulting in an imbalance in the ions in the electrolyte. The concentration of effective active electrodes in the electrolyte decreases, causing capacity decay, the electrolyte becomes passivated, the electrolyte is not active, and the charge and discharge efficiency becomes low. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a liquid mixing control method, device, flow battery system and storage medium to solve the problems in the related art.

[0005] To achieve the above objectives, a first aspect of an embodiment of the present disclosure provides a liquid mixing control method, which is applied to a controller connected to a liquid flow battery, wherein the liquid flow battery includes a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator, wherein the electrolyte storage tank includes a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area are separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area share the electrolyte storage tank, and the liquid mixing control method includes:

[0006] determining an ion concentration difference between a positive electrode electrolyte in the positive electrode electrolyte storage region and a negative electrode electrolyte in the negative electrode electrolyte storage region;

[0007] determining a liquid mixing control strategy according to the liquid mixing cycle and the ion concentration difference;

[0008] The movement of the partition is controlled according to the liquid mixing control strategy to mix the liquid.

[0009] Optionally, the mixed liquid control method further includes:

[0010] The liquid mixing period is determined according to the ion concentration difference.

[0011] Optionally, determining the liquid mixing period according to the ion concentration difference includes:

[0012] determining a maximum available capacity of the battery stack according to the ion concentration difference, wherein the ion concentration difference is negatively correlated with the maximum available capacity of the battery stack;

[0013] The liquid mixing period is determined according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate of the fuel cell stack.

[0014] Optionally, determining the liquid mixing period according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate includes:

[0015] Determining a constant value according to the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack;

[0016] The liquid mixing period is obtained according to the constant value and the stack rate of the stack.

[0017] Optionally, the liquid mixing control strategy includes: a connectivity range and a liquid mixing speed, wherein the connectivity range includes a first connectivity range and a second connectivity range, the first connectivity range being larger than the second connectivity range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed being larger than the second liquid mixing speed;

[0018] Determine a mixing control strategy based on the mixing cycle and the ion concentration difference, including:

[0019] According to the ion concentration difference and the maximum concentration difference, the concentration difference ratio is obtained;

[0020] When the time from the last mixing of liquid reaches the mixing period, determining whether the fuel cell stack is supplying power to the outside;

[0021] When the stack is not powered externally, the connectivity range in the liquid mixing control strategy is determined according to the concentration difference ratio, and the liquid mixing speed in the liquid mixing control strategy is determined according to the liquid mixing demand time and the liquid mixing given time.

[0022] Optionally, the mixed liquid control method further includes:

[0023] When the stack supplies power to the outside, or when the time since the last mixing of liquids has not reached the mixing cycle, the concentration difference ratio is compared with a first preset value;

[0024] When the concentration difference ratio is greater than the first preset value, comparing the concentration difference ratio with a second preset value, wherein the second preset value is greater than the first preset value;

[0025] When the concentration difference ratio is greater than the second preset value, the connection range in the liquid mixing control strategy is determined to be the first connection range, and the liquid mixing speed in the liquid mixing control strategy is determined to be the first liquid mixing speed.

[0026] Optionally, determining the connectivity range in the mixed liquid control strategy according to the concentration difference ratio includes:

[0027] comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value;

[0028] When the concentration difference ratio is less than the third preset value, determining the connection range in the mixed liquid control strategy as the second connection range;

[0029] When the concentration difference ratio is greater than or equal to the third preset value, the connectivity range in the liquid mixing control strategy is determined to be the first connectivity range.

[0030] Optionally, determining the liquid mixing speed in the liquid mixing control strategy according to the liquid mixing demand time and the liquid mixing given time includes:

[0031] Compare the required mixing time with the given mixing time;

[0032] When the required liquid mixing time is less than the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined to be the second liquid mixing speed;

[0033] When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined as the first liquid mixing speed.

[0034] Optionally, controlling the movement of the partition to mix the liquid according to the liquid mixing control strategy includes:

[0035] According to the connectivity range in the liquid mixing control strategy, controlling the partition to contract and / or fold to mix the liquid;

[0036] According to the liquid mixing speed in the liquid mixing control strategy, the partition is controlled to rotate and / or stir to mix the liquid.

[0037] According to a second aspect of an embodiment of the present disclosure, there is provided a liquid mixing control device, which is applied to a controller connected to a liquid flow battery. The liquid flow battery includes a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator. The electrolyte storage tank includes a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area are separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area share the electrolyte storage tank. The liquid mixing control device includes:

[0038] a first processing module, configured to determine an ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage region and the negative electrode electrolyte in the negative electrode electrolyte storage region;

[0039] A second processing module is used to determine a liquid mixing control strategy according to the liquid mixing period and the ion concentration difference;

[0040] The third processing module is used to control the movement of the partition to mix the liquid according to the liquid mixing control strategy.

[0041] Optionally, the liquid mixing control device further includes:

[0042] The fourth processing module is used to determine the liquid mixing period according to the ion concentration difference.

[0043] Optionally, the fourth processing module includes:

[0044] a first sub-processing module, configured to determine a maximum available capacity of the fuel cell stack according to the ion concentration difference, wherein the ion concentration difference is negatively correlated with the maximum available capacity of the fuel cell stack;

[0045] The second sub-processing module is configured to determine the liquid mixing period according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate.

[0046] Optionally, the second sub-processing module is specifically configured to:

[0047] Determining a constant value according to the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack;

[0048] The liquid mixing period is obtained according to the constant value and the stack rate of the stack.

[0049] Optionally, the liquid mixing control strategy includes: a connectivity range and a liquid mixing speed, wherein the connectivity range includes a first connectivity range and a second connectivity range, the first connectivity range being larger than the second connectivity range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed being larger than the second liquid mixing speed;

[0050] The second processing module includes:

[0051] A third sub-processing module is used to obtain a concentration difference ratio based on the ion concentration difference and the maximum concentration difference;

[0052] A fourth sub-processing module is configured to determine whether the stack is supplying power externally when the time since the last mixing reaches the mixing period;

[0053] The fifth sub-processing module is used to determine the connectivity range in the mixed liquid control strategy according to the concentration difference ratio when the fuel cell stack is not powered externally, and to determine the mixing speed in the mixed liquid control strategy according to the mixed liquid demand time and the mixed liquid given time.

[0054] Optionally, the liquid mixing control device further includes:

[0055] a fifth processing module, configured to compare the concentration difference ratio with a first preset value when the stack supplies power to an external user or when the time since the last mixing of liquids has not reached a mixing cycle;

[0056] a sixth processing module, configured to compare the concentration difference ratio with a second preset value when the concentration difference ratio is greater than the first preset value, wherein the second preset value is greater than the first preset value;

[0057] The seventh processing module is used to determine the connection range in the mixing liquid control strategy as the first connection range and the mixing liquid speed in the mixing liquid control strategy as the first mixing liquid speed when the concentration difference ratio is greater than the second preset value.

[0058] Optionally, the fifth sub-processing module is specifically configured to:

[0059] comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value;

[0060] When the concentration difference ratio is less than the third preset value, determining the connection range in the mixed liquid control strategy as the second connection range;

[0061] When the concentration difference ratio is greater than or equal to the third preset value, the connectivity range in the liquid mixing control strategy is determined to be the first connectivity range.

[0062] Optionally, the fifth sub-processing module is specifically configured to:

[0063] Compare the required mixing time with the given mixing time;

[0064] When the required liquid mixing time is less than the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined to be the second liquid mixing speed;

[0065] When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined as the first liquid mixing speed.

[0066] Optionally, the third processing module includes:

[0067] a sixth sub-processing module, configured to control the partition to contract and / or fold to mix the liquid according to the connectivity range in the liquid mixing control strategy;

[0068] The seventh sub-processing module is used to control the rotation and / or stirring of the partition to mix the liquid according to the liquid mixing speed in the liquid mixing control strategy.

[0069] According to a third aspect of an embodiment of the present disclosure, there is provided a flow battery system, comprising:

[0070] A liquid flow battery, the liquid flow battery comprising a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator, the electrolyte storage tank comprising a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area being separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area sharing the electrolyte storage tank;

[0071] A controller is connected to the liquid flow battery and is used to execute a computer program to implement any step of the liquid mixing control method provided in the first aspect of the present disclosure.

[0072] According to a fourth aspect of an embodiment of the present disclosure, a non-temporary computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the program implements any step of the liquid mixing control method provided in the first aspect of the present disclosure.

[0073] By adopting the above technical solution, the ion concentration difference between the positive electrolyte in the positive electrolyte storage area and the negative electrolyte in the negative electrolyte storage area is determined; then the mixing control strategy is determined according to the mixing cycle and the ion concentration difference; finally, the partition movement is controlled according to the mixing control strategy to mix the liquids, so that the ions in the positive and negative electrolytes can quickly restore the balance, the activity of the electrolyte is improved, and the concentration of effective active electrodes in the electrolyte is increased, thereby restoring the battery capacity and improving the charging and discharging efficiency.

[0074] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0076] Figure 1 The figure is a schematic structural diagram of a flow battery according to an exemplary embodiment.

[0077] Figure 2 The figure is a flow chart showing a liquid mixing control method according to an exemplary embodiment.

[0078] Figure 3 is a flow chart showing another liquid mixing control method according to an exemplary embodiment.

[0079] Figure 4 is a flowchart of sub-steps of step S102 according to an exemplary embodiment.

[0080] Figure 5 is a flowchart of sub-steps of step S2 according to an exemplary embodiment.

[0081] Figure 6 is a flow chart showing another liquid mixing control method according to an exemplary embodiment.

[0082] Figure 7 It is a schematic structural diagram of a partition according to an exemplary embodiment.

[0083] Figure 8 is a schematic diagram showing the movement direction of a partition according to an exemplary embodiment.

[0084] Figure 9 It is a schematic structural diagram of another partition according to an exemplary embodiment.

[0085] Figure 10 is a flowchart of sub-steps of step S3 according to an exemplary embodiment.

[0086] Figure 11 is a schematic diagram showing another direction of movement of a partition according to an exemplary embodiment.

[0087] Figure 12 is a schematic diagram showing another direction of movement of a partition according to an exemplary embodiment.

[0088] Figure 13 is a schematic diagram showing another direction of movement of a partition according to an exemplary embodiment.

[0089] Figure 14 It is a schematic structural diagram of another partition according to an exemplary embodiment.

[0090] Figure 15 is a flow chart showing another liquid mixing control method according to an exemplary embodiment.

[0091] Figure 16 is a block diagram of a liquid mixing control device according to an exemplary embodiment.

[0092] Figure 17 The figure is a schematic structural diagram of a flow battery system according to an exemplary embodiment. DETAILED DESCRIPTION

[0093] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0094] In the following description, words such as “first” and “second” are only used for the purpose of distinguishing the description and should not be understood as indicating or implying relative importance or order.

[0095] Before introducing the specific implementation of the present disclosure, first, the application scenario of the present disclosure is described.

[0096] Liquid flow batteries, with their inherent safety, long cycle life, and environmental friendliness, are an important large-scale energy storage technology, having been demonstrated in numerous fields, including renewable energy power generation and measurement, and grid transmission and distribution. A liquid flow battery primarily consists of a stack, a reservoir (for storing the positive and negative electrolytes), and a circulation pump. The stack comprises an ion exchange membrane, bipolar plates, and electrodes. The positive and negative reservoirs contain vanadium ion solutions of varying valence states. During operation, the positive and negative electrolytes are introduced into the stack via a circulation pump, where redox reactions occur at the electrodes. The positive and negative electrodes are separated by an ion exchange membrane.

[0097] In related technologies, during the charge and discharge process, ions in the positive and negative electrolytes (such as vanadium ions and hydrogen ions) carry different amounts of water molecules through the ion exchange membrane to the other electrode, resulting in an imbalance in the ions in the electrolyte. The concentration of effective active electrodes in the electrolyte decreases, causing capacity decay, the electrolyte becomes passivated, the electrolyte is not active, and the charge and discharge efficiency becomes low.

[0098] To solve the above technical problems, please refer to Figure 1The electrolyte storage tank of the liquid flow battery includes a positive electrode electrolyte storage area 12 and a negative electrode electrolyte storage area 13. The positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 are separated by a partition 11. The positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 share an electrolyte storage tank. The positive electrode electrolyte storage area 12 is used to store positive electrode electrolyte, and the negative electrode electrolyte storage area 13 is used to store negative electrode electrolyte. The liquid flow battery includes a positive electrode electrolyte circulation pipeline 14, a negative electrode electrolyte circulation pipeline 15, and a battery stack 16. The positive electrode electrolyte in the positive electrode electrolyte storage area 12 flows into the battery stack 16 through the positive electrode electrolyte circulation pipeline 14, and the negative electrode electrolyte in the negative electrode electrolyte storage area 13 flows into the battery stack 16 through the negative electrode electrolyte circulation pipeline 15, undergoes redox reaction in the battery stack 16, and then flows back to the positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 respectively.

[0099] It should be understood that separator 11 effectively separates the positive and negative electrolytes, making them independent of each other. Separator 11 does not chemically react with the positive and negative electrolytes, nor does it adversely affect their performance. Separator 11 also offers excellent thermal insulation, ensuring that the temperatures within positive and negative electrolyte storage areas 12 and 13 do not affect each other.

[0100] In other embodiments, a positive electrolyte pipeline valve 17 and a positive electrolyte circulation pump 18 may be provided in the positive electrolyte circulation pipeline 14, and a negative electrolyte pipeline valve 19 and a negative electrolyte circulation pump 20 may be provided in the negative electrolyte circulation pipeline 15. Whether the electrolyte flows into the battery stack 16 can be controlled by controlling the corresponding pipeline valves.

[0101] Figure 2 This is a flow chart showing a method for controlling a mixed liquid according to an exemplary embodiment. The mixed liquid control method can be applied to a controller connected to a flow battery. Figure 2 The mixed liquid control method may include steps S1 to S3.

[0102] Step S1 : determining the ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage area 12 and the negative electrode electrolyte in the negative electrode electrolyte storage area 13 .

[0103] The vanadium ion concentration of the positive electrode electrolyte in the positive electrode electrolyte storage area 12 is measured, and the vanadium ion concentration of the negative electrode electrolyte in the negative electrode electrolyte storage area 13 is measured. Then, the difference between the vanadium ion concentration of the positive electrode electrolyte in the positive electrode electrolyte storage area 12 and the vanadium ion concentration of the negative electrode electrolyte in the negative electrode electrolyte storage area 13 is calculated to obtain the ion concentration difference.

[0104] The vanadium ion concentrations of the positive electrolyte in the positive electrolyte storage area 12 and the negative electrolyte in the negative electrolyte storage area 13 can be measured using a potentiometric titrator or the like. The vanadium ion concentration test object can be any valence state among II, III, IV, and V.

[0105] Step S2: determining a liquid mixing control strategy according to the liquid mixing cycle and the ion concentration difference.

[0106] The liquid mixing period may be a liquid mixing interval time threshold. The liquid mixing period may be set to a fixed value or a non-fixed value, and may be determined based on actual conditions.

[0107] The liquid mixing control strategy includes the connectivity range and / or the liquid mixing speed. The liquid mixing control strategy may include only the connectivity range, only the liquid mixing speed, or both the connectivity range and the liquid mixing speed, which is not limited here.

[0108] The corresponding connection range and / or mixing speed is determined according to the mixing period and the ion concentration difference.

[0109] Step S3: controlling the movement of the partition 11 to mix the liquid according to the liquid mixing control strategy.

[0110] The movement of the partition 11 is controlled to mix the liquid according to the connectivity range and / or the mixing speed in the mixing control strategy. It can be understood that the movement of the partition 11 is controlled to mix the liquid according to the connectivity range in the mixing control strategy, and / or the movement of the partition 11 is controlled to mix the liquid according to the mixing speed in the mixing control strategy.

[0111] Controlling the movement of the partition 11 to mix the liquid according to the connectivity range in the liquid mixing control strategy can be understood as controlling the partition 11 to contract and / or fold to mix the liquid according to the connectivity range in the liquid mixing control strategy.

[0112] Controlling the movement of the partition 11 to mix the liquid according to the liquid mixing speed in the liquid mixing control strategy can be understood as controlling the partition 11 to rotate and / or stir to mix the liquid according to the liquid mixing speed in the liquid mixing control strategy.

[0113] By determining the ion concentration difference between the positive electrolyte in the positive electrolyte storage area 12 and the negative electrolyte in the negative electrolyte storage area 13; then determining the mixing control strategy based on the mixing cycle and the ion concentration difference; finally, controlling the movement of the partition 11 to mix the liquids according to the mixing control strategy, so that the ions in the positive and negative electrolytes can quickly restore the balance, improve the activity of the electrolyte, increase the concentration of effective active pairs in the electrolyte, and thus restore the battery capacity and improve the charging and discharging efficiency.

[0114] In a possible implementation, when the mixing period is set to a non-fixed value and is determined according to actual conditions, please refer to Figure 3 , Figure 3 FIG2 is a flow chart of another liquid mixing control method according to an exemplary embodiment. The liquid mixing control method can be applied to a controller and can include steps S101 to S104.

[0115] Step S101 : determining the ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage region and the negative electrode electrolyte in the negative electrode electrolyte storage region.

[0116] Step S102: determining a liquid mixing period according to the ion concentration difference.

[0117] See also Figure 4 , step S102 may include step S121 and step S122.

[0118] Step S121: determining the maximum available capacity of the fuel cell stack based on the ion concentration difference.

[0119] The ion concentration difference is negatively correlated with the maximum available capacity of the stack. The larger the ion concentration difference, the smaller the maximum available capacity of the stack.

[0120] When there is a difference in ion concentration, the vanadium ion concentration is low on one side and high on the other side. The side with low vanadium ion concentration determines the maximum available capacity of the fuel cell stack.

[0121] Step S122: determining a liquid mixing period according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate.

[0122] A constant value is determined based on the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack, and the lower the maximum available capacity of the battery stack, the smaller the constant value.

[0123] The mixing period is obtained according to the constant value and the stack rate of the stack.

[0124] The mixing period may be a ratio between a constant value and the stack rate of the stack. Since stack rate*mixing period=constant value, mixing period=constant value / stack rate.

[0125] For example, when the maximum available capacity of the fuel cell stack is 100% of the rated capacity, the constant is 100. When the fuel cell stack ratio is 1, the mixed liquid cycle is 100 charge and discharge cycles, and when the fuel cell stack ratio is 10, the mixed liquid cycle is 10 charge and discharge cycles; when the maximum available capacity of the fuel cell stack is 50% of the rated capacity, the constant is 50. That is, when the fuel cell stack ratio is 1, the mixed liquid cycle is 50 charge and discharge cycles, and when the fuel cell stack ratio is 10, the mixed liquid cycle is 5 charge and discharge cycles.

[0126] Step S103: determining a liquid mixing control strategy according to the liquid mixing cycle and the ion concentration difference.

[0127] Step S104 , controlling the movement of the partition to mix the liquid according to the liquid mixing control strategy.

[0128] It should be noted that the detailed description of step S101, step S103, and step S104 may refer to step S1, step S2, and step S3 respectively, and will not be repeated herein in this embodiment.

[0129] The mixing period determined by the ion concentration difference is more suitable for actual application scenarios than the mixing period with a fixed value, making the mixing operation more reasonable.

[0130] In one possible embodiment, the liquid mixing control strategy may include a connectivity range and a liquid mixing speed, wherein the connectivity range includes a first connectivity range and a second connectivity range, the first connectivity range is greater than the second connectivity range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed is greater than the second liquid mixing speed.

[0131] See also Figure 5 , step S2 may include steps S21 to S23.

[0132] Step S21 : obtaining a concentration difference ratio according to the ion concentration difference and the maximum concentration difference.

[0133] The maximum concentration difference can be the maximum theoretical difference between the vanadium ion concentrations in the positive electrolyte and the negative electrolyte. The theoretical maximum ion concentration can generally be less than or equal to the vanadium ion saturation concentration.

[0134] The concentration difference ratio is calculated based on the ion concentration difference and the maximum concentration difference. The theoretical range of the concentration difference ratio is 0-100%, but the preset value is much less than 100%, and the preset value should be greater than 0.

[0135] Step S22: When the time since the last liquid mixing reaches the liquid mixing cycle, determine whether the fuel cell stack is supplying power to the outside.

[0136] Determine whether the time since the last mixing reaches the mixing cycle, and if the time since the last mixing reaches the mixing cycle, then determine whether the battery stack is supplying power to the outside.

[0137] In step S23, when the stack is not powered externally, the connectivity range in the liquid mixing control strategy is determined according to the concentration difference ratio, and the liquid mixing speed in the liquid mixing control strategy is determined according to the liquid mixing demand time and the liquid mixing given time.

[0138] In a possible implementation, determining the connectivity range in the mixed liquid control strategy according to the concentration difference ratio in step S23 may include:

[0139] comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value;

[0140] When the concentration difference ratio is less than a third preset value, the connection range in the mixed liquid control strategy is determined to be the second connection range;

[0141] When the concentration difference ratio is greater than or equal to the third preset value, the connectivity range in the liquid mixing control strategy is determined to be the first connectivity range, wherein the first connectivity range is greater than the second connectivity range.

[0142] When the concentration difference ratio is small, the liquid is mixed by connecting with a smaller connection range to reduce energy loss.

[0143] When the concentration difference ratio is large, the mixing is carried out with a larger connection range to speed up the mixing.

[0144] In a possible implementation, determining the liquid mixing speed in the liquid mixing control strategy according to the liquid mixing required time and the liquid mixing given time in step S23 may include:

[0145] Compare the required mixing time with the given mixing time;

[0146] When the required mixing time is less than the given mixing time, the mixing speed in the mixing control strategy is determined to be the second mixing speed;

[0147] When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined to be the first liquid mixing speed, wherein the first liquid mixing speed is greater than the second liquid mixing speed. For example, the second liquid mixing speed may be zero.

[0148] The required mixing time can be determined based on the electricity consumption side, and can be planned or temporarily scheduled, which is not limited here. The required mixing time can be calibrated in advance based on experiments. The required mixing time is directly related to the mixing speed, and the required mixing time can be related to the structure of the electrolyte tank. In a possible implementation, please refer to Figure 6 , Figure 6 FIG2 is a flow chart of another liquid mixing control method according to an exemplary embodiment. The liquid mixing control method can be applied to a controller and can include steps S201 to S209.

[0149] Step S201 : determining the ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage region and the negative electrode electrolyte in the negative electrode electrolyte storage region.

[0150] Step S202 : obtaining a concentration difference ratio according to the ion concentration difference and the maximum concentration difference.

[0151] Step S203: determining whether the time since the last liquid mixing reaches the liquid mixing cycle.

[0152] If the time from the last mixing of liquids reaches the mixing cycle, step S204 is executed. If the time from the last mixing of liquids does not reach the mixing cycle, step S206 is executed.

[0153] Step S204: determine whether the fuel cell stack is supplying power to the outside.

[0154] When the fuel cell stack is not supplying power to the outside, step S205 is executed; when the fuel cell stack is supplying power to the outside, step S206 is executed.

[0155] Step S205 : determining the connectivity range in the liquid mixing control strategy according to the concentration difference ratio, and determining the liquid mixing speed in the liquid mixing control strategy according to the liquid mixing demand time and the liquid mixing given time.

[0156] Step S206 : comparing the concentration difference ratio with a first preset value, ie, determining whether the concentration difference ratio is greater than the first preset value.

[0157] When the concentration difference ratio is greater than the first preset value, step S207 is executed; when the concentration difference ratio is less than or equal to the first preset value, no operation is performed.

[0158] The first preset value can represent the frequency of liquid mixing. The smaller the first preset value is, the more frequent the liquid mixing is.

[0159] Step S207 : comparing the concentration difference ratio with a second preset value, ie, determining whether the concentration difference ratio is greater than the second preset value.

[0160] The second preset value is greater than the first preset value.

[0161] When the concentration difference ratio is greater than the second preset value, it indicates that liquid mixing is urgently needed, and step S208 is executed. When the concentration difference ratio is less than or equal to the second preset value, the process returns to step S204.

[0162] Step S208 : determining the connection range in the liquid mixing control strategy as the first connection range, and determining the liquid mixing speed in the liquid mixing control strategy as the first liquid mixing speed.

[0163] The liquid mixing control strategy includes a connectivity range and a liquid mixing speed. The connectivity range includes a first connectivity range and a second connectivity range, wherein the first connectivity range is greater than the second connectivity range. The liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, wherein the first liquid mixing speed is greater than the second liquid mixing speed.

[0164] Step S209 , controlling the movement of the partition to mix the liquid according to the liquid mixing control strategy.

[0165] By adding a concentration difference ratio to compare with the second preset value, when liquid mixing is urgently needed, a large first connection range and a fast first liquid mixing speed are set to control the partition 11 to mix the liquid, so as to quickly restore the ions to a balanced state.

[0166] It should be noted that the detailed description of some steps in steps S201 to S209 can refer to steps S1 to S3 and steps S21 to S23, and will not be repeated here in this embodiment.

[0167] It should be understood that the first preset value, the second preset value and the third preset value can be adjusted according to actual working conditions. The first preset value is smaller than the third preset value, and the third preset value is smaller than the second preset value.

[0168] The partition 11 and the structural material of the electrolyte storage tank can be one or more of polyvinyl chloride (PVC), polycarbonate (PC), polymethyl methacrylate, and polypropylene (PPH). The partition 11 can be a deformable partition 11 with a rotating shaft 111, see Figure 7 The partition 11 includes a rotating shaft 111 and a plate surface 112. The plate surface 112 can rotate around the rotating shaft 111. The two ends of the rotating shaft 111 are fixed to the tank body of the electrolyte tank. The rotating shaft 111 and the plate surface 112 do not react with the electrolyte. The connection between the plate surface 112 and the rotating shaft 111 is well sealed. Before the plate surface 112 rotates, it can change its shape by folding, shrinking, etc. For shrinking as an example, please refer to Figure 8 The plate surface 112 can shrink in the radial direction of the rotation axis 111, shrink in the axial direction of the rotation axis 111, or expand and contract in the axial and radial directions at the same time.

[0169] The fixed end of the rotating shaft 111 can be placed inside the electrolyte tank (without penetrating the electrolyte tank body) to improve the sealing of the tank body, or it can be placed outside the electrolyte tank to improve the replacement efficiency; the outer surface of the rotating shaft 111 is provided with a track along the axial direction, and the plate 112 can slide along the track, and the track does not affect the sealing of the connection between the plate 112 and the slide rail. Figure 9The plate surface 112 can be arranged perpendicular to the bottom plate, and a heating device 113 and a cooling device 114 are provided inside the plate surface 112 to control the temperature in the positive electrolyte storage area 12 and the negative electrolyte storage area 13. The heating device 113 can be implemented by evenly distributing heating wires inside the cavity of the plate surface 112. The heating wires can shrink with the separator 11, and are surrounded by a heat exchange area filled with a material with a high thermal conductivity coefficient. When the shape of the plate surface 112 changes, the heating section of the heating wires can be changed at any time. The cooling device 114 can be implemented by cooling water. The partition 11 can use a heating device 113 and a cooling device 114 to control the temperature of the electrolyte in the electrolyte tank in real time within a reasonable temperature range, which can achieve both heating and cooling. It should be understood that the temperature of the end faces on both sides in contact with the electrolyte can be independently controlled, and the temperatures of the end faces on both sides can be increased and decreased at the same time, and the temperature on one side can be increased and decreased on the other side. The partition has a good built-in insulation layer, and the temperatures of the positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 will not affect each other.

[0170] In one possible implementation, see Figure 10 , step S3 may include step S31 and step S32.

[0171] Step S31 : According to the connection range in the liquid mixing control strategy, the partition is controlled to shrink and / or fold to mix the liquid.

[0172] The partition 11 can be contracted by fixing one end surface and contracting the other end surface to form a small range of communication, or by contracting both end surfaces at the same time to form a large range of communication. Figure 11 , Figure 11 The lower end of the middle partition 11 is fixed, and it shrinks from the upper end to the lower end. Figure 11 When the upper end surface of the separator 11 is flush with the initial equilibrium liquid level of the electrolyte, the positive and negative electrolytes achieve a second range of communication; when the upper end surface of the separator drops to the lowest point, the positive and negative electrolytes achieve a first range of communication within this example. Figure 12 , Figure 12 The upper end of the middle partition 11 is fixed and shrinks from the lower end to the upper end. Figure 13 , Figure 13 The upper end surface of the middle separator 11 shrinks toward the lower end surface, and the lower end surface of the separator 11 shrinks toward the upper end surface, so that both the positive electrode electrolyte and the negative electrode electrolyte can quickly achieve the first communication range.

[0173] The folding of the partition 11 can be done by fixing one end surface and folding the other end surface to form a small area of communication, or by folding both ends simultaneously to form a large area of communication. For example, the lower end surface of the partition 11 can be fixed and folded from the upper end surface toward the lower end surface; the upper end surface of the partition 11 can also be fixed and folded from the lower end surface toward the upper end surface; or the upper end surface of the partition 11 can be contracted toward the lower end surface, while the lower end surface of the partition 11 folds toward the upper end surface.

[0174] Step S32: According to the liquid mixing speed in the liquid mixing control strategy, the partition is controlled to rotate and / or stir to mix the liquid.

[0175] The control plate surface 112 is controlled to rotate and / or stir around the rotation axis 111 .

[0176] The separator 11 can fully mix the positive electrode electrolyte and the negative electrode electrolyte through actions such as rotation and stirring, thereby improving the mixing efficiency.

[0177] In some embodiments, see Figure 14 The partition includes a rotating shaft 31, a first partition 32 and a second partition 33. The first partition 32 and the second partition 33 are perpendicular to the bottom plate of the electrolyte tank. The rotating shaft 31 is parallel to the bottom plate of the electrolyte tank. Two slide rails 34 are arranged along the rotating shaft 31. The first partition 32 can slide on one of the slide rails, and the second partition 33 can slide on the other slide rail. The rotating shaft 31 is used to drive the first partition 32 and the second partition 33 to rotate. The controller is connected to the rotating shaft 31, the first partition 32, and the second partition 33 respectively. The controller can control the transmission device through the driving device to fold and shrink the first partition 32 and the second partition 33. The first partition 32 and the second partition 33 can be wider as they are closer to the rotating shaft 31 and narrower as they are farther away from the rotating shaft 31. The dotted lines in the first partition 32 and the second partition 33 can represent the folding creases. The controller can control the rotating shaft 31 to drive the first partition 32 and the second partition 33 to rotate so that the positive electrode electrolyte and the negative electrode electrolyte are mixed. In this embodiment, the rotating shaft 31 does not react with the electrolyte, and the connection between the first partition 32, the second partition 33 and the rotating shaft 31 is well sealed. The slide rail 34 does not affect the sealing of the connection between the partition and the slide rail 34.

[0178] Exemplarily, the first separator 32 includes a first plate and a second plate, and the second separator 33 includes a third plate and a fourth plate. The controller can control the first plate to move along the slide rail to overlap with the second plate, or control the third plate to move along the slide rail to overlap with the fourth plate, and control the rotating shaft to drive the overlapping plates to rotate so that the positive electrode electrolyte and the negative electrode electrolyte are mixed.

[0179] For example, the first preset value is 3%, the second preset value is 8%, and the third preset value is 5%. Figure 15 , Figure 15 FIG. 1 is a flow chart of another liquid mixing control method according to an exemplary embodiment. The liquid mixing control method may include steps S501 to S517:

[0180] Step S501: determining the concentration difference ratio.

[0181] The concentration difference ratio can be calculated based on the ion concentration difference and the maximum concentration difference.

[0182] Step S502: determining the liquid mixing cycle.

[0183] The mixing period can be set to a fixed value or a non-fixed value.

[0184] Step S503, determine whether the liquid mixing cycle has been reached?

[0185] It is determined whether the time since the last liquid mixing reaches the liquid mixing cycle. If the liquid mixing cycle has not been reached, step S504 is executed; if the liquid mixing cycle has been reached, step S507 is executed.

[0186] Step S504: determine whether the concentration difference ratio is greater than 3%.

[0187] When the concentration difference ratio is greater than 3%, step S506 is executed; when the concentration difference ratio is less than or equal to 3%, step S505 is executed.

[0188] Step S505: no operation.

[0189] Step S506: determine whether the concentration difference ratio is greater than 8%.

[0190] When the concentration difference ratio is greater than 8%, step S508 and step S509 are executed; when the concentration difference ratio is less than or equal to 8%, step S507 is executed.

[0191] Step S507, determine whether the fuel cell stack is supplying power to the outside.

[0192] When the fuel cell stack supplies power to an external source, step S504 is executed; when the fuel cell stack does not supply power to an external source, step S510 is executed.

[0193] Step S508: the battery stack stops charging and supplying power.

[0194] Step S509: large-scale communication and rapid liquid mixing.

[0195] Step S510: The battery stack stops charging (if any).

[0196] Step S511, determine whether the concentration difference ratio is less than 5%?

[0197] When the concentration difference ratio is greater than or equal to 5%, step S512 is executed; when the concentration difference ratio is less than 5%, step S513 is executed.

[0198] Step S512: large-scale connectivity.

[0199] Step S513: small-scale connectivity.

[0200] Step S514: Determine whether the given mixing time is sufficient.

[0201] If the given mixing time is sufficient, step S516 is executed; if the given mixing time is insufficient, step S515 is executed.

[0202] Step S515: rapid liquid mixing.

[0203] Step S516: no operation.

[0204] Step S517: Control the movement of the partition to mix the liquid.

[0205] When the flow battery system reaches the mixing cycle, if the stack does not currently need to output electrical energy to the outside, the stack stops charging (if any) and starts the mixing operation. During the mixing operation, the specific action of the partition is related to the electrolyte concentration difference ratio. In this example, 5% is used as the boundary. If the concentration difference ratio is less than 5%, a small range of connected mixing is used, such as the lower end face of the partition is fixed, and the upper end face is contracted to the same position as the initial equilibrium liquid level of the electrolyte; if the concentration difference ratio is greater than or equal to 5%, a large range of connected mixing is used, such as the upper end face of the partition is fixed, the lower end face is contracted, or both end faces are contracted at the same time. If the given time for electrolyte mixing is insufficient, the partition is quickly mixed by actions such as rotation. If the mixing cycle is reached and the stack needs to be powered externally, or if the mixing cycle has not been reached, the subsequent operation is determined by the concentration difference ratio. If the vanadium ion concentration difference ratio is less than the first preset value, that is, 3%, the system will not operate. If the concentration difference ratio is greater than or equal to 3% at this time, and the stack currently does not need to output external power, the stack will stop charging (if any), the partition will be activated, and the mixing operation will be started. If the concentration difference ratio is greater than or equal to 3% at this time, and the stack currently needs to output external power, if the concentration difference ratio is less than or equal to the warning value, that is, 8%, then return to the previous step to continue monitoring whether the stack needs to be powered externally. If the concentration difference ratio is greater than or equal to 3% at this time, and the stack currently needs to output external power, if the concentration difference ratio is greater than 8%, the stack will stop charging / discharging and other operations, and immediately start large-scale electrolyte connection and rapid mixing operations.

[0206] Based on the same inventive concept, in order to implement the above method embodiment, this embodiment provides a mixed liquid control device 800, which can be applied to a controller connected to a flow battery, see Figure 16, the liquid mixing control device 800 may include:

[0207] The first processing module 801 is used to determine the ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage area and the negative electrode electrolyte in the negative electrode electrolyte storage area;

[0208] The second processing module 802 is used to determine a liquid mixing control strategy according to the liquid mixing period and the ion concentration difference;

[0209] The third processing module 803 is used to control the movement of the partition to mix the liquid according to the liquid mixing control strategy.

[0210] Optionally, the liquid mixing control device 800 may further include:

[0211] The fourth processing module is used to determine the liquid mixing period according to the ion concentration difference.

[0212] Optionally, the fourth processing module includes:

[0213] A first sub-processing module is configured to determine a maximum available capacity of the battery stack based on the ion concentration difference, wherein the ion concentration difference is negatively correlated with the maximum available capacity of the battery stack;

[0214] The second sub-processing module is used to determine the liquid mixing cycle according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate.

[0215] Optionally, the second sub-processing module is specifically configured to:

[0216] Determine a constant value based on the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack;

[0217] The mixing period is obtained according to the constant value and the stack rate of the stack.

[0218] Optionally, the liquid mixing control strategy includes: a connection range and a liquid mixing speed, wherein the connection range includes a first connection range and a second connection range, the first connection range is larger than the second connection range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed is larger than the second liquid mixing speed;

[0219] The second processing module 802 may include:

[0220] A third sub-processing module is used to obtain a concentration difference ratio based on the ion concentration difference and the maximum concentration difference;

[0221] The fourth sub-processing module is used to determine whether the fuel cell stack is supplying power to the outside when the time since the last mixing reaches the mixing cycle;

[0222] The fifth sub-processing module is used to determine the connectivity range in the mixed liquid control strategy based on the concentration difference ratio when the fuel cell stack is not powered externally, and to determine the mixing speed in the mixed liquid control strategy based on the mixed liquid demand time and the mixed liquid given time.

[0223] Optionally, the liquid mixing control device 800 may further include:

[0224] a fifth processing module, configured to compare the concentration difference ratio with a first preset value when the stack supplies power to the outside or when the time since the last mixing of liquids has not reached the mixing period;

[0225] a sixth processing module, configured to compare the concentration difference ratio with a second preset value when the concentration difference ratio is greater than the first preset value, wherein the second preset value is greater than the first preset value;

[0226] The seventh processing module is configured to determine the connection range in the liquid mixing control strategy as the first connection range and the liquid mixing speed in the liquid mixing control strategy as the first liquid mixing speed when the concentration difference ratio is greater than the second preset value.

[0227] Optionally, the fifth sub-processing module is specifically configured to:

[0228] comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value;

[0229] When the concentration difference ratio is less than a third preset value, the connection range in the mixed liquid control strategy is determined to be the second connection range;

[0230] When the concentration difference ratio is greater than or equal to the third preset value, the communication range in the mixed liquid control strategy is determined to be the first communication range.

[0231] Optionally, the fifth sub-processing module is specifically configured to:

[0232] Compare the required mixing time with the given mixing time;

[0233] When the required mixing time is less than the given mixing time, the mixing speed in the mixing control strategy is determined to be the second mixing speed;

[0234] When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined as the first liquid mixing speed.

[0235] Optionally, the third processing module 803 may include:

[0236] a sixth sub-processing module, configured to control the contraction and / or folding of the partition to mix the liquid according to the connectivity range in the liquid mixing control strategy;

[0237] The seventh sub-processing module is used to control the rotation and / or stirring of the partition to mix the liquid according to the liquid mixing speed in the liquid mixing control strategy.

[0238] Regarding the liquid mixing control device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the liquid mixing control method, and will not be elaborated on here.

[0239] In another exemplary embodiment, a flow battery system is provided, comprising a flow battery and a controller:

[0240] A liquid flow battery includes a positive electrode electrolyte circulation pipeline 14, a negative electrode electrolyte circulation pipeline 15, a battery stack 16, an electrolyte storage tank, and a separator 11. The electrolyte storage tank includes a positive electrode electrolyte storage area 12 and a negative electrode electrolyte storage area 13. The positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 are separated by a separator 11. The positive electrode electrolyte storage area 12 and the negative electrode electrolyte storage area 13 share an electrolyte storage tank;

[0241] The controller is connected to the liquid flow battery and is used to execute a computer program to implement the steps of the above-mentioned liquid mixing control method.

[0242] In other embodiments, the flow battery system may further include a memory having a computer program stored therein.

[0243] In other embodiments, see Figure 17 The flow battery system may further include an electrolytic cell device, a new electrolyte replenishing device, and a chemical additive replenishing device.

[0244] The electrolytic cell device includes a positive electrolytic cell pipeline valve 61 provided on the positive electrolyte circulation pipeline 14, an electrolytic cell 63, and a negative electrolytic cell pipeline valve 62 provided on the negative electrolyte circulation pipeline 15. The electrolytic cell 63 is connected to the positive electrolytic cell pipeline valve 61 via an electrolyte inlet pipeline, and the electrolytic cell 63 is connected to the negative electrolytic cell pipeline valve 62 via an electrolyte outlet pipeline. The controller can control whether the electrolyte flows into the electrolytic cell 63 by controlling the positive electrolytic cell pipeline valve 61, and the controller can control whether the electrolyte flows out of the electrolytic cell 63 by controlling the negative electrolytic cell pipeline valve 62.

[0245] The new electrolyte replenishing device includes a new electrolyte storage container 64, a new electrolyte flow controller 65 and a new electrolyte pipeline valve 66. The new electrolyte in the new electrolyte storage container 64 can reach the positive electrode electrolyte storage area 12 through the new electrolyte flow controller 65 and the new electrolyte pipeline valve 66 in sequence. The controller can control the flow rate of the new electrolyte during replenishment by controlling the new electrolyte flow controller 65. The controller can control whether to replenish the positive electrode electrolyte storage area 12 with new electrolyte through the new electrolyte pipeline valve 66.

[0246] The chemical additive replenishing device includes a chemical additive storage container 67, a chemical additive flow controller 68 and a chemical additive pipeline valve 69. The chemical additives in the chemical additive storage container 67 can reach the negative electrode electrolyte storage area 13 through the chemical additive flow controller 68 and the chemical additive pipeline valve 69 in sequence. The controller can control the flow rate of new electrolyte when replenishing through the chemical additive flow controller 68, and the controller can control whether to replenish the chemical additives to the negative electrode electrolyte storage area 13 through the chemical additive pipeline valve 69.

[0247] In another exemplary embodiment, a non-transitory computer-readable storage medium is further provided, on which a computer program is stored. When the program is executed by a processor, the steps of any of the above-mentioned liquid mixing control methods are implemented.

[0248] In another exemplary embodiment, a computer program product is further provided. The computer program product includes a computer program executable by a programmable device, and the computer program has a code portion for executing the above-mentioned liquid mixing control method when executed by the programmable device.

[0249] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0250] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0251] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for controlling a mixed liquid, characterized in that: A controller is applied to a flow battery, wherein the flow battery includes a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator. The electrolyte storage tank includes a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area are separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area share the electrolyte storage tank. The mixed liquid control method includes: determining an ion concentration difference between a positive electrode electrolyte in the positive electrode electrolyte storage region and a negative electrode electrolyte in the negative electrode electrolyte storage region; determining a liquid mixing control strategy according to the liquid mixing cycle and the ion concentration difference; The movement of the partition is controlled according to the liquid mixing control strategy to mix the liquid.

2. The liquid mixing control method according to claim 1, wherein: The mixed liquid control method further includes: The liquid mixing period is determined according to the ion concentration difference.

3. The liquid mixing control method according to claim 2, wherein: Determining the liquid mixing period according to the ion concentration difference includes: determining a maximum available capacity of the battery stack according to the ion concentration difference, wherein the ion concentration difference is negatively correlated with the maximum available capacity of the battery stack; The liquid mixing period is determined according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate of the fuel cell stack.

4. The liquid mixing control method according to claim 3, characterized in that: The step of determining the liquid mixing period according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate includes: Determining a constant value according to the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack; The liquid mixing period is obtained according to the constant value and the stack rate of the stack.

5. The liquid mixing control method according to claim 1, wherein: The liquid mixing control strategy includes: a communication range and a liquid mixing speed, wherein the communication range includes a first communication range and a second communication range, the first communication range is larger than the second communication range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed is larger than the second liquid mixing speed; Determine a mixing control strategy based on the mixing cycle and the ion concentration difference, including: According to the ion concentration difference and the maximum concentration difference, the concentration difference ratio is obtained; When the time from the last mixing reaches the mixing period, determining whether the stack is supplying power externally; When the stack is not powered externally, the connectivity range in the liquid mixing control strategy is determined according to the concentration difference ratio, and the liquid mixing speed in the liquid mixing control strategy is determined according to the liquid mixing demand time and the liquid mixing given time.

6. The liquid mixing control method according to claim 5, characterized in that: The mixed liquid control method further includes: When the stack supplies power to the outside, or when the time since the last mixing of liquids has not reached the mixing cycle, the concentration difference ratio is compared with a first preset value; When the concentration difference ratio is greater than the first preset value, comparing the concentration difference ratio with a second preset value, wherein the second preset value is greater than the first preset value; When the concentration difference ratio is greater than the second preset value, the connection range in the liquid mixing control strategy is determined to be the first connection range, and the liquid mixing speed in the liquid mixing control strategy is determined to be the first liquid mixing speed.

7. The liquid mixing control method according to claim 5, characterized in that: Determining the connectivity range in the mixed liquid control strategy according to the concentration difference ratio includes: comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value; When the concentration difference ratio is less than the third preset value, determining the connection range in the mixed liquid control strategy as the second connection range; When the concentration difference ratio is greater than or equal to the third preset value, the connectivity range in the liquid mixing control strategy is determined to be the first connectivity range.

8. The liquid mixing control method according to claim 5, characterized in that: Determining the liquid mixing speed in the liquid mixing control strategy according to the liquid mixing demand time and the liquid mixing given time includes: Compare the required mixing time with the given mixing time; When the required liquid mixing time is less than the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined to be the second liquid mixing speed; When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined as the first liquid mixing speed.

9. The liquid mixing control method according to claim 5, characterized in that: The controlling the movement of the partition to mix the liquid according to the liquid mixing control strategy includes: According to the connectivity range in the liquid mixing control strategy, controlling the partition to contract and / or fold to mix the liquid; According to the liquid mixing speed in the liquid mixing control strategy, the partition is controlled to rotate and / or stir to mix the liquid.

10. A liquid mixing control device, characterized in that: A controller is applied to a flow battery, wherein the flow battery includes a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator. The electrolyte storage tank includes a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area are separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area share the electrolyte storage tank. The mixed liquid control device includes: a first processing module, configured to determine an ion concentration difference between the positive electrode electrolyte in the positive electrode electrolyte storage region and the negative electrode electrolyte in the negative electrode electrolyte storage region; A second processing module is used to determine a liquid mixing control strategy according to the liquid mixing period and the ion concentration difference; The third processing module is used to control the movement of the partition to mix the liquid according to the liquid mixing control strategy.

11. The liquid mixing control device according to claim 10, characterized in that: The mixed liquid control device also includes: The fourth processing module is used to determine the liquid mixing period according to the ion concentration difference.

12. The liquid mixing control device according to claim 11, characterized in that: The fourth processing module includes: a first sub-processing module, configured to determine a maximum available capacity of the fuel cell stack according to the ion concentration difference, wherein the ion concentration difference is negatively correlated with the maximum available capacity of the fuel cell stack; The second sub-processing module is configured to determine the liquid mixing period according to the maximum available capacity of the fuel cell stack and the fuel cell stack rate.

13. The liquid mixing control device according to claim 12, characterized in that: The second sub-processing module is specifically configured to: Determining a constant value according to the maximum available capacity of the battery stack, wherein the constant value is positively correlated with the maximum available capacity of the battery stack; The liquid mixing period is obtained according to the constant value and the stack rate of the stack.

14. The liquid mixing control device according to claim 10, characterized in that: The liquid mixing control strategy includes: a communication range and a liquid mixing speed, wherein the communication range includes a first communication range and a second communication range, the first communication range is larger than the second communication range, and the liquid mixing speed includes a first liquid mixing speed and a second liquid mixing speed, the first liquid mixing speed is larger than the second liquid mixing speed; The second processing module includes: A third sub-processing module is used to obtain a concentration difference ratio based on the ion concentration difference and the maximum concentration difference; A fourth sub-processing module is configured to determine whether the fuel cell stack is supplying power to the outside when the time since the last mixing reaches the mixing period; The fifth sub-processing module is used to determine the connectivity range in the mixed liquid control strategy according to the concentration difference ratio when the fuel cell stack is not powered externally, and to determine the mixing speed in the mixed liquid control strategy according to the mixed liquid demand time and the mixed liquid given time.

15. The liquid mixing control device according to claim 14, characterized in that: The mixed liquid control device also includes: a fifth processing module, configured to compare the concentration difference ratio with a first preset value when the stack supplies power to an external user or when the time since the last mixing of liquids has not reached a mixing cycle; a sixth processing module, configured to compare the concentration difference ratio with a second preset value when the concentration difference ratio is greater than the first preset value, wherein the second preset value is greater than the first preset value; The seventh processing module is used to determine the connection range in the mixing liquid control strategy as the first connection range and the mixing liquid speed in the mixing liquid control strategy as the first mixing liquid speed when the concentration difference ratio is greater than the second preset value.

16. The liquid mixing control device according to claim 14, characterized in that: The fifth sub-processing module is specifically configured to: comparing the concentration difference ratio with a third preset value, wherein the third preset value is greater than the first preset value; When the concentration difference ratio is less than the third preset value, determining the connection range in the mixed liquid control strategy as the second connection range; When the concentration difference ratio is greater than or equal to the third preset value, the connectivity range in the liquid mixing control strategy is determined to be the first connectivity range.

17. The liquid mixing control device according to claim 14, characterized in that: The fifth sub-processing module is specifically configured to: Compare the required mixing time with the given mixing time; When the required liquid mixing time is less than the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined to be the second liquid mixing speed; When the required liquid mixing time is greater than or equal to the given liquid mixing time, the liquid mixing speed in the liquid mixing control strategy is determined as the first liquid mixing speed.

18. The liquid mixing control device according to claim 14, wherein: The third processing module includes: a sixth sub-processing module, configured to control the partition to contract and / or fold to mix the liquid according to the connectivity range in the liquid mixing control strategy; The seventh sub-processing module is used to control the rotation and / or stirring of the partition to mix the liquid according to the liquid mixing speed in the liquid mixing control strategy.

19. A liquid flow battery system, characterized in that: include: A liquid flow battery, the liquid flow battery comprising a positive electrolyte circulation pipeline, a negative electrolyte circulation pipeline, a battery stack, an electrolyte storage tank, and a separator, the electrolyte storage tank comprising a positive electrolyte storage area and a negative electrolyte storage area, the positive electrolyte storage area and the negative electrolyte storage area being separated by the separator, and the positive electrolyte storage area and the negative electrolyte storage area sharing the electrolyte storage tank; A controller is connected to the liquid flow battery and is used to execute a computer program to implement the steps of the liquid mixing control method according to any one of claims 1 to 9.

20. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the liquid mixing control method according to any one of claims 1 to 9 are implemented.

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