KR20190084414A - System and method for operating redox flow battery - Google Patents

Abstract

The present invention relates to a redox flow battery system and a method of operation. More particularly, the present invention relates to a redox flow battery system in which a pressure measurement unit and a flow rate measurement unit are disposed on a flow path, and a controller controls the flow rate of an electrolyte based on the pressure value of the pressure measurement unit and the flow rate value of flow rate measurement unit, thereby minimizing crossover phenomenon due to convention and preventing performance deterioration, and to a method of operation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redox flow battery system,

The present invention relates to a redox flow battery system and a method of operating the same. More particularly, the present invention relates to a redox flow battery system and a method for operating the redox flow battery system, The present invention relates to a redox flow battery system and a method of operating the same so that a crossover phenomenon due to a convection phenomenon can be minimized and performance degradation can be prevented.

Recently, renewable energy using solar energy or wind energy is attracting attention as a method to reduce greenhouse gas emission, which is a main cause of global warming, and related researches are actively carried out. However, since there is a disadvantage that the renewable energy can not continuously supply the energy because the output fluctuation is large, the system which can store the energy when the output is high and the stored energy when the output is low .

The power storage devices that are emerging as such systems are indispensable factors for the replenishment and expansion of renewable energy. The secondary batteries for large-capacity power storage include lead acid batteries, NaS batteries, redow flow batteries (RFB) . Among them, the redox flow battery has a low maintenance cost and can be operated at room temperature. Since the capacity and output can be independently designed, much research has been conducted with a large capacity secondary battery.

In a redox flow battery, a positive electrode electrolyte and a negative electrode electrolyte are circulated on both sides of a membrane to perform ion exchange, and in this process, electrons move to charge and discharge. At this time, when the anode electrolyte and cathode electrolyte are prepared by dissolving a redox couple active material having a different oxidation number in a solvent and charging a redox flow cell composed of a cathode electrolyte containing a redox couple and a cathode electrolyte, A reduction reaction takes place. At present, all vanadium redox flow batteries using vanadium are mainstream in both the positive electrode and negative electrode electrolytes, and researches on Zn / Br batteries are under way in recent years.

Such a conventional redox flow battery is known to be most suitable for an ESS (Energy Storage System) because it has a longer lifetime than a conventional secondary battery and can be manufactured as a MW-class medium-sized system from KW.

However, the conventional redox flow battery has a problem that it is difficult to accurately measure the flow rate of the electrolyte flowing into the stack because there is no flow meter for measuring the flow rate. In particular, It is difficult to precisely measure the pressure of the electrolytic solution and thus it is difficult to control the flow rate of the electrolytic solution.

Also, in the case of the conventional redox flow battery, when the same electrolyte is injected into the positive and negative electrodes of the stack and the properties of the positive and negative electrodes are different, convection through the separator may occur due to the difference in fluid pressure between the positive and negative electrodes There is a problem that a crossover phenomenon occurs, and in particular, the efficiency of the battery is lowered and the performance is lowered due to the crossover phenomenon.

Korean Patent No. 10-1357822

According to an embodiment of the present invention, there is provided an apparatus for measuring a flow rate of a pump, comprising: a pressure measuring unit and a flow rate measuring unit disposed on a flow path, wherein the control unit calculates, based on a pressure value measured at the pressure measuring unit and a flow rate value measured at the flow rate measuring unit, The flow rate of the electrolytic solution flowing into the stack can be controlled by controlling the flow rate of the electrolytic solution, thereby preventing a decrease in efficiency due to a crossover phenomenon.

It is an object of the present invention to provide a fuel cell system in which a pressure measuring unit is placed on a flow path connecting a stack and a pump and a flow measuring unit is placed on a flow path connecting a pressure measuring unit and a pump, And to provide a redox flow battery system and method that can precisely measure the flow rate of an electrolyte flowing into a stack.

It is another object of the present invention to provide an apparatus and a method for measuring a flow rate of an electrolytic solution including a high flow rate measurement unit and a low flow rate measurement unit, And to provide a redox flow battery system and method of operation that can be measured.

It is an object of the present invention to provide an apparatus and a method for measuring the level of an electrolyte solution supplied to a stack in an anode and a cathode electrolyte tank by locating a level measuring unit in an anode and a cathode electrolyte tank for supplying an electrolyte solution to a stack, Flow battery system and method of operation.

The redox flow battery system according to the present invention includes a positive electrode and a negative electrode electrolyte tank for supplying an electrolyte solution to an anode and a cathode of a stack, an electrolyte solution tank disposed on a flow path connecting the stack and the anode and the cathode electrolyte tank, A pressure measuring unit positioned on the flow path connecting the stack to the pump and measuring a pressure of the positive electrode and the negative electrode of the stack, and a pressure measuring unit positioned on the flow path connecting the pressure measuring unit and the pump, And a flow rate measuring unit for measuring a flow rate of the electrolytic solution flowing into the electrolytic cell.

According to one embodiment, the redox flow battery system includes a water level measuring unit for measuring a level of an electrolyte solution in the anode and the anode electrolyte tank for supplying an electrolyte to the stack, and a water level measuring unit for measuring the water level of the electrolyte, And a control unit for controlling the operation of the level measuring unit.

According to one embodiment, the control unit controls the number of revolutions of the pump so that the pressure values of the positive and negative electrodes of the stack measured by the pressure measuring unit are the same, and the flow rate of the electrolytic solution is adjusted.

According to an embodiment of the present invention, the controller controls the number of revolutions of the pump and adjusts the flow rate of the electrolyte so that the level of the electrolyte solution in the anode and the cathode electrolyte tanks measured by the level measuring unit is the same.

According to one embodiment, the flow measuring unit includes a high flow rate measuring unit and a low flow rate measuring unit, and the valve is located on a flow path connecting the pump and the high flow rate measuring unit.

The method of operating a redox flow battery according to the present invention includes the steps of injecting an electrolyte solution into an anode and a cathode electrolyte tank by a pump, measuring a pressure value of an anode and a cathode of the stack through which the electrolyte passes, And controlling the rotation speed of the pump based on the pressure value.

According to an embodiment, when a difference in pressure value between the positive electrode and the negative electrode of the stack occurs, the control unit controls the rotation number of the pump to adjust the flow rate of the electrolyte supplied to the stack so that the pressure value of the electrolyte is the same. .

According to one embodiment, the redox flow battery operation method further includes a step of measuring a level of an electrolyte solution in the anode and the cathode electrolyte tanks, wherein the difference in the electrolyte level of the anode and the cathode electrolyte tanks The control unit controls the rotation speed of the pump to adjust the flow rate of the electrolytic solution supplied to the stack such that the electrolyte level of the electrolytic solution in the anode and the cathode electrolytic solution tank is the same.

According to one embodiment, the redox flow battery operating method further includes measuring a flow rate of the electrolyte solution supplied to the stack.

According to one embodiment, the step of measuring the flow rate of the electrolytic solution supplied to the stack is characterized by measuring the flow rate of the electrolytic solution by closing the valve when the flow rate of the electrolytic solution supplied to the stack is smaller than the predetermined flow rate value .

According to an embodiment of the present invention, the step of measuring the flow rate of the electrolytic solution supplied to the stack may include opening the valve to measure the flow rate of the electrolytic solution when the flow rate of the electrolytic solution supplied to the stack exceeds a predetermined flow rate value do.

According to an aspect of the present invention, a pressure measuring unit and a flow measuring unit are disposed on a flow path, and the control unit controls the number of rotations of the pump based on the pressure value measured by the pressure measuring unit and the flow rate measured by the flow measuring unit The flow rate of the electrolytic solution flowing into the stack can be controlled, thereby reducing the efficiency deterioration due to the crossover phenomenon.

In addition, since the flow rate measuring portion is located on the flow path connecting the pressure measuring portion and the pump, the pressure value of the positive and negative electrodes of the stack and the flow rate of the electrolyte flowing into the stack are accurately So that it can be measured.

Particularly, since the flow rate measuring section includes the high flow rate measuring section and the low flow rate measuring section, it is possible to enlarge the flow rate measurement range of the electrolytic solution, thereby enabling to precisely measure the flow rate of the electrolyte flowing into the stack.

In addition, since the level measuring unit is disposed in the anode and cathode electrolyte tanks for supplying the electrolyte solution to the stack, it is possible to check the level of the electrolytic solution supplied to the stack from the anode and cathode electrolyte tanks in real time.

FIG. 1 is a development view schematically showing a configuration of a redox flow battery system 100 according to an embodiment of the present invention.
2 is a flowchart illustrating a method of operating the redox flow battery system 100 according to an embodiment.
FIG. 3 is a graph showing a comparison between the discharge capacity of the redox flow battery system and the electrolyte tank level of the redox flow battery system according to the embodiment, and the discharge capacity of the redox flow battery system and the electrolyte tank level of the comparative example.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a detailed description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. The embodiments of the present invention are provided to fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Throughout the specification, when a component is referred to as " comprising ", it means that it can include other components as well, rather than excluding other components, unless the context otherwise requires.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the better understanding of the present invention, and the present invention is not limited by the examples.

<Redox Flow Battery System>

FIG. 1 is a development view schematically showing a configuration of a redox flow battery system 100 according to an embodiment of the present invention.

The redox flow battery system 100 according to an embodiment of the present invention includes a stack 110, a positive electrode electrolyte tank 120, a negative electrode electrolyte tank 130, a pump 140, a pressure measuring unit 150, A part 160, a flow rate measuring part 170, and a valve 180.

First, the stack 110 configured in the redox flow battery system 100 may include an anode, a cathode, a current collector (not shown), a separator (not shown) and an end plate (not shown) (Not shown) may be formed in the electrolyte 110 and connected to the positive electrode and the negative electrode, respectively, so that the electrolyte can be supplied to the positive and negative electrodes of the stack 110.

For example, when the redox flow battery system 100 is a vanadium redox flow battery, tetravalent vanadium ions are oxidized at the anode electrode of the stack 110 during charging to convert the vanadium ions to pentavalent vanadium ions, And an oxidation reaction in which hydrogen ions migrate from the anode to the cathode through the separator may occur. Also, in the cathode of the stack 110, a reducing reaction may occur in which trivalent vanadium ions accept electrons and are converted into divalent vanadium ions.

On the other hand, during the discharge, the redox reaction in which the oxidation number of the vanadium ion is changed in the stack 110 as opposed to the charging reaction described above occurs, so that the charging and discharging can be effectively performed.

Next, the anode and cathode electrolyte tanks 120 and 130 are connected to the positive and negative electrodes of the stack 110, respectively, to supply the electrolyte solution to the positive and negative electrodes of the stack 110.

In this case, a cathode electrolyte containing a cathode electrolyte and a cathode electrolyte containing a cathode electrolyte may be stored in the anode and cathode electrolyte tanks 120 and 130, respectively.

The pump 140 may be located on the flow path connecting the stack 110 and the anode and cathode electrolyte tanks 120 and 130 and may inject the electrolyte into the anode and cathode of the stack 110.

The pump 140 is disposed on the anode electrolyte tank 120 side and includes a positive electrode pump 141 connected to the positive electrode electrolyte tank 120 and a negative electrode pump 141 connected to the negative electrode electrolyte tank 130, 142).

That is, the positive and negative electrode pumps 141 and 142 can inject the positive and negative electrode electrolytes into the positive and negative electrodes in the stack 110 with strong pressure, respectively, so that the positive electrode electrolyte flows from the positive electrode electrolyte tank 120 to the stack 110 And the negative electrode electrolyte can be circulated from the negative electrode electrolyte tank 130 to the negative electrode of the stack 110. In this case,

Here, the pump 140 is connected to the anode pump 141 and the cathode pump 141 using a pump of a centrifugal pump, a volute pump, a turbine pump, a single suction pump, a double suction pump, a single stage pump, (142).

Next, the pressure measuring unit 150 may be positioned on the flow path connecting the stack 110 and the pump 140, and the pressure of the anode and the cathode of the stack 110 may be measured.

That is, the positive electrode electrolyte stored in the positive electrode electrolyte tank 120 can measure the pressure of the positive electrode of the stack 110 generated while passing through the stack 110, and the negative electrode electrolyte stored in the negative electrode electrolyte 130 can be measured by the stack 110 The pressure of the cathode electrode of the stack 110 may be measured.

Accordingly, the pressure measuring unit 150 is positioned on the flow path connecting the stack 110 and the pump 140, so that the pressure values of the positive and negative electrodes of the stack 110 can be accurately measured in real time.

The level measuring unit 160 may measure the level of the electrolyte in the anode and cathode electrolyte tanks 120 and 130 that are located in the anode and cathode electrolyte tanks 120 and 130 and supply the electrolyte to the stack 110.

That is, when the positive electrode electrolyte solution stored in the positive electrode electrolyte tank 120 is injected into the stack 110, the level measuring unit 160 located at one side of the positive electrode electrolyte tank 120 senses a change in the level of the positive electrode electrolyte, 120) can be measured.

When the negative electrode electrolyte stored in the negative electrode electrolyte tank 130 is injected into the stack 110, the level measuring unit 160 located at one side of the negative electrode electrolyte tank 130 senses a change in the level of the negative electrode electrolyte, 130) can be measured.

Therefore, by placing the level measuring part in the anode and cathode electrolyte tanks 120 and 130 supplying the electrolyte solution to the stack 110, the level of the electrolyte solution in the anode and cathode electrolyte tanks 120 and 130 can be accurately measured in real time have.

The flow measuring unit 170 is located on the flow path connecting the pressure measuring unit 150 and the pump 140 and can measure the flow rate of the electrolyte flowing into the stack 110.

The flow rate measuring unit 170 may include a high flow rate measuring unit 171 and a low flow rate measuring unit 172. The high flow rate measuring unit 171 may measure an electrolyte at a predetermined flow rate or more.

The low flow rate measuring unit 172 may be disposed in a separate small flow path formed on the flow path connecting the pressure measuring unit 150 and the pump 140. The low flow rate measuring unit 172 may be configured to measure an amount of the electrolyte Can be measured.

That is, when the flow rate of the electrolytic solution supplied to the stack 110 exceeds the preset flow rate value, the high flow rate measurement unit 171 can measure the flow rate of the electrolytic solution, while the flow rate of the electrolytic solution supplied to the stack 110 The flow rate measuring unit 172 can measure the flow rate of the electrolytic solution.

When the flow rate of the electrolytic solution supplied to the stack 110 is less than a predetermined flow rate value, the valve 180 may be positioned on the flow path connecting the pump 140 and the high flow rate measurement unit 171. In this case, And may be opened when the flow rate of the electrolyte supplied to the stack 110 exceeds a predetermined flow rate value.

For example, when the 50 LPM flowmeter is used as the high flow rate measuring unit 171 and the 5 LPM flowmeter is used as the low flow rate measuring unit 172, when the flow rate of the electrolyte flowing into the stack 110 is less than 5 LPM, 190 opens the valve 180 and the low flow rate measurement unit 172 can measure the flow rate of the electrolyte solution.

On the other hand, when the flow rate of the electrolytic solution flowing into the stack 110 exceeds 5 LPM, the controller 190 opens the valve 180 so that the high flow rate measuring unit 171 can measure the flow rate of the electrolytic solution.

The flow rate measuring unit 170 is located on the flow path connecting the pressure measuring unit 150 and the pump 140 and includes the high flow rate measuring unit 171 and the low flow rate measuring unit 172, So that it is possible to precisely measure the flow rate of the electrolytic solution flowing into the anode and the cathode of the stack 110 in real time.

The control unit 190 may control the operation of the pump 140, the pressure measurement unit 150, the water level measurement unit 160, and the flow rate measurement unit 170 of the redox flow battery system 100, At the same time, the operation of the valve 180 can be controlled at the same time.

The control unit 190 may control the number of rotations of the pump 140 and adjust the flow rate of the electrolyte so that the pressure values of the positive and negative electrodes of the stack 110 measured by the pressure measuring unit 150 are the same.

That is, when the pressure difference between the positive and negative electrodes of the stack 110 is measured by the pressure measuring unit 150, the controller 190 controls the number of rotations of the pump 140 to flow into the stack 110 By controlling the flow rate of the electrolytic solution, the pressure values of the positive and negative electrodes of the stack 110 can be kept the same.

For example, when the redox flow battery system 100 is in the charging and discharging states, the ionic states of the anode and cathode electrolytes passing through the stack 110 may change and the fluid characteristics may vary, A pressure difference between the positive electrode and the negative electrode of the stack 110 into which the electrolytic solution flows may occur.

The control unit 190 detects the difference between the pressure values of the cathodes and the anodes of the stack 110 measured by the pressure measuring unit 150 and measures the pressure values of the positive and negative electrodes of the stack 140, The number of revolutions can be controlled, and the flow rate of the electrolytic solution flowing into the stack 110 can be controlled.

When the crossover phenomenon occurs in the redox flow battery system 100, the controller 190 selectively controls the number of rotations of the pump 140 of the anode and cathode pumps 141 and 142, And the flow rate of the electrolytic solution flowing into the anode and the cathode can be selectively controlled.

For example, when the viscosity of the positive electrode electrolyte flowing into the positive electrode of the stack 110 increases, a crossover phenomenon may occur in which the ions of the electrolyte move from the positive electrode to the negative electrode through the separation membrane of the stack 110.

At this time, the control unit 190 can selectively control the cathode pump 142 by sensing the crossover phenomenon based on the pressure value of the stack 110 measured by the pressure measuring unit 150. [

The control unit 190 controls the number of revolutions of the negative electrode pump 142 to increase the flow rate of the negative electrode electrolyte flowing into the stack 110 and temporarily increase the pressure of the negative electrode of the stack 110, To move the charge from the cathode to the anode.

Therefore, it is possible to prevent performance deterioration and efficiency deterioration due to the crossover phenomenon of the redox flow battery system 100 and to easily regenerate the state of the electrolyte solution without additional configuration for regenerating the electrolyte, Can be simplified.

The control unit 190 controls the rotation speed of the pump 140 so that the electrolyte level of the electrolyte solution in the anode and the anode electrolyte tanks 120 and 130 measured by the water level measuring unit 160 is equal to each other and controls the flow rate of the electrolyte solution .

That is, when the level difference of the electrolytic solution in the anode and cathode electrolyte tanks 120 and 130 is measured by the water level measuring unit 160, the controller 190 determines whether the redox flow battery system 100 is a crossover phenomenon can do.

The control unit 190 controls the rotation speed of the pump 140 to adjust the flow rate of the electrolytic solution flowing into the stack 110 so that the level of the electrolytic solution in the anode and the cathode electrolytic tanks 120 and 130 can be maintained at the same level have.

Thus, the crossover phenomenon of the redox flow battery system 100 can be prevented, and the performance of the redox flow battery system 100 can be prevented while maintaining the efficiency.

<Redox flow battery operation method>

2 is a flowchart illustrating a method of operating the redox flow battery system 100 according to an embodiment.

The operation of the redox flow battery system 100 includes the steps of injecting the electrolyte solution in the anode and cathode electrolyte tanks 120 and 130 into the stack 110 A step S200 of measuring the pressure values of the positive and negative electrodes of the stack 110 through which the electrolytic solution passes, a step of measuring the level of the electrolyte in the positive and negative electrolyte tanks 120 and 130 S300) and the control unit 190 may control the number of rotations of the pump 140 based on the pressure value and the water level (S400).

In step S100, the pump 140 injects the electrolyte solution in the anode and cathode electrolyte tanks 120 and 130 into the stack 110. The anode 110 and the anode 110 are disposed on the flow path connecting the anode electrolyte tank 120 and the stack 110 The positive electrode pump 141 can inject the positive electrode electrolyte stored in the positive electrode electrolyte tank 120 into the positive electrode of the stack 110 and the negative electrode pump disposed on the flow path connecting the negative electrode electrolyte tank 130 and the stack 110 142 may inject the negative electrode electrolyte stored in the negative electrode electrolyte tank 130 into the negative electrode of the stack 110.

In step S200, the pressure measuring unit 150 measures the pressure values of the positive and negative electrodes of the stack 110. The pressure measuring unit 150 is disposed on the flow path connecting the stack 110 and the pump 140, Can measure the pressure values of the positive electrode and the negative electrode of the stack 110 into which the electrolyte is injected, respectively.

Accordingly, the pressure measuring unit 150 measures the pressure of the cathode of the stack 110 into which the positive and negative electrode electrolytic solutions of the stack 110 into which the positive electrode electrolyte flows, respectively, Can be measured.

The control unit 190 controls the operation of the pressure measuring unit 150 including the pump 140 and the valve 180 based on the pressure value. Can be controlled.

The control unit 190 controls the rotation speed of the pump 140 so that the pressure values of the electrolytic solution are equal to each other when the redox flow battery system 100 is operating, The flow rate of the electrolytic solution supplied to the stack 110 can be adjusted.

The flow rate of the electrolytic solution is controlled by controlling the number of rotations of the pump 140 based on the pressure values of the positive and negative electrodes of the stack 110 measured by the pressure measuring unit 150, The efficiency deterioration of the battery system 100 can be prevented.

The operation of the redox flow battery system 100 may further include the step of measuring the level of the electrolyte in the anode and cathode electrolyte tanks 120 and 130 by the level measuring unit 160.

That is, the water level measuring unit 160 measures the water level of the electrolytic solution in the anode and the cathode electrolytic solution tanks 120 and 130 by being positioned in the anode and the cathode electrolytic tanks 120 and 130, respectively, At this time, the operation of the water level measuring unit 160 may be controlled by the controller 190. [

The control unit 190 controls the rotation speed of the pump 140 to control the flow rate of the electrolyte solution between the anode and cathode electrolyte tanks 120 and 130 when the redox flow battery system 100 is operated, The flow rate of the electrolytic solution supplied to the stack 110 can be adjusted so that the electrolyte level values in the tanks 120 and 130 are equal to each other.

In this way, the flow rate of the electrolytic solution is controlled by controlling the rotation speed of the pump based on the water level value of the electrolytic solution in the anode and cathode electrolytic solution tanks 120 and 130 measured by the water level measuring unit 160, The performance degradation of the flow battery system 100 can be prevented.

The operation of the redox flow battery system 100 may further include the step of measuring the flow rate of the electrolyte supplied to the stack 110 by the flow rate measuring unit 170, The operation of the measuring unit 170 can be controlled.

The step of measuring the flow rate of the electrolytic solution supplied to the stack 110 can measure the flow rate of the electrolytic solution by closing the valve 180 when the flow rate of the electrolytic solution supplied to the stack 110 is smaller than the predetermined flow rate value, At this time, the flow rate of the electrolytic solution can be measured by the low flow rate measuring unit 172.

The step of measuring the flow rate of the electrolytic solution supplied to the stack 110 may include measuring the flow rate of the electrolytic solution by opening the valve 180 when the flow rate of the electrolytic solution supplied to the stack 110 exceeds a predetermined flow rate value At this time, the flow rate of the electrolytic solution can be measured by the high flow rate measurement unit 171.

For example, when the flow rate of the predetermined electrolyte is 4LPM, if the flow rate of the electrolyte supplied to the positive and negative poles of the stack 110 is 2LPM, the controller 190 locks the valve 180, And can be measured by the measuring unit 172.

For example, when the flow rate of the predetermined electrolyte is 4LPM, if the flow rate of the electrolyte supplied to the positive and negative poles of the stack 110 is 10LPM, the controller 190 opens the valve 180, And can be measured by the high flow rate measurement section 171. [

Therefore, the flow rate measuring unit 170 is disposed on the flow path connecting the pressure measuring unit 150 and the pump 140 to measure the flow rate of the electrolyte solution flowing into the stack 110, thereby accurately measuring the flow rate of the electrolyte solution in real time So that the flow rate of the electrolytic solution flowing into the stack 110 can be easily controlled.

<Examples>

The control unit controls the number of rotations of the pump based on the pressure values of the positive and negative electrodes of the stack measured by the pressure measuring unit and the level of the electrolyte in the positive and negative electrode electrolyte tanks measured by the level measuring unit, The flow rate was adjusted.

<Comparative Example>

The flow rate of the electrolyte supplied to the stack is maintained by maintaining the same number of revolutions of the pump irrespective of the pressure values of the positive and negative electrodes of the stack measured by the pressure measuring unit and the level of the electrolyte in the positive and negative electrode electrolyte tanks measured by the level measuring unit The same.

<Experimental Example 1>

Measuring Discharge Capacity of Redox Flow Battery System

FIG. 3 is a graph showing a comparison between the discharge capacity of the redox flow battery system and the electrolyte tank level of the redox flow battery system according to the embodiment, and the discharge capacity of the redox flow battery system and the electrolyte tank level of the comparative example.

3, when the redox flow battery system of the comparative example continuously performs charge / discharge cycles, the water level value of the positive electrode electrolyte stored in the positive electrode electrolyte tank gradually decreased at 50 L, and the charge / discharge cycle of the comparative example was 14 The level of the anode electrolyte was measured to be about 30L.

The level of the negative electrode electrolyte stored in the negative electrode electrolyte tank of the comparative example was gradually increased at 50 L as the charge / discharge cycle progressed, and the level of the negative electrode electrolyte was measured at about 70 L when the charge / discharge cycle of the comparative example was 14.

Therefore, in the redox flow battery system of the comparative example, the crossover phenomenon in which the electrolyte moves through the separator of the stack occurred, and the discharge capacity gradually decreased at about 60 Ah, and when the charge / The discharge capacity of the sample was measured to be about 20 Ah.

On the other hand, the anode electrolyte level of the Redox flow battery system of the embodiment was initially measured at 50 L, and gradually decreased as the charge-discharge cycle progressed. When the charge-discharge cycle was 7 times, the anode electrolyte level reached about 40 L Respectively.

In addition, the level of the negative electrode electrolyte in the example was initially measured at 50 L, and gradually increased as the charge / discharge cycle progressed. When the charge / discharge cycle was 7 times, the level of the negative electrode electrolyte was measured to be about 60 L.

At this time, in the redox flow battery system of the embodiment, the control unit controls the number of revolutions of the pump based on the value of the electrolyte level and the pressure of the stack, thereby increasing the pressure of the anode while increasing the flow rate of the electrolyte supplied to the anode of the stack .

As a result, the anode electrolyte level was measured to be 50 L when the charge / discharge cycle was 14, and the cathode electrolyte level was 50 L when the charge / discharge cycle was 14, Respectively.

Accordingly, the discharge capacity of the redox flow battery system of the embodiment was gradually decreased at about 60 Ah, and then recovered when the charge / discharge cycle was 7 times, and when the charge / discharge cycle of the embodiment was 14 times, The discharge capacity was measured at about 60 Ah.

That is, according to the embodiment, by controlling the number of revolutions of the pump based on the level of the electrolyte and the pressure of the positive and negative poles of the stack, the level of the electrolyte is recovered to improve the discharging capacity The values were measured.

As a result, the redox flow battery system according to the embodiment regulates the flow rate of the electrolyte by controlling the rotation speed of the pump, thereby recovering the electrolyte level and the discharge capacity of the redox flow battery system, It can be seen that regeneration of the electrolyte occurs and performance deterioration of the redox flow battery system is prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

100: redox flow battery system
110: Stack
120: anode electrolyte tank
130: cathode Electrolyte tank
140: pump
141: anode pump
142: Cathode pump
150: pressure measuring unit
160:
170:
171:
172: Low flow rate measuring unit
180: Valve
190:

Claims (11)

A positive electrode and a negative electrode electrolyte tank for supplying an electrolyte solution to the positive and negative electrodes of the stack;
A pump located on the flow path connecting the stack with the anode and the cathode electrolyte tanks, respectively, and injecting an electrolyte into the stack;
A pressure measuring unit located on a flow path connecting the stack and the pump, the pressure measuring unit measuring a pressure of the positive electrode and the negative electrode of the stack; And
And a flow rate measuring unit located on the flow path connecting the pressure measuring unit and the pump and measuring a flow rate of the electrolyte flowing into the stack.
Redox flow battery system.
The method according to claim 1,
In the redox flow battery system,
A level measuring unit for measuring a level of the electrolyte in the anode and the cathode electrolyte tank that supplies the electrolyte to the stack; And
And a control unit for controlling operations of the pump, the pressure measuring unit, the flow measuring unit, and the water level measuring unit.
Redox flow battery system.
3. The method of claim 2,
Wherein,
Wherein the control unit controls the number of revolutions of the pump so as to equalize the pressure values of the positive and negative electrodes of the stack measured by the pressure measuring unit to adjust the flow rate of the electrolytic solution.
Redox flow battery system.
3. The method of claim 2,
Wherein,
And controlling the number of revolutions of the pump so that the flow rate of the electrolytic solution is adjusted so that the level of the electrolytic solution in the anode and the cathode electrolytic solution tank measured by the level measuring unit is the same.
Redox flow battery system.
The method according to claim 1,
Wherein the flow-
A high flow rate measuring unit; And a low flow rate measuring unit,
And a valve is disposed on a flow path connecting the pump and the high flow rate measurement unit.
Redox flow battery system.
Injecting the electrolyte in the anode and cathode electrolyte tanks into the stack;
Measuring a pressure value of a positive electrode and a negative electrode of the stack through which the electrolytic solution passes; And
And controlling the rotation speed of the pump based on the pressure value.
How to operate redox flow battery.
The method according to claim 6,
When a difference in pressure value between the anode and the cathode of the stack occurs,
Wherein the control unit controls the rotation speed of the pump to adjust the flow rate of the electrolyte supplied to the stack so that the pressure value of the electrolyte is the same.
How to operate redox flow battery.
The method according to claim 6,
The redox flow battery operating method includes:
And measuring a water level value of the electrolyte in the anode and cathode electrolyte tanks by the water level measuring unit,
The control unit controls the rotation speed of the pump to adjust the flow rate of the electrolytic solution supplied to the stack so that the electrolyte level of the electrolytic solution in the anode and the cathode electrolytic solution tank is equal to the value of the electrolytic solution level in the anode and cathode electrolytic solution tanks Lt; RTI ID = 0.0 &gt;
How to operate redox flow battery.
The method according to claim 6,
The redox flow battery operating method includes:
And measuring a flow rate of the electrolytic solution supplied to the stack.
How to operate redox flow battery.
10. The method of claim 9,
The step of measuring the flow rate of the electrolytic solution supplied to the stack may include:
Wherein when the flow rate of the electrolytic solution supplied to the stack is smaller than a predetermined flow rate value, the flow rate of the electrolytic solution is measured by closing the valve.
How to operate redox flow battery.
10. The method of claim 9,
The step of measuring the flow rate of the electrolytic solution supplied to the stack may include:
Wherein when the flow rate of the electrolytic solution supplied to the stack exceeds a predetermined flow rate value, the flow rate of the electrolytic solution is measured by opening the valve.
How to operate redox flow battery.

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