Flow battery circulation pipeline system based on galvanic pile series connection structure and control method of flow battery circulation pipeline system
By designing a circulating pipeline system based on a series structure of the stack in the liquid flow battery, and using control switches to ensure the independent liquid flow circuit of each stack, the problem of inconsistent effective current between the stacks is solved, and more efficient battery performance and stability are achieved.
Patent Information
- Application Number
- CN202411791571.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-03-18
AI Technical Summary
Due to the existence of bypass current in the deposition flow battery, the effective current between the stacks is inconsistent, which affects the charge and discharge capacity, and may lead to problems such as metal dendrites and diaphragm short circuits.
A liquid flow battery circulation pipeline system based on a stack series structure is designed. By setting a positive and negative control switch on each stack, it ensures that only one stack is connected to the liquid storage tank at any time, forming an independent liquid flow circuit to reduce leakage current.
It effectively reduces the leakage current, ensures effective current consistency between the stacks, improves the performance and stability of the flow battery, and avoids faults caused by stack inconsistency.
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Figure CN119650781A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of liquid flow batteries, and in particular to a liquid flow battery circulation pipeline system based on a battery stack series structure and a control method thereof. Background Art
[0002] Liquid flow battery is a new type of storage battery. Liquid flow battery is a high-performance storage battery that separates the positive and negative electrolytes and circulates them separately. It has the characteristics of high capacity, wide application field (environment), and long cycle life. It is a new energy product. In liquid flow batteries, the electrolyte enters the electrode reaction area of each single cell in the battery stack through the main channel and branch channel to undergo charge and discharge reactions. Since the electrolyte is conductive, in addition to the electrode reaction area of the bipolar plate and the electrolyte and diaphragm forming the main charge and discharge circuit in the battery stack, the electrodes and the electrolyte in the branch channel will form multiple groups of tiny bypasses, which will form bypass current (leakage current) during the battery charge and discharge process. The existence of this bypass current will cause the effective current of each piece in the multi-piece battery stack to be inconsistent, thereby affecting the actual charging capacity of each battery during the actual charge and discharge process.
[0003] For all-liquid flow battery systems, such as all-vanadium flow batteries, iron-chromium flow batteries, etc., since the charging and discharging products are all present in the electrolyte, during the cycle, the electrolyte of each battery will flow back to the electrolyte storage tank through a common pipeline, and the impact of inconsistent electrolyte capacity of each battery will be compensated by natural mixing. However, for sedimentation flow batteries, since the metal produced by charging will be deposited on the surface of each electrode, the charging products cannot be mixed by electrolyte reflux to compensate for the inconsistency between the sheets, so the existence of bypass current will cause inconsistency in the capacity between the battery stacks of sedimentation flow batteries. During charging, the amount of metal deposited in the middle sheet is generally small, and the closer to the two sides, the more metal deposited; during discharging, the metal in the middle sheet dissolves faster, becoming a bottleneck limiting the overall capacity of the battery stack. At the end of each discharge, the metal deposited in the middle sheet has been completely dissolved, but there are still remnants in the sheets on both sides. In addition, the higher the voltage of the battery stacks connected in series in the same set of electrolyte circulation system, the more obvious the differences between the sheets and between the battery stacks. In extreme cases, the accumulation of differences caused by multiple charge and discharge cycles will lead to the generation of metal dendrites, piercing the diaphragm and causing short circuits. In severe cases, the battery will fail.
[0004] Therefore, in sedimentation flow batteries, the energy storage system generally adopts a modular design. Each module has an independent electrolyte circulation system. In each independent electrolyte circulation system, each stack is a parallel structure to avoid inconsistency between stacks due to leakage current in the module due to series high voltage. The modules are connected in series to form high voltage, and the liquid circuits are isolated from each other, so as to achieve the matching of voltage level and inverter. However, there are also some problems with this method of use, such as: 1) The voltage of the single module is too low. If high voltage is required, more modules must be connected in series, which greatly limits the convenience and flexibility of use; 2) After the modules are connected in series, when any module in the group has a problem or failure, the entire system must be shut down to repair and replace the faulty module. In addition, this connection method will also have relatively high requirements for the consistency between the grouped modules. If the differences between the modules are large, it will have a great impact on the system performance and capacity. Summary of the invention
[0005] The purpose of the embodiments of the present disclosure is to provide a liquid flow battery circulation pipeline system based on a series structure of battery stacks and a control method thereof, so as to solve the problem of battery stack inconsistency caused by leakage current and the problem of inability to achieve high voltage output in the prior art.
[0006] The embodiment of the present disclosure adopts the following technical scheme: a liquid flow battery circulation pipeline system based on a series structure of battery stacks, comprising: a positive electrode liquid storage tank, a negative electrode liquid storage tank and a plurality of battery stacks; wherein a series electric circuit is formed between all the battery stacks; each of the battery stacks has a positive electrode liquid inlet, a negative electrode liquid inlet, a positive electrode liquid outlet and a negative electrode liquid outlet, the liquid outlet of the positive electrode liquid storage tank is connected to the positive electrode main pipeline, the positive electrode liquid inlet of each battery stack is connected to the positive electrode main pipeline through a positive electrode branch pipeline, the liquid outlet of the negative electrode liquid storage tank is connected to the negative electrode main pipeline, the negative electrode liquid inlet of each battery stack is connected to the negative electrode main pipeline through a negative electrode branch pipeline The positive electrode outlet of each of the battery stacks is connected with the liquid inlet of the positive electrode storage tank through the first liquid return pipeline, and the negative electrode outlet of each of the battery stacks is connected with the liquid inlet of the negative electrode storage tank through the second liquid return pipeline; each of the positive branch pipelines is provided with a positive control switch for controlling the on-off of the positive branch pipeline, and each of the negative branch pipelines is provided with a negative control switch for controlling the on-off of the negative branch pipeline. When the positive control switch and the negative control switch of any battery stack are in the on state, the positive control switches and the negative control switches of other battery stacks are in the off state.
[0007] In some embodiments, a first circulation pump is provided on the positive electrode main line, and a second circulation pump is provided on the negative electrode main line.
[0008] In some embodiments, the positive control switch and the negative control switch are both solenoid valves.
[0009] In some embodiments, the flow battery is a sedimentation flow battery.
[0010] The present embodiment also provides a control method for a liquid flow battery circulation pipeline system as described above, which at least includes: an initialization program, selecting any one of all the battery stacks as the current battery stack; a control program, controlling the positive control switch and the negative control switch of the current battery stack to be turned on, and controlling the positive control switch and the negative control switch of other battery stacks to be turned off; a detection program, detecting whether the turn-on time of the positive control switch and the negative control switch of the current battery stack reaches a preset time, and executing an adjustment program when the turn-on time of the positive control switch and the negative control switch of the current battery stack reaches the preset time, otherwise continuing to execute the control program; an adjustment program, controlling the positive control switch and the negative control switch of the current battery stack to be turned off, and selecting any one of the other battery stacks as the new current battery stack, and re-executing the control program.
[0011] In some embodiments, the preset duration is determined based on the total number of the battery stacks, the flow rate of the electrolyte in the pipeline, the effective volume of the battery stack, the battery stack current and the concentration of active substances in the electrolyte.
[0012] In some embodiments, the preset duration satisfies at least the following conditions:
[0013] Q*t≥V;
[0014]
[0015] Among them, t is the preset time, Q is the flow rate of the electrolyte in the pipeline, V is the effective volume of the battery stack, c is the battery stack current and the concentration of active substances in the electrolyte, I is the battery stack current, and n is the total number of battery stacks.
[0016] In some embodiments, selecting any one battery stack from other battery stacks as the new current battery stack includes: selecting the next battery stack of the current battery stack as the new current battery stack in ascending order of the battery stack numbers; wherein, when the current battery stack has the largest battery stack number, selecting the battery stack with the smallest battery stack number as the new current battery stack.
[0017] This embodiment further provides a storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the control method of the liquid flow battery circulation pipeline system.
[0018] This embodiment also provides an electronic device, comprising at least a memory and a processor, wherein the memory stores a computer program, and is characterized in that the processor implements the steps of the above-mentioned control method of the liquid flow battery circulation pipeline system when executing the computer program on the memory.
[0019] The beneficial effects of the embodiments of the present disclosure are as follows: by designing an independent electrolyte circulation pipe system for the liquid flow battery, it is possible to achieve series connection between all the battery stacks in the system, avoiding the inconsistency of the battery stacks caused by leakage current, and at the same time, using the control switch to ensure that at any time, only one battery stack is connected to the liquid storage tank to form a liquid flow loop, thereby effectively reducing the leakage current and ensuring the high efficiency of the battery stack, thereby ensuring that the liquid flow battery has better performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0021] Figure 1 This is a schematic diagram of the structure of a liquid flow battery circulation pipeline system based on a battery stack series structure in the first embodiment of the present disclosure;
[0022] Figure 2 This is a flow chart of a control method for a circulation pipeline system of a flow battery in the second embodiment of the present disclosure;
[0023] Figure 3 Schematic diagram of the structure of an electronic device in the fourth embodiment of the present disclosure. DETAILED DESCRIPTION
[0024] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will be combined with the drawings in one or more embodiments of this specification to clearly and completely describe the technical solutions in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this document.
[0025] For sedimentation-type flow batteries, since the metal produced by charging will be deposited on the surface of each electrode, the charging products cannot be mixed by electrolyte reflux to make up for the inconsistency between the sheets, so the existence of bypass current will cause inconsistency in the capacity between the sheets of the sedimentation-type flow battery stack. When charging, the amount of metal deposited on the middle sheet is generally small, and the closer to the two sides, the more metal deposited; when discharging, the metal in the middle sheet dissolves faster, becoming a bottleneck limiting the overall capacity of the stack. At the end of each discharge, the metal deposited on the middle sheet has been completely dissolved, but there are still remnants on the sheets on both sides. In addition, the higher the voltage of the stack connected in series in the same set of electrolyte circulation system, the more obvious the difference between the sheets and between the stacks. In extreme cases, due to the accumulation of differences caused by multiple charge and discharge cycles, metal dendrites will be generated, piercing the diaphragm to cause short circuits, and in severe cases, the battery will fail.
[0026] Therefore, in sedimentation flow batteries, the energy storage system generally adopts a modular design. Each module has an independent electrolyte circulation system. In each independent electrolyte circulation system, each stack is a parallel structure to avoid inconsistency between stacks due to leakage current in the module due to series high voltage. The modules are connected in series to form high voltage, and the liquid circuits are isolated from each other, so as to achieve the matching of voltage level and inverter. However, there are also some problems with this method of use, such as: 1) The voltage of the single module is too low. If high voltage is required, more modules must be connected in series, which greatly limits the convenience and flexibility of use; 2) After the modules are connected in series, when any module in the group has a problem or failure, the entire system must be shut down to repair and replace the faulty module. In addition, this connection method will also have relatively high requirements for the consistency between the grouped modules. If the differences between the modules are large, it will have a great impact on the system performance and capacity.
[0027] In order to solve the above problems, the first embodiment of the present disclosure provides a liquid flow battery circulation pipeline system based on a battery stack series structure, and the system structure schematic diagram is as follows: Figure 1 As shown, the system mainly includes a positive electrode liquid storage tank 10, a negative electrode liquid storage tank 20 and a plurality of battery stacks 30, and the battery stack 30 is connected to the two liquid storage tanks through a pipeline to realize the circulation of the electrolyte. Specifically, each battery stack 30 has a positive electrode liquid inlet 31, a negative electrode liquid inlet 32, a positive electrode liquid outlet 33 and a negative electrode liquid outlet 34, which are used to realize the input and output of positive and negative electrolytes. The positive electrode liquid storage tank 10 and the negative electrode liquid storage tank 20 also have a liquid outlet and a liquid inlet, which are used to output the electrolyte to the battery stack and recover the electrolyte after the battery stack reaction, so as to form a circulation loop of the electrolyte to meet the charging and discharging requirements of the battery stack.
[0028] In this embodiment, the liquid outlet of the positive electrode storage tank 10 is connected to the positive electrode main line 40, the positive electrode liquid inlet 31 of each battery stack 30 is connected to the positive electrode main line 40 through its corresponding positive electrode branch line 41, and the positive electrode liquid outlet 33 of the battery stack 30 is connected to the liquid inlet of the positive electrode storage tank 10 through the first return liquid line 42, thereby realizing the connection of the liquid flow circuit between the battery stack and the positive electrode storage tank 10; similarly, the liquid outlet of the negative electrode storage tank 20 is connected to the negative electrode main line 50, the negative electrode liquid inlet 32 of each battery stack 30 is connected to the negative electrode main line 50 through its corresponding negative electrode branch line 51, and the negative electrode liquid outlet 34 of the battery stack 30 is connected to the liquid inlet of the negative electrode storage tank 20 through the second return liquid line 52, thereby realizing the connection of the liquid flow circuit between the battery stack and the negative electrode storage tank 20. Through the design and arrangement of the above-mentioned pipelines, each battery stack and the liquid storage tank have an independent liquid inlet channel, which is convenient for subsequent independent battery stack liquid flow control.
[0029] At the same time, a positive control switch 43 for controlling the on / off of the positive branch pipeline 41 is provided on the positive branch pipeline 41 corresponding to each battery stack, and a negative control switch 53 for controlling the on / off of the negative branch pipeline 51 is provided on the negative branch pipeline 51 corresponding to each battery stack. In this embodiment, by driving the two control switches of different battery stacks 30, when the positive control switch 43 and the negative control switch 53 of any battery stack 30 are in the on state, the positive control switches 43 and the negative control switches 53 of other battery stacks 30 are all in the off state, that is, to ensure that at any time, there is only one battery stack and a liquid flow loop formed between the positive and negative liquid storage tanks, effectively reducing the bypass formed by the electrolyte and other battery stacks in the branch pipeline, thereby reducing the generation of leakage current.
[0030] Furthermore, in conjunction with the electrolyte circulation pipeline design of the flow battery of this embodiment, multiple battery stacks 30 in this embodiment can be connected in series to achieve high voltage output. Since the electrolyte circulation loop of each battery stack in this embodiment is independent, the problem of inconsistent effective current between battery stacks caused by leakage current is avoided. It should be noted that Figure 1 It mainly shows the specific connectivity of the liquid flow circulation loop between the battery stack and the liquid storage tank, while the series connection of the circuits between the battery stacks is not reflected. In the specific implementation, the negative electrode of the current battery stack can be directly connected to the positive electrode of the next battery stack, and so on to complete the series connection of all the battery stacks.
[0031] Further references Figure 1As shown, a first circulation pump 61 is provided on the positive electrode main line 40, and a second circulation pump 62 is provided on the negative electrode main line 50, which is used to drive the electrolyte to flow in the pipeline when the liquid flow loop is formed between the liquid storage tank and the battery stack, so as to complete the renewal of the electrolyte in the battery stack. In some embodiments, the positive electrode control switch 43 and the negative electrode control switch 53 can be implemented by solenoid valves, which have the advantages of fast response, high accuracy, strong reliability and adaptability, etc., and can be remotely controlled, which is more conducive to the realization of automatic control of the entire system. It should be noted that this embodiment is mainly aimed at sedimentation-type liquid flow batteries, such as zinc-bromine liquid flow batteries, zinc-iron liquid flow batteries, zinc-nickel liquid flow batteries, copper-chromium liquid flow batteries, etc., and the corresponding electrolyte can be selected according to actual needs.
[0032] This embodiment designs an independent electrolyte circulation pipe system for the liquid flow battery, which can realize the series connection between all the battery stacks in the system, avoid the inconsistency of the battery stack caused by leakage current, and use the control switch to ensure that at any time, only one battery stack is connected to the liquid storage tank to form a liquid flow loop, effectively reducing the leakage current and ensuring the high efficiency of the battery stack, thereby ensuring that the liquid flow battery has better performance.
[0033] Based on the same inventive concept, the second embodiment of the present disclosure provides a control method for the liquid flow battery circulation pipeline system of the first embodiment, which is used to adjust the opening and closing states of the control switches corresponding to each battery stack in the liquid flow battery circulation pipeline system to complete the control of the liquid flow circuit. Figure 2 The flowchart of the control method of this embodiment is shown, which mainly includes four program steps, specifically:
[0034] S10, initializing the program, selecting any one of all the battery stacks as the current battery stack;
[0035] S20, control program, control the positive electrode control switch and the negative electrode control switch of the current battery stack to turn on, and control the positive electrode control switches and the negative electrode control switches of other battery stacks to turn off;
[0036] S30, a detection program, detecting whether the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches a preset time, and executing an adjustment program if the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches the preset time, otherwise continuing to execute the control program;
[0037] S40, adjusting the program, controlling the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned off, and selecting any one of the other battery stacks as a new current battery stack, and re-executing the control program.
[0038] In actual implementation, a control terminal can be set up corresponding to the liquid flow battery circulation pipeline system to execute the control method of this embodiment to complete the control of the above system. When the control switch of each branch pipeline in the system is a solenoid valve, the on-off control of each branch pipeline can be completed by remote control.
[0039] It should be noted that in this embodiment, the duration of each current fuel cell stack being turned on is a preset duration, and the specific duration is determined based on the total number of fuel cells, the flow rate of the electrolyte in the pipeline, the effective volume of the fuel cell stack, the fuel cell stack current and the concentration of active substances in the electrolyte, so as to ensure that the duration of each fuel cell stack being turned on can not only satisfy the requirement that the electrolyte in the fuel cell stack is updated once within the preset duration, but also meet the normal working requirements of other fuel cells.
[0040] Generally, in actual implementation, a liquid flow battery is usually configured with 4 or 6 stacks. The effective volume and stack current of the stack are fixed. When the liquid flow pipeline is set up, the flow rate of the electrolyte in the pipeline is usually a fixed parameter, and the electrolyte concentration cannot be adjusted at any time. Therefore, in a complete liquid flow battery circulation pipeline system, the only adjustable parameter is the opening time of the control switch. Therefore, the preset time must at least meet the following conditions:
[0041] Q*t≥V; (1)
[0042]
[0043] Wherein, t is the preset duration, Q is the flow rate of the electrolyte in the pipeline, V is the effective volume of the stack, c is the concentration of active substances in the electrolyte, I is the stack current, and n is the total number of stacks. The coefficient multiplied by the right side of the inequality in formula (2) represents the conversion constant between ampere-hour and the number of moles of zinc bromide. In fact, the specific value of the conversion constant will also change for different types of electrolytes, and this embodiment does not limit it. Specifically, formula (1) indicates that within the preset duration, the volume of the electrolyte circulating in the stack should be greater than the effective volume of the stack, while formula (2) indicates that when the stack is not connected to the liquid storage tank, the amount of active substances in the electrolyte currently retained needs to meet the electrochemical reaction of the stack within the entire operating time (i.e., n*t). It should be noted that, when the other parameters are known, the preset time length that can be obtained by combining the above formulas (1) and (2) usually has a larger range, for example, greater than or equal to 12 seconds and less than or equal to 300 seconds. Therefore, when actually selecting a specific value for the preset time length, it is preferred to select a value close to its lower limit, such as 15 seconds or 25 seconds, which is close to 12 seconds, so as to maximize the cycle period of each battery and ensure the stability of the battery stack operation.
[0044] In such Figure 2In the flowchart shown, when the adjustment program is specifically executed to select the next battery stack as the current battery stack, a random selection method can be used, but this method is likely to cause a certain battery stack to be unable to be selected, thereby affecting the overall operating efficiency. Therefore, in some embodiments, the battery stacks can be numbered, and the battery stack with the smallest number (that is, the first battery stack) can be selected as the current battery stack in the initialization program. In the adjustment program, the next battery stack of the current battery stack can be selected as the new current battery stack in ascending order of the battery stack numbers. If the current battery stack is the battery stack with the largest number (that is, the last battery stack), the battery stack with the smallest battery stack number is selected as the new current battery stack. At this time, it is equivalent to completing a complete cycle control cycle. During this cycle, the electrolyte in all battery stacks should be updated once to ensure the balance and stability of the overall operation of the system.
[0045] The effectiveness of the control method of this embodiment is illustrated below by combining a comparative example controlled by a conventional method and an improved example controlled by the method of this embodiment. The batteries used in the comparative example and the improved example are all sedimentation-type zinc-bromine flow batteries. Corresponding to each stack unit, the effective volume in the stack is 6L, the stack current is 20A, the flow rate of the liquid inlet and return pipelines is 0.5L / s, and the concentration of the active substance (zinc bromide) in the electrolyte is 1.44mol / L (the concentration when the SOC is 100%).
[0046] This embodiment uses the battery energy efficiency of the zinc-bromine flow battery after multiple normal charge and discharge cycles as the evaluation basis. Battery energy efficiency refers to the percentage of discharge energy to charge energy in the battery charge and discharge cycle under given conditions. It is a key parameter for evaluating battery performance. Its specific expression is:
[0047] η=Ed / Ec*100%;
[0048] Among them, v represents the battery energy efficiency, Ed represents the maximum discharge watt-hour capacity released in this cycle, in kilowatt-hour (kWh), and Ec represents the total charging watt-hour capacity of this cycle, in kilowatt-hour (kWh).
[0049] Specifically, Table 1 shows the energy efficiency of the battery stack of the comparative example and the improved example under different valve opening times and different numbers of battery stacks in series:
[0050] Table 1 Energy efficiency of the battery stack for the comparative example and the improved example at different valve opening times and different numbers of battery stacks in series
[0051] Solenoid valve opening time (s) Number of battery stacks in series Stack energy efficiency (%) Comparative Example 1 Keep open 4 68.4 Comparative Example 2 Keep open 5 66.2 Comparative Example 3 Keep open 6 63.5 Improvement Example 1 15 4 78.1 Improved Example 2 15 5 77.5 Improved Example 3 15 6 77.1
[0052] It can be seen from the above table that when the solenoid valve is continuously opened, that is, all the stack electrolytes in the system form a loop, the higher the positive electrode bromine concentration in the stack, the greater the self-discharge, and the less energy released by the stack (that is, Ed). Therefore, in this case, the stack energy efficiency is low and the system performance is poor; when the stack valve opening time in the system is 15s, that is, only one stack electrolyte in the system forms a loop and other stack electrolytes are disconnected, the stack positive electrode self-discharge problem is effectively reduced, the stack energy efficiency is improved, and the system performance is better. In addition, as the number of battery stacks connected in series increases, the overall voltage of the circuit will rise accordingly. At this time, the leakage current will also increase, and the energy released by the battery stack will also become smaller, resulting in a decrease in the energy efficiency of the battery stack. However, combined with the battery stack energy efficiency results of the comparative example and the improved example recorded in Table 1, even if Improved Example 3 has more battery stacks, because it realizes electrolyte circulation through the control method of this embodiment, its battery stack energy efficiency is also much higher than the value presented in Comparative Example 1. Therefore, this embodiment can realize series connection between battery stacks in an independent electrolyte circulation system, avoiding battery stack inconsistency caused by leakage current while ensuring higher efficiency of the battery stack, thereby ensuring better performance of the liquid flow battery.
[0053] The third embodiment of the present disclosure provides a storage medium, which can be installed in any device that is communicatively connected to the control switch of the liquid flow battery circulation pipeline system of the first embodiment, and is specifically a computer-readable medium, storing a computer program, and when the computer program is executed by a processor, the method provided by any embodiment of the present disclosure is implemented, including the following steps S31 to S34:
[0054] S31, initializing the program, selecting any one of all the battery stacks as the current battery stack;
[0055] S32, a control program to control the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned on, and to control the positive electrode control switches and the negative electrode control switches of other battery stacks to be turned off;
[0056] S33, a detection program, detecting whether the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches a preset time, and executing an adjustment program if the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches the preset time, otherwise continuing to execute the control program;
[0057] S34, adjusting the program, controlling the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned off, and selecting any one battery stack from other battery stacks as a new current battery stack, and re-executing the control program.
[0058] The computer program is also executed by the processor to perform the following steps: determining the preset time length according to the total number of the battery stacks, the flow rate of the electrolyte in the pipeline, the effective volume of the battery stack, the battery stack current and the concentration of the active substance in the electrolyte.
[0059] Specifically, the preset duration at least meets the following conditions:
[0060] Q*t≥V;
[0061]
[0062] Among them, t is the preset time, Q is the flow rate of the electrolyte in the pipeline, V is the effective volume of the battery stack, c is the battery stack current and the concentration of active substances in the electrolyte, I is the battery stack current, and n is the total number of battery stacks.
[0063] When the computer program is executed by the processor to select any one battery stack from other battery stacks as the new current battery stack, the processor specifically executes the following steps: select the next battery stack of the current battery stack as the new current battery stack in ascending order of the battery stack numbers; wherein, when the current battery stack has the largest battery stack number, select the battery stack with the smallest battery stack number as the new current battery stack.
[0064] This embodiment designs an independent electrolyte circulation pipe system for the liquid flow battery, which can realize the series connection between all the battery stacks in the system, avoid the inconsistency of the battery stack caused by leakage current, and use the control switch to ensure that at any time, only one battery stack is connected to the liquid storage tank to form a liquid flow loop, effectively reducing the leakage current and ensuring the high efficiency of the battery stack, thereby ensuring that the liquid flow battery has better performance.
[0065] The fourth embodiment of the present disclosure provides an electronic device, which is communicatively connected to the control switch of the liquid flow battery circulation pipeline system of the first embodiment, and its structural schematic diagram is shown as follows: Figure 3 As shown, at least a memory 100 and a processor 200 are included. The memory 100 stores a computer program. The processor 200 implements the method provided by any embodiment of the present disclosure when executing the computer program on the memory 100. Exemplarily, the steps of the electronic device computer program are as follows S41 to S44:
[0066] S41, initializing the program, selecting any one of all the battery stacks as the current battery stack;
[0067] S42, a control program to control the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned on, and to control the positive electrode control switches and the negative electrode control switches of other battery stacks to be turned off;
[0068] S43, a detection program, detecting whether the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches a preset time, and executing an adjustment program if the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches the preset time, otherwise continuing to execute the control program;
[0069] S44, adjusting the program, controlling the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned off, and selecting any one battery stack from other battery stacks as a new current battery stack, and re-executing the control program.
[0070] The processor also executes the following computer program stored in the memory: determining the preset time length according to the total number of the battery stacks, the flow rate of the electrolyte in the pipeline, the effective volume of the battery stack, the battery stack current and the concentration of the active substance in the electrolyte.
[0071] Specifically, the preset duration at least meets the following conditions:
[0072] Q*t≥V;
[0073]
[0074] Among them, t is the preset time, Q is the flow rate of the electrolyte in the pipeline, V is the effective volume of the battery stack, c is the battery stack current and the concentration of active substances in the electrolyte, I is the battery stack current, and n is the total number of battery stacks.
[0075] When the processor selects any one of the battery stacks from other battery stacks as the new current battery stack stored in the execution memory, it specifically executes the following computer program: select the next battery stack of the current battery stack as the new current battery stack in ascending order of the battery stack numbers; wherein, when the current battery stack has the largest battery stack number, select the battery stack with the smallest battery stack number as the new current battery stack.
[0076] This embodiment designs an independent electrolyte circulation pipe system for the liquid flow battery, which can realize the series connection between all the battery stacks in the system, avoid the inconsistency of the battery stack caused by leakage current, and use the control switch to ensure that at any time, only one battery stack is connected to the liquid storage tank to form a liquid flow loop, effectively reducing the leakage current and ensuring the high efficiency of the battery stack, thereby ensuring that the liquid flow battery has better performance.
[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.
Claims
1. A liquid flow battery circulation pipeline system based on a series structure of battery stacks, characterized in that: include: A positive electrode liquid storage tank, a negative electrode liquid storage tank and a plurality of battery stacks; wherein all the battery stacks form a series electric circuit; Each of the battery stacks has a positive electrode liquid inlet, a negative electrode liquid inlet, a positive electrode liquid outlet and a negative electrode liquid outlet. The liquid outlet of the positive electrode storage tank is connected to the positive electrode main line. The positive electrode liquid inlet of each battery stack is connected to the positive electrode main line through a positive electrode branch line. The liquid outlet of the negative electrode storage tank is connected to the negative electrode main line. The negative electrode liquid inlet of each battery stack is connected to the negative electrode main line through a negative electrode branch line. The positive electrode liquid outlet of each battery stack is connected to the liquid inlet of the positive electrode storage tank through a first liquid return line. The negative electrode liquid outlet of each battery stack is connected to the liquid inlet of the negative electrode storage tank through a second liquid return line. Each of the positive branch pipelines is provided with a positive control switch for controlling the on-off of the positive branch pipeline, and each of the negative branch pipelines is provided with a negative control switch for controlling the on-off of the negative branch pipeline. When the positive control switch and the negative control switch of any battery stack are in the on state, the positive control switches and the negative control switches of other battery stacks are in the off state.
2. The liquid flow battery circulation pipeline system according to claim 1, characterized in that: A first circulation pump is provided on the positive electrode main line, and a second circulation pump is provided on the negative electrode main line.
3. The liquid flow battery circulation pipeline system according to claim 1, characterized in that: The positive control switch and the negative control switch are both solenoid valves.
4. The liquid flow battery circulation pipeline system according to any one of claims 1 to 3, characterized in that: The liquid flow battery is a sedimentation type liquid flow battery.
5. A control method for a liquid flow battery circulation pipeline system according to any one of claims 1 to 4, characterized in that: At least: Initialize the program and select any one of all the battery stacks as the current battery stack; A control program, controlling the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned on, and controlling the positive electrode control switches and the negative electrode control switches of other battery stacks to be turned off; A detection program is used to detect whether the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches a preset time. If the opening time of the positive electrode control switch and the negative electrode control switch of the current battery stack reaches the preset time, an adjustment program is executed, otherwise, the control program is continued to be executed; The program is adjusted to control the positive electrode control switch and the negative electrode control switch of the current battery stack to be turned off, and any one battery stack is selected from other battery stacks as a new current battery stack, and the control program is re-executed.
6. The control method according to claim 5, characterized in that: The preset duration is determined based on the total number of the battery stacks, the flow rate of the electrolyte in the pipeline, the effective volume of the battery stack, the battery stack current and the concentration of active substances in the electrolyte.
7. The control method according to claim 6, characterized in that: The preset duration at least meets the following conditions: Q*t≥V; Among them, t is the preset time, Q is the flow rate of the electrolyte in the pipeline, V is the effective volume of the battery stack, c is the battery stack current and the concentration of active substances in the electrolyte, I is the battery stack current, and n is the total number of battery stacks.
8. The control method according to any one of claims 4 to 7, characterized in that: The selecting any one of the other battery stacks as the new current battery stack includes: In ascending order of the stack numbers, the next stack of the current stack is selected as the new current stack; wherein, when the current stack has the largest stack number, the stack with the smallest stack number is selected as the new current stack.
9. A storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for controlling a liquid flow battery circulation pipeline system according to any one of claims 5 to 8 are implemented.
10. An electronic device, comprising at least a memory and a processor, wherein a computer program is stored in the memory, wherein: The processor implements the steps of the control method of the liquid flow battery circulation pipeline system according to any one of claims 5 to 8 when executing the computer program on the memory.