All-vanadium redox flow battery capacity recovery device based on charge and discharge online monitoring and automatic control

Abstract

The utility model discloses an all-vanadium redox flow battery capacity recovery device based on charge and discharge online monitoring and automatic control. The all-vanadium redox flow battery capacity recovery device comprises a reducing agent storage tank, a stirring liquid storage tank and a data acquisition controller, the stirring liquid storage tank is provided with a first opening and a second opening; a positive electrode electrolyte storage tank of the all-vanadium redox flow battery is provided with a first opening and a second opening; the data acquisition controller acquires and displays the capacity data of the all-vanadium redox flow battery; a precise metering pump is arranged in the reducing agent storage tank, and an outlet of the precise metering pump is connected with a first opening of the positive electrode electrolyte storage tank; a second opening of the positive electrode electrolyte storage tank is connected with a second opening of the stirring liquid storage tank, and a second pump and a second flow meter are arranged on a connecting pipeline; a first opening of the stirring liquid storage tank is connected with a negative electrode electrolyte storage tank of the all-vanadium redox flow battery, and a first pump and a first flow meter are arranged on a connecting pipeline. According to the utility model, the capacity of the all-vanadium redox flow battery can be accurately and quickly recovered, no potential safety hazard exists, the service life of the battery is prolonged, and the overall efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to energy storage device technical field, especially relates to a kind of full vanadium flow battery capacity recovery device based on on-line monitoring automatic control of charge and discharge. BACKGROUND

[0002] Flow battery has the characteristics of high safety, large capacity, long life, easy to expand and flexible design, and has great application prospect in grid-scale energy storage. In flow battery, full vanadium flow battery attracts a lot of attention because its positive and negative active materials are both vanadium ions, and there is no cross contamination problem.

[0003] However, one of the key technical obstacles hindering the widespread commercialization of full vanadium flow battery is the inevitable capacity decay during long-term cycle operation, which greatly reduces the service life of full vanadium flow battery. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a kind of full vanadium flow battery capacity recovery device based on on-line monitoring automatic control of charge and discharge, to solve the problem of capacity decay of full vanadium flow battery, accurately and quickly restore capacity, and there is no security risk, and further meet the requirements of real-time monitoring and automatic recovery of modern large-scale energy storage system, improve the service life and overall efficiency of battery.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the technical scheme of:

[0006] A kind of full vanadium flow battery capacity recovery device based on on-line monitoring automatic control of charge and discharge, including reducing agent storage tank, stirring liquid storage tank and data acquisition controller;The stirring liquid storage tank has first mouth and second mouth;The positive electrolyte storage tank of the full vanadium flow battery has first mouth and second mouth;The data acquisition controller collects and displays the capacity data of the full vanadium flow battery;

[0007] A precision metering pump is arranged in the reducing agent storage tank, and the outlet of the precision metering pump is connected with the first mouth of the positive electrolyte storage tank;The second mouth of the positive electrolyte storage tank is connected with the second mouth of the stirring liquid storage tank, and a second pump and a second flowmeter are arranged on the connecting pipeline;The first mouth of the stirring liquid storage tank is connected with the negative electrolyte storage tank of the full vanadium flow battery, and a first pump and a first flowmeter are arranged on the connecting pipeline.

[0008] In one embodiment, the load is connected between the positive electrode and the negative electrode of the full vanadium flow battery, and the data acquisition controller includes a current sensor and a voltage sensor, which collect current and voltage data during the charging and discharging process at the load as a representation of capacity data.

[0009] In one embodiment, the data acquisition controller comprises an online spectrum analyzer to acquire data of vanadium ion composition and concentration in electrolyte at the positive electrolyte tank and / or the negative electrolyte tank as a representation of capacity data.

[0010] In one embodiment, a valve is arranged on a connecting pipeline between the outlet of the precision metering pump and the first port of the positive electrolyte tank.

[0011] In one embodiment, the data acquisition controller outputs start-stop control signals to the precision metering pump, the first pump and the second pump, and receives flow data of the first flow meter and the second flow meter.

[0012] In one embodiment, the data acquisition controller outputs start-stop control signals to the stirring motor of the stirring tank.

[0013] In one embodiment, the data acquisition controller outputs start-stop control signals to the first peristaltic pump and the second peristaltic pump, the first peristaltic pump being a pump on a circulating pipeline between the positive electrolyte tank and the positive electrode chamber, and the second peristaltic pump being a pump on a circulating pipeline between the negative electrolyte tank and the negative electrode chamber.

[0014] In one embodiment, the first pump and the second pump are gear pumps or peristaltic pumps.

[0015] Compared with the prior art, the utility model has the beneficial effects that:

[0016] 1. The data acquisition controller is used to acquire capacity data in real time, and take recovery operation in time when the capacity data is below a threshold value. The external reducing agent tank and the stirring tank are used to reduce part of the pentavalent vanadium ions in the positive electrolyte tank to tetravalent vanadium ions by the reducing agent tank, the amount of the reducing agent can be set according to the threshold value in advance, and the amount of the reducing agent is accurately controlled by the precision metering pump. The electrolyte in the negative electrolyte tank and the electrolyte in the positive electrolyte tank after reduction are mixed by the stirring tank, and then the mixed electrolyte is uniformly distributed to the positive electrolyte tank and the negative electrolyte tank by the pump and the flow meter, so that the capacity recovery operation is completed. The whole process is clear in principle, simple in operation, and free of complicated procedures, so that the capacity can be accurately and quickly recovered, and there is no safety hazard.

[0017] 2. The output control signals of the data acquisition controller are designed, the start-stop control of the pumps is realized, the automation of the above operation is realized, and the capacity recovery of the all-vanadium redox flow battery based on the online monitoring and automatic control of charging and discharging is realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The utility model system structure schematic diagram is shown. DETAILED DESCRIPTION

[0019] The embodiments of this utility model are described in detail below with reference to the accompanying drawings and examples.

[0020] like Figure 1 As shown, the vanadium redox flow battery mainly includes a positive electrolyte storage tank 1, a negative electrolyte storage tank 2, a positive electrode 3, a negative electrode 4, and a separator 5. A positive electrode chamber is formed between the positive electrode 3 and the separator 5, and a negative electrode chamber is formed between the negative electrode 4 and the separator 5. The positive electrolyte storage tank 1 and the positive electrode chamber form a circulation loop, with a first peristaltic pump 141 on the loop. The negative electrolyte storage tank 2 and the negative electrode chamber form a circulation loop, with a second peristaltic pump 142 on the loop. A load 9 is connected between the positive electrode 3 and the negative electrode 4 for operation.

[0021] In existing technologies, when the capacity of a vanadium redox flow battery decays, it is often necessary to stop working and replace the positive and negative electrolytes, which is time-consuming and labor-intensive.

[0022] Therefore, this utility model provides a vanadium redox flow battery capacity recovery device based on online charging and discharging monitoring and automatic control, including a reducing agent storage tank 8, a stirring storage tank 7, and a data acquisition controller 6.

[0023] The reducing agent storage tank 8 stores the reducing agent, which is used to reduce pentavalent vanadium ions to tetravalent vanadium ions. Typical examples include oxalic acid, formic acid, and ferrous sulfate.

[0024] The stirring tank 7 is used to thoroughly mix the negative electrode electrolyte with the reduced positive electrode electrolyte. Therefore, it should be able to connect to both the positive electrode electrolyte storage tank 1 and the negative electrode electrolyte storage tank 2 simultaneously. In this invention, the stirring tank 7 has a first inlet and a second inlet, and the positive electrode electrolyte storage tank 1 of the vanadium redox flow battery also has a first inlet and a second inlet.

[0025] To achieve precise addition of the reducing agent, a precision metering pump 13 is installed in the reducing agent storage tank 8 of this invention. The outlet of the precision metering pump 13 is connected to the first port of the positive electrode electrolyte storage tank 1, and is used to accurately add a preset volume or weight of reducing agent to the positive electrode electrolyte storage tank 1. After the reducing agent is added, some of the pentavalent vanadium ions in the positive electrode electrolyte are reduced to tetravalent vanadium ions. For example, the precision metering pump 13 can be of model LP03-P100C or LBC2EB-PTC1, and it can be directly connected to the reducing agent storage tank 8 and start working upon power-on.

[0026] The second port of the positive electrode electrolyte storage tank 1 is connected to the second port of the stirred storage tank 7, and a second pump 102 and a second flow meter 112 are installed on the connecting pipeline to deliver the positive electrode electrolyte that has completed the reduction reaction into the stirred storage tank 7. Installing a pump and flow meter on the pipeline is common knowledge in the field and will not be elaborated further here.

[0027] The negative electrolyte storage tank 2 is connected with the first port of the stirring liquid storage tank 7, and a first pump 101 and a first flow meter 111 are arranged on the connecting pipeline, for sending the negative electrolyte into the stirring liquid storage tank 7.

[0028] In order to stir and mix, a stirring device, such as a paddle, a stirring motor and the like, should also be arranged in the stirring liquid storage tank 7, which is well known in the art and will not be described here.

[0029] The data acquisition controller 6 is a data acquisition unit of the utility model, and the acquisition object is the capacity data of the all-vanadium redox flow battery, which can be displayed on an electronic screen and the like. The connection between the electronic screen and the data acquisition controller 6 can be a wired connection mode based on a standard connector or a wireless connection mode based on a wireless communication protocol. When the connection is wireless, the data can be displayed in a mobile phone, a computer and the like.

[0030] The utility model can preset a threshold value, and when the capacity data acquired by the data acquisition controller 6 is lower than the preset threshold value, the operation can be started. First, the precise metering pump 13 is started, the starting time of the precise metering pump 13 is controlled according to the corresponding reducing agent addition amount of the preset threshold value, and the reducing agent can be accurately added to the positive electrolyte storage tank 1. The reaction of the reducing agent with the positive electrolyte in the positive electrolyte storage tank 1 can be known by continuing to pass the time. After the preset reaction time, the second pump 102 is started in the forward direction, the positive electrolyte is sent into the stirring liquid storage tank 7, and at the same time or in advance or subsequently, the first pump 101 is started in the forward direction, and the negative electrolyte is sent into the stirring liquid storage tank 7. Then, the stirring motor of the stirring liquid storage tank 7 is started, and stirring and mixing are carried out according to the preset time. After the preset stirring time, the first pump is started in the reverse direction, the second pump 102 is started in the reverse direction, the mixed electrolyte is uniformly distributed to the positive electrolyte storage tank 1 and the negative electrolyte storage tank 2, and the capacity recovery operation is completed. The distribution amount can be monitored in real time by the first flow meter 111 and the second flow meter 112.

[0031] According to the above operation, it is not necessary to replace all the electrolyte, the operation steps are simple, and the capacity recovery can be accurately and quickly realized.

[0032] Further, the utility model discloses the current, voltage data in the process of charging and discharging as the representation of capacity data, that is, without calculating, through the preset current voltage threshold value, directly as the threshold value of judging whether the capacity is attenuated. At this time, the data acquisition controller 6 includes current sensor and voltage sensor, and the current, voltage data in the process of charging and discharging is collected at the load 9, and the capacity of the battery is determined by real-time monitoring of the current and voltage of the flow battery. Obviously, the power can also be calculated, and the power data is used as the basis for judging whether the capacity is attenuated. For example, the model of the current sensor can be JXK-10VD, MJZCK22, and the model of the voltage sensor can be LEM LV 25-P, RS-485.

[0033] Further, the utility model discloses the vanadium ion composition and concentration data in electrolyte as the representation of capacity data, that is, without calculating, through the preset vanadium ion composition and concentration threshold value, directly as the threshold value of judging whether the capacity is attenuated. At this time, the data acquisition controller 6 includes built-in ultraviolet-visible spectrophotometer, and the vanadium ion composition and concentration data in electrolyte are collected at the positive electrolyte tank 1 and / or the negative electrolyte tank 2. In the embodiment, it is preferred to collect at the positive electrolyte tank 1, because the characteristic peak of the positive V (V) / V (IV) in the ultraviolet-visible light region is more obvious than that of the negative V (II) / V (III), and the model of the ultraviolet-visible spectrophotometer can be HD-UV90, HD-V50.

[0034] Obviously, the utility model can also be combined with the above two kinds of data for comprehensive judgment, and the selected data and the associated relationship between the capacity data can be selected according to the needs. For example, in the long-term operation of the all-vanadium redox flow battery, when the capacity is attenuated to 70%-75% of the initial capacity, it is considered to reach the capacity threshold value, and capacity recovery is needed. At this time, the corresponding voltage, current, vanadium ion composition and concentration data all have corresponding determined values, that is, the corresponding threshold values.

[0035] Further, the utility model sets up the valve 12 on the connecting pipeline of the outlet of the precision metering pump 13 and the first port of the positive electrolyte tank 1, and the setting of the valve 12 can disconnect the passage in time, so that the stopping time of the reducing agent is more accurately controlled. The valve 12 is preferably a corrosion-resistant electromagnetic valve or a corrosion-resistant pneumatic valve.

[0036] Further, when automatic control is adopted, the data acquisition controller 6 can output start-stop control signals to the precision metering pump 13, the first pump 101 and the second pump 102 according to preset conditions, and perform the foregoing operations, which are all controlled by preset time to control the start-stop time, and controlled by simple circuit on-off signal to control the start-stop of the pump, without complex software calculation process. Obviously, the start-stop control signal of the stirring motor of the stirring liquid storage tank 7 can also be output by the data acquisition controller 6, and the mixing time is generally controlled to about 3 minutes.

[0037] The control part of the data acquisition controller 6 can adopt any processing unit with simple control function, such as a single-chip microcomputer, a microprocessor or a PC, which only needs to output a start signal after triggering a threshold value, and output a stop signal or a start signal again after a set time, without complex control software. In the embodiment, the model adopted is NI cDAQ-9178.

[0038] Through automatic control of the data acquisition controller 6, real-time acquisition and analysis are performed on various parameters such as current, voltage, composition and concentration of the positive electrolyte in the battery during the charging and discharging process, when the capacity is detected to decrease to a preset level, the preset recovery instruction is quickly executed to control the opening and closing of the corresponding pump and valve, the reducing agent can be automatically added to the positive electrolyte tank 1 to reduce the pentavalent vanadium ion, and then the positive and negative electrolytes are mixed in a short time and then uniformly delivered to the positive and negative electrolyte tanks. Therefore, the capacity of the all-vanadium redox flow battery can be automatically recovered, other impurities are not introduced, manual operation is not required, and efficient, stable and long-time operation of the all-vanadium redox flow battery is realized.

[0039] The first pump 101 and the second pump 102 of the utility model can be gear pumps or peristaltic pumps, which have forward and reverse rotation functions, and the specific model can be BT100-2J or BT100-01, which rotates forward after adding the reducing agent, and rotates reverse after the electrolyte in the liquid storage tank is fully mixed, so as to realize the delivery of the electrolyte from the electrolyte storage tank to the stirring liquid storage tank 7, or from the stirring liquid storage tank 7 to the electrolyte storage tank.

[0040] The precision metering pump 13 of the utility model can be driven by a stepping motor, and the injection precision can be controlled within ±0.5%.

[0041] In a specific embodiment, the positive and negative electrolytes are each 15ml, the initial positive electrolyte is 1mol / L VO 2+ +3mol / L H2SO4, the initial negative electrolyte is 1mol / L V 3+ +3mol / L H2SO4, and the operation is performed under a current density of 200mA / cm 2 .

[0042] In the long-term operation of the all-vanadium redox flow battery, when the capacity attenuation of the flow battery is monitored to a certain extent, the valve 12 and the precision metering pump 13 are opened, a certain amount of reducing agent is added to the positive electrolyte, part of the vanadium ions in the positive electrolyte is reduced to vanadium ions in the fourth valence, then the valve 12, the precision metering pump 13 and the peristaltic pump 14 are closed, the two magnetic pumps 101 and 102 and the two flow meters 111 and 112 are opened, the positive and negative electrolytes are mixed, and then the mixed electrolyte is uniformly distributed to the positive and negative electrolyte tanks, the two magnetic pumps 101 and 102 and the two flow meters 111 and 112 are closed, the two peristaltic pumps 141 and 142 are opened, and the capacity recovery operation is completed.

[0043] The structure of the utility model adds the reducing agent to the positive electrolyte, reduces part of the vanadium ions in the positive electrolyte to the vanadium ions in the fourth valence, and the reaction equation is as follows.

[0044]

[0045] Then the positive and negative electrolytes are mixed, and the mixed electrolyte is uniformly distributed to the positive and negative electrolyte tanks. Since the average valence of the vanadium ions in the positive and negative electrolytes is +3.5, after the first charging and discharging, the valence of the vanadium ions in the positive electrolyte circulates between the fourth valence and the fifth valence, and the valence of the vanadium ions in the negative electrolyte circulates between the third valence and the second valence. Therefore, the volume, concentration and valence of the positive and negative electrolytes can be balanced, the capacity recovery can be realized, and the operation is simple. Through the above further optimization scheme, the utility model device can realize the full-process automatic control from data acquisition, state judgment to recovery operation, significantly improve the recovery efficiency and precision, and shorten the recovery period.

Claims

1. A device for recovering the capacity of a vanadium redox flow battery based on automatic control of online charge and discharge, characterized in that, The application relates to a full-vanadium redox flow battery capacity data acquisition and control device, which comprises a reducing agent storage tank (8), a stirring liquid storage tank (7) and a data acquisition controller (6); the stirring liquid storage tank (7) has a first port and a second port; the positive electrolyte storage tank (1) of the full-vanadium redox flow battery has a first port and a second port; the data acquisition controller (6) acquires and displays capacity data of the full-vanadium redox flow battery. A precision metering pump (13) is arranged in the reducing agent storage tank (8), the outlet of the precision metering pump (13) is connected with the first port of the positive electrolyte storage tank (1); the second port of the positive electrolyte storage tank (1) is connected with the second port of the stirring liquid storage tank (7), and a second pump (102) and a second flowmeter (112) are arranged on the connecting pipeline; the first port of the stirring liquid storage tank (7) is connected with the negative electrolyte storage tank (2) of the full-vanadium redox flow battery, and a first pump (101) and a first flowmeter (111) are arranged on the connecting pipeline. 2.The device according to claim 1, wherein, A load (9) is connected between the positive electrode (3) and the negative electrode (4) of the full-vanadium redox flow battery; the data acquisition controller (6) comprises a current sensor and a voltage sensor, and the current and voltage data in the charging and discharging process are acquired at the load (9) and are taken as the representation of the capacity data. 3.The device for capacity recovery of a vanadium redox flow battery based on automatic control of on-line monitoring of charging and discharging according to claim 1 or 2, characterized in that, The data acquisition controller (6) comprises an online spectrum analyzer, and the vanadium ion composition and concentration data in the electrolyte are acquired at the positive electrolyte storage tank (1) and / or the negative electrolyte storage tank (2) and are taken as the representation of the capacity data. 4.The device of claim 1, wherein, A valve (12) is arranged on the connecting pipeline between the outlet of the precision metering pump (13) and the first port of the positive electrolyte storage tank (1). 5.The device for capacity recovery of a vanadium redox flow battery based on automatic control of on-line monitoring of charging and discharging according to claim 1, characterized in that, The data acquisition controller (6) outputs start-stop control signals to the precision metering pump (13), the first pump (101) and the second pump (102), and receives the flow data of the first flowmeter (111) and the second flowmeter (112). 6.The device for capacity recovery of a vanadium redox flow battery based on automatic control of on-line monitoring of charging and discharging according to claim 1, characterized in that, The data acquisition controller (6) outputs start-stop control signals to the stirring motor of the stirring liquid storage tank (7). 7.The device of claim 1, wherein, The data acquisition controller (6) outputs start-stop control signals to the first peristaltic pump (141) and the second peristaltic pump (142), the first peristaltic pump (141) is a pump arranged on the circulating pipeline between the positive electrolyte storage tank (1) and the positive electrode chamber, and the second peristaltic pump (142) is a pump arranged on the circulating pipeline between the negative electrolyte storage tank (2) and the negative electrode chamber. 8.The device of claim 1, wherein, The first pump (101) and the second pump (102) are gear pumps or peristaltic pumps.

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