JP2021012787A - Redox flow cell - Google Patents

Abstract

To specifically form a structure of a redox flow cell using a vanadium sulfate solution as an electrolyte so as to have a mutually common shape, and simplify a structure of a more complex secondary battery by simplifying them.SOLUTION: A redox flow cell 300 in which vanadium sulfate solutions 15 and 35 are used as an electrolyte, comprises: a cylinder 52 sending the electrolyte from liquid circulation pumps 12 and 32 that makes the electrolyte circulate, and diffusing the electrolyte; electrolyte containers 11 and 31 that house the cylinder 52; and discharge pipes 61 and 62 that are distributed in parallel to the cylinder 52 that discharge the electrolyte in the electrolyte containers 11 and 31 to the outside of the electrolyte containers 11 and 31 by an applied pressure of the electrolyte sent from the liquid circulation pumps 12 and 32.SELECTED DRAWING: Figure 1

Description

The present invention relates to a redox flow battery in which an aqueous solution of vanadium sulfate can be used as an electrolytic solution and the degree of charge / discharge state can be measured. The redox flow battery charges and discharges by separating two kinds of ion solutions with a cation exchange membrane and simultaneously advancing an oxidation reaction and a reduction reaction on electrodes (made of carbon) provided in both solutions.
The entire configuration of the redox flow battery includes a positive electrode, a negative electrode, and a diaphragm interposed between the two electrodes, and supplies and discharges a positive electrode and a negative electrode.
The negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and the additive metal ions contained in the positive electrode electrolyte are aluminum ions, cadmium ions, and indium. It contains at least one of an ion, a tin ion, an antimony ion, an iridium ion, a gold ion, a lead ion, a bismuth ion and a magnesium ion.

Specifically, the positive electrode electrolyte contains manganese ions and added metal ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions. The added metal ion contained in the positive electrode electrolyte is at least one of aluminum ion, cadmium ion, indium ion, tin ion, antimony ion, iridium ion, gold ion, lead ion, bismus ion and magnesium ion.

In addition to the metal ions exemplified above, lithium ion, beryllium ion, sodium ion, potassium ion, calcium ion, scandium ion, nickel ion, zinc ion, gallium ion, germanium ion, rubidium ion, strontium ion, yttrium ion, Zirconium ion, niobium ion, technetium ion, rhodium ion, cesium ion, barium ion, lanthanoid element (excluding cerium) ion, hafnium ion, tantalum ion, renium ion, osmium ion, platinum ion, tarium ion, polonium ion, Francium ion, radium ion, actinium ion, thorium ion, protoactinium ion, and uranium ion can be mentioned as added metal ions.

The redox flow batteries described in Patent Documents 1 and 2 have an active material in a liquid state, and the positive and negative electrode battery active materials are circulated in a liquid-permeable electrolytic cell and charged and discharged using a redox reaction. Is to do. It has the following advantages over other secondary batteries.
(1) In order to increase the amount of active material, the storage container capacity may be increased, and the electrolytic cell itself does not need to be increased unless the output is increased.
(2) The positive electrode and negative electrode active materials can be completely separated and stored in a container, and there is little possibility of self-discharge.
(3) In the liquid-permeable carbon porous electrode to be used, the charge / discharge characteristics (electrode reaction) of the active material ion are such that electrons are simply exchanged on the surface of the electrode without depositing on the electrode. The reaction is simple.

This redox flow type battery is composed of a diaphragm made of an ion exchange membrane, carbon cross electrodes (positive electrode and negative electrode) provided on both sides thereof, and end plates provided on the outside thereof, and the positive electrode electrolyte and the negative electrode electrolyte are It is sent from the positive electrode electrolyte container and the negative electrode electrolyte container to the positive electrode and the negative electrode, respectively.
In the initial charge, vanadium tetravalent is oxidized to pentavalent at the positive electrode, vanadium tetravalent is reduced to trivalent at the negative electrode, and vanadium trivalent is reduced to divalent at the negative electrode, but overcharge and oxygen evolution are generated at the positive electrode. Produces. In order to avoid this, it was necessary to replace the electrolytic solution with a tetravalent vanadium solution when the positive electrode solution was fully charged. When the battery is charged in this state, vanadium is oxidized from tetravalent to pentavalent on the positive electrode side, while vanadium is reduced from trivalent to divalent on the negative electrode side. In the discharged state, the opposite reaction will occur.

Japanese Unexamined Patent Publication No. 5-242905 Japanese Unexamined Patent Publication No. 2018-137238

In addition, both are used to estimate the capacity of the secondary battery. However, since the repetitive charge / discharge characteristics of the secondary battery itself change over time and the change over time is large, there is a high tendency for the secondary battery to be overcharged under normal use conditions. That is, there was no accurate method for determining the capacity of the battery to the extent that it was decisive.
Then, the secondary battery itself became large and was not suitable for general household use.

Therefore, in order to solve the above-mentioned conventional problems, in particular, the structure of the redox flow battery using the vanadium sulfate aqueous solution as the electrolytic solution is made into a common component and simplified to simplify the structure of the complicated secondary battery. The challenge is to provide a redox flow battery.

The redox flow battery of the invention of claim 1 is an electrolysis composed of the tetravalent vanadium and the pentavalent vanadium during the conversion of tetravalent vanadium to pentavalent vanadium by charging or the conversion of pentavalent vanadium to tetravalent vanadium by discharge. The charge / discharge circulation path on the positive electrode side consisting of a flow of liquid, and the divalent vanadium and trivalent vanadium said while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging. In a redox flow battery using a vanadium sulfate aqueous solution as an electrolytic solution, which includes a charge / discharge circulation path on the negative electrode side composed of a flow of the electrolytic solution, the electrolytic solution is sent from a liquid circulation pump that circulates the electrolytic solution. The electrolytic solution container that houses the tubular body and the tubular body, and the electrolytic solution that is discharged from the liquid circulation pump to discharge the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container. It is provided with a discharge pipe arranged in parallel with the cylinder.

In the redox flow battery using the vanadium sulfate aqueous solution of the invention of claim 1 as the electrolytic solution, the charge / discharge circulation path on the positive side, which is composed of the flow of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium, is charged with tetravalent vanadium. It consists of a flow of an electrolytic solution composed of the above-mentioned tetravalent vanadium and pentavalent vanadium during the conversion to valent vanadium or during the conversion of pentavalent vanadium to tetravalent vanadium by discharge.
In addition, the charge / discharge circulation path on the negative side, which consists of a flow of an electrolytic solution composed of divalent vanadium and trivalent vanadium, changes divalent vanadium to trivalent vanadium while changing trivalent vanadium to divalent vanadium by discharging or by charging. It consists of the divalent vanadium and trivalent vanadium during the change.

That is, the charge / discharge circulation path on the positive electrode side forms a positive electrode as a secondary battery, and is a terminal for taking out current. Further, the charge / discharge circulation path on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. Independent charge / discharge circulation paths on the positive electrode side and the negative electrode side are formed in the charge / discharge circulation paths on the positive electrode side and the negative electrode side, and electromotive force is generated by the electrolytic solution flowing through them.

Then, the cylinder and the electrolytic solution container accommodating the cylinder diffuse the electrolytic solutions having different valences sent from the liquid circulation pump that circulates the electrolytic solution so as to average them. The electrolytic solution container for accommodating is the electrolytic solution accommodating container.
Further, the discharge pipe circulates the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container via a pipeline and a cell stack by the pressure of the electrolytic solution sent from the liquid circulation pump. An arrangement method in which the cylinder is arranged in parallel with the cylinder is preferable.

The liquid circulation pump for circulating the electrolytic solution of the redox flow battery of the invention of claim 2 is attached so as to be housed in the upper part of the cylinder.
Here, the liquid circulation pump that circulates the electrolytic solution of the redox flow battery is housed in the upper part of the cylinder and integrated with the upper part of the cylinder so that the outer shape is made into the size of the cylinder. Can be done.

The LED illumination that determines the color of the electrolytic solution of the redox flow battery of the invention of claim 3 and the color sensor that detects the color of the electrolytic solution under the LED illumination use the LED illumination as an ambient light source. White is preferable, but other colors are not unusable. The color sensor determines the color of the electrolytic solution, and it is sufficient if the color can be determined as well as the lightness and darkness.

The redox flow battery of the invention of claim 4 is further provided with a float sensor in the cylinder for detecting the liquid level position of the electrolytic solution in the cylinder.
Here, since the float sensor operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.

The redox flow battery according to the fifth aspect of the present invention further has a breathing hole formed in the upper part of the tubular body, and a filter is attached thereto.
Here, the breathing hole provided in the upper part of the tubular body is not limited to the upper surface of the tubular body, and may be the upper position of the side surface. Further, the filter preferably has no hygroscopicity of the electrolytic solution, and by repelling the liquid, the liquid blocking effect can be obtained by the surface tension thereof.

The liquid circulation pump of the electrolytic solution of the invention of claim 6 is arranged on the upper plane side formed by the entire electrolytic solution container.
Here, the upper surface formed by the entire electrolytic solution container means a flat surface on a plane of the upper surface of the electrolytic solution container or a back surface thereof. The liquid circulation pump can be attached to the upper flat or a position below it, and may be attached to any position as long as the workability of the electrolytic solution container can be ensured. In particular, the movable part may be in a position where parts can be easily replaced.

The charge / discharge circulation path on the positive side of the redox flow battery using the vanadium sulfate aqueous solution of the invention of claim 1 as an electrolytic solution changes tetravalent vanadium to pentavalent vanadium by charging or changes pentavalent vanadium to tetravalent vanadium by discharging. It consists of a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the change to. The charge / discharge circulation path on the negative electrode side is an electrolysis composed of the divalent vanadium and the trivalent vanadium while the trivalent vanadium is changed to divalent vanadium by discharge or the divalent vanadium is changed to trivalent vanadium by charging. It consists of a flow of liquid.
The electrolytic solution delivered from the liquid circulation pump circulates. The cylinder for diffusing the electrolytic solution and the electrolytic solution container for accommodating the tubular body move the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container by the pressure of the electrolytic solution sent from the liquid circulation pump. That is, it circulates in the cell stack via the pipeline.

Therefore, the electrolytic solution delivered from the liquid circulation pump circulates the electrolytic solution of the electrolytic solution container delivered from the liquid circulation pump, and circulates the cylinder and the electrolytic solution container accommodating the cylinder. Diffuse the liquid. Therefore, the electrolytic solution in the electrolytic solution container that circulates in the cell stack in the pipeline is uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pump has a complicated flow of the electrolytic solution due to the double-layered tubular body and the electrolytic solution container accommodating the tubular body. Therefore, vanadium having different valences. As a result of better mixing and circulating it as the electrolytic solution, the electrolytic solution in the electrolytic solution container circulating in the cell stack is uniformly distributed, and the redox flow battery using the vanadium sulfate aqueous solution as the electrolytic solution The electromotive force is stable.

Since the liquid circulation pump for circulating the electrolytic solution of the redox flow battery of the invention of claim 2 is attached so as to be accommodated in the upper part of the cylinder, in addition to the effect according to claim 1, the cylinder Since the liquid circulation pump to be accommodated in the upper part of the body is attached, when the liquid circulation pump is accommodated in the upper part of the cylinder, various parts can be accommodated in the cylinder, and parts can be replaced in units of the cylinder in case of failure. It will be possible.

The redox flow battery of the invention of claim 3 is provided with LED illumination for determining the color of the electrolytic solution and a color sensor for detecting the color of the electrolytic solution under the LED illumination. In addition to the effect according to claim 2, since the color of the electrolytic solution of the redox flow battery is detected by the LED illumination and the color sensor under the LED illumination, it affects the depth of the electrolytic solution. There is no need for maintenance because it is not affected and is not affected by the number of years of use.

The redox flow battery of the invention of claim 4 further provides a float sensor in the cylinder for detecting the liquid level position of the electrolytic solution in the cylinder, and therefore any of claims 1 to 3. In addition to the effect described in one, since the float sensor for detecting the liquid level position of the electrolytic solution is provided in the cylinder, the float sensor can be managed by the cylinder, and the movement can be performed in the controlled state. Since it is possible, it is possible to save the trouble of protecting it with a cushioning material or the like.

Since the redox flow battery of the invention of claim 5 further has a breathing hole and a filter attached to the upper part of the cylinder, in addition to the effect according to any one of claims 1 to 4. Since the breathing hole and the filter are assembled in the upper part of the cylinder, the change in the volume of the outside temperature of the electrolytic solution with respect to the change in the outside temperature is offset by the change in the volume of the electrolytic solution container. The change is small with respect to the amount of change in the air for breathing.
Further, since the amount of air passing through the filter changes with a small amount of air, dust and the like are not drawn in.

Since the liquid circulation pump of the redox flow battery of the invention of claim 6 is arranged on the upper plane side formed by the entire electrolytic solution container, any one of claims 1 to 5 is applied. In addition to the effects described, it is arranged on the upper surface side formed by the entire electrolyte container.

FIG. 1 is a configuration diagram illustrating the principle of the redox flow battery according to the embodiment of the present invention. FIG. 2 is a configuration diagram illustrating the principle of a redox flow battery of another example of the embodiment of the present invention. FIG. 3 is a configuration diagram for explaining the principle of the cell stack of the redox flow battery according to the embodiment of the present invention, (a) is a partially developed view of the cell stack, (b) is a partial assembly drawing, and (c) is a redox flow. It is a partial assembly drawing as a battery. FIG. 4 is a configuration diagram illustrating the principle of the impeller pump of the redox flow battery according to the embodiment of the present invention. FIG. 5 is an explanatory diagram illustrating an operation using one liquid circulation pump of the redox flow battery according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating an operation using two liquid circulation pumps of the redox flow battery according to the embodiment of the present invention. FIG. 7 is a wavelength / sensitivity characteristic diagram of “purple” and “green” and “yellow” and “blue” for explaining the principle of the redox flow battery according to the embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating the principle of the color triangle used in the redox flow battery according to the embodiment of the present invention. FIG. 9 is an explanatory diagram illustrating an electrolytic solution distributor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 10 is an explanatory diagram illustrating attachment of an electrolytic solution distributor to be attached to an electrolytic solution container used in the redox flow battery of the embodiment of the present invention to the electrolytic solution container. FIG. 11 is an explanatory diagram of a float sensor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 12 is an explanatory diagram illustrating an arrangement of a float sensor and an electrolytic solution distributor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 13 is a block diagram showing a control operation used in the redox flow battery according to the embodiment of the present invention. FIG. 14 is a flowchart showing a control operation used in the redox flow battery according to the embodiment of the present invention. FIG. 15 is an explanatory view using a pair of electrolyte containers used in the redox flow battery according to the embodiment of the present invention. FIG. 16 is an explanatory view using two pairs of electrolyte containers used in the redox flow battery according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, the same symbols and the same symbols shown in the drawings are the same or corresponding functional parts, and thus the duplicate description thereof will be omitted here.

[Embodiment]
In FIG. 1, the known solar panel 301 is an aggregate of solar cells, and although one electromotive force is small, it is boosted to a specific voltage by connecting a plurality of them in series. In order to charge the redox flow battery 300, the voltage is applied so that the applied voltage of the electromotive force on the solar panel 301 side is approximately 1.4 to 1.6 times. In some cases, the initial charging voltage is lowered and the charging voltage is increased as the charging progresses. The electric power that can be generated by one battery (one cell) is roughly 10 to 100 watts if one side is several tens of centimeters. In a photovoltaic power generation system used for a house, a plurality of solar panels 301 are used and are connected to a power conditioner via a junction box. The power generated by the solar panel 301 is consumed in the home via the inverter 304 or transmitted to another home via the electric wire for selling power, and is connected to the power selling power grid according to the regulation of selling power. In this case, power is supplied to the power sale power grid. The description of this junction box will be omitted, and only the backflow prevention diodes 302 and 303 will be described.

Further, the backflow prevention diodes 302 and 303 are connected to both ends of the backflow prevention diodes 302 and 303 so as not to short-circuit the redox flow battery 300 with the solar panel 301 when charging the redox flow battery 300. The forward voltage drop of the backflow prevention diodes 302 and 303 can be ignored by increasing the electromotive force on the solar panel 301 side when charging the redox flow battery 300.

However, since the backflow prevention diodes 302 and 303 have a high backflow withstand voltage, they can be used as protection for the solar panel 301. If a power diode is used, the withstand voltage can be increased, and if n diodes are connected in series, the reverse withstand voltage can be increased by n times or the like.

The inverter 304 is a device that converts a direct current into an alternating current having a predetermined frequency and a predetermined voltage, and technically performs PWM modulation or the like. Since it is difficult to convert the voltage and frequency of alternating current as it is, we have adopted a technology that converts alternating current to direct current and then back to alternating current. A device that converts alternating current to direct current and then returns it to alternating current is called an "inverter circuit" or "inverter device." Generally, a circuit that converts alternating current to direct current is a "converter," and a circuit that converts direct current to direct current again is called an "inverter circuit." , Here it is called "inverter".
In FIG. 1, the commercial power supply 305 is a single-phase 100 [V], but it may be sold at 200 [V] or another voltage.

When the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], when charging the redox flow battery 300 at the terminal of the solar panel 301, Vb> Va, and the lead Charging the negative electrode 24 and lead wire 26A of the cell stack 20 through the wire 27B and the positive electrode 65 of the cell stack 60, through the negative electrode 64 and the lead wire 26B of the cell stack 60, and further through the lead wire 26B and the positive electrode 25 of the cell stack 20. It becomes a circuit.

Further, when the output of the solar panel 301 decreases and Vb <Va, the voltage of the redox flow battery 300 is maintained. Even if the output of the solar panel 301 is exhausted, the voltage of the redox flow battery 300 is maintained if there is charging power of the redox flow battery 300.
When Vb <Va, the backflow prevention diodes 302 and 303 are in a reverse bias state. That is, the backflow prevention diodes 302 and 303 are turned off. At this time, the inverter 304 draws power from the redox flow battery 300 from the lead wire 27B and the positive electrode 65 of the redox flow battery 300 and the lead wire 26A of the negative electrode 24 of the cell stack 20, and is a commercial power source (power sale) of 50 Hz or 60 Hz. Output can be performed on the 305 side.
The output of the solar panel 301 can always be the output of the inverter 304, and the surplus power can be used for charging the redox flow battery 300.

Then, even if the backflow prevention diode 302 and the backflow prevention diode 303 are flowed in the forward direction by the solar panel 301, when the remaining discharge amount (charge electrification amount) of the redox flow battery 300 is small, the power of the redox flow battery 300 is first. Increase the amount by charging.
In particular, the color of the electrolytic solution of the color detection unit 44 shown in FIG. 10 is 100% for "yellow", ... "blue" is on the 0% side, and the color of the electrolytic solution of the color detection unit 44 is "purple". 100%, ... When "green" is set to 0%, the redox flow battery 300 is charged so that the discharge completion on the 0% side with less remaining discharge becomes "blue" or "green". ..

Further, even if the backflow prevention diode 302 and the backflow prevention diode 303 flow in the forward direction due to the increase in the output of the solar panel 301, the electric energy of the redox flow battery 300 is increased when the remaining discharge amount of the redox flow battery 300 is large. Since it is not necessary, for example, the color of the electrolytic solution of the color detection unit 44 may be displayed by an LED corresponding to the color, and the remaining discharge amount of the redox flow battery 300 due to charging may not be increased.

In the normal state, the remaining amount of discharge is 100% when it is "yellow" and 100% when it is "purple", and the 100% is changed to 90% or 80% by setting the threshold value. can do. In any case, it suffices if the remaining discharge amount of the redox flow battery 300 can be expressed in stages such as numerical expression by the LED 18 that lights up on the display 17.

To summarize this, the solar panel 301 that performs solar power generation according to this embodiment, the redox flow battery 300 that uses the vanadium sulfate aqueous solutions 15, 35 and the vanadium sulfate aqueous solutions 55, 75 as electrolytic solutions, the solar panel 301, and the solar panel 301. / Or an inverter 304 that converts the DC output of the redox flow battery 300 into AC, the solar panel 301 has a high electromotive force, and a pair of backflow prevention diodes 302 and 303 connected to the solar panel 301. When the input of the inverter 304 and the charging input of the redox flow battery 300 are obtained from the pair of cathode sides and the output of the solar panel 301 becomes low, the solar panel 301, the inverter 304, and the redox flow battery 300 It cuts off the electrical connection.

The output of the solar panel 301 changes greatly depending on the weather. For example, if one cell has an output of 1.1 to 1.6 [V], one cell stack will change from 44 [V] to 64 [V], and the input of the inverter will be from 60 [V] to 400. When it is [V], when the output of the solar panel is used, the electric power of less than 60 [V] is wasted, and the efficient use of sunlight cannot be performed.

In order to efficiently use the output of the solar panel 301, a capacitor having a large capacity such as a DC-DC converter was required, and electric power was required for boosting.
Therefore, in order to automatically solve the above-mentioned conventional problems, in particular, even in a constant voltage state where the secondary battery is not charged, the flow of the electrolytic solution of one cell stack is connected like a parallel connection. By increasing the secondary voltage in which the output is connected in series with a lower fluid resistance, the power of the solar panel can be sold directly through a normal inverter, and the input voltage that can be used by the inverter can be increased.

The solar panel 301, the inverter 304, and the redox flow battery 300 are collectively referred to as a redox flow battery configuration.
As described above, when the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], the operation is performed with Va ≦ Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va ≦ Vb becomes Va <Vb due to the forward voltage drop of the pair of backflow prevention diodes 302 and 303.

In the redox flow battery 300 of the present embodiment, the color (color) of the electrolytic solution of the color detection unit 44 is guided by the optical fiber 46 (see FIG. 10) on the negative electrode side. The color is guided from the color detection unit 44 to the color sensor 17 at the end, and the remaining amount of discharge is output to the LED 18 as a display for each output.
As for the remaining amount of discharge, the color sensor 17 at the upper end of the optical fiber 46 can display "yellow" as the remaining amount of 90 to 100% and "purple" as the remaining amount of 90 to 100%.
In any case, the magnitude of the remaining discharge amount of the redox flow battery 300 can be expressed.

If there is a color corresponding to any of the "purple" and "green" regions and the "yellow" and "blue" regions of the electrolytic solution from the color of the electrolytic solution of the color detection unit 44, it is located at the upper end of the optical fiber 46. It can be detected by the color sensor 17. At this time, the numerical value with the display 18 such as the LED should be the same in principle. However, there are times when the numbers are far apart. The reason is that when a foreign substance is mixed in the electrolytic solution on the negative electrode side or the positive electrode side, the optical fiber 46 and the color sensor 17 are abnormal.

When the numerical value with the display 18 is wide open, it is an abnormality of the redox flow battery 300 of the present embodiment, and it is necessary to notice it and repair it as soon as possible. Even when foreign matter enters the electrolytic solution, the characteristics of the redox flow battery 300 are lost, so it is necessary to repair it as soon as possible.
Of course, in the color display composed of the optical fiber 46 and the color sensor 17, the values calculated from both colors do not match exactly, so one display 18 is used rather than two displays 18 on the negative electrode side and the positive electrode side. Is cheap.

Therefore, when the backflow prevention diode 302 and the backflow prevention diode 303 flow in the forward direction by the solar panel 301, the operation when the remaining discharge amount of the redox flow battery 300 is large and the remaining amount of discharge of the redox flow battery 300 is low. For example, when the remaining amount of discharge is 60% or less, the electric energy of the redox flow battery 300 is raised to 100%, and then normal control is started. For example, when the color of the electrolytic solution of the color detection unit 44 is "yellow" 100% or less, or when the color of the electrolytic solution of the color detection unit 44 is "purple" 100% or less, the remaining discharge amount becomes 100%. In some cases.
In this case, the backflow prevention diode 302 and the backflow prevention diode 303 are flowed in the forward direction by the solar panel 301, and the redox flow battery 300 is charged by the solar panel 301 while being used as power sales to the commercial power supply 305 by the inverter 304. To do.

When the remaining amount of discharge is set to, for example, "yellow" is less than 100% and "purple" is less than 100% by the color sensor 17 at the end of the optical fiber 46, the inverter 304 is controlled by the inverter. The input can be cut off and the redox flow battery 300 can be charged. In this case, the redox flow battery 300 is started from a 100% charged state, and only the electric power required for charging the redox flow battery 300 is supplied. The original surplus power operates the inverter 304 side, and even if the output of the solar panel 301 decreases, the inverter 304 continues its control.

In this way, when the LED 18 as a display by the color sensor 17 corresponds to the "yellow" and "purple" of the electrolytic solution, the input of the inverter 304 can be cut off and the redox flow battery 300 can be started from 100% charge completion. it can. Further, the redox flow battery 300 has a remaining amount for one day, and the redox flow battery 300 can also output the remaining amount.

As shown in FIG. 1, the electrolytic solution containers 11, 31, 51, 71 on the negative electrode side are filled with the vanadium sulfate aqueous solutions 15, 25, 55, 75. The vanadium sulfate aqueous solutions 15, 25, 55, 75 are combined with the cell stacks 20, 60 in which the required number of diaphragms 23A, 23B are laminated and the electrolyte containers 15, 25, 55, 75 by the liquid circulation pumps 12, 32, 52, 72. A circulation pipe for the electrolytic solution is formed between the circulation pipe 13a, the liquid circulation pump 12, the circulation pipe 13b, and the circulation pipe 13c. At the same time, a circulation pipe for the electrolytic solution is formed between the cell stacks 20 and 60 and the electrolyte containers 11 and 15 by the circulation pipe 53a, the liquid circulation pump 52, the circulation pipe 53b, and the circulation pipe 53c. Regarding the circulation pipe line 13 and the circulation pipe line 33, the subscripts a, b, c, and d may be omitted.

Similarly, the electrolytic solution containers 11, 31, 51, 71 on the positive electrode side are filled with the vanadium sulfate aqueous solutions 15, 25, 55, 75. The vanadium sulfate aqueous solution 15, 25, 55, 75 is provided between the cell stacks 20, 60 in which the required number of diaphragms are laminated and the electrolyte container 15, 25, 55, 75 by the liquid circulation pumps 12, 32, 52, 72. Circulation pipelines 33a, 73a, liquid circulation pumps 12, 32, 52, 72, circulation pipelines 33b, 73b, and circulation pipelines 33c, 73c form circulation pipelines.

Next, as the present embodiment, the stacking steps of the cell stacks 20 and 60 shown in FIGS. 3A to 3C will be described.
A single cell having a plurality of positive electrode 102, diaphragm 103, negative electrode 104, bipolar plate 105, a pair of current collector plates, a pair of cushion layers, a bipolar plate 105 on which a metal layer is formed, and a frame 101 mounted on the outer periphery thereof. The cell stacks 20 and 60 are composed of a set of (smallest unit cells).

More specifically, a pair of end plates 101 and a tightening mechanism 107 for tightening the end plates 101 are prepared. The tightening mechanism 107 is interposed between the tightening shaft 108, the nuts 110 screwed to both ends of the tightening shaft 108, and the nut 110 and the end plate 101.

The entire cell stacks 20 and 60 are housed in a self-tack container 120 having an air passage for the fan 111 arranged at the top along a fin functioning as a heat exchanger. The self-tack container 120 is provided with a required number of cooling fans 111 for cooling the cell stacks 20 and 60 so that cooling can be performed as needed.

The bottom surface side of the cell stacks 20 and 60 also has a wave structure 112 in which the self-tack container 120 floats from the cell stacks 20 and 60. That is, the cell stacks 20 and 60 are stored in the self-tack container 120 and are cooled by the cell stacks 20 and 60 and the self-tack container 120.

Then, the tightening shaft 108 and the nut 110 are attached to the end plate 101. The end plate 101 to which the tightening shaft 108 is attached is parallel to the installation surface, a current collector plate is arranged on the end plate 101, and a cushion layer is interposed therein to form a bipolar plate 105 on which a metal layer is formed. Stack the cell frames you have. Subsequently, a single cell composed of a positive electrode 102, a negative electrode 104, a diaphragm 104, and a negative electrode 104 (positive electrode 102) is repeatedly laminated. In this laminating step, the positive electrode 102, the diaphragm 103, and the negative electrode 104 are sequentially stacked one by one on the current collecting structure. A predetermined number of cell frames, a laminated body in which a positive electrode 102, a diaphragm 103, and a negative electrode 104 are laminated may be repeatedly placed on the current collecting structure on the end plate 101. Then, after laminating the desired number of cells, the cell frame having the bipolar plate 105 on which the metal layer is formed is attached to the last cell again, and the current collector plate is laminated with the cushion layer interposed therebetween.

By forming a metal layer made of a metal material having a higher conductivity than the bipolar plate 105 on the bipolar plate 105, the electrode plates 102 and 102 and the bipolar plate 105 can be easily made conductive. In addition, by interposing a flexible cushion layer between the bipolar plate 105 and the current collector plate, particularly between the metal layer formed on the bipolar plate and the current collector plate, even under negative pressure, A large conduction area between the metal layer and the current collector plate can be obtained. Therefore, the resistance between the current collector plate and the bipolar plate 105 can be reduced, and the increase in resistance can be suppressed.
Since the resistance between the current collector plate and the bipolar plate 105 can be reduced and the increase in resistance under negative pressure can be suppressed, the electrical loss due to resistance such as a decrease in battery output and a decrease in battery capacity can be reduced. Can be done. Therefore, the battery has less electrical loss.

In the cell stacks 20 and 60, electrode plates 102 are alternately arranged, and the negative electrode side cell paths 21, 61 or the positive electrode side cell paths 22, 82 are formed by the diaphragms 23A and 23B between the negative electrodes 24 and 64 and the positive electrodes 25 and 65. The charge / discharge circuit is formed by the lead wires 26A and 27B.
That is, the cell stacks 20 and 60 have the negative electrode side cell paths 21 and 61 and the positive electrode side cell paths 22 and 62 in which the vanadium sulfate aqueous solutions 15, 35, 55 and 75 of the electrolytic solution containers 11, 31, 51 and 71 circulate. It is formed and the electrolytic solution is circulated by the liquid circulation pumps 12, 32, 52 and 72.

The redox flow battery 300 of the present embodiment is charged from the solar panel 301 when its terminal voltage is low. To be precise, the redox flow battery 300 is charged from the solar panel 301 with a voltage equal to or higher than the voltage obtained by adding twice the forward voltage drop of the backflow prevention diodes 302 and 303 to the output of the solar panel 301.
When the terminal voltage of the redox flow battery 300 is the output voltage value of the solar panel 301, the inverter 304 converts direct current into alternating current and outputs electric power to the commercial power supply 305 side.

At this time, if the output of the solar panel 301 is reduced, the solar panel 301 is in a reverse bias state by the backflow prevention diodes 302 and 303, so that the solar panel 301 is protected from the redox flow battery 300. However, since the redox flow battery 300 is the input of the inverter 304, there is a possibility that the charging voltage of the redox flow battery 300 will be used.
Therefore, as shown in FIGS. 1 and 2, the backflow prevention diode 302 is connected in the forward direction to the connection point between the solar panel 301 and the inverter 304, and the side connected to the connection point between the solar panel 301 and the inverter 304. The backflow prevention diode 302 is connected in the forward direction to the lead wires 26A and 27B of the above.

As a result, the electromotive force of the solar panel 301 is output to the inverter 304, and the redox flow battery 300 can be charged when the load on the inverter 304 side is small or when the electromotive force of the solar panel 301 is large.
Therefore, when the load of the inverter 304 is light, the electromotive power of the solar panel 301 mainly charges the redox flow battery 300, and in the normal state, the electromotive power of the solar panel 301 is output according to the load of the inverter 304. , The redox flow battery 300 is charged with the surplus electric power.
When there is no electromotive force of the solar panel 301 as in the nighttime, the redox flow battery 300 is discharged to output from the inverter 304. This output can be used as a domestic load and as an external load.

As the liquid circulation pumps 12, 32, 52, 71 used in this embodiment, smooth flow pumps (manufactured by Takumina Co., Ltd.) were used in the examples, but for example, an all-resin submersible pump sempon and a solenoid-driven diaphragm quantification Anything such as a pump (Sem Corporation) or the like in which the entire flow rate of the electrolytic solution is covered with a synthetic resin may be used. It is sufficient that the entire liquid circulation pump function is covered with resin. In any case, the constituent material constituting the pump for liquid feeding may be made of synthetic resin, and the vanadium electrolytic sulfate aqueous solutions 15, 35, 55, 75 are fed with polyethylene, polypropylene, polystyrene, nylon, polyester or the like. It forms a structure to supply.

In particular, FIG. 2 shows the cell stacks 20 and 60 of the embodiment of FIG. 1 being used as they are, and the DC output thereof is connected in series between the cell stack 20 and the cell stack 60. The negative electrode side cell path 21 of the cell stack 20 outputs the negative electrode, and the positive electrode side cell path 22 of the cell stack 20 outputs the positive electrode. Further, the negative electrode side cell path 61 of the cell stack 60 outputs the negative electrode, and the positive electrode side cell path 62 of the cell stack 60 outputs the positive electrode.
Then, in the electrolytic solution container 11, the negative electrode side cell path 21 supplies the electrolytic solution to the negative electrode side cell path 21 via the two liquid circulation pumps 12 and 52. Further, in the electrolytic solution container 31, the positive electrode side cell path 22 supplies the electrolytic solution to the negative electrode side cell path 62 via two liquid circulation pumps 32 and 72.

The redox flow battery of the present embodiment passes through an output circuit composed of at least lead wires 26A, 26B, 27A, 27B in which the outputs of two or more cell stacks 20, 60 are connected in series, and the cell stacks 20, 60. Electrode passing through the positive electrode side electrolytic solution containers 31 and 71 containing the electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 containing the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The positive electrode side charge / discharge circulation passages 33 and 73 in which the liquid flow is in the same direction for both charging and discharging, and the negative electrode side charging / discharging circulation in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. Positive electrode side liquid circulation pump 12 that increases the flow velocity between the paths 13 and 53 and the positive electrode side charge / discharge circulation paths 33 and 73 between the cell stacks 20 and 60 and the positive electrode side electrolytic solution containers 31 and 71. , 32, 52, 72 and the electrolytic solution of the negative electrode side charge / discharge circulation passages 13, 53, increase the flow velocity between the cell stacks 20, 60 and the negative electrode side electrolytic solution containers 11, 31, 51, 71. It includes the negative electrode side liquid circulation pumps 12, 32, 52, and 71.

The common liquid circulation pumps 12, 32, 52, 72 shown in FIG. 5 will be described.
The liquid circulation pump 12 enters the vanadium sulfate aqueous solution 15 of the electrolytic solution container 11 from the circulation line 13a, the liquid circulation pump 12, and the circulation line 13b from the negative side cell line 21, and is a negative circulation line via the circulation line 13a. To form.
Further, the liquid circulation pump 52 enters the vanadium sulfate aqueous solution 15 of the electrolytic solution container 15 from the negative cell side cell path 61 through the circulation line 53a, the liquid circulation pump 52, and the circulation line 53b, and enters the circulation line 13c and the circulation line 13d. A negative circulation path is formed through the pipe.

The liquid circulation pump 32 enters the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31 from the positive electrode side cell path 22 through the circulation line 33a, the liquid circulation pump 32, and the circulation line 33b, and enters the negative electrode type circulation line via the circulation line 33c. To form.
Further, the liquid circulation pump 72 enters the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31 from the positive electrode side cell path 62 through the circulation line 73a, the liquid circulation pump 72, and the circulation line 73b, and enters the circulation line 13c and the circulation line 13d. In this way, the liquid circulation pumps 12, 32, 52, 72 circulate the vanadium sulfate aqueous solutions 15, 55, 35, 65 of the negative electrode side cell paths 21, 61 to form a negative electrode circulation path through the negative electrode. A circulation path is formed for the side cell paths 21 and 61 to clarify the difference in the "valence" number of vanadium ions.

In FIG. 5, the circulation line 13a, one liquid circulation pump 12, the circulation line 13b, the electrolytic solution container 11, the circulation line 13c, the negative side cell line 21, and the vanadium sulfate aqueous solution 15 circulate from the negative side cell line 21. To do. At the same time, on the positive side, the rotation of the liquid circulation pump 32 circulates the circulation line 33a, one liquid circulation pump 32, the circulation line 33b, the positive side cell container 31 and the vanadium sulfate aqueous solution 25 from the positive side cell container 31. It shows the circulatory system.
Further, the circulation line 53a, one liquid circulation pump 52, the circulation line 53b, the electrolytic solution container 51, the circulation line 53c, the negative side cell line 61 and the vanadium sulfate aqueous solution 51 circulate from the negative side cell line 61. At the same time, due to the rotation of the liquid circulation pump 72, from the positive side cell container 62 to the circulation line 73a, one liquid circulation pump 72, the circulation line 73b, the electrolytic solution container 71, the circulation line 73c, and the negative side cell container 61. It shows a circulation system in which a vanadium sulfate aqueous solution 15 circulates.

FIG. 6 is another example of the liquid circulation pumps 12, 32, 52, and 72, and is an explanatory diagram illustrating an operation using two pumps.
The vanadium sulfate aqueous solution 15a in the electrolytic solution container 11a is discharged from the insertion circulation line 53a by the circulation line 13a, the liquid circulation pump 12a, and the circulation line 13b from the negative side cell lines 21 and 61, and is stirred. The stirred vanadium sulfate aqueous solution 15 is absorbed from the pipe line 61a, and further, from the circulation pipe line 13 _b1 , the liquid circulation pump 12b, and the circulation pipe line 13 _b2, from the insertion circulation line 53b in the electrolytic solution container 11b in the vanadium sulfate aqueous solution 15b. The discharged and stirred vanadium sulfate aqueous solutions 15 and 55 are absorbed from the pipe line 61b and returned to the negative side cell lines 21 and 61 via the circulation line 13c in the first circulation path and the second circulation path of the liquid. is there. The vanadium sulfate aqueous solution 15 of the negative electrode side cell paths 21 and 61 is circulated to form a circulation path for clarifying the difference in the "valence" number of vanadium ions with respect to the negative electrode side cell path 21.

The schematic diagram of the impeller pump as the liquid circulation pumps 12, 32, 52, 72 shown in FIGS. 1 and 2 is summarized in FIG. In addition, a gear pump, a vane pump, and the like can also be used, and the present invention is not limited to the impeller pump.
In FIG. 4, the impeller pump has a main body 201 containing an electric motor, a suction port 206 and a discharge port 207 attached to a flange 204 of the main body 201, and a flange 203 of the pump part 209 attached to the flange 204. The impeller 208 is attached to the shaft of the electric motor of the main body 201, and rotates at the same rotation speed as the electric motor.
The seat portion 202 is arranged in the opposite direction to the discharge port 207 of the impeller 208.
Therefore, when the electric motor inside the main body 201 rotates, a centrifugal force is applied to the electrolytic solution, and the electric motor jumps out from the discharge port 207 in the radial direction, and the suction port 206 side becomes a negative pressure. Therefore, the impeller pump functions as a liquid circulation pump 12, 32, 52, 72.
Normally, the liquid circulation pumps 12, 32, 52, 72 are used in a configuration that does not involve air.

Here, the liquid circulation pumps 12, 32, 52, and 72 are rotated at a constant speed, and the circulation pipes 13a, the liquid circulation pump 12, the circulation pipe 13b, the electrolytic solution container 11, and the circulation pipes are rotated from the negative side cell lines 21 and 61. 13c, the negative side cell paths 21, 61 and the vanadium sulfate aqueous solution 15, 55 circulate. At the same time, due to the rotation of the liquid circulation pumps 12, 32, 52, 72, the positive cell path 22 to the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, the electrolyte container 31, the circulation line 33c, and the positive side cell. Roads 22, 62 and vanadium sulfate aqueous solutions 35, 75 circulate.
At this time, the solar panel 301 charges and discharges the redox flow battery 300, and the inverter 304 supplies electric power to the AC generator 305 side for selling electric power according to a specific program. The output of the solar panel 301 applies a negative voltage to the lead wire 27B and a positive voltage to the lead wire 27B as a predetermined DC voltage.

Further, even if two liquid circulation pumps 12 and 32 are arranged on the positive pressure side and the negative pressure side, the impeller 208 and the pump unit 209 are sealed between the suction port 206 side and the discharge port 207 of the impeller 208. Since it is not in a state, the fluid resistance is small and it does not make it difficult for the liquid to flow, and it can be operated with a load of 1/2 unit.
When the two liquid circulation pumps 12 and the two liquid circulation pumps 32 are driven at the same time, the flow velocity of the electrolytic solution is doubled between the suction port 206 side of the impeller 208 and the discharge port 207. Since a flow is generated, it can be driven with 0.5 times and 2 times the capacity. The same applies when three liquid circulation pumps 12 and three liquid circulation pumps 32 are arranged, and the pumps can be driven with a set capacity as needed.
Although it is described that the liquid circulation pumps 12, 32, 52, and 71 are used in series, they may be connected in parallel or in series-parallel connection.

FIG. 6 shows the circulation pipe line 13a, one liquid circulation pump 12a, the circulation pipe line 13b, the circulation pipe line 13 _b1 of the electrolytic solution container 11a, the other liquid circulation pump 12b, and the electrolytic solution from the negative side cell path 21. It circulates with the circulation line 13 _{b2 of} the container 11b, the circulation line 13c of the electrolyte container 11b, and the cell line 21 on the negative side.

Further, the vanadium sulfate aqueous solution 15, 35, 55, 65 changes as shown in the following chemical formula.
Positive reactions _{^{VO 2+ + H 2 O → /}} ← VO 2 + + e - + 2H +
(4 valence (blue)) (5 valence (yellow))
The negative electrode reaction ^{VO 3+ + e - → / ←} VO 2+
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions.
As described above, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions, so that sulfuric acid as the electrolytic solution can be charged and discharged. Since the vanadium aqueous solutions 15 and 35 do not deteriorate in principle, the vanadium sulfate aqueous solutions 15, 35, 55, 65 do not deteriorate.

The negative electrode divalent vanadium used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution is "purple", the trivalent vanadium is "green", and the positive electrode tetravalent vanadium is "blue". , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is “blue” and the pentavalent vanadium is “yellow”, and the colors on the region connecting “yellow” and “blue” with a straight line. Will be moved.
It moves on the region where the divalent vanadium "purple" and the trivalent vanadium "green" of the negative electrode are connected by a straight line. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode. Logically, the color changes linearly, but it can be said that the area changes due to an error or the like.

The negative electrode used for the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution is "purple" for divalent vanadium, "green" for trivalent vanadium, and "green" for the positive electrode. "Blue" and pentavalent vanadium are "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is “blue (450 to 495 nm)” and the pentavalent vanadium is “yellow (570 to 590 nm)”, which is “yellow” shown in FIG. You will move the color on the area between the "blue" and. It will move on the line connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.
Note that FIG. 7 shows the relationship between wavelength and sensitivity.

As shown in the figure, the three primary colors of light, "red (Red wavelength: 625 to 740 nm)", "green (Green wavelength: 500 to 560 nm)", and "blue (Blue wavelength: 445 to 485 nm)" are the three primary colors of light. , In the present embodiment, since the color sensor 17 detects the color between "yellow" and "blue" and "purple" and "green", the three primary colors of light are not used for color detection. .. Of course, the color sensor 17 may have three colors.

Therefore, the change between "yellow" and "blue" or "purple" and "green" can be regarded as a single color "yellow change" or "blue change" having a wavelength of 380 to 780 [nm]. The color sensor 17 can detect a change in a single color and a change in a plurality of colors, respectively.
Further, according to the experiments of the inventors, it was confirmed that it can be realized by detecting a single color having a wavelength of 380 to 780 [nm].

For example, the light from the lower end of the optical fiber (8φ) is guided so that the input of the spectrophotometer (CM-700d; Konica Minolta Co., Ltd.) 16 receives light at de: 8 °. When the start of charging and the completion of discharge are measured and the reaction of the positive electrode is shown in the color triangle of FIG. 8, it becomes pentavalent "yellow" when charging is completed and becomes tetravalent "blue" when discharging is completed. As for the current remaining discharge amount, the value of the remaining discharge amount exists on the line connecting "yellow" and "blue".
In addition, white moves the position on the line connecting "yellow" and "blue". In the normal remaining discharge amount, "yellow" when charging is completed and "blue" when discharging is completed are on the region, "yellow" is 100% capacity, and "blue" is 0% remaining discharge amount. ..
According to the experiments of the inventors, a reading error was large, but a substantially proportional relationship was confirmed.

The color sensor 17 as a spectrophotometer (CM-700d; Konica Minolta Co., Ltd.) is an attempt to replace it with a circuit equipped with a color sensor (TCS34725) manufactured by Strawberry Linux (registered trademark). In addition, it was confirmed that DM-18TN manufactured by Optex FA can also be used if it is coated with a resin.
The module of the color sensor 16 equipped with the TCS34725 makes it possible to discriminate the color even in the dark by mounting the color sensor 17 so that the color of the environment does not change and by mounting the white LED.

The white light emitting diode, that is, the LED 45, approximates the emitted light of the reference color and prevents the periphery of the color detecting unit 44 from becoming dark. Further, the vanadium sulfate aqueous solution 15, 35, 55, 65 can accurately detect the color of the electrolytic solution by the transmitted light, the scattered light or the reflected light. Therefore, the electrolytic solution can be easily dispersed uniformly in the vanadium sulfate aqueous solutions 15, 35, 55, 65. The lower end of the optical fiber provided in the color detection unit 44 accurately detects the color of the electrolytic solution of the vanadium sulfate aqueous solutions 15, 35, 55, 65 by using transmitted light, scattered light, or reflected light. The upper end of the optical fiber is connected to the detection hole of a spectrocolorimeter (CM-700d; Konica Minolta Co., Ltd.).

When charging on the positive electrode side shown in the color triangle of FIG. 8 is completed, it becomes pentavalent "yellow", and when discharging is completed, it becomes tetravalent "blue". The current remaining discharge value is that the remaining discharge value is on the line connecting "yellow" and "blue".
Also, when viewed from the negative electrode side, there is a remaining discharge amount on the line connecting "purple" and "green", and "purple" when charging is completed and "green" when discharging is completed are 100 in the area. The capacity is%, and "green" is the remaining discharge amount of 0%.
These independently appear on the positive electrode on the positive electrode side and the negative electrode on the negative electrode side. However, since the positive electrode side and the negative electrode side are independent, the line connecting "yellow" and "blue" and the line connecting "purple" and "green" do not coexist. Therefore, the same information can be obtained from two systems, the positive electrode side and the negative electrode side.
In particular, it is set so that there is a remaining amount of discharge in the line connecting "yellow" to "blue" and from "purple" to "green" on the negative electrode side when charging is completed on the positive electrode side, but the change is linear. Can also be detected as an area by fixing a specific color.

In the present embodiment, "yellow" is changed to "blue" and "purple" is changed to "green", and the space between them is divided into 8 or 3 and used for evaluation of the remaining discharge amount. Of course, it may be divided arbitrarily. Explaining from "yellow" to "blue", "yellow" is the remaining discharge amount that holds 100% charged electric power. On the contrary, "blue" is 0% of the remaining discharge amount. Therefore,
100% (yellow), 75%, 50%, 25%, 0% (blue)
It can also be explained by dividing it into five stages from "yellow" to "blue" and from "yellow" to "blue".

The positive electrode tetravalent vanadium "blue (450 to 495 nm)" and pentavalent vanadium "yellow (570-590 nm)" are simply wavelengths, "yellow 590 nm", "yellow 580 nm",
It is divided into 5 or 10 pieces of "yellow 570 nm", "orange 560 nm", "orange 550 nm", "orange 540 nm", "yellow green 530 nm", "yellow green 520 nm", "yellow 810 nm", and "blue 500 nm". You can also do it.

The color sensor 17 at the upper end of the optical fiber 46 detects three colors and has a resolution of 16 bits for each color.
The white LED (380 to 780 colors) emits light so that the colors of the vanadium sulfate aqueous solution 15, 35, 55, 65, which is the electrolytic solution contained in the negative electrode side electrolytic solution containers 11, 51, can be discriminated. By installing it, it is possible to distinguish colors even in the dark.
Since the three colors of "red", "green", and "blue" of the color sensor 17 are white LEDs (380 to 780 colors), they are output by the other party. The configuration as a photocoupler is shown, and of course, it may be positively configured as a photocoupler.

Therefore, in the negative electrode, the current remaining charge / discharge amount is in the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium. Further, in the positive electrode, there is a remaining discharge amount in the amplitude at a specific wavelength estimated to be below the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.
In particular, the remaining amount of discharge can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the remaining charge / discharge amount is generally measured from the charging time and the energizing current, but a redox flow battery using vanadium sulfate aqueous solutions 15, 35, 55, 65 as an electrolytic solution. Then, when the load of the redox flow battery is applied, the remaining charge / discharge level at that time can be measured regardless of whether or not the load is applied.

Moreover, the color of the vanadium sulfate aqueous solution is under the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium and the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium. Therefore, it is determined by the color, and the reading error can be reduced.
Further, for light emission, the LDE 18 emits light at a specific frequency (white), and the negative cell paths 21 of the cell stacks 20 and 60 in which the vanadium sulfate aqueous solutions 15, 35, 55, 65 circulate and the specific frequency thereof. Since it is detected, the frequency of the emission color can be detected with a small error.

In particular, when the detection of the two emission colors is different, the detection value of the remaining charge / discharge amount with a small remaining amount of discharge is adopted so that the timing of recharging can be efficiently performed.
It is detected at which wavelength 380 to 700 [nm] in one scan the color of the current electrolytic solution composed of the vanadium sulfate aqueous solution 15, 35, 55, 65 is located.

That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" at the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium at the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple" (380 nm) and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green" (570 nm) of trivalent vanadium. At least, it suffices to have a photodetection ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

That is, the wavelength of the electrolytic solution is 380 to 700 [nm], 100% (yellow), 90%, 80%, ..., 20%, 10%, 0% (blue).
It may be divided evenly with, or weighting may be performed on three types of 〇 (yellow), Δ, and × (blue). Usually, it is desirable to evaluate on a scale of about 5.

As described above, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. In principle, the vanadium sulfate aqueous solution 15, 35, 55, 65 does not deteriorate, so that the vanadium sulfate aqueous solution 15, 35, 55, 65 does not deteriorate.
In the redox flow battery 300, since the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions, the vanadium sulfate aqueous solutions 15 and 35 as the electrolytic solution do not deteriorate in principle, and therefore vanadium sulfate. No deterioration occurs in the aqueous solutions 15, 35, 55, 65.

Next, the electrolytic solution distributor 50 that homogenizes the ends of the electrolytic solution containers 11, 31, 51, and 71 will be described.
As shown in FIGS. 1 and 2, FIGS. 9 to 15, liquid circulation is performed in circulation pipelines 13, 33, 53, 73 composed of pipes formed of a synthetic resin, for example, an electrolytic solution such as polyethylene terephthalate. It is connected to the pumps 12, 32, 52, 71 and circulates the electrolytic solutions of the vanadium sulfate aqueous solutions 15, 35, 55, 65 from the electrolytic solution containers 11, 31, 51, 71. In order to make these circulatory systems uniform, the electrolytic solution distributor 50 is standardized so that it can be applied to any electrolytic solution containers 11, 31, 51, 71.

Examples of the thermoplastic resin formed by the electrolytic solution include polyamide 46 (PA46) resin belonging to engineering plastic (engineering plastic), polyamide (PA) resin (nylon, etc.), polyacetal (POM) resin, and polycarbonate (PC). Resins, modified polyphenylene ether resins, polyethylene terephthalate (PET) resins, polybutylene terephthalates (PBT) resins, glass fiber reinforced polyethylene terephthalate resins, cyclic polyolefin resins, etc., and polytetrafluoroethylene belonging to super engineering plastics (super engineering plastics). (PTFE) resin, polysulfone (PSF) resin, polyether sulfone (PES) resin, amorphous polyarylate (PAR) resin, liquid crystal polymer (LCP) resin, polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) Resins, polyamideimide resins, etc., polyethylene (PE) resins belonging to general-purpose resins, polypropylene (PP) resins, polyvinyl chloride (PVC) resins, polystyrene (PS) resins, polyvinyl acetate (PVAc) resins, ABS resins, acrylics A nitrile styrene (AS) resin, an acrylic (PMMA) resin, or the like can be used. These may be used individually by 1 type and may be used in combination of 2 or more type. When such a thermoplastic resin is used, there is a plasticizer for plasticizing the thermoplastic resin, if necessary.

First, the electrolytic solution distributor 50 connects the insertion circulation pipes 53 to the circulation pipes 13 and 33. Further, the circulation pipes 13 and 33 may be integrally formed with the insertion circulation pipe 53 (13).
A plurality of opening holes 54 bored in the insertion circulation pipes 53 (13) through which the circulation pipes 13 and 33 discharge are provided. The area of the opening hole 54 in which the circulation pipe 53 is branched to prevent the circulation pipe 53 from descending is larger than the opening cross-sectional area of the circulation pipe 53.
The insertion circulation line 53 (13) connected to the electrolytic solution containers 11 and 31 is connected by using a connecting means such as a connector or an adhesive (not shown). Of course, packing and the like (not shown) are also used in order to improve the sealing property. However, when carrying out the present invention, it is desirable that the electrolytic solution containers 11 and 31 and the insertion circulation pipe line 53 are integrally connected and bent as necessary.

The circulation pipes 13a and 33a of the electrolyte distributor 50 are connected to the liquid circulation pumps 12, 32, 52 and 72, pass through the circulation pipes 13a and 33a from the outside of the electrolyte distributor 50, and have a large diameter pipe. The electrolytic solution is circulated inside the path 80 from top to bottom by the liquid circulation pumps 12, 32, 52, 71.
That is, the circulation pipes 13a and 33a are inserted through the upper end of the electrolyte distributor 50, and the electrolyte distributor 50, the inserted circulation pipe 93, the circulation pipe 51, and the circulation pipe 82 (13b) are made of synthetic resin pipes. It is formed integrally. The length of the electrolytic solution distributor 50 is preferably in the position range of 7/10 to 10/10, preferably 8/10 to 9/10, which is the ratio of the lengths of the electrolytic solution containers 11 and 31.
Further, the length of the electrolytic solution distributor 50 is preferably in the range of 1/10 to 810, preferably 2/10 to 4/10. The electrolytic solution distributor 50, the pipe line 51 (13b), and the pipe line 82 (13b) are integrally formed by the synthetic resin pipe.

The circulation pipe 51 (13b) and the pipe 82 (13b) of the electrolyte distributor 50 are formed as the circulation pipe 13c, and the lower end of the circulation pipe 51 (13b) is from the electrolyte distributor 50 to the electrolyte container. The electrolytic solution is made to move from the lower circulation line 51 (13b) to the circulation line 82 (13b) through 11 and 31.
The filter 84 is used for removing dust and for breathing vanadium sulfate aqueous solutions 15 and 35. Since the fastener 81 of the electrolytic solution distributor 50 is firmly fixed to the electrolytic solution containers 11 and 31, it has an elastic packing, an elastic filter, and a sealing structure so that the processing liquid does not leak. Then, the fastener 81 can be firmly attached to the electrolytic solution containers 11 and 31.
A color detection unit 44 is formed in the lower part of the electrolytic solution distributor 50, and a white LED 45 is fixed on one surface of the substrate 48. The entire surface of the white LED 45 is molded with a synthetic resin.

Next, the operation of the electrolytic solution distributor 50 will be described.
The electrolytic solution in the transparent large-diameter tube 92 of the electrolytic solution distributor 50 connected to the liquid circulation pumps 12, 32, 52, 72 is sent out from the liquid circulation pumps 12, 32, 52, 72, and is sent out from the liquid circulation pumps 12, 32, 52, 72. It passes through 13a and 33a and the insertion circulation pipe 93, flows into the transparent large-diameter pipe 92 through the opening hole 94 formed in the insertion circulation pipe 93, becomes a rectifying unit 49, and is supplied to the color detection unit 44. Will be done. In the color detection unit 44, the white LED 45 is electrically guided, the electrolytic solution rectified by the rectifying unit 49 is supplied to the white LED 45, and the color detection unit 44 outputs a predetermined color. The color detection unit 44 detects the internal light of the color detection unit 44 from the end of the optical fiber 46 as transmitted light, scattered light, or reflected light.

The rectifying unit 49 allows the flow of the electrolytic solution to flow without partially disturbing it, and a known shape can be used. Further, the internal light of the color detection unit 44 is detected as transmitted light, scattered light or reflected light from the end of the optical fiber 46 by the flow rate of the vanadium sulfate aqueous solution 15, 35, 55, 65 flowing through the color detection unit 44, and the color is detected. When the optical fiber 46 detects transmitted light, scattered light, or reflected light in the unit 44, the tip fixed with the adhesive of the optical fiber 46 can detect only the color by removing the focal length without adjusting the special focus. I am trying to do it. Further, by making the inside of the color detection unit 44 white, transmitted light, scattered light, or reflected light can be clearly discriminated.

Further, the lower end side of the large-diameter transparent large-diameter tube 86 is integrally joined with the end member 40 by means known for synthetic resin. On the bottom surface, a rectifying unit 49 through which an electrolytic solution flows is formed as a slit. Then, the lower portion of the insertion circulation pipe line 93 (13a) is formed as an end member 40 with a plurality of opening holes 94 provided, and a passage for the electrolytic solution is formed. That is, the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 71 descends the insertion circulation line 93, exits the insertion circulation line 93 through the plurality of opening holes 94, and exits the insertion circulation line 93, and the transparent large-diameter tube 86. It enters, descends the slit 49a, and is detected by the tips of the white LED 45 and the optical fiber 46.

When DM-18TN or the like manufactured by Optex FA is used as the color sensor 17, a photocoupler composed of a white LED 45 and three photodiodes of "red", "blue" and "green" (not shown) is used. , 380 to 700 [nm] wavelengths are swept, and it has a light detection ability to detect which color of the electrolytic solution is.
In the present embodiment, measured by Sekonic Spectromaster C-7000, the negative electrode has a divalent vanadium “purple” to a trivalent vanadium “green”, and similarly, a tetravalent vanadium “blue” to a pentavalent vanadium at the positive electrode. "Yellow" is measured, and the distance between "purple" and "green" and "blue" and "yellow" is measured, and discharge and charge are divided into 3 to 20.

Therefore, the discharge and charge are divided into 3 to 20 even scales. That is, the value of the remaining discharge amount detected by the color sensor 17 is divided into 3 to 20.
The remaining discharge amount of the redox flow battery 300 may be directly displayed on the display 17, but since it is usually sufficient to numerically express the electric power required for operation, for example, the remaining discharge amount of the redox flow battery 300 is the minimum of 3. It suffices if it can be set in the stage. In particular, since it is unlikely that a situation requiring charging will occur, the setting may be finely set to 20 steps or more. However, its importance is not high.

In the present embodiment, the liquid circulation pumps 12, 32, 52, 71 may be entirely covered with synthetic resin and the entire pump function is entirely covered with resin or rubber, or may be composed of them. You may be.
1 unit for circulation of divalent vanadium "purple" to trivalent vanadium "green" electrolyte at the negative electrode, 1 for circulation of tetravalent vanadium "blue" to pentavalent vanadium "yellow" electrolyte at the positive electrode Requires a stand, measure between its "purple" and "green", "blue" and "yellow", and change discharge and charge from "purple" to "green" and "blue" to "yellow" As mentioned above, it can be divided into 3 to 20 evaluations.
Therefore, at least two liquid circulation pumps 12, 32, 52, 71 are required. In any case, the number of the liquid circulation pump 12 and the liquid circulation pump 32 is an even number when two or four are added. If you look at this in pairs, it will be one or more pairs.

Next, the float sensor 100 will be described.
Vanadium sulfate aqueous solutions 15, 35, 55, 65 are in the negative electrode side electrolyte containers 11, 31, 51, 71, and vanadium sulfate aqueous solutions 15, 35, 55 are in the positive electrode side electrolyte containers 11, 31, 51, 71. , 75 are filled. The liquid levels of the electrolytic solution containers 11, 31, 51, 71 and the electrolytic solution container 31 are detected, and the liquid levels of the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 and the electrolytic solution containers 11, 31, 51, 71 are determined. The float sensor 100 to know is arranged in the electrolytic solution containers 11, 31, 51, 71 or the electrolytic solution containers 11, 31, 51, 71 containing the vanadium sulfate aqueous solutions 15, 35, 55, 75. The screw portions 105 formed on the float sensor 100 are fastened to the electrolyte containers 11, 31, 51, 71.
The float sensor 100 is provided with a center moving rod 101 at the center, and the float 123 moves up and down around the center moving rod 101. A permanent magnet is embedded in the float 123, and a float sensor 100 composed of a reed switch 124 embedded in the central moving rod 101 is arranged.
The guide cylinder 105 prevents the float 123 from colliding with the surroundings when the float 123 moves up and down around the center moving rod 101.

Therefore, for example, the electrolytic solution containers 31 and 71 on the positive electrode side are attached to the mounting holes of the center moving rod 101 provided on the top plate from the upper surface of the container in which the vanadium sulfate aqueous solutions 15, 35, 55, 75 are placed. The float sensor 100 is a float sensor 100 made of foamed synthetic resin in which a reed switch 124 is embedded inside. The float sensor 100 freely moves by a distance L, and the float sensor 100 of the float sensor 100 moves within a movement range of a distance L. There is a liquid level of the electrolytic solution, and the float sensor 100 outputs an on / off signal at a predetermined liquid level.
The water level sensor knob 128 is for screwing the electrolytic solution containers 11, 51 on the negative electrode side, and the filter 109 is for breathing the fluctuating water level of the electrolytic solution containers 11, 51 on the negative electrode side.
Further, in the present embodiment, the float sensor 100 is provided separately from the electrolytic solution distributor 50, but in the case of carrying out the present invention, the float sensor 100 can be assembled to the electrolytic solution distributor 50. For example, the float 123 may be attached to the insertion circulation pipe 93 (13a) and the pipe 81 (13b), or the float sensor 100 may be provided inside the electrolytic solution distributor 50.

In FIG. 9, for example, the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 provided with the vent holes 109 of the positive electrode side cell are firmly tightened, and the electrolytic solution container 11 and the electrolytic solution are firmly tightened. The float sensor 100 is also firmly screwed into the container 31. At this time, if necessary, a rubber packing or the like is used to perform joining with good sealing properties. Therefore, the electrolytic solution containers 11, 31, 51, 71 have two circulation pipes 13 or circulation with respect to the electrolytic solution containers 11, 31, 51, 71 connected to the liquid circulation pumps 12, 32, 52, 72. The pipeline 33 is arranged.

One optical fiber 46 and the lead wire 107 of the float sensor 100 are pulled out, and the signal of the color sensor 17, the liquid circulation pump 12, and the liquid circulation pump 32 are connected to the controller (CPU). ..

Handles 19a and 19b are formed in the electrolytic solution containers 11, 31, 51, and 71, respectively, and are movable. The electrolytic solution containers 11, 31, 51, 71 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell 22 are paired. The electrolytic solution containers 11, 31, 51, 71 circulate the electrolytic solution in the cell stack 20 divided into the negative electrode side cell path 21 and the positive electrode side cell path 22.

At this time, one liquid circulation pump 12, 32, 52, 71 is arranged, but as described above, two or two or more liquid circulation pumps may be arranged in series. As a matter of course, one or more liquid circulation pumps may be provided to equalize the sales expansion of the vanadium sulfate aqueous solution 15 and the vanadium sulfate aqueous solution 15, 25, 55, 75.

For example, as shown in FIG. 13, the liquid circulation pump 12 is paired with the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell path 22, or as shown in FIG. , Two pairs of the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell path 22 may be provided as one pair, or three or four pairs may be provided (not shown).

In the present embodiment, since the electrolytic solution distributor 50, the float sensor 100, and the electrolytic solution containers 11, 31, 51, 71 are standardized, the standardized redox flow battery 300 can be formed by selecting the battery storage body 400. ..
FIG. 13 shows an explanation in which the float sensor 100 and the electrolytic solution distributor 50 mounted on the electrolytic solution containers 11, 31, 51, 71 used in the redox flow battery 300 of the embodiment of the present invention are arranged on the frame. It is a figure.
The battery frame 401 of the battery storage body 400 is configured by molding a metal rod having a square cross section with a synthetic resin so as not to be easily corroded by acid. Inside the battery frame 401, container spaces 402 and 403 into which the electrolytic solution container 11 or the electrolytic solution container 31 can be inserted from above are integrated, and the controller storage space 404 is also integrated to form the container space 402, If the 403 and the controller storage space 404 are integrated to cause an electrolytic solution leak to a height of 1/3 to 2/3 of the electrolytic solution container 11 and the electrolytic solution container 31, if an electrolytic solution leaks, the inside thereof Liquid leakage is prevented by a container in which the container spaces 402 and 403 and the controller storage space 404 are integrated.

Further, the container integrated with the container space 402, 403 and the controller storage space 404 of the present embodiment is blow-molded using a synthetic resin film or the like, but the container space 402, 403 and the controller storage space are stored. It may be shaped so that the lower part of the space 404 communicates with each other.
A space for storing the negative electrode side cell path 21 is formed in the upper part of the controller storage space 404, and the cell stacks 20 and 60 are connected to the space.
In the present embodiment, the upper part of the controller storage space 404 constitutes the space for storing the cell stack 40B and the back surface of the lid 406 constitutes the controller of the electrolytic solution.

A control device CPU composed of a microcomputer and a control line thereof are arranged on the upper surface of the lid 206, and liquid circulation pumps 12, 32, 52, 72 and each pipe shown in FIG. 15 are arranged on the lower surface.
For example, the lead wire of the white LED 45 of the electrolyte distributor 50, the lead wire of the float sensor 100, the humidity sensor or water leak sensor of the container in which the container spaces 402 and 403 and the controller storage space 404 are integrated, a water sensor, etc. Is connected to the microcomputer CPU. In addition, it is also displayed whether or not it is operating normally, whether it is being charged or being discharged, and the like.

FIG. 13 shows that one electrolytic solution container 11 and one electrolytic solution container 31, and the electrolytic solution containers 11 and 31 are basically two pairs of a positive electrode and a negative electrode and have the same shape. The number of parts is reduced. Further, in FIG. 14, two electrolyte containers 11 and two electrolyte containers 31 are used, and the electrolyte containers 11 and 31 are basically doubled and have the same shape, so that the number of parts is different. Is reduced.
The feature of this embodiment is that one electrolytic solution container 11, 31, 51, 71 can be used several times. Other configurations are not different from FIG. One electrolyte container 11, 31, 51, 71 is 4 times, 6 times, 8 times, and so on, indicating that the number can be increased for each pair.

Further, in FIG. 14, two electrolytic solution containers 11 and two electrolytic solution containers 31 are arranged.
Of course, the negative electrode side circulates with the negative electrode side cell path 21, the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, the vanadium sulfate aqueous solution 15, the circulation line 13c, and the positive electrode side cell line 21, and the positive electrode side cell line. Return to 21. Further, the positive electrode side is connected to the liquid circulation pump 32 in series with the positive electrode side cell line 22, the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, the vanadium sulfate aqueous solution 35, the circulation line 33c, and the negative electrode side cell line 21. A system that circulates with and returns to the positive electrode side cell path 22 is added.

At this time, the outlet of the vanadium sulfate aqueous solution 15 of the negative electrode side cell path 21 and the outlet of the vanadium sulfate aqueous solution 35 of the positive electrode side cell path 22 are at the same end, or both outlets of the vanadium sulfate aqueous solution 15 of the negative electrode side cell path 21 are used. It can be the opposite end.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution in the present embodiment, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. While changing, and / or the color of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium is detected by the color sensor 17, and the positive electrode side charge / discharge state detecting unit that specifies the charging state of the positive electrode of the electrolytic solution from the color. , While changing trivalent vanadium to divalent vanadium by electric discharge or while changing divalent vanadium to trivalent vanadium by charging, and / or the color of the electrolytic solution composed of divalent vanadium and trivalent vanadium is measured by the color sensor 17. The negative electrode side charge / discharge state detection unit for detecting and specifying the charge state of the negative electrode of the electrolytic solution from the color is provided, and the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is described. The wavelength (frequency) of the remaining discharge amount is calculated from the detected value of any one or more of the transmitted light, scattered light, and reflected light of the LED arranged in the circulation conduit of the electrolytic solution, and is used from the wavelength (frequency). Identify the remaining amount of discharge.

Positive reactions _{^{VO 2+ + H 2 O → /}} ← VO 2 + + e - + 2H +
(4 valence (blue)) (5 valence (yellow))
The negative electrode reaction ^{VO 3+ + e - → / ←} VO 2+
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, vanadium sulfate as the electrolytic solution Since the aqueous solution does not deteriorate in principle, the vanadium sulfate aqueous solution 15, 35, 55, 75 does not deteriorate.

The negative electrode divalent vanadium used in the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is "purple", the trivalent vanadium is "green", and the positive electrode tetravalent vanadium is "blue". , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode changes between “blue (450 to 495 nm)” and the pentavalent vanadium changes between “yellow (570 to 590 nm)”, which is shown in FIG. You will move the colors on the area between "yellow" and "blue".
Similarly, the divalent vanadium of the negative electrode is "purple (380-450 nm)", the trivalent vanadium is "green (495-570 nm)", and the pentavalent vanadium is "yellow" and the trivalent vanadium is "green". You will move the colors on the area. It will move on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 as the electrolytic solution is "purple (380-450 nm)", the trivalent vanadium is "green (495-570 nm)", and the positive electrode. The tetravalent vanadium is "blue (450 to 495 nm)" and the pentavalent vanadium is "yellow (570 to 590 nm)". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the positive electrode has "blue (450 to 495 nm)" for tetravalent vanadium and "yellow (570 to 590 nm)" for pentavalent vanadium, which is "yellow" shown in FIG. You will move the color on the area between the "blue" and.
It will move on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

The white LED 45 constituting the light emitting element is made to output a wavelength having a frequency including 380 to 700 [nm]. In the light receiving element, since the peak of the output of the light receiving element is at any of the specific wavelengths 380 to 700 [nm] with respect to the emitted light having a specific wavelength of 380 to 700 [nm], 2 is obtained from the peak value at the negative electrode. Vanadium valence "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)", and positive vanadium "blue (450-495 nm)" to pentavalent vanadium "yellow (yellow)" 570 to 590 nm) ”.
Therefore, in the negative electrode, the current remaining charge / discharge amount is on the region connecting the “purple” of divalent vanadium and the “green” of trivalent vanadium. Further, in the positive electrode, it can be seen that there is a charge / discharge remaining amount in the amplitude at a specific wavelength estimated to be below the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, the remaining charge / discharge amount can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the remaining charge / discharge amount is generally measured from the charging time and the energizing current, but a redox flow battery using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution. In 300, when the load of the redox flow battery 300 is applied, the remaining charge / discharge amount at that time can be measured regardless of whether or not the load is applied.
Moreover, under the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, and the region connecting the blue color of tetravalent vanadium and the "yellow" of pentavalent vanadium, the vanadium sulfate aqueous solutions 15, 35, Since the colors 55 and 75 are discriminated, it is judged by the color, and the reading error can be reduced.
Further, since the LDE emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emission color can be sharply detected.

In particular, when the remaining discharge amounts of the two emission colors are different, the detection value of the remaining discharge amount that reduces the remaining charge amount is adopted, and the timing of recharging is efficiently performed.
For example, it is detected which of the scans of about 380 to 700 [nm] is the color of the current electrolytic solution composed of the vanadium sulfate aqueous solution 15, 35, 55, 75.
That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" in the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium in the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple (380 nm)" and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetecting ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution in the present embodiment, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. While changing, and / or the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium is detected by the color sensor 17, and the positive electrode side charge / discharge state detecting unit specifies the charging state of the positive electrode of the electrolytic solution from the color. And, while changing the trivalent vanadium to divalent vanadium by electric discharge or while changing divalent vanadium to trivalent vanadium by charging, and / or the color of the electrolytic solution composed of the divalent vanadium and trivalent vanadium is a color sensor. Charge / discharge state detector determined by the colors of vanadium sulfate aqueous solutions 15, 35, 55, 75 and the detection value of the color sensor 17 on the negative electrode side, which are detected by 17 and specify the charge state of the negative electrode of the electrolytic solution from the colors. The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is a detection value of transmitted light, scattered light, and reflected light of a light emitting diode arranged in the circulation conduit of the electrolytic solution. The wavelength (frequency) of the remaining discharge amount is calculated, and the smaller detected value of the wavelength (frequency) is specified as the charging power amount.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of this embodiment as the electrolytic solution, the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is a circulation tube of the electrolytic solution. The wavelength (frequency) of the remaining discharge amount is calculated from the detected values of the transmitted light or the reflected light arranged on the paths 11, 31, 51, and 71, and the smaller detected value of the wavelength (frequency) is used as the remaining amount of discharge. Identified.
In the redox flow battery 300 used as the vanadium sulfate aqueous solution 15, 35, 55, 75, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, the vanadium sulfate aqueous solution 15 as an electrolytic solution, Since 35, 55, 75 does not deteriorate in principle, the vanadium sulfate aqueous solution 15, 35, 55, 75 is unlikely to deteriorate.

Further, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 25, 55, 75 as the electrolytic solution, the pentavalent vanadium is changed to the pentavalent vanadium by charging or the pentavalent vanadium is changed to the tetravalent vanadium by the discharge. During that time, the color sensor 17 detects the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium, and the positive electrode side charge / discharge state detection unit that specifies the charging state of the positive electrode of the electrolytic solution from the color, and the discharge 3 While the valent vanadium is changed to divalent vanadium or while the divalent vanadium is changed to trivalent vanadium by charging, the color of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17 and is detected from the colors. The negative electrode side charge / discharge state detection unit that specifies the charge state of the negative electrode of the electrolytic solution is the wavelength of the charge power amount based on the peak value of the transmitted light or the reflected light of the light emitting diode arranged in the circulation conduit of the electrolytic solution. Since the (frequency) is calculated from the color, the current charging status can be accurately known.

Then, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is the electrolytic solution circulation pipeline 13. Based on the peak values of the transmitted light or reflected light of the light emitting diodes arranged at 33, 53, and 73, the smaller detection value of the positive electrode side charge / discharge state detection unit or the negative electrode side charge / discharge state detection unit is calculated as the charging power amount. Therefore, the voltage does not drop abnormally when the battery is used.

Further, since the charging power amount is calculated based on the color of the electrolytic solution, the timing of switching the spare electrolytic solution container is clarified, and the plurality of spare electrolytic solution containers can be accurately switched.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation pipeline of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection of scattered light or reflected light of the white light emitting diodes 45 arranged at 13, 33, 53, 73, the detection values of the positive electrode side charge state detection unit and / or the negative electrode side charge state detection unit are the current vanadium sulfate aqueous solution. It is detected in which of 380 to 700 scanning [nm] the color of the electrolytic solution consisting of 15, 35, 55 and 75 is.

That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" at the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium at the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple (380 nm)" and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetection ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the electrolytic solution in the detection charge / discharge state detection unit on the positive electrode side and / or the charge / discharge state detection unit on the negative electrode side. The detection value of the negative electrode side charge state detection unit of the white LED arranged in the circulation pipelines 13, 33, 53, 73 is "purple (380 to 450 nm)" of the electrolytic solution of the vanadium sulfate aqueous solution 15, 35, 55, 75. Detects at any position connecting "green (495-570 nm)" and at any position connecting "blue (450-495 nm)" and "yellow (570-590 nm)", and determines the remaining discharge amount. It is to be calculated.

At this time, from the remaining discharge amount obtained from the region of "purple (380 to 450 nm)" to "green" (495 to 570 nm) and from the region of "blue" (450 to 495 nm) to "yellow (570 to 590 nm)". The remaining amount of discharge of the electrolytic solution may be calculated by simply averaging the remaining amount of discharge obtained, or the amount of power with a small amount of discharge or the amount of power with a large amount of discharge of the remaining amount of discharge may be selected.
In any case, the difference between the two will be small during repeated use, so there is no big difference regardless of which one is selected.

FIG. 15 is an example of a redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as an electrolytic solution, and only the differences from FIG. 1 or FIG. 2 will be described.
The liquid circulation pumps 12, 32, 52, 71 rotate at a constant speed, and the cell stack is passed through the electrolytic solution container 11 and the circulation pipe 13c for accommodating the vanadium sulfate aqueous solutions 15, 35, 55, 75 via the circulation pipe 13b. It rotates in the order of the negative side cell path 21 via the negative side cell path 21 and the circulation pipe line 13d of 20.
Similarly, the liquid circulation pumps 12, 32, 52, and 71 are rotated at a constant speed, and the liquid circulation pumps 12, 32, 52, and 71 are rotated at a constant speed, and are passed through the electrolytic solution container 31 and the circulation pipe 33c for accommodating the vanadium sulfate aqueous solutions 15, 35, 55, 75 via the circulation pipe 33a. The cell stack 20 rotates the negative electrode side cell path 21 of the cell stack 20 via the positive electrode side cell path 22B and the circulation line 33c.

Here, the electrolytic solution container 11 and the negative electrode side cell in which the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, and the vanadium sulfate aqueous solutions 15, 25, 55, 75 of the electrolytic solution container 11 circulate from the negative electrode side cell path 21 Road 21, negative electrode side cell line 21, negative electrode side cell line 21, circulation line of circulation line 13d, and from positive electrode side cell line 22 to circulation line 33a, liquid circulation pump 32, circulation line 33b, electrolyte container. It circulates in the electrolytic solution container 31 in which the vanadium sulfate aqueous solution 35 of 31 circulates, the positive electrode side cell path 22, and the circulation conduit of the circulation conduit 33d.
In this embodiment, the liquid circulation pumps 12, 32, 52, and 71 are not increased.

In this way, the cell stacks 20 and 60 make the circulation pipelines of the vanadium sulfate aqueous solution 15, 35, 55, 75 and the vanadium sulfate aqueous solution 15, 35, 55, 75 independent, and the vanadium sulfate aqueous solution 15, 35, 55, By making 75 independent of each other and increasing the volumes of the electrolytic solution container 11 and the electrolytic solution container 31 of the vanadium sulfate aqueous solution 15, 35, 55, 75 and the vanadium sulfate aqueous solution 15, 35, 55, 75, the output time is lengthened. can do.
The output voltage can be determined by connecting the cell stacks 20 and 60 in series in the circulation direction. The voltage of the cell stacks 20 and 60 is determined by the positive electrode 24 and the negative electrode 25 sandwiching the diaphragm plate 23, and the area of the positive electrode 24 and the negative electrode 25 determines the rated energizing current.

That is, in FIG. 15, the areas of the positive electrode 24 and the negative electrode 25 on the cell stack 20 side and the areas of the positive electrode 24 and the negative electrode 25 on the cell stack 20 side are the same, and the rated energizing current is not changed. The power consumption on the cell stack 20 side is increased.
The electric power of the cell stack 20 and the cell stack 20 is used for the electric power of the control device of the redox flow battery 300 which uses the cell stack 20 as a small power consumption and the vanadium sulfate aqueous solutions 15 and 35 of the present embodiment as the electrolytic solution. is there.

When the present invention is carried out, it is not always necessary to separate the cells into the cell stack 20, but if the structure of the cell stack 20 is added as in this embodiment, the cells are circulated as the vanadium sulfate aqueous solutions 15, 35, 55, 75. Since the number of charge / discharge cycles and the reuse of the electrolytic solution have not changed, there is no disadvantage even if the cell stack 20 is mixed.
In particular, if the power for controlling the redox flow battery of the present embodiment is used from the cell stack 20 side, the deterioration of the cell stack 20 can be reduced.
The output voltage V1 of the cell stack 20 and the output voltage V2 of the cell stack 20 have a relationship of V1> V2, but V1 ≧ V2 can also be satisfied.
It is also possible to change their rated currents.

When the present invention is carried out, the cell stacks 20 and 60 have electrical characteristics such as changes in the electromotive force of the redox flow battery 300 and changes in the electromotive force of the redox flow battery 300 when charging is completed. It is for understanding the difference.
In particular, the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the redox flow battery 300 circulate as an electrolytic solution, and the number of charge / discharge cycles and the reuse of the electrolytic solution do not change. Therefore, the cell stacks 20 and 60 have a proportional relationship. Become. However, it can be changed by the power used for the characteristics of the secondary battery such as the redox flow battery 300.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation tube of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection by the transmitted light, scattered light or reflected light of the white LEDs arranged on the paths 13 and 33, the detection values of the positive electrode side charging state detecting unit and / or the negative electrode side charging state detecting unit are the vanadium sulfate aqueous solution 15, 35, 55, 75 are located in any of the "purple (380-450 nm)" and "green (495-570 nm)", "blue (450-495 nm)" and "yellow (570-590 nm)" regions of the electrolytic solution. The remaining amount of discharge is calculated from the charge / discharge characteristics of the auxiliary cells arranged in the circulation pipelines 15 and 35 of the electrolytic solution of the vanadium sulfate aqueous solution 15, 35, 55, 75, and corrected accordingly. You may.

FIG. 13 describes a control configuration of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution.
Since the redox flow battery 300, the solar panel 301, the inverter 304, and the commercial power supply 305 are the same as those in FIGS. 1 and 2, the description thereof will be omitted.

Although not shown, the control device CPU outputs a required number of humidity sensors for detecting leakage of the electrolytic solution from the electrolytic solution container 11 and the electrolytic solution container 31 and leakage from the self-tack 20 to the self-tack container 120. Is entered in two values.
Further, the required number of float sensors 100 are used as binary inputs of the control device CPU. Then, the output for lighting the required number of white LEDs 45 is output from the control device CPU for the detection output of the required number of color sensors 17. Further, the remaining discharge amount of the redox flow battery 300 is displayed on the display 18, and the display target is divided into 3 to 20. The liquid circulation pump 12 and the liquid circulation pump 32 also supply electric power to the required number of pairs of liquid circulation pumps 12, 32, 52, and 72. In the present embodiment, charging and discharging are usually performed by rotating with 100% electric power. When the charge and discharge are low, the charge and discharge are performed at a rotation speed of 1/3 to 1/10.

The redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 of the present embodiment as the electrolytic solution is controlled as shown in the flowchart of FIG.

In step S1, the humidity sensor of the redox flow battery 300 determines whether the vanadium sulfate aqueous solutions 15, 35, 55, 75 have leaked, and if so, the vanadium sulfate aqueous solution 15, 35, 55 is leaked in step S2. , 75 is used as the electrolytic solution, the positive and negative terminals of the redox flow battery 300 are opened, the charging / discharging from the redox flow battery 300 is stopped, and in step S3, the display 18 composed of LEDs blinks or one side or both sides are turned red and continuously lit. Do.
At this time, the color sensor 17 is not working at all. When the humidity sensor operates, the routine processing of steps S1 to S3 is repeatedly executed.

When it is determined in step S1 that the vanadium sulfate aqueous solutions 15, 35, 55, 75 have not leaked from the humidity sensor, the color sensor 17 in step S4 lights the numerical value or color on the display 18 made of LED in step S5. The remaining discharge amount of the vanadium sulfate aqueous solution 15, 35, 55, 75 is shown. Lighting the numerical value or color on the display 18 is not a problem during use of the redox flow battery 300, but data provided as a monitoring effect on the maintenance of the surrounding secondary batteries.
It is determined whether the value of the float sensor 100 in step S6 is within a predetermined range (a range sandwiched between a high value and a low value), and in the embodiment, the value of the float sensor 100 is higher than the predetermined liquid level. At this time, the rotation speed of the liquid circulation pump 12 is reduced.

On the contrary, when the value of the float sensor 100 is lower than the predetermined liquid level, the rotation speed of the liquid circulation pump 12 is increased. The speeds of the liquid circulation pumps 15, 35, 55, and 75 are similarly controlled in steps S6 and S7.
In step S8, the vanadium sulfate aqueous solutions 15, 35, 55, 75 are used as the electrolytic solution of the redox flow battery 300. Here, when the discharge load of the redox flow battery 300 is small, in other words, when the charge load of the redox flow battery 300 is small, this means that when the charge current or the discharge current is small, the liquid circulation pumps 12, 32, in step S9, The currents of 52 and 71 are reduced to about 1/2 to 1/10. At least the vanadium sulfate aqueous solution 15, 35, 55, 75 is circulated.

Further, in step S8, the vanadium sulfate aqueous solutions 15, 35, 55, 75 are used as the electrolytic solution of the redox flow battery 300, but when the discharge load of the redox flow battery 300 is large, that is, the charging load of the redox flow battery 300 is high. When it is large, it means that the charging current or the discharging current is large. Therefore, in step S10, the current of the liquid circulation pumps 12, 32, 52, 71 is increased to 100%, and the vanadium sulfate aqueous solution 15, 35, 55, 75 is electrolyzed. It is circulated so that it can function as a liquid.
Of course, in step S8, the redox flow battery 300 was divided into two when the charge / discharge load was large and when it was small, but in the case of carrying out the present invention, it may be divided into 1 to 5. Good.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the above embodiment as the electrolytic solution, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. During the change, the color sensor 17 detects the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium, and the positive electrode side charge / discharge state detection unit that specifies the charge state of the positive electrode of the electrolytic solution from the color, and the discharge. The color of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17 while the trivalent vanadium is changed to the divalent vanadium or the divalent vanadium is changed to the trivalent vanadium by charging. The negative electrode side charge / discharge state detection unit for specifying the charge state of the negative electrode of the electrolytic solution from the color is provided, and the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is the electrolytic solution. The remaining amount of discharge is calculated from the detection value of the color sensor 17 which is one or more of the transmitted light, the scattered light, and the reflected light of the white LED 45 of the color detection unit arranged in the circulation pipeline.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, vanadium sulfate as the electrolytic solution Since the aqueous solutions 15, 35, 55, and 75 do not deteriorate in principle, the electrolytic solution does not deteriorate.
The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. , The pentavalent vanadium is "yellow".
When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

As a precaution, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is "blue (450 to 495 nm)" and the pentavalent vanadium is "yellow (570 to 590 nm)", and "yellow" and "blue". The color between "" and "" is linearly moved as shown in FIG. 8, and is moved on the line connecting the "purple" of divalent vanadium of the negative electrode and the "green" of trivalent vanadium. In principle, it moves on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode. However, even if the error is taken into consideration, it will move on the region connecting the "blue" and "yellow" of the positive electrode.

The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, the tetravalent vanadium of the positive electrode becomes "blue" and the pentavalent vanadium becomes "yellow", and the color region between "yellow" and "blue" shown in FIG. 8 is moved.
It will move on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

Therefore, the light emitting element outputs light of a specific wavelength, and the photodiode constituting the light receiving element has a divalent vanadium "purple" to a trivalent vanadium "green" at the negative electrode based on the peak value of the output of the light receiving element. Or, in the positive electrode, it changes from "blue" of tetravalent vanadium to "yellow" of pentavalent vanadium.
Therefore, in the negative electrode, the current remaining charge / discharge amount can be detected in the region connecting the “purple” of divalent vanadium and the “green” of trivalent vanadium. Further, it can be seen that in the positive electrode, there is a charge / discharge remaining amount at a specific wavelength estimated to be on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, the remaining charge / discharge amount can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the charging time can generally be calculated from the charging time and the energizing current, but in the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution The remaining charge / discharge capacity at that time can be measured regardless of whether the load on the redox flow battery is applied or not.
Moreover, the color of the vanadium sulfate aqueous solution is discriminated by the line connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, and the line connecting the blue color of tetravalent vanadium and the "yellow" of pentavalent vanadium. Since it is a thing, it is judged by the color, and the reading error can be reduced.
Further, since the LDE 18 emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emission color can be accurately detected.

If the remaining discharge amount of the negative electrode and the positive electrode is different depending on the two colors, the detected value of the remaining amount of discharge with a small remaining amount of charge may be adopted as the detection value, or the detected value of the remaining amount of discharge may be used. The average value may be calculated. Alternatively, the power side with a large detection value of the remaining discharge amount may be used as the detection value. That is, it is detected at which wavelength the color of the current electrolytic solution consisting of vanadium sulfate aqueous solution 15, 35, 55, 75 is, and an error occurs. When there is, the divalent vanadium “purple” to trivalent vanadium “green” electrolyte at the negative electrode, as well as the tetravalent vanadium “blue” to pentavalent vanadium “yellow” electrolyte at the positive electrode, For example, the negative electrode changes the divalent vanadium "purple" and the trivalent vanadium "green", or the negative electrode changes the divalent vanadium "purple" and the trivalent vanadium "green". At least, it suffices to have a light detection ability to detect where the color of the electrolytic solution is.

Here, when the remaining amount of discharge with a small amount of remaining charge is set as the detection value, both are matched by repeated charging. Further, even if the average value of the detected values of the remaining discharge amount is calculated or the detected value of the remaining discharge amount is set as the detected value, both can be matched by repeated charging. That is, even if the detected value changes depending on the load fluctuation, the positive electrode and the negative electrode are in a well-balanced steady state by continuously charging and discharging.

The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit disposes a color detection unit 44 in the circulation pipelines 13 and 33 of the electrolytic solution, and transmits the white LED 45 arranged therein. Detects whether there is a remaining amount of discharge between the initial filling or supplementary charging of the positive electrode and / or the negative electrode and full charging by light, scattered light, or reflected light.
The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is provided in the electrolytic solution circulation pipelines 13, 33. Whether there is a remaining amount of discharge between the initial filling or supplementary charging of the positive electrode and / or the negative electrode and the full charge due to the transmitted light, scattered light, and reflected light of the white LED 45 arranged on the color detecting unit 44. Is detected.
Since the color detection unit 44 is arranged in the circulation pipes 13 and 33 of the electrolytic solution, the vanadium sulfate aqueous solution 15, 35, 55, 75 cannot stagnate. Therefore, the color sensor 17 accurately adjusts the color. I can judge.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation pipeline of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection by the transmitted light, scattered light or reflected light of the white LEDs arranged in 13 and 33, the detection values of the positive electrode side charging state detecting unit and / or the negative electrode side charging state detecting unit are vanadium sulfate aqueous solutions 15, 35. , 55, 75 are detected in any of the "purple" and "green", "blue" and "yellow" regions of the electrolytic solution, and the redox is arranged in the circulation pipelines 13 and 33 of the electrolytic solution. The remaining discharge amount is calculated by specifying from the charge / discharge characteristics of a part or all of the flow battery.

For example, the average value, the minimum value, or the maximum value is detected as to whether it is in the "purple" to "green" region or the "blue" to "yellow" region between the initial charge or supplementary charge and the full charge. From the charge / discharge characteristics of a part or all of the secondary battery arranged in the circulation conduit of the electrolytic solution, for example, the redox flow battery 300, with respect to the remaining discharge amount consisting of the average value, the minimum value, or the maximum value. It specifies and calculates the remaining discharge amount.

Further, from the viewpoint of the redox flow battery configuration, when the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], it is operated as Va ≦ Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va ≦ Vb becomes Va <Vb due to the forward voltage drop of the pair of backflow prevention diodes 302 and 303.
Then, this includes a solar panel 301 that performs solar power generation according to the embodiment, a redox flow battery 300 that uses vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, and the solar panel 301 and / or the redox flow. The inverter 304 that converts the DC output of the battery 300 into AC is provided, the solar panel 301 has a high electromotive force, and the pair of backflow prevention diodes 302 and 303 connected to the solar panel 301 are viewed from the cathode side. When the input of the inverter 304 and the charge input of the redox flow battery 300 are obtained and the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301 and the inverter 304 and the redox flow battery 300 is cut off. It is something to do.

A solar panel 301 for performing photovoltaic power generation according to this embodiment, a redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, and the solar panel 301 and / or the redox flow battery 300. It is provided with an inverter 304 that converts a DC output into an AC, and when the electromotive force of the solar panel 301 includes a forward voltage drop and Va ≦ Vb, a pair of backflow prevention connected to the solar panel 301 is provided. The input of the inverter 304 and the charging input of the redox flow battery 300 are obtained from the pair of cathode sides of the solar panels 302 and 303.
When the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301, the inverter 304, and the redox flow battery 300 is cut off. At this time, the output of the redox flow battery 300 is taken out as the output of the inverter 304, but since the load of the commercial power supply 305 becomes a light load at night, the power at night can be supplied from the redox flow battery 300 according to its capacity.
Further, when the capacity of the redox flow battery 300 is large, the electric power can be sold to the electric power company.

The above embodiment comprises a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. The charge / discharge circulation path consisting of circulation lines 33, 33a, 33b, 33c on the positive electrode side, and the above-mentioned while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging. Electrolyte solutions of vanadium sulfate aqueous solutions 15, 35, 55, 75 having a negative electrode side circulation line consisting of a flow of an electrolytic solution composed of divalent vanadium and trivalent vanadium and a charge / discharge circulation line composed of charge / discharge circulation lines 13, 13a, 13b, 13c. In the redox flow battery 300, the tubular body made of a transparent large-diameter tube 52 made of synthetic resin, which is sent out from the liquid circulation pumps 12 and 32 for circulating the electrolytic solution and diffuses the electrolytic solution, and the transparent large tube. The electrolytic solution container 11, 31, 51, 71 containing the tubular body made of the diameter tube body 52 and the electrolytic solution container 11, the electrolytic solution container 11, by the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 71. It includes a discharge pipe arranged in parallel with a cylinder made of the transparent large-diameter pipe body 86 for discharging the electrolytic solution in 31, 51, 71 to the outside of the electrolytic solution container 11, 31, 51, 71. ..

The redox flow battery using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present invention as the electrolytic solution has circulation pipelines 33, 33a, 33b on the positive side, which are composed of an electrolytic solution flow composed of tetravalent vanadium and pentavalent vanadium. The charge / discharge circulation path composed of 33c is the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the conversion of tetravalent vanadium to pentavalent vanadium by charging or the conversion of pentavalent vanadium to tetravalent vanadium by discharge. It consists of a flow.
Further, the charge / discharge circulation line consisting of the negative side circulation lines 13, 13a, 13b, 13c consisting of the flow of the electrolytic solution composed of divalent vanadium and trivalent vanadium changes the trivalent vanadium into divalent vanadium by discharge. It consists of the divalent vanadium and the trivalent vanadium while the divalent vanadium is changed to trivalent vanadium by interval or charging.

That is, the charge / discharge circulation path including the circulation lines 33, 33a, 33b, 33c, 33d on the positive electrode side forms a positive electrode as a secondary battery and is a terminal for extracting current. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 33d on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. The charge / discharge circulation paths on the positive electrode side and the negative electrode side are composed of independent charge / discharge circulation lines 33, 33a, 33b, 33c on the positive electrode side, and circulation lines 13, 13a, 13b, 13c on the negative electrode side. A charge / discharge circulation path is formed, and an electromotive force is generated by the electrolytic solution flowing there.

The electrolytic solution containers 11, 31, 51, and 71 that accommodate the tubular body made of the transparent large-diameter tube 86 and the tubular body made of the transparent large-diameter tube 92 are liquid circulation pumps 12 that circulate the electrolytic solution. The electrolytic solutions sent from 32, 52, 72 are diffused so as to be averaged, and the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tube 92 are the electrolytic solutions. It is a container for liquid.
The transparent circulation line 92 and the insertion circulation line 93 are basically not different from the circulation lines 33, 33a, 33b, 33c, 33d.
Further, the discharge pipes 81, 82 electrolyze the electrolytic solution in the electrolytic solution containers 11, 31, 51, 71 by the pressure of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. An arrangement method in which the liquid containers are circulated outside the liquid containers 11, 31, 51, 71, that is, through the pipelines to the cell stacks 20 and 60, and arranged in parallel with the cylinder made of the transparent large-diameter pipe 52. Is preferable.

In particular, the charge / discharge circulation path composed of the circulation tubes 33, 33a, 33b, 33c on the positive side of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 25, 55, 75 as the electrolytic solution is charged with tetravalent vanadium. It consists of a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the conversion to pentavalent vanadium or during the conversion of pentavalent vanadium to tetravalent vanadium by electric discharge. Further, in the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c on the negative electrode side, the divalent vanadium is changed to divalent vanadium by discharge or the divalent vanadium is changed to trivalent vanadium by charging. It consists of a flow of an electrolytic solution composed of the above-mentioned divalent vanadium and trivalent vanadium.
A cylinder made of a transparent large-diameter pipe body 85 that circulates the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72 and diffuses the electrolytic liquid, and a cylinder made of the transparent large-diameter pipe body 85 are housed. The electrolytic solution containers 11, 31, 51, 71 are the electrolytic solutions in the electrolytic solution containers 11, 31, 51, 71 due to the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. Is circulated in the cell stack via the conduit outside the electrolyte containers 11, 31, 51, 71.

Therefore, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 71 circulates the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 delivered from the liquid circulation pumps 12, 32, 52, 72. Then, the electrolytic solution circulating in the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tube 86 and the tubular body made of the transparent large-diameter tube 86 is diffused. Therefore, the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stacks 20 and 60 are uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 is subjected to the electrolytic solution by the electrolytic solution containers 11, 31, 51, 71 that accommodate the cylinder and the cylinder that are double-stacked. Is a complicated flow, so that vanadium having different valences is mixed well, and as a result of circulating it as the electrolytic solution, the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20. Is uniformly distributed, and the electromotive force of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is stable.

The liquid circulation pumps 12, 32, 52, 71 for circulating the electrolytic solution of the redox flow battery 300 of the above embodiment are attached so as to be housed in the upper part of the cylinder made of the transparent large-diameter tube 52. ..
Here, the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are housed in the upper part of the tubular body made of the transparent large-diameter tube 86, and the transparent large-diameter tube 92 By integrating it with the upper part of the tubular body made of, the outer shape can be summarized into the size of the tubular body made of the transparent large-diameter tube 92.

Since the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are attached to be housed in the upper part of the cylinder, the cylinder made of the transparent large-diameter pipe 92 is formed. Since the liquid circulation pumps 12, 32, 52, 72 to be accommodated in the upper part of the body are attached, the liquid circulation pumps 12, 32, 52, 72 can be accommodated in the upper part of the cylinder made of the transparent large-diameter pipe body 952. Then, various parts can be accommodated in the tubular body made of the transparent large-diameter tube 92, and parts can be replaced in the case of failure in the tubular unit made of the transparent large-diameter tube 92.

The LED illumination for determining the color of the electrolytic solution of the redox flow battery 300 of the present invention and the color sensor 17 for detecting the color of the electrolytic solution under the LED illumination composed of the white LED 45 are the ambient light sources. White is preferable, but other colors are not unusable. The color sensor 17 determines the color of the electrolytic solution, and it is sufficient that the color can be determined as well as the lightness and darkness.
Since the redox flow battery 300 of the present invention includes an LED illumination composed of a white LED 45 that determines the color of the electrolytic solution and a color sensor 17 that detects the color of the electrolytic solution under the LED illumination, the redox flow battery Since the color of the electrolytic solution of 300 is detected by the LED illumination and the color sensor 17 under the LED illumination, it is not affected by the depth of the electrolytic solution and also affects the number of years of use. There is no need for maintenance because it is not received.

Further, in the redox flow battery 300 of the present invention, a float sensor for detecting the liquid level position of the electrolytic solution in the cylinder made of the transparent large diameter tube 86 is further provided in the cylinder made of the transparent large diameter tube 86. It is a thing.
Here, since the float sensor 100 operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.
In the redox flow battery 300 of the present invention, since the float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder is further provided in the cylinder made of the transparent large-diameter tube 86, the transparent diameter Since the float sensor 100 can be managed with a tube body or a tube body having a square cross section and can be moved in the controlled state, the trouble of protecting with a cushioning material or the like can be saved.

Further, since the redox flow battery 300 of the present invention has a breathing hole and a filter 84 attached to the upper part of a cylinder made of a transparent large-diameter tube 92, the outside temperature of the electrolytic solution with respect to a change in the outside air temperature. Since the volume change of the above is offset by the volume change of the electrolytic solution containers 11, 31, 51, 71, the change is small with respect to the original change amount of the breathing air. Further, the amount of air passing through the filter 84 changes with a small amount of air and does not attract dust or the like.
Further, a breathing hole and a filter 84 are attached to the upper part of the tubular body made of the transparent large-diameter tube 92.
Here, the breathing hole in the upper part of the tubular body made of the transparent large-diameter tube 92 is not limited to the upper surface of the tubular body made of the transparent large-diameter tube 92, and may be at the upper position of the side surface. Good. Further, the filter 84 preferably has no hygroscopicity of the electrolytic solution, and a liquid blocking effect can be obtained by repelling the liquid.

The electrolytic solution liquid circulation pumps 12, 32, 52, 71 are arranged on the upper plane side formed by the entire electrolytic solution containers 11, 31, 51, 71.
Here, the upper plane side formed by the entire electrolyte container 11, 31, 51, 71 means a plane on the plane of the upper surface of the electrolyte container 11, 31, 51, 71 or the back surface thereof. The liquid circulation pumps 12 and 32 can be attached to the upper flat or a position below the upper flat, and any position can be used as long as the workability of the electrolytic solution containers 11, 31, 51, 71 can be ensured. .. In particular, the movable part may be in a position where parts can be easily replaced.
Since the liquid circulation pumps 12, 31, 51, 71 of the redox flow battery 300 of the present invention are arranged on the upper plane side formed by the entire electrolytic solution container 11, 31, 51, 71, the electrolytic solution Since the containers 11, 31, 51, and 71 are arranged on the upper surface side formed by the whole, maintenance can be freely performed and the workability thereof can be improved.

The redox flow battery of the present embodiment passes through an output circuit composed of lead wires 26A and 26B and lead wires 27A and 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series and the cell stacks 20 and 60. Passes through the positive electrode side electrolytic solution containers 31 and 71 for accommodating the electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The positive electrode side charge / discharge circulation paths 33 and 73 in which the flow of the electrolytic solution is in the same direction for both charging and discharging, and the negative electrode side in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. The flow velocity between the charge / discharge circulation passages 13, 53 and the electrolytic solution of the positive electrode side charge / discharge circulation passages 13, 33, 53, 73 between the cell stacks 20, 60 and the positive electrode side electrolytic solution containers 31, 71. The positive electrode side liquid circulation pumps 12, 32, 52, 72 and the negative electrode side charge / discharge circulation passages 13, 33, 53, 73 are combined with the cell stacks 20, 60 and the negative electrode side electrolytic solution container. It is provided with a negative electrode side liquid circulation pump 12, 32, 52, 71 that increases the flow velocity between the 11, 31, 51, and 71.

In the redox flow battery 300 of the present embodiment, the output voltage can be determined by an output circuit composed of a lead wire 26A and a lead wire 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series. Further, the output circuit including the lead wire 26A and the lead wire 27B connected in series can be determined in consideration of the fluid resistance of the electrolytic solution passing through the cell stacks 20 and 60.
Further, the positive electrode side electrolytic solution containers 31 and 71 and the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60 accommodate the electrolytic solution, and have a charging capacity for the electrolyzed solution. Determines the amount of electricity charged.

The positive electrode side charge / discharge circulation paths and the negative electrode side charge / discharge circulation paths 11, 31, 51, 71 in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 are in the same direction for both charging and discharging are the electrolytic solutions. Since the flow is unidirectional for both charging and discharging, the positive electrode side electrolytic solution containers 11, 31, 51, 71, the negative electrode side electrolytic solution containers 11, 31, 51, 71, and the positive electrode side charge / discharge circulation path 33. , 73, the negative electrode side charge / discharge circulation passages 31, 51, the positive electrode side liquid circulation pumps 12, 32, 52, 71 and the negative electrode side liquid circulation pumps 12, 32, 52, 72 are charged with the redox flow battery 300. It does not control the discharge, and can be naturally charged and discharged from the outside, for example, from the solar panel 301 or the like by its electromotive force.
That is, for example, even if the charging voltage of a secondary battery such as the redox flow battery 300 is low, the secondary voltage is such that the flow of the electrolytic solutions of one cell stack 20 and 60 is connected in parallel and the outputs are connected in series. By increasing the voltage, the usable input voltage of the inverter 304 can be increased.

Further, the input of the inverter 304 can be naturally converted (modulated) into alternating current by the electromotive force of the solar panel 301 or the like regardless of the charge / discharge of the redox flow battery 300.
The positive electrode side liquid circulation pumps 32, 72 for increasing the electrolyte flow velocity of the positive electrode side charge / discharge circulation passages 33, 73 and the negative electrode side liquid circulation pump for increasing the electrolyte flow velocity of the negative electrode side charge / discharge circulation passages 13, 53. In the positions 12 and 52, the positive electrode side liquid circulation pumps 32 and 72 and the negative electrode side liquid are located at any of the positive electrode side charge / discharge circulation paths 33 and 73 and the negative electrode side charge / discharge circulation paths 13 and 53 for circulating the electrolytic solution. Since the circulation pumps 12 and 52 may be arranged, the degree of freedom in design and maintenance is high.

In the redox flow battery 300 of the present embodiment, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 are single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution. A plurality of positive electrode side charge / discharge circulation paths 33, 73 and a plurality of negative electrode side charge / discharge circulation paths 13, 53 are independently piped to the containers 11 and 51 except for the diaphragms of the cell stacks 20 and 60.
Therefore, the positive electrode side electrolytic solution container 31, 71 or the negative electrode side electrolytic solution container 11, 51 of the redox flow battery 300 is a single positive electrode side electrolytic solution container 31, 71 or the negative electrode side electrolytic solution container 11, Since the plurality of positive electrode side charge / discharge circulation passages 33 and 73 and the plurality of negative electrode side charge / discharge circulation passages 13 and 53 are independently piped to 51 except for the diaphragms of the cell stacks 20 and 60, standardization is possible. On the contrary, the shape and volume of the positive electrode side electrolytic solution container 11,51 or the negative electrode side electrolytic solution container 11,51 can be arbitrary.

The redox flow battery of the present embodiment has positive electrode side electrolytic solution containers 31, 71, negative electrode side electrolytic solution containers 13, 53, positive electrode side charge / discharge circulation paths 33, 73, negative electrode side charge / discharge circulation paths 13, 53, and positive electrode side. Since one or more of the liquid circulation pumps 32 and 72 and the negative electrode side liquid circulation pumps 12 and 52 are provided for the single cell stacks 20 and 60, the liquid pressure rises with respect to the single cell stacks 20 and 60. Live less. Further, since the charge / discharge does not change depending on the location, the temperature of the electrodes 24, 25, 64, 65 does not rise due to the partial current.
Therefore, the positive electrode side electrolytic solution containers 31, 71 and the negative electrode side electrolytic solution containers 11, 51, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 73, 73a, 73b, 73c and the negative electrode side charge / discharge circulation paths. 13, 13a, 13b, 13c, 53, 53a, 53b, 53c, the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 are one for a single cell stack 20, 60. The above is provided and others.

The above embodiment comprises a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. A charge / discharge circulation path consisting of circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive electrode side, and 3 divalent vanadium during or during charging to change trivalent vanadium to divalent vanadium by discharge. The charge / discharge circulation path consisting of the negative electrode side circulation pipelines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c consisting of the flow of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium during the change to the valent vanadium. In the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, the electrolytic solution is discharged from the liquid circulation pumps 12, 32, 52, 72 that circulate the electrolytic solution. Electrolyte containers 11, 31, 51, 71 accommodating a cylinder made of a transparent large-diameter tube 92 made of synthetic resin to be diffused and a cylinder made of the transparent large-diameter tube 92, and the liquid circulation pumps 12, 32. , 52, 72 The transparent large diameter that discharges the electrolytic solution in the electrolytic solution container 11, 31, 51, 71 to the outside of the electrolytic solution container 11, 31, 51, 71 by the pressing force of the electrolytic solution sent out from It includes a discharge pipe arranged in parallel with a cylinder made of a pipe body 92.

The redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present invention as an electrolytic solution has circulation pipelines 33, 33a, 33b on the positive side, which is composed of a flow of an electrolytic solution composed of tetravalent vanadium and pentavalent vanadium. The charge / discharge circulation path composed of, 33c, 73, 73a, 73b, 73c is the above-mentioned tetravalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. It consists of a flow of an electrolytic solution composed of pentavalent vanadium and pentadium vanadium.
Further, the charge / discharge circulation path composed of the negative electrode side circulation pipelines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c composed of the flow of the electrolytic solution composed of divalent vanadium and trivalent vanadium is trivalent due to discharge. It is composed of the above-mentioned divalent vanadium and trivalent vanadium while changing vanadium to divalent vanadium or while changing divalent vanadium to trivalent vanadium by charging.

That is, the charge / discharge circulation path including the circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive electrode side forms a positive electrode as a secondary battery and is a terminal for taking out current. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. The charge / discharge circulation paths 13, 33, 53, 73 on the positive electrode side and the negative electrode side have charge / discharge circulation paths composed of independent positive electrode side circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c. A charge / discharge circulation path composed of circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side is formed, and an electromotive force is generated by an electrolytic solution flowing through the charge / discharge circulation line.

The electrolytic solution containers 11, 31, 51, and 71 that accommodate the tubular body made of the transparent large-diameter tube 92 and the tubular body made of the transparent large-diameter tube 92 are liquid circulation pumps 12 that circulate the electrolytic solution. The electrolytic solution containers 11, 31, 51, 71 for accommodating the tubular body made of the transparent large-diameter tubular body 92 are the electrolytic solution accommodating containers for averaging the electrolytic solution delivered from 32. Is.
Further, the discharge pipes 81, 82 electrolyze the electrolytic solution in the electrolytic solution containers 11, 31, 51, 71 by the pressure of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. It is circulated outside the liquid containers 11, 31, 51, 71, that is, through the pipeline, and is preferably arranged in parallel with the cylinder made of the transparent large-diameter pipe 92. is there.

In particular, a charge / discharge circulation path composed of circulation tubes 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive side of the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution. Consists of a flow of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing the tetravalent vanadium to the pentavalent vanadium by charging or changing the pentavalent vanadium to the tetravalent vanadium by the discharge. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side is divided into divalent vanadium while changing trivalent vanadium to divalent vanadium by discharge or by charging. It consists of a flow of an electrolytic solution composed of the divalent vanadium and the trivalent vanadium while changing to trivalent vanadium.
A cylinder made of a transparent large-diameter pipe 92 that circulates the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72 and diffuses the electrolytic liquid and a cylinder made of the transparent large-diameter pipe 92 are housed. The electrolytic solution containers 11, 31, 51, 71 are the electrolytic solutions in the electrolytic solution containers 11, 31, 51, 71 due to the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. Is circulated in the cell stack via the conduit outside the electrolyte containers 11 and 31.

Therefore, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 circulates the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 delivered from the liquid circulation pumps 12, 32, 52, 72. Then, the electrolytic solution circulating in the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tubular body 92 and the tubular body made of the transparent large-diameter tubular body 92 is diffused. Therefore, the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20 are uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 is subjected to the electrolytic solution by the electrolytic solution containers 11, 31, 51, 71 that accommodate the cylinder and the cylinder that are double-stacked. Is a complicated flow, so that vanadium having different valences is mixed well, and as a result of circulating it as the electrolytic solution, the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20. Is uniformly distributed, and the electromotive force of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is stable.

The liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 of the above embodiment are attached so as to be housed in the upper part of the cylinder made of the transparent large-diameter tube 92. ..
Here, the liquid circulation pumps 11, 31, 51, 71 for circulating the electrolytic solution of the redox flow battery 300 are housed in the upper part of the tubular body made of the transparent large-diameter tube 92, and the transparent large-diameter tube 92 By integrating it with the upper part of the tubular body made of the above, the outer shape can be summarized into the size of the tubular body made of the transparent large-diameter tube 92.

Since the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are attached to be housed in the upper part of the cylinder, the cylinder made of the transparent large-diameter pipe 92 is formed. Since the liquid circulation pumps 12, 32, 52, 72 to be accommodated in the upper part of the body are attached, the liquid circulation pumps 12, 32, 52, 72 can be accommodated in the upper part of the cylinder made of the transparent large-diameter tube 92. Then, various parts can be accommodated in the tubular body made of the transparent large-diameter tube 92, and parts can be replaced in the case of failure in the tubular unit made of the transparent large-diameter tube 92.

The LED illumination for determining the color of the electrolytic solution of the redox flow battery 300 of the present invention and the color sensor 17 for detecting the color of the electrolytic solution under the LED illumination composed of the white LED 45 are the ambient light sources. White is preferable, but other colors are not unusable. The color sensor 17 determines the color of the electrolytic solution, and it is sufficient that the color can be determined as well as the lightness and darkness.
Since the redox flow battery 300 of the present invention includes an LED illumination composed of a white LED 45 that determines the color of the electrolytic solution and a color sensor 17 that detects the color of the electrolytic solution under the LED illumination, the redox flow battery Since the color of the electrolytic solution of 300 is detected by the LED illumination and the color sensor 17 under the LED illumination, it is not affected by the depth of the electrolytic solution and also affects the number of years of use. There is no need for maintenance because it is not received.

Further, in the redox flow battery 300 of the present invention, a float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder made of the transparent large diameter tube 92 is further placed in the cylinder made of the transparent large diameter tube 92. It is provided.
Here, since the float sensor 100 operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.
In the redox flow battery 300 of the present invention, since the float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder is further provided in the cylinder made of the transparent large diameter tube 92, the transparent diameter Since the float sensor 100 can be managed with a tube body or a tube body having a square cross section and can be moved in the controlled state, the trouble of protecting with a cushioning material or the like can be saved.

Further, since the redox flow battery 300 of the present invention has a breathing hole and a filter 84 attached to the upper part of a cylinder made of a transparent large-diameter tube 92, the outside temperature of the electrolytic solution with respect to a change in the outside air temperature. Since the volume change of the above is offset by the volume change of the electrolytic solution containers 11, 31, 51, 71, the change is small with respect to the original change amount of the breathing air. Further, the amount of air passing through the filter 84 changes with a small amount of air and does not attract dust or the like.
Further, a breathing hole and a filter 84 are attached to the upper part of the tubular body made of the transparent large-diameter tube 92.
Here, the breathing hole in the upper part of the tubular body made of the transparent large-diameter tube 92 is not limited to the upper surface of the tubular body made of the transparent large-diameter tube 92, and may be at the upper position of the side surface. Good. Further, the filter 84 preferably has no hygroscopicity of the electrolytic solution, and a liquid blocking effect can be obtained by repelling the liquid.

The electrolytic solution liquid circulation pumps 12, 32, 52, 72 are arranged on the upper plane side formed by the entire electrolytic solution containers 11, 31, 51, 71.
Here, the upper plane side formed by the entire electrolyte container 11, 31, 51, 71 means a plane on the plane of the upper surface of the electrolyte container 11, 31, 51, 71 or the back surface thereof. The liquid circulation pumps 12 and 32 can be attached to the upper flat or a position below the upper flat, and any position can be used as long as the workability of the electrolytic solution containers 11, 31, 51, 71 can be ensured. .. In particular, the movable part may be in a position where parts can be easily replaced.
The liquid circulation pumps 12, 32, 52, 72 of the redox flow battery 300 of the present invention are arranged on the upper plane side formed by the entire electrolytic solution container 11, 31, 51, 71. Since the electrolytic solution containers 11, 31, 51, and 71 are arranged on the upper surface side formed by the whole, maintenance can be freely performed and the workability thereof can be improved.

The redox flow battery 300 of the present embodiment includes an output circuit composed of lead wires 26A and 26B and lead wires 27A and 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series, and the cell stacks 20 and 60. Passes through the positive electrode side electrolytic solution containers 31 and 71 for accommodating the passing electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The flow of the electrolytic solution passes through the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the cell stacks 20, 60 in which both charging and discharging are in the same direction. The negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, and the positive electrode side charge / discharge circulation paths 33, in which the flow of the electrolytic solution is in the same direction for both charging and discharging. , 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d, the positive electrode side that increases the flow velocity between the cell stacks 20, 60 and the positive electrode side electrolytic solution containers 31, 71. The liquid circulation pumps 32, 72 and the electrolytic solutions of the negative electrode side charge / discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are applied to the cell stacks 20, 60 and the negative electrode side. It is provided with negative electrode side liquid circulation pumps 12 and 52 that increase the flow velocity between the electrolyte containers 11 and 51.

In the redox flow battery 300 of the present embodiment, the DC output voltage can be determined by an output circuit composed of lead wires 26A and lead wires 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series. Further, the output circuit including the lead wire 26A and the lead wire 27B connected in series can be determined in consideration of the fluid resistance of the electrolytic solution passing through the cell stacks 20 and 60.
Further, the positive electrode side electrolytic solution containers 31 and 71 and the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60 accommodate the electrolytic solution, and have a charging capacity for the electrolyzed solution. Determines the amount of electricity charged.

Then, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. In the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, since the flow of the electrolytic solution is unidirectional for both charging and discharging, the positive electrode side electrolytic solution Containers 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side electrolytic solution containers 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, the positive electrode side. Charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d. The positive electrode side liquid circulation pumps 12, 32, 52, 71 and the negative electrode side liquid circulation pumps 12, 32, 52, 72 do not control the charging and discharging of the redox flow battery 300, and from the outside, for example, It can be charged and discharged naturally from the solar panel 301 or the like by its electromotive force.
That is, for example, even if the charging voltage of a secondary battery such as the redox flow battery 300 is low, the secondary voltage is such that the flow of the electrolytic solutions of one cell stack 20 and 60 is connected in parallel and the outputs are connected in series. By increasing the voltage, the usable input voltage of the inverter 304 can be increased.

Further, the input of the inverter 304 can be naturally converted (modulated) into alternating current by the electromotive force of the solar panel 301 or the like regardless of the charge / discharge of the redox flow battery 300.
The positive electrode side liquid circulation pumps 12, 32, 52, 72 and the negative electrode side charging that increase the flow velocity of the electrolytic solution in the positive electrode side charging / discharging circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d. The negative electrode side liquid circulation pumps 12 and 52 for increasing the flow velocity of the electrolytic solution in the discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are filled with the positive electrode side for circulating the electrolytic solution. The positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 may be arranged at any of the discharge circulation paths 13, 33, 53, 73 and the negative electrode side charge / discharge circulation paths 13, 53. Therefore, the degree of freedom in design and maintenance is high.
In particular, the cell stacks 20 and 60 of the redox flow battery 300 can be shortened, and even if the fluid resistance is not increased, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d And the current capacities of the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d can be secured.

In the redox flow battery 300 of the present embodiment, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 are single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution container 11. , 51, and a plurality of positive electrode side charge / discharge circulation paths and a plurality of negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are used as diaphragms of the cell stacks 20, 60. It is an independent pipe except for.
Therefore, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 of the redox flow battery 300 are combined with the single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51. On the other hand, a plurality of positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and a plurality of negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, Since 53a, 53b, 53c, 53d are independently piped except for the diaphragms of the cell stacks 20 and 60, standardization is possible, and conversely, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution The shapes and volumes of the containers 11 and 51 can be arbitrary.

The positive electrode side electrolytic solution containers 31, 71 of the redox flow battery 300 of the present invention, the negative electrode side electrolytic solution containers 11, 51, and the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c. , 73d, the negative electrode side charge / discharge circulation path, the positive electrode side liquid circulation pumps 32, 72, and the negative electrode side liquid circulation pumps 12, 52 are provided at least one for a single cell stack 20, 60. The rise in liquid pressure for a single cell stack 20, 60 lives low. Further, since the charge / discharge does not change depending on the location, the temperature of the electric 15 pole does not rise due to the partial current.
Therefore, the positive electrode side electrolytic solution containers 31, 71 and the negative electrode side electrolytic solution containers 11, 51, the positive electrode side charging / discharging circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side charging The discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, the positive electrode side liquid circulation pumps 32, 71 and the negative electrode side liquid circulation pumps 12, 52 are single cell stacks 20, One or more is provided for 60, and the other is provided.

11, 31, 51, 71 Electrode container 12, 32, 52, 72 Liquid circulation pump 13, 13a, 13b, 13c, 13d Circulation line 15, 35, 55, 75 Vanadium sulfate aqueous solution 33, 33a, 33b, 33c, 33d Circulation pipeline 53, 53a, 53b, 53c, 53d Circulation pipeline 73, 73a, 73b, 73c, 73d Circulation pipeline 17 Color sensor 20, 60 Cell stack 21 Negative electrode side cell path 22 Positive electrode side cell path 61 Negative electrode side cell Road 62 Positive electrode side cell road 44 Color detector 45 White LED
46 Optical fiber 50 Electrolytic solution distributor 92 Transparent large diameter tube 93 Insertion circulation line 100 Float sensor 121 Center moving rod 123 Float 124 Reed switch 300 Redox flow battery 400 Battery storage body

The present invention relates to a redox flow battery in which an aqueous solution of vanadium sulfate can be used as an electrolytic solution and the degree of charge / discharge state can be measured. The redox flow battery charges and discharges by separating two kinds of ion solutions with a cation exchange membrane and simultaneously advancing an oxidation reaction and a reduction reaction on electrodes (made of carbon) provided in both solutions.
The entire configuration of the redox flow battery includes a positive electrode, a negative electrode, and a diaphragm interposed between the two electrodes, and supplies and discharges a positive electrode and a negative electrode.
The negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and the additive metal ions contained in the positive electrode electrolyte are aluminum ions, cadmium ions, and indium. It contains at least one of an ion, a tin ion, an antimony ion, an iridium ion, a gold ion, a lead ion, a bismuth ion and a magnesium ion.

Specifically, the positive electrode electrolyte contains manganese ions and added metal ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, and zinc ions. The added metal ion contained in the positive electrode electrolyte is at least one of aluminum ion, cadmium ion, indium ion, tin ion, antimony ion, iridium ion, gold ion, lead ion, bismus ion and magnesium ion.

In addition to the metal ions exemplified above, lithium ion, beryllium ion, sodium ion, potassium ion, calcium ion, scandium ion, nickel ion, zinc ion, gallium ion, germanium ion, rubidium ion, strontium ion, yttrium ion, Zirconium ion, niobium ion, technetium ion, rhodium ion, cesium ion, barium ion, lanthanoid element (excluding cerium) ion, hafnium ion, tantalum ion, renium ion, osmium ion, platinum ion, tarium ion, polonium ion, Francium ion, radium ion, actinium ion, thorium ion, protoactinium ion, and uranium ion can be mentioned as added metal ions.

The redox flow batteries described in Patent Documents 1 and 2 have an active material in a liquid state, and the positive and negative electrode battery active materials are circulated in a liquid-permeable electrolytic cell and charged and discharged using a redox reaction. Is to do. It has the following advantages over other secondary batteries.
(1) In order to increase the amount of active material, the storage container capacity may be increased, and the electrolytic cell itself does not need to be increased unless the output is increased.
(2) The positive electrode and negative electrode active materials can be completely separated and stored in a container, and there is little possibility of self-discharge.
(3) In the liquid-permeable carbon porous electrode to be used, the charge / discharge characteristics (electrode reaction) of the active material ion are such that electrons are simply exchanged on the surface of the electrode without depositing on the electrode. The reaction is simple.

This redox flow type battery is composed of a diaphragm made of an ion exchange membrane, carbon cross electrodes (positive electrode and negative electrode) provided on both sides thereof, and end plates provided on the outside thereof, and the positive electrode electrolyte and the negative electrode electrolyte are It is sent from the positive electrode electrolyte container and the negative electrode electrolyte container to the positive electrode and the negative electrode, respectively.
In the initial charge, vanadium tetravalent is oxidized to pentavalent at the positive electrode, vanadium tetravalent is reduced to trivalent at the negative electrode, and vanadium trivalent is reduced to divalent at the negative electrode, but overcharge and oxygen evolution are generated at the positive electrode. Produces. In order to avoid this, it was necessary to replace the electrolytic solution with a tetravalent vanadium solution when the positive electrode solution was fully charged. When the battery is charged in this state, vanadium is oxidized from tetravalent to pentavalent on the positive electrode side, while vanadium is reduced from trivalent to divalent on the negative electrode side. In the discharged state, the opposite reaction will occur.

Japanese Unexamined Patent Publication No. 5-242905 Japanese Unexamined Patent Publication No. 2018-137238

In addition, both are used to estimate the capacity of the secondary battery. However, since the repetitive charge / discharge characteristics of the secondary battery itself change over time and the change over time is large, there is a high tendency for the secondary battery to be overcharged under normal use conditions. That is, there was no accurate method for determining the capacity of the battery to the extent that it was decisive.
Then, the secondary battery itself became large and was not suitable for general household use.

Therefore, in order to solve the above-mentioned conventional problems, in particular, the structure of the redox flow battery using the vanadium sulfate aqueous solution as the electrolytic solution is made into a common component and simplified to simplify the structure of the complicated secondary battery. The challenge is to provide a redox flow battery.

The redox flow battery of the invention of claim 1 is an electrolysis composed of the tetravalent vanadium and the pentavalent vanadium during the conversion of tetravalent vanadium to pentavalent vanadium by charging or the conversion of pentavalent vanadium to tetravalent vanadium by discharge. The charge / discharge circulation path on the positive electrode side consisting of a flow of liquid, and the divalent vanadium and trivalent vanadium said while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging. In a redox flow battery using a vanadium sulfate aqueous solution as an electrolytic solution, which includes a charge / discharge circulation path on the negative electrode side composed of a flow of the electrolytic solution, the electrolytic solution is sent from a liquid circulation pump that circulates the electrolytic solution. The electrolytic solution container that houses the tubular body and the tubular body, and the electrolytic solution that is discharged from the liquid circulation pump to discharge the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container. It is provided with a discharge pipe arranged in parallel with the cylinder.

In the redox flow battery using the vanadium sulfate aqueous solution of the invention of claim 1 as the electrolytic solution, the charge / discharge circulation path on the positive side, which is composed of the flow of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium, is charged with tetravalent vanadium. It consists of a flow of an electrolytic solution composed of the above-mentioned tetravalent vanadium and pentavalent vanadium during the conversion to valent vanadium or during the conversion of pentavalent vanadium to tetravalent vanadium by discharge.
In addition, the charge / discharge circulation path on the negative side, which consists of a flow of an electrolytic solution composed of divalent vanadium and trivalent vanadium, changes divalent vanadium to trivalent vanadium while changing trivalent vanadium to divalent vanadium by discharging or by charging. It consists of the divalent vanadium and trivalent vanadium during the change.

That is, the charge / discharge circulation path on the positive electrode side forms a positive electrode as a secondary battery, and is a terminal for taking out current. Further, the charge / discharge circulation path on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. Independent charge / discharge circulation paths on the positive electrode side and the negative electrode side are formed in the charge / discharge circulation paths on the positive electrode side and the negative electrode side, and electromotive force is generated by the electrolytic solution flowing through them.

Then, the cylinder and the electrolytic solution container accommodating the cylinder diffuse the electrolytic solutions having different valences sent from the liquid circulation pump that circulates the electrolytic solution so as to average them. The electrolytic solution container for accommodating is the electrolytic solution accommodating container.
Further, the discharge pipe circulates the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container via a pipeline and a cell stack by the pressure of the electrolytic solution sent from the liquid circulation pump. An arrangement method in which the cylinder is arranged in parallel with the cylinder is preferable.

The charge / discharge circulation path on the positive side of the redox flow battery using the vanadium sulfate aqueous solution of the invention of claim 1 as an electrolytic solution changes tetravalent vanadium to pentavalent vanadium by charging or changes pentavalent vanadium to tetravalent vanadium by discharging. It consists of a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the change to. The charge / discharge circulation path on the negative electrode side is an electrolysis composed of the divalent vanadium and the trivalent vanadium while the trivalent vanadium is changed to divalent vanadium by discharge or the divalent vanadium is changed to trivalent vanadium by charging. It consists of a flow of liquid.
The electrolytic solution delivered from the liquid circulation pump circulates. The cylinder for diffusing the electrolytic solution and the electrolytic solution container for accommodating the tubular body move the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container by the pressure of the electrolytic solution sent from the liquid circulation pump. That is, it circulates in the cell stack via the pipeline.

Therefore, the electrolytic solution delivered from the liquid circulation pump circulates the electrolytic solution of the electrolytic solution container delivered from the liquid circulation pump, and circulates the cylinder and the electrolytic solution container accommodating the cylinder. Diffuse the liquid. Therefore, the electrolytic solution in the electrolytic solution container that circulates in the cell stack in the pipeline is uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pump has a complicated flow of the electrolytic solution due to the double-layered tubular body and the electrolytic solution container accommodating the tubular body. Therefore, vanadium having different valences. As a result of better mixing and circulating it as the electrolytic solution, the electrolytic solution in the electrolytic solution container circulating in the cell stack is uniformly distributed, and the redox flow battery using the vanadium sulfate aqueous solution as the electrolytic solution The electromotive force is stable.

FIG. 1 is a configuration diagram illustrating the principle of the redox flow battery according to the embodiment of the present invention. FIG. 2 is a configuration diagram illustrating the principle of a redox flow battery of another example of the embodiment of the present invention. FIG. 3 is a configuration diagram for explaining the principle of the cell stack of the redox flow battery according to the embodiment of the present invention, (a) is a partially developed view of the cell stack, (b) is a partial assembly drawing, and (c) is a redox flow. It is a partial assembly drawing as a battery. FIG. 4 is a configuration diagram illustrating the principle of the impeller pump of the redox flow battery according to the embodiment of the present invention. FIG. 5 is an explanatory diagram illustrating an operation using one liquid circulation pump of the redox flow battery according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating an operation using two liquid circulation pumps of the redox flow battery according to the embodiment of the present invention. FIG. 7 is a wavelength / sensitivity characteristic diagram of “purple” and “green” and “yellow” and “blue” for explaining the principle of the redox flow battery according to the embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating the principle of the color triangle used in the redox flow battery according to the embodiment of the present invention. FIG. 9 is an explanatory diagram illustrating an electrolytic solution distributor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 10 is an explanatory diagram illustrating attachment of an electrolytic solution distributor to be attached to an electrolytic solution container used in the redox flow battery of the embodiment of the present invention to the electrolytic solution container. FIG. 11 is an explanatory diagram of a float sensor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 12 is an explanatory diagram illustrating an arrangement of a float sensor and an electrolytic solution distributor mounted on an electrolytic solution container used in the redox flow battery according to the embodiment of the present invention. FIG. 13 is a block diagram showing a control operation used in the redox flow battery according to the embodiment of the present invention. FIG. 14 is a flowchart showing a control operation used in the redox flow battery according to the embodiment of the present invention. FIG. 15 is an explanatory view using a pair of electrolyte containers used in the redox flow battery according to the embodiment of the present invention. FIG. 16 is an explanatory view using two pairs of electrolyte containers used in the redox flow battery according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, the same symbols and the same symbols shown in the drawings are the same or corresponding functional parts, and thus the duplicate description thereof will be omitted here.

[Embodiment]
In FIG. 1, the known solar panel 301 is an aggregate of solar cells, and although one electromotive force is small, it is boosted to a specific voltage by connecting a plurality of them in series. In order to charge the redox flow battery 300, the voltage is applied so that the applied voltage of the electromotive force on the solar panel 301 side is approximately 1.4 to 1.6 times. In some cases, the initial charging voltage is lowered and the charging voltage is increased as the charging progresses. The electric power that can be generated by one battery (one cell) is roughly 10 to 100 watts if one side is several tens of centimeters. In a photovoltaic power generation system used for a house, a plurality of solar panels 301 are used and are connected to a power conditioner via a junction box. The power generated by the solar panel 301 is consumed in the home via the inverter 304 or transmitted to another home via the electric wire for selling power, and is connected to the power selling power grid according to the regulation of selling power. In this case, power is supplied to the power sale power grid. The description of this junction box will be omitted, and only the backflow prevention diodes 302 and 303 will be described.

Further, the backflow prevention diodes 302 and 303 are connected to both ends of the backflow prevention diodes 302 and 303 so as not to short-circuit the redox flow battery 300 with the solar panel 301 when charging the redox flow battery 300. The forward voltage drop of the backflow prevention diodes 302 and 303 can be ignored by increasing the electromotive force on the solar panel 301 side when charging the redox flow battery 300.

However, since the backflow prevention diodes 302 and 303 have a high backflow withstand voltage, they can be used as protection for the solar panel 301. If a power diode is used, the withstand voltage can be increased, and if n diodes are connected in series, the reverse withstand voltage can be increased by n times or the like.

The inverter 304 is a device that converts a direct current into an alternating current having a predetermined frequency and a predetermined voltage, and technically performs PWM modulation or the like. Since it is difficult to convert the voltage and frequency of alternating current as it is, we have adopted a technology that converts alternating current to direct current and then back to alternating current. A device that converts alternating current to direct current and then returns it to alternating current is called an "inverter circuit" or "inverter device." Generally, a circuit that converts alternating current to direct current is a "converter," and a circuit that converts direct current to direct current again is called an "inverter circuit." , Here it is called "inverter".
In FIG. 1, the commercial power supply 305 is a single-phase 100 [V], but it may be sold at 200 [V] or another voltage.

When the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], when charging the redox flow battery 300 at the terminal of the solar panel 301, Vb> Va, and the lead Charging the negative electrode 24 and lead wire 26A of the cell stack 20 through the wire 27B and the positive electrode 65 of the cell stack 60, through the negative electrode 64 and the lead wire 26B of the cell stack 60, and further through the lead wire 26B and the positive electrode 25 of the cell stack 20. It becomes a circuit.

Further, when the output of the solar panel 301 decreases and Vb <Va, the voltage of the redox flow battery 300 is maintained. Even if the output of the solar panel 301 is exhausted, the voltage of the redox flow battery 300 is maintained if there is charging power of the redox flow battery 300.
When Vb <Va, the backflow prevention diodes 302 and 303 are in a reverse bias state. That is, the backflow prevention diodes 302 and 303 are turned off. At this time, the inverter 304 draws power from the redox flow battery 300 from the lead wire 27B and the positive electrode 65 of the redox flow battery 300 and the lead wire 26A of the negative electrode 24 of the cell stack 20, and is a commercial power source (power sale) of 50 Hz or 60 Hz. Output can be performed on the 305 side.
The output of the solar panel 301 can always be the output of the inverter 304, and the surplus power can be used for charging the redox flow battery 300.

Then, even if the backflow prevention diode 302 and the backflow prevention diode 303 are flowed in the forward direction by the solar panel 301, when the remaining discharge amount (charge electrification amount) of the redox flow battery 300 is small, the power of the redox flow battery 300 is first. Increase the amount by charging.
In particular, the color of the electrolytic solution of the color detection unit 44 shown in FIG. 10 is 100% for "yellow", ... "blue" is on the 0% side, and the color of the electrolytic solution of the color detection unit 44 is "purple". 100%, ... When "green" is set to 0%, the redox flow battery 300 is charged so that the discharge completion on the 0% side with less remaining discharge becomes "blue" or "green". ..

Further, even if the backflow prevention diode 302 and the backflow prevention diode 303 flow in the forward direction due to the increase in the output of the solar panel 301, the electric energy of the redox flow battery 300 is increased when the remaining discharge amount of the redox flow battery 300 is large. Since it is not necessary, for example, the color of the electrolytic solution of the color detection unit 44 may be displayed by an LED corresponding to the color, and the remaining discharge amount of the redox flow battery 300 due to charging may not be increased.

In the normal state, the remaining amount of discharge is 100% when it is "yellow" and 100% when it is "purple", and the 100% is changed to 90% or 80% by setting the threshold value. can do. In any case, it suffices if the remaining discharge amount of the redox flow battery 300 can be expressed in stages such as numerical expression by the LED 18 that lights up on the display 17.

To summarize this, the solar panel 301 that performs solar power generation according to this embodiment, the redox flow battery 300 that uses the vanadium sulfate aqueous solutions 15, 35 and the vanadium sulfate aqueous solutions 55, 75 as electrolytic solutions, the solar panel 301, and the solar panel 301. / Or an inverter 304 that converts the DC output of the redox flow battery 300 into AC, the solar panel 301 has a high electromotive force, and a pair of backflow prevention diodes 302 and 303 connected to the solar panel 301. When the input of the inverter 304 and the charging input of the redox flow battery 300 are obtained from the pair of cathode sides and the output of the solar panel 301 becomes low, the solar panel 301, the inverter 304, and the redox flow battery 300 It cuts off the electrical connection.

The output of the solar panel 301 changes greatly depending on the weather. For example, if one cell has an output of 1.1 to 1.6 [V], one cell stack will change from 44 [V] to 64 [V], and the input of the inverter will be from 60 [V] to 400. When it is [V], when the output of the solar panel is used, the electric power of less than 60 [V] is wasted, and the efficient use of sunlight cannot be performed.

In order to efficiently use the output of the solar panel 301, a capacitor having a large capacity such as a DC-DC converter was required, and electric power was required for boosting.
Therefore, in order to automatically solve the above-mentioned conventional problems, in particular, even in a constant voltage state where the secondary battery is not charged, the flow of the electrolytic solution of one cell stack is connected like a parallel connection. By increasing the secondary voltage in which the output is connected in series with a lower fluid resistance, the power of the solar panel can be sold directly through a normal inverter, and the input voltage that can be used by the inverter can be increased.

The solar panel 301, the inverter 304, and the redox flow battery 300 are collectively referred to as a redox flow battery configuration.
As described above, when the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], the operation is performed with Va ≦ Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va ≦ Vb becomes Va <Vb due to the forward voltage drop of the pair of backflow prevention diodes 302 and 303.

In the redox flow battery 300 of the present embodiment, the color (color) of the electrolytic solution of the color detection unit 44 is guided by the optical fiber 46 (see FIG. 10) on the negative electrode side. The color is guided from the color detection unit 44 to the color sensor 17 at the end, and the remaining amount of discharge is output to the LED 18 as a display for each output.
As for the remaining amount of discharge, the color sensor 17 at the upper end of the optical fiber 46 can display "yellow" as the remaining amount of 90 to 100% and "purple" as the remaining amount of 90 to 100%.
In any case, the magnitude of the remaining discharge amount of the redox flow battery 300 can be expressed.

If there is a color corresponding to any of the "purple" and "green" regions and the "yellow" and "blue" regions of the electrolytic solution from the color of the electrolytic solution of the color detection unit 44, it is located at the upper end of the optical fiber 46. It can be detected by the color sensor 17. At this time, the numerical value with the display 18 such as the LED should be the same in principle. However, there are times when the numbers are far apart. The reason is that when a foreign substance is mixed in the electrolytic solution on the negative electrode side or the positive electrode side, the optical fiber 46 and the color sensor 17 are abnormal.

When the numerical value with the display 18 is wide open, it is an abnormality of the redox flow battery 300 of the present embodiment, and it is necessary to notice it and repair it as soon as possible. Even when foreign matter enters the electrolytic solution, the characteristics of the redox flow battery 300 are lost, so it is necessary to repair it as soon as possible.
Of course, in the color display composed of the optical fiber 46 and the color sensor 17, the values calculated from both colors do not match exactly, so one display 18 is used rather than two displays 18 on the negative electrode side and the positive electrode side. Is cheap.

Therefore, when the backflow prevention diode 302 and the backflow prevention diode 303 flow in the forward direction by the solar panel 301, the operation when the remaining discharge amount of the redox flow battery 300 is large and the remaining amount of discharge of the redox flow battery 300 is low. For example, when the remaining amount of discharge is 60% or less, the electric energy of the redox flow battery 300 is raised to 100%, and then normal control is started. For example, when the color of the electrolytic solution of the color detection unit 44 is "yellow" 100% or less, or when the color of the electrolytic solution of the color detection unit 44 is "purple" 100% or less, the remaining discharge amount becomes 100%. In some cases.
In this case, the backflow prevention diode 302 and the backflow prevention diode 303 are flowed in the forward direction by the solar panel 301, and the redox flow battery 300 is charged by the solar panel 301 while being used as power sales to the commercial power supply 305 by the inverter 304. To do.

When the remaining amount of discharge is set to, for example, "yellow" is less than 100% and "purple" is less than 100% by the color sensor 17 at the end of the optical fiber 46, the inverter 304 is controlled by the inverter. The input can be cut off and the redox flow battery 300 can be charged. In this case, the redox flow battery 300 is started from a 100% charged state, and only the electric power required for charging the redox flow battery 300 is supplied. The original surplus power operates the inverter 304 side, and even if the output of the solar panel 301 decreases, the inverter 304 continues its control.

In this way, when the LED 18 as a display by the color sensor 17 corresponds to the "yellow" and "purple" of the electrolytic solution, the input of the inverter 304 can be cut off and the redox flow battery 300 can be started from 100% charge completion. it can. Further, the redox flow battery 300 has a remaining amount for one day, and the redox flow battery 300 can also output the remaining amount.

As shown in FIG. 1, the electrolytic solution containers 11, 31, 51, 71 on the negative electrode side are filled with the vanadium sulfate aqueous solutions 15, 25, 55, 75. The vanadium sulfate aqueous solutions 15, 25, 55, 75 are combined with the cell stacks 20, 60 in which the required number of diaphragms 23A, 23B are laminated and the electrolyte containers 15, 25, 55, 75 by the liquid circulation pumps 12, 32, 52, 72. A circulation pipe for the electrolytic solution is formed between the circulation pipe 13a, the liquid circulation pump 12, the circulation pipe 13b, and the circulation pipe 13c. At the same time, a circulation pipe for the electrolytic solution is formed between the cell stacks 20 and 60 and the electrolyte containers 11 and 15 by the circulation pipe 53a, the liquid circulation pump 52, the circulation pipe 53b, and the circulation pipe 53c. Regarding the circulation pipe line 13 and the circulation pipe line 33, the subscripts a, b, c, and d may be omitted.

Similarly, the electrolytic solution containers 11, 31, 51, 71 on the positive electrode side are filled with the vanadium sulfate aqueous solutions 15, 25, 55, 75. The vanadium sulfate aqueous solution 15, 25, 55, 75 is provided between the cell stacks 20, 60 in which the required number of diaphragms are laminated and the electrolyte container 15, 25, 55, 75 by the liquid circulation pumps 12, 32, 52, 72. Circulation pipelines 33a, 73a, liquid circulation pumps 12, 32, 52, 72, circulation pipelines 33b, 73b, and circulation pipelines 33c, 73c form circulation pipelines.

Next, as the present embodiment, the stacking steps of the cell stacks 20 and 60 shown in FIGS. 3A to 3C will be described.
A single cell having a plurality of positive electrode 102, diaphragm 103, negative electrode 104, bipolar plate 105, a pair of current collector plates, a pair of cushion layers, a bipolar plate 105 on which a metal layer is formed, and a frame 101 mounted on the outer periphery thereof. The cell stacks 20 and 60 are composed of a set of (smallest unit cells).

More specifically, a pair of end plates 101 and a tightening mechanism 107 for tightening the end plates 101 are prepared. The tightening mechanism 107 is interposed between the tightening shaft 108, the nuts 110 screwed to both ends of the tightening shaft 108, and the nut 110 and the end plate 101.

The entire cell stacks 20 and 60 are housed in a self-tacking container 120 having an air passage for the fan 111 arranged at the top along a fin that functions as a heat exchanger. The self-tack container 120 is provided with a required number of cooling fans 111 for cooling the cell stacks 20 and 60, so that cooling can be performed as needed.

The bottom surface side of the cell stacks 20 and 60 also has a wave structure 112 in which the self-tack container 120 floats from the cell stacks 20 and 60. That is, the cell stacks 20 and 60 are stored in the self-tack container 120 and are cooled by the cell stacks 20 and 60 and the self-tack container 120.

Then, the tightening shaft 108 and the nut 110 are attached to the end plate 101. The end plate 101 to which the tightening shaft 108 is attached is parallel to the installation surface, a current collector plate is arranged on the end plate 101, and a cushion layer is interposed therein to form a bipolar plate 105 on which a metal layer is formed. Stack the cell frames you have. Subsequently, a single cell composed of a positive electrode 102, a negative electrode 104, a diaphragm 104, and a negative electrode 104 (positive electrode 102) is repeatedly laminated. In this laminating step, the positive electrode 102, the diaphragm 103, and the negative electrode 104 are sequentially stacked one by one on the current collecting structure. A predetermined number of cell frames, a laminated body in which a positive electrode 102, a diaphragm 103, and a negative electrode 104 are laminated may be repeatedly placed on the current collecting structure on the end plate 101. Then, after laminating the desired number of cells, the cell frame having the bipolar plate 105 on which the metal layer is formed is attached to the last cell again, and the current collector plate is laminated with the cushion layer interposed therebetween.

By forming a metal layer made of a metal material having a higher conductivity than the bipolar plate 105 on the bipolar plate 105, the electrode plates 102 and 102 and the bipolar plate 105 can be easily made conductive. In addition, by interposing a flexible cushion layer between the bipolar plate 105 and the current collector plate, particularly between the metal layer formed on the bipolar plate and the current collector plate, even under negative pressure, A large conduction area between the metal layer and the current collector plate can be obtained. Therefore, the resistance between the current collector plate and the bipolar plate 105 can be reduced, and the increase in resistance can be suppressed.
Since the resistance between the current collector plate and the bipolar plate 105 can be reduced and the increase in resistance under negative pressure can be suppressed, the electrical loss due to resistance such as a decrease in battery output and a decrease in battery capacity can be reduced. Can be done. Therefore, the battery has less electrical loss.

In the cell stacks 20 and 60, electrode plates 102 are alternately arranged, and the negative electrode side cell paths 21, 61 or the positive electrode side cell paths 22, 82 are formed by the diaphragms 23A and 23B between the negative electrodes 24 and 64 and the positive electrodes 25 and 65. The charge / discharge circuit is formed by the lead wires 26A and 27B.
That is, the cell stacks 20 and 60 have the negative electrode side cell paths 21 and 61 and the positive electrode side cell paths 22 and 62 in which the vanadium sulfate aqueous solutions 15, 35, 55 and 75 of the electrolytic solution containers 11, 31, 51 and 71 circulate. It is formed and the electrolytic solution is circulated by the liquid circulation pumps 12, 32, 52 and 72.

The redox flow battery 300 of the present embodiment is charged from the solar panel 301 when its terminal voltage is low. To be precise, the redox flow battery 300 is charged from the solar panel 301 with a voltage equal to or higher than the voltage obtained by adding twice the forward voltage drop of the backflow prevention diodes 302 and 303 to the output of the solar panel 301.
When the terminal voltage of the redox flow battery 300 is the output voltage value of the solar panel 301, the inverter 304 converts direct current into alternating current and outputs electric power to the commercial power supply 305 side.

At this time, if the output of the solar panel 301 is reduced, the solar panel 301 is in a reverse bias state by the backflow prevention diodes 302 and 303, so that the solar panel 301 is protected from the redox flow battery 300. However, since the redox flow battery 300 is the input of the inverter 304, there is a possibility that the charging voltage of the redox flow battery 300 will be used.
Therefore, as shown in FIGS. 1 and 2, the backflow prevention diode 302 is connected in the forward direction to the connection point between the solar panel 301 and the inverter 304, and the side connected to the connection point between the solar panel 301 and the inverter 304. The backflow prevention diode 302 is connected in the forward direction to the lead wires 26A and 27B of the above.

As a result, the electromotive force of the solar panel 301 is output to the inverter 304, and the redox flow battery 300 can be charged when the load on the inverter 304 side is small or when the electromotive force of the solar panel 301 is large.
Therefore, when the load of the inverter 304 is light, the electromotive power of the solar panel 301 mainly charges the redox flow battery 300, and in the normal state, the electromotive power of the solar panel 301 is output according to the load of the inverter 304. , The redox flow battery 300 is charged with the surplus electric power.
When there is no electromotive force of the solar panel 301 as in the nighttime, the redox flow battery 300 is discharged to output from the inverter 304. This output can be used as a domestic load and as an external load.

As the liquid circulation pumps 12, 32, 52, 71 used in this embodiment, smooth flow pumps (manufactured by Takumina Co., Ltd.) were used in the examples, but for example, an all-resin submersible pump sempon and a solenoid-driven diaphragm quantification Anything such as a pump (Sem Corporation) or the like in which the entire flow rate of the electrolytic solution is covered with a synthetic resin may be used. It is sufficient that the entire liquid circulation pump function is covered with resin. In any case, the constituent material constituting the pump for liquid feeding may be made of synthetic resin, and the vanadium electrolytic sulfate aqueous solutions 15, 35, 55, 75 are fed with polyethylene, polypropylene, polystyrene, nylon, polyester or the like. It forms a structure to supply.

In particular, FIG. 2 shows the cell stacks 20 and 60 of the embodiment of FIG. 1 being used as they are, and the DC output thereof is connected in series between the cell stack 20 and the cell stack 60. The negative electrode side cell path 21 of the cell stack 20 outputs the negative electrode, and the positive electrode side cell path 22 of the cell stack 20 outputs the positive electrode. Further, the negative electrode side cell path 61 of the cell stack 60 outputs the negative electrode, and the positive electrode side cell path 62 of the cell stack 60 outputs the positive electrode.
Then, in the electrolytic solution container 11, the negative electrode side cell path 21 supplies the electrolytic solution to the negative electrode side cell path 21 via the two liquid circulation pumps 12 and 52. Further, in the electrolytic solution container 31, the positive electrode side cell path 22 supplies the electrolytic solution to the negative electrode side cell path 62 via two liquid circulation pumps 32 and 72.

The redox flow battery of the present embodiment passes through an output circuit composed of at least lead wires 26A, 26B, 27A, 27B in which the outputs of two or more cell stacks 20, 60 are connected in series, and the cell stacks 20, 60. Electrode passing through the positive electrode side electrolytic solution containers 31 and 71 containing the electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 containing the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The positive electrode side charge / discharge circulation passages 33 and 73 in which the liquid flow is in the same direction for both charging and discharging, and the negative electrode side charging / discharging circulation in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. Positive electrode side liquid circulation pump 12 that increases the flow velocity between the paths 13 and 53 and the positive electrode side charge / discharge circulation paths 33 and 73 between the cell stacks 20 and 60 and the positive electrode side electrolytic solution containers 31 and 71. , 32, 52, 72 and the electrolytic solution of the negative electrode side charge / discharge circulation passages 13, 53, increase the flow velocity between the cell stacks 20, 60 and the negative electrode side electrolytic solution containers 11, 31, 51, 71. It includes the negative electrode side liquid circulation pumps 12, 32, 52, and 71.

The common liquid circulation pumps 12, 32, 52, 72 shown in FIG. 5 will be described.
The liquid circulation pump 12 enters the vanadium sulfate aqueous solution 15 of the electrolytic solution container 11 from the circulation line 13a, the liquid circulation pump 12, and the circulation line 13b from the negative side cell line 21, and is a negative circulation line via the circulation line 13a. To form.
Further, the liquid circulation pump 52 enters the vanadium sulfate aqueous solution 15 of the electrolytic solution container 15 from the negative cell side cell path 61 through the circulation line 53a, the liquid circulation pump 52, and the circulation line 53b, and enters the circulation line 13c and the circulation line 13d. A negative circulation path is formed through the pipe.

The liquid circulation pump 32 enters the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31 from the positive electrode side cell path 22 through the circulation line 33a, the liquid circulation pump 32, and the circulation line 33b, and enters the negative electrode type circulation line via the circulation line 33c. To form.
Further, the liquid circulation pump 72 enters the vanadium sulfate aqueous solution 35 of the electrolytic solution container 31 from the positive electrode side cell path 62 through the circulation line 73a, the liquid circulation pump 72, and the circulation line 73b, and enters the circulation line 13c and the circulation line 13d. In this way, the liquid circulation pumps 12, 32, 52, 72 circulate the vanadium sulfate aqueous solutions 15, 55, 35, 65 of the negative electrode side cell paths 21, 61 to form a negative electrode circulation path through the negative electrode. A circulation path is formed for the side cell paths 21 and 61 to clarify the difference in the "valence" number of vanadium ions.

In FIG. 5, the circulation line 13a, one liquid circulation pump 12, the circulation line 13b, the electrolytic solution container 11, the circulation line 13c, the negative side cell line 21, and the vanadium sulfate aqueous solution 15 circulate from the negative side cell line 21. To do. At the same time, on the positive side, the rotation of the liquid circulation pump 32 circulates the circulation line 33a, one liquid circulation pump 32, the circulation line 33b, the positive side cell container 31 and the vanadium sulfate aqueous solution 25 from the positive side cell container 31. It shows the circulatory system.
Further, the circulation line 53a, one liquid circulation pump 52, the circulation line 53b, the electrolytic solution container 51, the circulation line 53c, the negative side cell line 61 and the vanadium sulfate aqueous solution 51 circulate from the negative side cell line 61. At the same time, due to the rotation of the liquid circulation pump 72, from the positive side cell container 62 to the circulation line 73a, one liquid circulation pump 72, the circulation line 73b, the electrolytic solution container 71, the circulation line 73c, and the negative side cell container 61. It shows a circulation system in which a vanadium sulfate aqueous solution 15 circulates.

FIG. 6 is another example of the liquid circulation pumps 12, 32, 52, and 72, and is an explanatory diagram illustrating an operation using two pumps.
The vanadium sulfate aqueous solution 15a in the electrolytic solution container 11a is discharged from the insertion circulation line 53a by the circulation line 13a, the liquid circulation pump 12a, and the circulation line 13b from the negative side cell lines 21 and 61, and is stirred. The stirred vanadium sulfate aqueous solution 15 is absorbed from the pipe line 61a, and further, from the circulation pipe line 13 _b1 , the liquid circulation pump 12b, and the circulation pipe line 13 _b2, from the insertion circulation line 53b in the electrolytic solution container 11b in the vanadium sulfate aqueous solution 15b. The discharged and stirred vanadium sulfate aqueous solutions 15 and 55 are absorbed from the pipe line 61b and returned to the negative side cell lines 21 and 61 via the circulation line 13c in the first circulation path and the second circulation path of the liquid. is there. The vanadium sulfate aqueous solution 15 of the negative electrode side cell paths 21 and 61 is circulated to form a circulation path for clarifying the difference in the "valence" number of vanadium ions with respect to the negative electrode side cell path 21.

The schematic diagram of the impeller pump as the liquid circulation pumps 12, 32, 52, 72 shown in FIGS. 1 and 2 is summarized in FIG. In addition, a gear pump, a vane pump, and the like can also be used, and the present invention is not limited to the impeller pump.
In FIG. 4, the impeller pump has a main body 201 containing an electric motor, a suction port 206 and a discharge port 207 attached to a flange 204 of the main body 201, and a flange 203 of the pump part 209 attached to the flange 204. The impeller 208 is attached to the shaft of the electric motor of the main body 201, and rotates at the same rotation speed as the electric motor.
The seat portion 202 is arranged in the opposite direction to the discharge port 207 of the impeller 208.
Therefore, when the electric motor inside the main body 201 rotates, a centrifugal force is applied to the electrolytic solution, and the electric motor jumps out from the discharge port 207 in the radial direction, and the suction port 206 side becomes a negative pressure. Therefore, the impeller pump functions as a liquid circulation pump 12, 32, 52, 72.
Normally, the liquid circulation pumps 12, 32, 52, 72 are used in a configuration that does not involve air.

Here, the liquid circulation pumps 12, 32, 52, and 72 are rotated at a constant speed, and the circulation pipes 13a, the liquid circulation pump 12, the circulation pipe 13b, the electrolytic solution container 11, and the circulation pipes are rotated from the negative side cell lines 21 and 61. 13c, the negative side cell paths 21, 61 and the vanadium sulfate aqueous solution 15, 55 circulate. At the same time, due to the rotation of the liquid circulation pumps 12, 32, 52, 72, the positive cell path 22 to the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, the electrolyte container 31, the circulation line 33c, and the positive side cell. Roads 22, 62 and vanadium sulfate aqueous solutions 35, 75 circulate.
At this time, the solar panel 301 charges and discharges the redox flow battery 300, and the inverter 304 supplies electric power to the AC generator 305 side for selling electric power according to a specific program. The output of the solar panel 301 applies a negative voltage to the lead wire 27B and a positive voltage to the lead wire 27B as a predetermined DC voltage.

Further, even if two liquid circulation pumps 12 and 32 are arranged on the positive pressure side and the negative pressure side, the impeller 208 and the pump unit 209 are sealed between the suction port 206 side and the discharge port 207 of the impeller 208. Since it is not in a state, the fluid resistance is small and it does not make it difficult for the liquid to flow, and it can be operated with a load of 1/2 unit.
When the two liquid circulation pumps 12 and the two liquid circulation pumps 32 are driven at the same time, the flow velocity of the electrolytic solution is doubled between the suction port 206 side of the impeller 208 and the discharge port 207. Since a flow is generated, it can be driven with 0.5 times and 2 times the capacity. The same applies when three liquid circulation pumps 12 and three liquid circulation pumps 32 are arranged, and the pumps can be driven with a set capacity as needed.
Although it is described that the liquid circulation pumps 12, 32, 52, and 71 are used in series, they may be connected in parallel or in series-parallel connection.

FIG. 6 shows the circulation pipe line 13a, one liquid circulation pump 12a, the circulation pipe line 13b, the circulation pipe line 13 _b1 of the electrolytic solution container 11a, the other liquid circulation pump 12b, and the electrolytic solution from the negative side cell path 21. It circulates with the circulation line 13 _{b2 of} the container 11b, the circulation line 13c of the electrolyte container 11b, and the cell line 21 on the negative side.

Further, the vanadium sulfate aqueous solution 15, 35, 55, 65 changes as shown in the following chemical formula.
Positive reactions _{^{VO 2+ + H 2 O → /}} ← VO 2 + + e - + 2H +
(4 valence (blue)) (5 valence (yellow))
The negative electrode reaction ^{VO 3+ + e - → / ←} VO 2+
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions.
As described above, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions, so that sulfuric acid as the electrolytic solution can be charged and discharged. Since the vanadium aqueous solutions 15 and 35 do not deteriorate in principle, the vanadium sulfate aqueous solutions 15, 35, 55, 65 do not deteriorate.

The negative electrode divalent vanadium used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution is "purple", the trivalent vanadium is "green", and the positive electrode tetravalent vanadium is "blue". , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is “blue” and the pentavalent vanadium is “yellow”, and the colors on the region connecting “yellow” and “blue” with a straight line. Will be moved.
It moves on the region where the divalent vanadium "purple" and the trivalent vanadium "green" of the negative electrode are connected by a straight line. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode. Logically, the color changes linearly, but it can be said that the area changes due to an error or the like.

The negative electrode used for the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution is "purple" for divalent vanadium, "green" for trivalent vanadium, and "green" for the positive electrode. "Blue" and pentavalent vanadium are "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is “blue (450 to 495 nm)” and the pentavalent vanadium is “yellow (570 to 590 nm)”, which is “yellow” shown in FIG. You will move the color on the area between the "blue" and. It will move on the line connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.
Note that FIG. 7 shows the relationship between wavelength and sensitivity.

As shown in the figure, the three primary colors of light, "red (Red wavelength: 625 to 740 nm)", "green (Green wavelength: 500 to 560 nm)", and "blue (Blue wavelength: 445 to 485 nm)" are the three primary colors of light. , In the present embodiment, since the color sensor 17 detects the color between "yellow" and "blue" and "purple" and "green", the three primary colors of light are not used for color detection. .. Of course, the color sensor 17 may have three colors.

Therefore, the change between "yellow" and "blue" or "purple" and "green" can be regarded as a single color "yellow change" or "blue change" having a wavelength of 380 to 780 [nm]. The color sensor 17 can detect a change in a single color and a change in a plurality of colors, respectively.
Further, according to the experiments of the inventors, it was confirmed that it can be realized by detecting a single color having a wavelength of 380 to 780 [nm].

For example, the light from the lower end of the optical fiber (8φ) is guided so that the input of the spectrophotometer (CM-700d; Konica Minolta Co., Ltd.) 16 receives light at de: 8 °. When the start of charging and the completion of discharge are measured and the reaction of the positive electrode is shown in the color triangle of FIG. 8, it becomes pentavalent "yellow" when charging is completed and becomes tetravalent "blue" when discharging is completed. As for the current remaining discharge amount, the value of the remaining discharge amount exists on the line connecting "yellow" and "blue".
In addition, white moves the position on the line connecting "yellow" and "blue". In the normal remaining discharge amount, "yellow" when charging is completed and "blue" when discharging is completed are on the region, "yellow" is 100% capacity, and "blue" is 0% remaining discharge amount. ..
According to the experiments of the inventors, a reading error was large, but a substantially proportional relationship was confirmed.

The color sensor 17 as a spectrophotometer (CM-700d; Konica Minolta Co., Ltd.) is an attempt to replace it with a circuit equipped with a color sensor (TCS34725) manufactured by Strawberry Linux (registered trademark). In addition, it was confirmed that DM-18TN manufactured by Optex FA can also be used if it is coated with a resin.
The module of the color sensor 16 equipped with the TCS34725 makes it possible to discriminate the color even in the dark by mounting the color sensor 17 so that the color of the environment does not change and by mounting the white LED.

The white light emitting diode, that is, the LED 45, approximates the emitted light of the reference color and prevents the periphery of the color detecting unit 44 from becoming dark. Further, the vanadium sulfate aqueous solution 15, 35, 55, 65 can accurately detect the color of the electrolytic solution by the transmitted light, the scattered light or the reflected light. Therefore, the electrolytic solution can be easily dispersed uniformly in the vanadium sulfate aqueous solutions 15, 35, 55, 65. The lower end of the optical fiber provided in the color detection unit 44 accurately detects the color of the electrolytic solution of the vanadium sulfate aqueous solutions 15, 35, 55, 65 by using transmitted light, scattered light, or reflected light. The upper end of the optical fiber is connected to the detection hole of a spectrocolorimeter (CM-700d; Konica Minolta Co., Ltd.).

When charging on the positive electrode side shown in the color triangle of FIG. 8 is completed, it becomes pentavalent "yellow", and when discharging is completed, it becomes tetravalent "blue". The current remaining discharge value is that the remaining discharge value is on the line connecting "yellow" and "blue".
Also, when viewed from the negative electrode side, there is a remaining discharge amount on the line connecting "purple" and "green", and "purple" when charging is completed and "green" when discharging is completed are 100 in the area. The capacity is%, and "green" is the remaining discharge amount of 0%.
These independently appear on the positive electrode on the positive electrode side and the negative electrode on the negative electrode side. However, since the positive electrode side and the negative electrode side are independent, the line connecting "yellow" and "blue" and the line connecting "purple" and "green" do not coexist. Therefore, the same information can be obtained from two systems, the positive electrode side and the negative electrode side.
In particular, it is set so that there is a remaining amount of discharge in the line connecting "yellow" to "blue" and from "purple" to "green" on the negative electrode side when charging is completed on the positive electrode side, but the change is linear. Can also be detected as an area by fixing a specific color.

In the present embodiment, "yellow" is changed to "blue" and "purple" is changed to "green", and the space between them is divided into 8 or 3 and used for evaluation of the remaining discharge amount. Of course, it may be divided arbitrarily. Explaining from "yellow" to "blue", "yellow" is the remaining discharge amount that holds 100% charged electric power. On the contrary, "blue" is 0% of the remaining discharge amount. Therefore,
100% (yellow), 75%, 50%, 25%, 0% (blue)
It can also be explained by dividing it into five stages from "yellow" to "blue" and from "yellow" to "blue".

The positive electrode tetravalent vanadium "blue (450 to 495 nm)" and pentavalent vanadium "yellow (570-590 nm)" are simply wavelengths, "yellow 590 nm", "yellow 580 nm",
It is divided into 5 or 10 pieces of "yellow 570 nm", "orange 560 nm", "orange 550 nm", "orange 540 nm", "yellow green 530 nm", "yellow green 520 nm", "yellow 810 nm", and "blue 500 nm". You can also do it.

The color sensor 17 at the upper end of the optical fiber 46 detects three colors and has a resolution of 16 bits for each color.
The white LED (380 to 780 colors) emits light so that the colors of the vanadium sulfate aqueous solution 15, 35, 55, 65, which is the electrolytic solution contained in the negative electrode side electrolytic solution containers 11, 51, can be discriminated. By installing it, it is possible to distinguish colors even in the dark.
Since the three colors of "red", "green", and "blue" of the color sensor 17 are white LEDs (380 to 780 colors), they are output by the other party. The configuration as a photocoupler is shown, and of course, it may be positively configured as a photocoupler.

Therefore, in the negative electrode, the current remaining charge / discharge amount is in the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium. Further, in the positive electrode, there is a remaining discharge amount in the amplitude at a specific wavelength estimated to be below the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.
In particular, the remaining amount of discharge can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the remaining charge / discharge amount is generally measured from the charging time and the energizing current, but a redox flow battery using vanadium sulfate aqueous solutions 15, 35, 55, 65 as an electrolytic solution. Then, when the load of the redox flow battery is applied, the remaining charge / discharge level at that time can be measured regardless of whether or not the load is applied.

Moreover, the color of the vanadium sulfate aqueous solution is under the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium and the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium. Therefore, it is determined by the color, and the reading error can be reduced.
Further, for light emission, the LDE 18 emits light at a specific frequency (white), and the negative cell paths 21 of the cell stacks 20 and 60 in which the vanadium sulfate aqueous solutions 15, 35, 55, 65 circulate and the specific frequency thereof. Since it is detected, the frequency of the emission color can be detected with a small error.

In particular, when the detection of the two emission colors is different, the detection value of the remaining charge / discharge amount with a small remaining amount of discharge is adopted so that the timing of recharging can be efficiently performed.
It is detected at which wavelength 380 to 700 [nm] in one scan the color of the current electrolytic solution composed of the vanadium sulfate aqueous solution 15, 35, 55, 65 is located.

That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" at the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium at the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple" (380 nm) and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green" (570 nm) of trivalent vanadium. At least, it suffices to have a photodetection ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

That is, the wavelength of the electrolytic solution is 380 to 700 [nm], 100% (yellow), 90%, 80%, ..., 20%, 10%, 0% (blue).
It may be divided evenly with, or weighting may be performed on three types of 〇 (yellow), Δ, and × (blue). Usually, it is desirable to evaluate on a scale of about 5.

As described above, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 65 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. In principle, the vanadium sulfate aqueous solution 15, 35, 55, 65 does not deteriorate, so that the vanadium sulfate aqueous solution 15, 35, 55, 65 does not deteriorate.
In the redox flow battery 300, since the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions, the vanadium sulfate aqueous solutions 15 and 35 as the electrolytic solution do not deteriorate in principle, and therefore vanadium sulfate. No deterioration occurs in the aqueous solutions 15, 35, 55, 65.

Next, the electrolytic solution distributor 50 that homogenizes the ends of the electrolytic solution containers 11, 31, 51, and 71 will be described.
As shown in FIGS. 1 and 2, FIGS. 9 to 15, liquid circulation is performed in circulation pipelines 13, 33, 53, 73 composed of pipes formed of a synthetic resin, for example, an electrolytic solution such as polyethylene terephthalate. It is connected to the pumps 12, 32, 52, 71 and circulates the electrolytic solutions of the vanadium sulfate aqueous solutions 15, 35, 55, 65 from the electrolytic solution containers 11, 31, 51, 71. In order to make these circulatory systems uniform, the electrolytic solution distributor 50 is standardized so that it can be applied to any electrolytic solution containers 11, 31, 51, 71.

Examples of the thermoplastic resin formed by the electrolytic solution include polyamide 46 (PA46) resin belonging to engineering plastic (engineering plastic), polyamide (PA) resin (nylon, etc.), polyacetal (POM) resin, and polycarbonate (PC). Resins, modified polyphenylene ether resins, polyethylene terephthalate (PET) resins, polybutylene terephthalates (PBT) resins, glass fiber reinforced polyethylene terephthalate resins, cyclic polyolefin resins, etc., and polytetrafluoroethylene belonging to super engineering plastics (super engineering plastics). (PTFE) resin, polysulfone (PSF) resin, polyether sulfone (PES) resin, amorphous polyarylate (PAR) resin, liquid crystal polymer (LCP) resin, polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) Resins, polyamideimide resins, etc., polyethylene (PE) resins belonging to general-purpose resins, polypropylene (PP) resins, polyvinyl chloride (PVC) resins, polystyrene (PS) resins, polyvinyl acetate (PVAc) resins, ABS resins, acrylics A nitrile styrene (AS) resin, an acrylic (PMMA) resin, or the like can be used. These may be used individually by 1 type and may be used in combination of 2 or more type. When such a thermoplastic resin is used, there is a plasticizer for plasticizing the thermoplastic resin, if necessary.

First, the electrolytic solution distributor 50 connects the insertion circulation pipes 53 to the circulation pipes 13 and 33. Further, the circulation pipes 13 and 33 may be integrally formed with the insertion circulation pipe 53 (13).
A plurality of opening holes 54 bored in the insertion circulation pipes 53 (13) through which the circulation pipes 13 and 33 discharge are provided. The area of the opening hole 54 in which the circulation pipe 53 is branched to prevent the circulation pipe 53 from descending is larger than the opening cross-sectional area of the circulation pipe 53.
The insertion circulation line 53 (13) connected to the electrolytic solution containers 11 and 31 is connected by using a connecting means such as a connector or an adhesive (not shown). Of course, packing and the like (not shown) are also used in order to improve the sealing property. However, when carrying out the present invention, it is desirable that the electrolytic solution containers 11 and 31 and the insertion circulation pipe line 53 are integrally connected and bent as necessary.

The circulation pipes 13a and 33a of the electrolyte distributor 50 are connected to the liquid circulation pumps 12, 32, 52 and 72, pass through the circulation pipes 13a and 33a from the outside of the electrolyte distributor 50, and have a large diameter pipe. The electrolytic solution is circulated inside the path 80 from top to bottom by the liquid circulation pumps 12, 32, 52, 71.
That is, the circulation pipes 13a and 33a are inserted through the upper end of the electrolyte distributor 50, and the electrolyte distributor 50, the inserted circulation pipe 93, the circulation pipe 51, and the circulation pipe 82 (13b) are made of synthetic resin pipes. It is formed integrally. The length of the electrolytic solution distributor 50 is preferably in the position range of 7/10 to 10/10, preferably 8/10 to 9/10, which is the ratio of the lengths of the electrolytic solution containers 11 and 31.
Further, the length of the electrolytic solution distributor 50 is preferably in the range of 1/10 to 810, preferably 2/10 to 4/10. The electrolytic solution distributor 50, the pipe line 51 (13b), and the pipe line 82 (13b) are integrally formed by the synthetic resin pipe.

The circulation pipe 51 (13b) and the pipe 82 (13b) of the electrolyte distributor 50 are formed as the circulation pipe 13c, and the lower end of the circulation pipe 51 (13b) is from the electrolyte distributor 50 to the electrolyte container. The electrolytic solution is made to move from the lower circulation line 51 (13b) to the circulation line 82 (13b) through 11 and 31.
The filter 84 is used for removing dust and for breathing vanadium sulfate aqueous solutions 15 and 35. Since the fastener 81 of the electrolytic solution distributor 50 is firmly fixed to the electrolytic solution containers 11 and 31, it has an elastic packing, an elastic filter, and a sealing structure so that the processing liquid does not leak. Then, the fastener 81 can be firmly attached to the electrolytic solution containers 11 and 31.
A color detection unit 44 is formed in the lower part of the electrolytic solution distributor 50, and a white LED 45 is fixed on one surface of the substrate 48. The entire surface of the white LED 45 is molded with a synthetic resin.

Next, the operation of the electrolytic solution distributor 50 will be described.
The electrolytic solution in the transparent large-diameter tube 92 of the electrolytic solution distributor 50 connected to the liquid circulation pumps 12, 32, 52, 72 is sent out from the liquid circulation pumps 12, 32, 52, 72, and is sent out from the liquid circulation pumps 12, 32, 52, 72. It passes through 13a and 33a and the insertion circulation pipe 93, flows into the transparent large-diameter pipe 92 through the opening hole 94 formed in the insertion circulation pipe 93, becomes a rectifying unit 49, and is supplied to the color detection unit 44. Will be done. In the color detection unit 44, the white LED 45 is electrically guided, the electrolytic solution rectified by the rectifying unit 49 is supplied to the white LED 45, and the color detection unit 44 outputs a predetermined color. The color detection unit 44 detects the internal light of the color detection unit 44 from the end of the optical fiber 46 as transmitted light, scattered light, or reflected light.

The rectifying unit 49 allows the flow of the electrolytic solution to flow without partially disturbing it, and a known shape can be used. Further, the internal light of the color detection unit 44 is detected as transmitted light, scattered light or reflected light from the end of the optical fiber 46 by the flow rate of the vanadium sulfate aqueous solution 15, 35, 55, 65 flowing through the color detection unit 44, and the color is detected. When the optical fiber 46 detects transmitted light, scattered light, or reflected light in the unit 44, the tip fixed with the adhesive of the optical fiber 46 can detect only the color by removing the focal length without adjusting the special focus. I am trying to do it. Further, by making the inside of the color detection unit 44 white, transmitted light, scattered light, or reflected light can be clearly discriminated.

Further, the lower end side of the large-diameter transparent large-diameter tube 86 is integrally joined with the end member 40 by means known for synthetic resin. On the bottom surface, a rectifying unit 49 through which an electrolytic solution flows is formed as a slit. Then, the lower portion of the insertion circulation pipe line 93 (13a) is formed as an end member 40 with a plurality of opening holes 94 provided, and a passage for the electrolytic solution is formed. That is, the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 71 descends the insertion circulation line 93, exits the insertion circulation line 93 through the plurality of opening holes 94, and exits the insertion circulation line 93, and the transparent large-diameter tube 86. It enters, descends the slit 49a, and is detected by the tips of the white LED 45 and the optical fiber 46.

When DM-18TN or the like manufactured by Optex FA is used as the color sensor 17, a photocoupler composed of a white LED 45 and three photodiodes of "red", "blue" and "green" (not shown) is used. , 380 to 700 [nm] wavelengths are swept, and it has a light detection ability to detect which color of the electrolytic solution is.
In the present embodiment, measured by Sekonic Spectromaster C-7000, the negative electrode has a divalent vanadium “purple” to a trivalent vanadium “green”, and similarly, a tetravalent vanadium “blue” to a pentavalent vanadium at the positive electrode. "Yellow" is measured, and the distance between "purple" and "green" and "blue" and "yellow" is measured, and discharge and charge are divided into 3 to 20.

Therefore, the discharge and charge are divided into 3 to 20 even scales. That is, the value of the remaining discharge amount detected by the color sensor 17 is divided into 3 to 20.
The remaining discharge amount of the redox flow battery 300 may be directly displayed on the display 17, but since it is usually sufficient to numerically express the electric power required for operation, for example, the remaining discharge amount of the redox flow battery 300 is the minimum of 3. It suffices if it can be set in the stage. In particular, since it is unlikely that a situation requiring charging will occur, the setting may be finely set to 20 steps or more. However, its importance is not high.

In the present embodiment, the liquid circulation pumps 12, 32, 52, 71 may be entirely covered with synthetic resin and the entire pump function is entirely covered with resin or rubber, or may be composed of them. You may be.
1 unit for circulation of divalent vanadium "purple" to trivalent vanadium "green" electrolyte at the negative electrode, 1 for circulation of tetravalent vanadium "blue" to pentavalent vanadium "yellow" electrolyte at the positive electrode Requires a stand, measure between its "purple" and "green", "blue" and "yellow", and change discharge and charge from "purple" to "green" and "blue" to "yellow" As mentioned above, it can be divided into 3 to 20 evaluations.
Therefore, at least two liquid circulation pumps 12, 32, 52, 71 are required. In any case, the number of the liquid circulation pump 12 and the liquid circulation pump 32 is an even number when two or four are added. If you look at this in pairs, it will be one or more pairs.

Next, the float sensor 100 will be described.
Vanadium sulfate aqueous solutions 15, 35, 55, 65 are in the negative electrode side electrolyte containers 11, 31, 51, 71, and vanadium sulfate aqueous solutions 15, 35, 55 are in the positive electrode side electrolyte containers 11, 31, 51, 71. , 75 are filled. The liquid levels of the electrolytic solution containers 11, 31, 51, 71 and the electrolytic solution container 31 are detected, and the liquid levels of the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 and the electrolytic solution containers 11, 31, 51, 71 are determined. The float sensor 100 to know is arranged in the electrolytic solution containers 11, 31, 51, 71 or the electrolytic solution containers 11, 31, 51, 71 containing the vanadium sulfate aqueous solutions 15, 35, 55, 75. The screw portions 105 formed on the float sensor 100 are fastened to the electrolyte containers 11, 31, 51, 71.
The float sensor 100 is provided with a center moving rod 101 at the center, and the float 123 moves up and down around the center moving rod 101. A permanent magnet is embedded in the float 123, and a float sensor 100 composed of a reed switch 124 embedded in the central moving rod 101 is arranged.
The guide cylinder 105 prevents the float 123 from colliding with the surroundings when the float 123 moves up and down around the center moving rod 101.

Therefore, for example, the electrolytic solution containers 31 and 71 on the positive electrode side are attached to the mounting holes of the center moving rod 101 provided on the top plate from the upper surface of the container in which the vanadium sulfate aqueous solutions 15, 35, 55, 75 are placed. The float sensor 100 is a float sensor 100 made of foamed synthetic resin in which a reed switch 124 is embedded inside. The float sensor 100 freely moves by a distance L, and the float sensor 100 of the float sensor 100 moves within a movement range of a distance L. There is a liquid level of the electrolytic solution, and the float sensor 100 outputs an on / off signal at a predetermined liquid level.
The water level sensor knob 128 is for screwing the electrolytic solution containers 11, 51 on the negative electrode side, and the filter 109 is for breathing the fluctuating water level of the electrolytic solution containers 11, 51 on the negative electrode side.
Further, in the present embodiment, the float sensor 100 is provided separately from the electrolytic solution distributor 50, but in the case of carrying out the present invention, the float sensor 100 can be assembled to the electrolytic solution distributor 50. For example, the float 123 may be attached to the insertion circulation pipe 93 (13a) and the pipe 81 (13b), or the float sensor 100 may be provided inside the electrolytic solution distributor 50.

In FIG. 9, for example, the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 provided with the vent holes 109 of the positive electrode side cell are firmly tightened, and the electrolytic solution container 11 and the electrolytic solution are firmly tightened. The float sensor 100 is also firmly screwed into the container 31. At this time, if necessary, a rubber packing or the like is used to perform joining with good sealing properties. Therefore, the electrolytic solution containers 11, 31, 51, 71 have two circulation pipes 13 or circulation with respect to the electrolytic solution containers 11, 31, 51, 71 connected to the liquid circulation pumps 12, 32, 52, 72. The pipeline 33 is arranged.

One optical fiber 46 and the lead wire 107 of the float sensor 100 are pulled out, and the signal of the color sensor 17, the liquid circulation pump 12, and the liquid circulation pump 32 are connected to the controller (CPU). ..

Handles 19a and 19b are formed in the electrolytic solution containers 11, 31, 51, and 71, respectively, and are movable. The electrolytic solution containers 11, 31, 51, 71 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell 22 are paired. The electrolytic solution containers 11, 31, 51, 71 circulate the electrolytic solution in the cell stack 20 divided into the negative electrode side cell path 21 and the positive electrode side cell path 22.

At this time, one liquid circulation pump 12, 32, 52, 71 is arranged, but as described above, two or two or more liquid circulation pumps may be arranged in series. As a matter of course, one or more liquid circulation pumps may be provided to equalize the sales expansion of the vanadium sulfate aqueous solution 15 and the vanadium sulfate aqueous solution 15, 25, 55, 75.

For example, as shown in FIG. 13, the liquid circulation pump 12 is paired with the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell path 22, or as shown in FIG. , Two pairs of the electrolytic solution container 11 of the negative electrode side cell path 21 and the electrolytic solution container 31 of the positive electrode side cell path 22 may be provided as one pair, or three or four pairs may be provided (not shown).

In the present embodiment, since the electrolytic solution distributor 50, the float sensor 100, and the electrolytic solution containers 11, 31, 51, 71 are standardized, the standardized redox flow battery 300 can be formed by selecting the battery storage body 400. ..
FIG. 13 shows an explanation in which the float sensor 100 and the electrolytic solution distributor 50 mounted on the electrolytic solution containers 11, 31, 51, 71 used in the redox flow battery 300 of the embodiment of the present invention are arranged on the frame. It is a figure.
The battery frame 401 of the battery storage body 400 is configured by molding a metal rod having a square cross section with a synthetic resin so as not to be easily corroded by acid. Inside the battery frame 401, container spaces 402 and 403 into which the electrolytic solution container 11 or the electrolytic solution container 31 can be inserted from above are integrated, and the controller storage space 404 is also integrated to form the container space 402, If the 403 and the controller storage space 404 are integrated to cause an electrolytic solution leak to a height of 1/3 to 2/3 of the electrolytic solution container 11 and the electrolytic solution container 31, if an electrolytic solution leaks, the inside thereof Liquid leakage is prevented by a container in which the container spaces 402 and 403 and the controller storage space 404 are integrated.

Further, the container integrated with the container space 402, 403 and the controller storage space 404 of the present embodiment is blow-molded using a synthetic resin film or the like, but the container space 402, 403 and the controller storage space are stored. It may be shaped so that the lower part of the space 404 communicates with each other.
A space for storing the negative electrode side cell path 21 is formed in the upper part of the controller storage space 404, and the cell stacks 20 and 60 are connected to the space.
In the present embodiment, the upper part of the controller storage space 404 constitutes the space for storing the cell stack 40B and the back surface of the lid 406 constitutes the controller of the electrolytic solution.

A control device CPU composed of a microcomputer and a control line thereof are arranged on the upper surface of the lid 206, and liquid circulation pumps 12, 32, 52, 72 and each pipe shown in FIG. 15 are arranged on the lower surface.
For example, the lead wire of the white LED 45 of the electrolyte distributor 50, the lead wire of the float sensor 100, the humidity sensor or water leak sensor of the container in which the container spaces 402 and 403 and the controller storage space 404 are integrated, a water sensor, etc. Is connected to the microcomputer CPU. In addition, it is also displayed whether or not it is operating normally, whether it is being charged or being discharged, and the like.

FIG. 13 shows that one electrolytic solution container 11 and one electrolytic solution container 31, and the electrolytic solution containers 11 and 31 are basically two pairs of a positive electrode and a negative electrode and have the same shape. The number of parts is reduced. Further, in FIG. 14, two electrolyte containers 11 and two electrolyte containers 31 are used, and the electrolyte containers 11 and 31 are basically doubled and have the same shape, so that the number of parts is different. Is reduced.
The feature of this embodiment is that one electrolytic solution container 11, 31, 51, 71 can be used several times. Other configurations are not different from FIG. One electrolyte container 11, 31, 51, 71 is 4 times, 6 times, 8 times, and so on, indicating that the number can be increased for each pair.

Further, in FIG. 14, two electrolytic solution containers 11 and two electrolytic solution containers 31 are arranged.
Of course, the negative electrode side circulates with the negative electrode side cell path 21, the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, the vanadium sulfate aqueous solution 15, the circulation line 13c, and the positive electrode side cell line 21, and the positive electrode side cell line. Return to 21. Further, the positive electrode side is connected to the liquid circulation pump 32 in series with the positive electrode side cell line 22, the circulation line 33a, the liquid circulation pump 32, the circulation line 33b, the vanadium sulfate aqueous solution 35, the circulation line 33c, and the negative electrode side cell line 21. A system that circulates with and returns to the positive electrode side cell path 22 is added.

At this time, the outlet of the vanadium sulfate aqueous solution 15 of the negative electrode side cell path 21 and the outlet of the vanadium sulfate aqueous solution 35 of the positive electrode side cell path 22 are at the same end, or both outlets of the vanadium sulfate aqueous solution 15 of the negative electrode side cell path 21 are used. It can be the opposite end.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution in the present embodiment, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. While changing, and / or the color of the electrolytic solution composed of tetravalent vanadium and pentavalent vanadium is detected by the color sensor 17, and the positive electrode side charge / discharge state detecting unit that specifies the charging state of the positive electrode of the electrolytic solution from the color. , While changing trivalent vanadium to divalent vanadium by electric discharge or while changing divalent vanadium to trivalent vanadium by charging, and / or the color of the electrolytic solution composed of divalent vanadium and trivalent vanadium is measured by the color sensor 17. The negative electrode side charge / discharge state detection unit for detecting and specifying the charge state of the negative electrode of the electrolytic solution from the color is provided, and the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is described. The wavelength (frequency) of the remaining discharge amount is calculated from the detected value of any one or more of the transmitted light, scattered light, and reflected light of the LED arranged in the circulation conduit of the electrolytic solution, and is used from the wavelength (frequency). Identify the remaining amount of discharge.

Positive reactions _{^{VO 2+ + H 2 O → /}} ← VO 2 + + e - + 2H +
(4 valence (blue)) (5 valence (yellow))
The negative electrode reaction ^{VO 3+ + e - → / ←} VO 2+
(Trivalent (green)) (Divalent (purple))
However, the arrow → indicates charging, and the arrow ← indicates discharging.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, vanadium sulfate as the electrolytic solution Since the aqueous solution does not deteriorate in principle, the vanadium sulfate aqueous solution 15, 35, 55, 75 does not deteriorate.

The negative electrode divalent vanadium used in the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is "purple", the trivalent vanadium is "green", and the positive electrode tetravalent vanadium is "blue". , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode changes between “blue (450 to 495 nm)” and the pentavalent vanadium changes between “yellow (570 to 590 nm)”, which is shown in FIG. You will move the colors on the area between "yellow" and "blue".
Similarly, the divalent vanadium of the negative electrode is "purple (380-450 nm)", the trivalent vanadium is "green (495-570 nm)", and the pentavalent vanadium is "yellow" and the trivalent vanadium is "green". You will move the colors on the area. It will move on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 as the electrolytic solution is "purple (380-450 nm)", the trivalent vanadium is "green (495-570 nm)", and the positive electrode. The tetravalent vanadium is "blue (450 to 495 nm)" and the pentavalent vanadium is "yellow (570 to 590 nm)". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, when this is shown by the color triangle of FIG. 8, the positive electrode has "blue (450 to 495 nm)" for tetravalent vanadium and "yellow (570 to 590 nm)" for pentavalent vanadium, which is "yellow" shown in FIG. You will move the color on the area between the "blue" and.
It will move on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

The white LED 45 constituting the light emitting element is made to output a wavelength having a frequency including 380 to 700 [nm]. In the light receiving element, since the peak of the output of the light receiving element is at any of the specific wavelengths 380 to 700 [nm] with respect to the emitted light having a specific wavelength of 380 to 700 [nm], 2 is obtained from the peak value at the negative electrode. Vanadium valence "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)", and positive vanadium "blue (450-495 nm)" to pentavalent vanadium "yellow (yellow)" 570 to 590 nm) ”.
Therefore, in the negative electrode, the current remaining charge / discharge amount is on the region connecting the “purple” of divalent vanadium and the “green” of trivalent vanadium. Further, in the positive electrode, it can be seen that there is a charge / discharge remaining amount in the amplitude at a specific wavelength estimated to be below the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, the remaining charge / discharge amount can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the remaining charge / discharge amount is generally measured from the charging time and the energizing current, but a redox flow battery using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution. In 300, when the load of the redox flow battery 300 is applied, the remaining charge / discharge amount at that time can be measured regardless of whether or not the load is applied.
Moreover, under the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, and the region connecting the blue color of tetravalent vanadium and the "yellow" of pentavalent vanadium, the vanadium sulfate aqueous solutions 15, 35, Since the colors 55 and 75 are discriminated, it is judged by the color, and the reading error can be reduced.
Further, since the LDE emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emission color can be sharply detected.

In particular, when the remaining discharge amounts of the two emission colors are different, the detection value of the remaining discharge amount that reduces the remaining charge amount is adopted, and the timing of recharging is efficiently performed.
For example, it is detected which of the scans of about 380 to 700 [nm] is the color of the current electrolytic solution composed of the vanadium sulfate aqueous solution 15, 35, 55, 75.
That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" in the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium in the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple (380 nm)" and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetecting ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution in the present embodiment, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. While changing, and / or the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium is detected by the color sensor 17, and the positive electrode side charge / discharge state detecting unit specifies the charging state of the positive electrode of the electrolytic solution from the color. And, while changing the trivalent vanadium to divalent vanadium by electric discharge or while changing divalent vanadium to trivalent vanadium by charging, and / or the color of the electrolytic solution composed of the divalent vanadium and trivalent vanadium is a color sensor. Charge / discharge state detector determined by the colors of vanadium sulfate aqueous solutions 15, 35, 55, 75 and the detection value of the color sensor 17 on the negative electrode side, which are detected by 17 and specify the charge state of the negative electrode of the electrolytic solution from the colors. The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is a detection value of transmitted light, scattered light, and reflected light of a light emitting diode arranged in the circulation conduit of the electrolytic solution. The wavelength (frequency) of the remaining discharge amount is calculated, and the smaller detected value of the wavelength (frequency) is specified as the charging power amount.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of this embodiment as the electrolytic solution, the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is a circulation tube of the electrolytic solution. The wavelength (frequency) of the remaining discharge amount is calculated from the detected values of the transmitted light or the reflected light arranged on the paths 11, 31, 51, and 71, and the smaller detected value of the wavelength (frequency) is used as the remaining amount of discharge. Identified.
In the redox flow battery 300 used as the vanadium sulfate aqueous solution 15, 35, 55, 75, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, the vanadium sulfate aqueous solution 15 as an electrolytic solution, Since 35, 55, 75 does not deteriorate in principle, the vanadium sulfate aqueous solution 15, 35, 55, 75 is unlikely to deteriorate.

Further, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 25, 55, 75 as the electrolytic solution, the pentavalent vanadium is changed to the pentavalent vanadium by charging or the pentavalent vanadium is changed to the tetravalent vanadium by the discharge. During that time, the color sensor 17 detects the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium, and the positive electrode side charge / discharge state detection unit that specifies the charging state of the positive electrode of the electrolytic solution from the color, and the discharge 3 While the valent vanadium is changed to divalent vanadium or while the divalent vanadium is changed to trivalent vanadium by charging, the color of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17 and is detected from the colors. The negative electrode side charge / discharge state detection unit that specifies the charge state of the negative electrode of the electrolytic solution is the wavelength of the charge power amount based on the peak value of the transmitted light or the reflected light of the light emitting diode arranged in the circulation conduit of the electrolytic solution. Since the (frequency) is calculated from the color, the current charging status can be accurately known.

Then, in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is the electrolytic solution circulation pipeline 13. Based on the peak values of the transmitted light or reflected light of the light emitting diodes arranged at 33, 53, and 73, the smaller detection value of the positive electrode side charge / discharge state detection unit or the negative electrode side charge / discharge state detection unit is calculated as the charging power amount. Therefore, the voltage does not drop abnormally when the battery is used.

Further, since the charging power amount is calculated based on the color of the electrolytic solution, the timing of switching the spare electrolytic solution container is clarified, and the plurality of spare electrolytic solution containers can be accurately switched.
In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation pipeline of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection of scattered light or reflected light of the white light emitting diodes 45 arranged at 13, 33, 53, 73, the detection values of the positive electrode side charge state detection unit and / or the negative electrode side charge state detection unit are the current vanadium sulfate aqueous solution. It is detected in which of 380 to 700 scanning [nm] the color of the electrolytic solution consisting of 15, 35, 55 and 75 is.

That is, the electrolytic solution of divalent vanadium "purple (380-450 nm)" to trivalent vanadium "green (495-570 nm)" at the negative electrode, and similarly, "blue (450-495 nm)" of tetravalent vanadium at the positive electrode. To pentavalent vanadium "yellow (570-590 nm)" electrolyte, for example, the negative electrode is divalent vanadium "purple (380 nm)" and trivalent vanadium "green (495 nm)" or the negative electrode is divalent vanadium. The region will change between "purple (450 nm)" and "green (570 nm)" of trivalent vanadium. At least, it suffices to have a photodetection ability to detect whether the color of the electrolytic solution is between 380 and 700 [nm].

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the electrolytic solution in the detection charge / discharge state detection unit on the positive electrode side and / or the charge / discharge state detection unit on the negative electrode side. The detection value of the negative electrode side charge state detection unit of the white LED arranged in the circulation pipelines 13, 33, 53, 73 is "purple (380 to 450 nm)" of the electrolytic solution of the vanadium sulfate aqueous solution 15, 35, 55, 75. Detects at any position connecting "green (495-570 nm)" and at any position connecting "blue (450-495 nm)" and "yellow (570-590 nm)", and determines the remaining discharge amount. It is to be calculated.

At this time, from the remaining discharge amount obtained from the region of "purple (380 to 450 nm)" to "green" (495 to 570 nm) and from the region of "blue" (450 to 495 nm) to "yellow (570 to 590 nm)". The remaining amount of discharge of the electrolytic solution may be calculated by simply averaging the remaining amount of discharge obtained, or the amount of power with a small amount of discharge or the amount of power with a large amount of discharge of the remaining amount of discharge may be selected.
In any case, the difference between the two will be small during repeated use, so there is no big difference regardless of which one is selected.

FIG. 15 is an example of a redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as an electrolytic solution, and only the differences from FIG. 1 or FIG. 2 will be described.
The liquid circulation pumps 12, 32, 52, 71 rotate at a constant speed, and the cell stack is passed through the electrolytic solution container 11 and the circulation pipe 13c for accommodating the vanadium sulfate aqueous solutions 15, 35, 55, 75 via the circulation pipe 13b. It rotates in the order of the negative side cell path 21 via the negative side cell path 21 and the circulation pipe line 13d of 20.
Similarly, the liquid circulation pumps 12, 32, 52, and 71 are rotated at a constant speed, and the liquid circulation pumps 12, 32, 52, and 71 are rotated at a constant speed, and are passed through the electrolytic solution container 31 and the circulation pipe 33c for accommodating the vanadium sulfate aqueous solutions 15, 35, 55, 75 via the circulation pipe 33a. The cell stack 20 rotates the negative electrode side cell path 21 of the cell stack 20 via the positive electrode side cell path 22B and the circulation line 33c.

Here, the electrolytic solution container 11 and the negative electrode side cell in which the circulation line 13a, the liquid circulation pump 12, the circulation line 13b, and the vanadium sulfate aqueous solutions 15, 25, 55, 75 of the electrolytic solution container 11 circulate from the negative electrode side cell path 21 Road 21, negative electrode side cell line 21, negative electrode side cell line 21, circulation line of circulation line 13d, and from positive electrode side cell line 22 to circulation line 33a, liquid circulation pump 32, circulation line 33b, electrolyte container. It circulates in the electrolytic solution container 31 in which the vanadium sulfate aqueous solution 35 of 31 circulates, the positive electrode side cell path 22, and the circulation conduit of the circulation conduit 33d.
In this embodiment, the liquid circulation pumps 12, 32, 52, and 71 are not increased.

In this way, the cell stacks 20 and 60 make the circulation pipelines of the vanadium sulfate aqueous solution 15, 35, 55, 75 and the vanadium sulfate aqueous solution 15, 35, 55, 75 independent, and the vanadium sulfate aqueous solution 15, 35, 55, By making 75 independent of each other and increasing the volumes of the electrolytic solution container 11 and the electrolytic solution container 31 of the vanadium sulfate aqueous solution 15, 35, 55, 75 and the vanadium sulfate aqueous solution 15, 35, 55, 75, the output time is lengthened. can do.
The output voltage can be determined by connecting the cell stacks 20 and 60 in series in the circulation direction. The voltage of the cell stacks 20 and 60 is determined by the positive electrode 24 and the negative electrode 25 sandwiching the diaphragm plate 23, and the area of the positive electrode 24 and the negative electrode 25 determines the rated energizing current.

That is, in FIG. 15, the areas of the positive electrode 24 and the negative electrode 25 on the cell stack 20 side and the areas of the positive electrode 24 and the negative electrode 25 on the cell stack 20 side are the same, and the rated energizing current is not changed. The power consumption on the cell stack 20 side is increased.
The electric power of the cell stack 20 and the cell stack 20 is used for the electric power of the control device of the redox flow battery 300 which uses the cell stack 20 as a small power consumption and the vanadium sulfate aqueous solutions 15 and 35 of the present embodiment as the electrolytic solution. is there.

When the present invention is carried out, it is not always necessary to separate the cells into the cell stack 20, but if the structure of the cell stack 20 is added as in this embodiment, the cells are circulated as the vanadium sulfate aqueous solutions 15, 35, 55, 75. Since the number of charge / discharge cycles and the reuse of the electrolytic solution have not changed, there is no disadvantage even if the cell stack 20 is mixed.
In particular, if the power for controlling the redox flow battery of the present embodiment is used from the cell stack 20 side, the deterioration of the cell stack 20 can be reduced.
The output voltage V1 of the cell stack 20 and the output voltage V2 of the cell stack 20 have a relationship of V1> V2, but V1 ≧ V2 can also be satisfied.
It is also possible to change their rated currents.

When the present invention is carried out, the cell stacks 20 and 60 have electrical characteristics such as changes in the electromotive force of the redox flow battery 300 and changes in the electromotive force of the redox flow battery 300 when charging is completed. It is for understanding the difference.
In particular, the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the redox flow battery 300 circulate as an electrolytic solution, and the number of charge / discharge cycles and the reuse of the electrolytic solution do not change. Therefore, the cell stacks 20 and 60 have a proportional relationship. Become. However, it can be changed by the power used for the characteristics of the secondary battery such as the redox flow battery 300.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation tube of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection by the transmitted light, scattered light or reflected light of the white LEDs arranged on the paths 13 and 33, the detection values of the positive electrode side charging state detecting unit and / or the negative electrode side charging state detecting unit are the vanadium sulfate aqueous solution 15, 35, 55, 75 are located in any of the "purple (380-450 nm)" and "green (495-570 nm)", "blue (450-495 nm)" and "yellow (570-590 nm)" regions of the electrolytic solution. The remaining amount of discharge is calculated from the charge / discharge characteristics of the auxiliary cells arranged in the circulation pipelines 15 and 35 of the electrolytic solution of the vanadium sulfate aqueous solution 15, 35, 55, 75, and corrected accordingly. You may.

FIG. 13 describes a control configuration of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution.
Since the redox flow battery 300, the solar panel 301, the inverter 304, and the commercial power supply 305 are the same as those in FIGS. 1 and 2, the description thereof will be omitted.

Although not shown, the control device CPU outputs a required number of humidity sensors for detecting leakage of the electrolytic solution from the electrolytic solution container 11 and the electrolytic solution container 31 and leakage from the self-tack 20 to the self-tack container 120. Is entered in two values.
Further, the required number of float sensors 100 are used as binary inputs of the control device CPU. Then, the output for lighting the required number of white LEDs 45 is output from the control device CPU for the detection output of the required number of color sensors 17. Further, the remaining discharge amount of the redox flow battery 300 is displayed on the display 18, and the display target is divided into 3 to 20. The liquid circulation pump 12 and the liquid circulation pump 32 also supply electric power to the required number of pairs of liquid circulation pumps 12, 32, 52, and 72. In the present embodiment, charging and discharging are usually performed by rotating with 100% electric power. When the charge and discharge are low, the charge and discharge are performed at a rotation speed of 1/3 to 1/10.

The redox flow battery 300 using the vanadium sulfate aqueous solutions 15 and 35 of the present embodiment as the electrolytic solution is controlled as shown in the flowchart of FIG.

In step S1, the humidity sensor of the redox flow battery 300 determines whether the vanadium sulfate aqueous solutions 15, 35, 55, 75 have leaked, and if so, the vanadium sulfate aqueous solution 15, 35, 55 is leaked in step S2. , 75 is used as the electrolytic solution, the positive and negative terminals of the redox flow battery 300 are opened, the charging / discharging from the redox flow battery 300 is stopped, and in step S3, the display 18 composed of LEDs blinks or one side or both sides are turned red and continuously lit. Do.
At this time, the color sensor 17 is not working at all. When the humidity sensor operates, the routine processing of steps S1 to S3 is repeatedly executed.

When it is determined in step S1 that the vanadium sulfate aqueous solutions 15, 35, 55, 75 have not leaked from the humidity sensor, the color sensor 17 in step S4 lights the numerical value or color on the display 18 made of LED in step S5. The remaining discharge amount of the vanadium sulfate aqueous solution 15, 35, 55, 75 is shown. Lighting the numerical value or color on the display 18 is not a problem during use of the redox flow battery 300, but data provided as a monitoring effect on the maintenance of the surrounding secondary batteries.
It is determined whether the value of the float sensor 100 in step S6 is within a predetermined range (a range sandwiched between a high value and a low value), and in the embodiment, the value of the float sensor 100 is higher than the predetermined liquid level. At this time, the rotation speed of the liquid circulation pump 12 is reduced.

On the contrary, when the value of the float sensor 100 is lower than the predetermined liquid level, the rotation speed of the liquid circulation pump 12 is increased. The speeds of the liquid circulation pumps 15, 35, 55, and 75 are similarly controlled in steps S6 and S7.
In step S8, the vanadium sulfate aqueous solutions 15, 35, 55, 75 are used as the electrolytic solution of the redox flow battery 300. Here, when the discharge load of the redox flow battery 300 is small, in other words, when the charge load of the redox flow battery 300 is small, this means that when the charge current or the discharge current is small, the liquid circulation pumps 12, 32, in step S9, The currents of 52 and 71 are reduced to about 1/2 to 1/10. At least the vanadium sulfate aqueous solution 15, 35, 55, 75 is circulated.

Further, in step S8, the vanadium sulfate aqueous solutions 15, 35, 55, 75 are used as the electrolytic solution of the redox flow battery 300, but when the discharge load of the redox flow battery 300 is large, that is, the charging load of the redox flow battery 300 is high. When it is large, it means that the charging current or the discharging current is large. Therefore, in step S10, the current of the liquid circulation pumps 12, 32, 52, 71 is increased to 100%, and the vanadium sulfate aqueous solution 15, 35, 55, 75 is electrolyzed. It is circulated so that it can function as a liquid.
Of course, in step S8, the redox flow battery 300 was divided into two when the charge / discharge load was large and when it was small, but in the case of carrying out the present invention, it may be divided into 1 to 5. Good.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the above embodiment as the electrolytic solution, the pentavalent vanadium is converted to the tetravalent vanadium while the tetravalent vanadium is changed to the pentavalent vanadium by charging or by the discharge. During the change, the color sensor 17 detects the color of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium, and the positive electrode side charge / discharge state detection unit that specifies the charge state of the positive electrode of the electrolytic solution from the color, and the discharge. The color of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium is detected by the color sensor 17 while the trivalent vanadium is changed to the divalent vanadium or the divalent vanadium is changed to the trivalent vanadium by charging. The negative electrode side charge / discharge state detection unit for specifying the charge state of the negative electrode of the electrolytic solution from the color is provided, and the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit is the electrolytic solution. The remaining amount of discharge is calculated from the detection value of the color sensor 17 which is one or more of the transmitted light, the scattered light, and the reflected light of the white LED 45 of the color detection unit arranged in the circulation pipeline.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution, the positive electrode and the negative electrode can be charged and discharged by increasing or decreasing the "valence" of vanadium ions. Therefore, vanadium sulfate as the electrolytic solution Since the aqueous solutions 15, 35, 55, and 75 do not deteriorate in principle, the electrolytic solution does not deteriorate.
The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. , The pentavalent vanadium is "yellow".
When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

As a precaution, when this is shown by the color triangle of FIG. 8, the tetravalent vanadium of the positive electrode is "blue (450 to 495 nm)" and the pentavalent vanadium is "yellow (570 to 590 nm)", and "yellow" and "blue". The color between "" and "" is linearly moved as shown in FIG. 8, and is moved on the line connecting the "purple" of divalent vanadium of the negative electrode and the "green" of trivalent vanadium. In principle, it moves on the line connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode. However, even if the error is taken into consideration, it will move on the region connecting the "blue" and "yellow" of the positive electrode.

The divalent vanadium of the negative electrode used in the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is “purple”, the trivalent vanadium is “green”, and the tetravalent vanadium of the positive electrode is “blue”. , The pentavalent vanadium is "yellow". When the negative electrode is fully charged, the divalent vanadium becomes "purple", and when the discharge is completed, the trivalent vanadium becomes "green". The tetravalent vanadium of the positive electrode is "blue" and the pentavalent vanadium is "yellow". When the positive electrode is fully charged, the divalent vanadium becomes "yellow", and when the discharge is completed, the tetravalent vanadium becomes "blue".

Therefore, the tetravalent vanadium of the positive electrode becomes "blue" and the pentavalent vanadium becomes "yellow", and the color region between "yellow" and "blue" shown in FIG. 8 is moved.
It will move on the region connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium of the negative electrode. It will move on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium of the positive electrode.

Therefore, the light emitting element outputs light of a specific wavelength, and the photodiode constituting the light receiving element has a divalent vanadium "purple" to a trivalent vanadium "green" at the negative electrode based on the peak value of the output of the light receiving element. Or, in the positive electrode, it changes from "blue" of tetravalent vanadium to "yellow" of pentavalent vanadium.
Therefore, in the negative electrode, the current remaining charge / discharge amount can be detected in the region connecting the “purple” of divalent vanadium and the “green” of trivalent vanadium. Further, it can be seen that in the positive electrode, there is a charge / discharge remaining amount at a specific wavelength estimated to be on the region connecting the "blue" of tetravalent vanadium and the "yellow" of pentavalent vanadium.

In particular, the remaining charge / discharge amount can be measured regardless of whether the battery is being charged or discharged. Therefore, in the case of a normal secondary battery, the charging time can generally be calculated from the charging time and the energizing current, but in the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution The remaining charge / discharge capacity at that time can be measured regardless of whether the load on the redox flow battery is applied or not.
Moreover, the color of the vanadium sulfate aqueous solution is discriminated by the line connecting the "purple" of divalent vanadium and the "green" of trivalent vanadium, and the line connecting the blue color of tetravalent vanadium and the "yellow" of pentavalent vanadium. Since it is a thing, it is judged by the color, and the reading error can be reduced.
Further, since the LDE 18 emits light at a specific frequency and the photodiode constituting the photocoupler detects the specific frequency, the frequency of the emission color can be accurately detected.

If the remaining discharge amount of the negative electrode and the positive electrode is different depending on the two colors, the detected value of the remaining amount of discharge with a small remaining amount of charge may be adopted as the detection value, or the detected value of the remaining amount of discharge may be used. The average value may be calculated. Alternatively, the power side with a large detection value of the remaining discharge amount may be used as the detection value. That is, it is detected at which wavelength the color of the current electrolytic solution consisting of vanadium sulfate aqueous solution 15, 35, 55, 75 is, and an error occurs. When there is, the divalent vanadium “purple” to trivalent vanadium “green” electrolyte at the negative electrode, as well as the tetravalent vanadium “blue” to pentavalent vanadium “yellow” electrolyte at the positive electrode, For example, the negative electrode changes the divalent vanadium "purple" and the trivalent vanadium "green", or the negative electrode changes the divalent vanadium "purple" and the trivalent vanadium "green". At least, it suffices to have a light detection ability to detect where the color of the electrolytic solution is.

Here, when the remaining amount of discharge with a small amount of remaining charge is set as the detection value, both are matched by repeated charging. Further, even if the average value of the detected values of the remaining discharge amount is calculated or the detected value of the remaining discharge amount is set as the detected value, both can be matched by repeated charging. That is, even if the detected value changes depending on the load fluctuation, the positive electrode and the negative electrode are in a well-balanced steady state by continuously charging and discharging.

The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit disposes a color detection unit 44 in the circulation pipelines 13 and 33 of the electrolytic solution, and transmits the white LED 45 arranged therein. Detects whether there is a remaining amount of discharge between the initial filling or supplementary charging of the positive electrode and / or the negative electrode and full charging by light, scattered light, or reflected light.
The positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is provided in the electrolytic solution circulation pipelines 13, 33. Whether there is a remaining amount of discharge between the initial filling or supplementary charging of the positive electrode and / or the negative electrode and the full charge due to the transmitted light, scattered light, and reflected light of the white LED 45 arranged on the color detecting unit 44. Is detected.
Since the color detection unit 44 is arranged in the circulation pipes 13 and 33 of the electrolytic solution, the vanadium sulfate aqueous solution 15, 35, 55, 75 cannot stagnate. Therefore, the color sensor 17 accurately adjusts the color. I can judge.

In the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present embodiment as the electrolytic solution, the circulation pipeline of the electrolytic solution in the positive electrode side charge / discharge state detection unit and / or the negative electrode side charge / discharge state detection unit. In the detection by the transmitted light, scattered light or reflected light of the white LEDs arranged in 13 and 33, the detection values of the positive electrode side charging state detecting unit and / or the negative electrode side charging state detecting unit are vanadium sulfate aqueous solutions 15, 35. , 55, 75 are detected in any of the "purple" and "green", "blue" and "yellow" regions of the electrolytic solution, and the redox is arranged in the circulation pipelines 13 and 33 of the electrolytic solution. The remaining discharge amount is calculated by specifying from the charge / discharge characteristics of a part or all of the flow battery.

For example, the average value, the minimum value, or the maximum value is detected as to whether it is in the "purple" to "green" region or the "blue" to "yellow" region between the initial charge or supplementary charge and the full charge. From the charge / discharge characteristics of a part or all of the secondary battery arranged in the circulation conduit of the electrolytic solution, for example, the redox flow battery 300, with respect to the remaining discharge amount consisting of the average value, the minimum value, or the maximum value. It specifies and calculates the remaining discharge amount.

Further, from the viewpoint of the redox flow battery configuration, when the output voltage of the redox flow battery 300 is Va [V] and the output voltage of the solar panel 301 is Vb [V], it is operated as Va ≦ Vb. When a pair of backflow prevention diodes 302 and 303 are used, Va ≦ Vb becomes Va <Vb due to the forward voltage drop of the pair of backflow prevention diodes 302 and 303.
Then, this includes a solar panel 301 that performs solar power generation according to the embodiment, a redox flow battery 300 that uses vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, and the solar panel 301 and / or the redox flow. The inverter 304 that converts the DC output of the battery 300 into AC is provided, the solar panel 301 has a high electromotive force, and the pair of backflow prevention diodes 302 and 303 connected to the solar panel 301 are viewed from the cathode side. When the input of the inverter 304 and the charge input of the redox flow battery 300 are obtained and the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301 and the inverter 304 and the redox flow battery 300 is cut off. It is something to do.

A solar panel 301 for performing photovoltaic power generation according to this embodiment, a redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, and the solar panel 301 and / or the redox flow battery 300. It is provided with an inverter 304 that converts a DC output into an AC, and when the electromotive force of the solar panel 301 includes a forward voltage drop and Va ≦ Vb, a pair of backflow prevention connected to the solar panel 301 is provided. The input of the inverter 304 and the charging input of the redox flow battery 300 are obtained from the pair of cathode sides of the solar panels 302 and 303.
When the output of the solar panel 301 becomes low, the electrical connection between the solar panel 301, the inverter 304, and the redox flow battery 300 is cut off. At this time, the output of the redox flow battery 300 is taken out as the output of the inverter 304, but since the load of the commercial power supply 305 becomes a light load at night, the power at night can be supplied from the redox flow battery 300 according to its capacity.
Further, when the capacity of the redox flow battery 300 is large, the electric power can be sold to the electric power company.

The above embodiment comprises a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. The charge / discharge circulation path consisting of circulation lines 33, 33a, 33b, 33c on the positive electrode side, and the above-mentioned while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging. Electrolyte solutions of vanadium sulfate aqueous solutions 15, 35, 55, 75 having a negative electrode side circulation line consisting of a flow of an electrolytic solution composed of divalent vanadium and trivalent vanadium and a charge / discharge circulation line composed of charge / discharge circulation lines 13, 13a, 13b, 13c. In the redox flow battery 300, the tubular body made of a transparent large-diameter tube 52 made of synthetic resin, which is sent out from the liquid circulation pumps 12 and 32 for circulating the electrolytic solution and diffuses the electrolytic solution, and the transparent large tube. The electrolytic solution container 11, 31, 51, 71 containing the tubular body made of the diameter tube body 52 and the electrolytic solution container 11, the electrolytic solution container 11, by the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 71. It includes a discharge pipe arranged in parallel with a cylinder made of the transparent large-diameter pipe body 86 for discharging the electrolytic solution in 31, 51, 71 to the outside of the electrolytic solution container 11, 31, 51, 71. ..

The redox flow battery using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present invention as the electrolytic solution has circulation pipelines 33, 33a, 33b on the positive side, which are composed of an electrolytic solution flow composed of tetravalent vanadium and pentavalent vanadium. The charge / discharge circulation path composed of 33c is the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the conversion of tetravalent vanadium to pentavalent vanadium by charging or the conversion of pentavalent vanadium to tetravalent vanadium by discharge. It consists of a flow.
Further, the charge / discharge circulation line consisting of the negative side circulation lines 13, 13a, 13b, 13c consisting of the flow of the electrolytic solution composed of divalent vanadium and trivalent vanadium changes the trivalent vanadium into divalent vanadium by discharge. It consists of the divalent vanadium and the trivalent vanadium while the divalent vanadium is changed to trivalent vanadium by interval or charging.

That is, the charge / discharge circulation path including the circulation lines 33, 33a, 33b, 33c, 33d on the positive electrode side forms a positive electrode as a secondary battery and is a terminal for extracting current. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 33d on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. The charge / discharge circulation paths on the positive electrode side and the negative electrode side are composed of independent charge / discharge circulation lines 33, 33a, 33b, 33c on the positive electrode side, and circulation lines 13, 13a, 13b, 13c on the negative electrode side. A charge / discharge circulation path is formed, and an electromotive force is generated by the electrolytic solution flowing there.

The electrolytic solution containers 11, 31, 51, and 71 that accommodate the tubular body made of the transparent large-diameter tube 86 and the tubular body made of the transparent large-diameter tube 92 are liquid circulation pumps 12 that circulate the electrolytic solution. The electrolytic solutions sent from 32, 52, 72 are diffused so as to be averaged, and the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tube 92 are the electrolytic solutions. It is a container for liquid.
The transparent circulation line 92 and the insertion circulation line 93 are basically not different from the circulation lines 33, 33a, 33b, 33c, 33d.
Further, the discharge pipes 81, 82 electrolyze the electrolytic solution in the electrolytic solution containers 11, 31, 51, 71 by the pressure of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. An arrangement method in which the liquid containers are circulated outside the liquid containers 11, 31, 51, 71, that is, through the pipelines to the cell stacks 20 and 60, and arranged in parallel with the cylinder made of the transparent large-diameter pipe 52. Is preferable.

In particular, the charge / discharge circulation path composed of the circulation tubes 33, 33a, 33b, 33c on the positive side of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 25, 55, 75 as the electrolytic solution is charged with tetravalent vanadium. It consists of a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium during the conversion to pentavalent vanadium or during the conversion of pentavalent vanadium to tetravalent vanadium by electric discharge. Further, in the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c on the negative electrode side, the divalent vanadium is changed to divalent vanadium by discharge or the divalent vanadium is changed to trivalent vanadium by charging. It consists of a flow of an electrolytic solution composed of the above-mentioned divalent vanadium and trivalent vanadium.
A cylinder made of a transparent large-diameter pipe body 85 that circulates the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72 and diffuses the electrolytic liquid, and a cylinder made of the transparent large-diameter pipe body 85 are housed. The electrolytic solution containers 11, 31, 51, 71 are the electrolytic solutions in the electrolytic solution containers 11, 31, 51, 71 due to the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. Is circulated in the cell stack via the conduit outside the electrolyte containers 11, 31, 51, 71.

Therefore, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 71 circulates the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 delivered from the liquid circulation pumps 12, 32, 52, 72. Then, the electrolytic solution circulating in the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tube 86 and the tubular body made of the transparent large-diameter tube 86 is diffused. Therefore, the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stacks 20 and 60 are uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 is subjected to the electrolytic solution by the electrolytic solution containers 11, 31, 51, 71 that accommodate the cylinder and the cylinder that are double-stacked. Is a complicated flow, so that vanadium having different valences is mixed well, and as a result of circulating it as the electrolytic solution, the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20. Is uniformly distributed, and the electromotive force of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is stable.

The liquid circulation pumps 12, 32, 52, 71 for circulating the electrolytic solution of the redox flow battery 300 of the above embodiment are attached so as to be housed in the upper part of the cylinder made of the transparent large-diameter tube 52. ..
Here, the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are housed in the upper part of the tubular body made of the transparent large-diameter tube 86, and the transparent large-diameter tube 92 By integrating it with the upper part of the tubular body made of, the outer shape can be summarized into the size of the tubular body made of the transparent large-diameter tube 92.

Since the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are attached to be housed in the upper part of the cylinder, the cylinder made of the transparent large-diameter pipe 92 is formed. Since the liquid circulation pumps 12, 32, 52, 72 to be accommodated in the upper part of the body are attached, the liquid circulation pumps 12, 32, 52, 72 can be accommodated in the upper part of the cylinder made of the transparent large-diameter pipe body 952. Then, various parts can be accommodated in the tubular body made of the transparent large-diameter tube 92, and parts can be replaced in the case of failure in the tubular unit made of the transparent large-diameter tube 92.

The LED illumination for determining the color of the electrolytic solution of the redox flow battery 300 of the present invention and the color sensor 17 for detecting the color of the electrolytic solution under the LED illumination composed of the white LED 45 are the ambient light sources. White is preferable, but other colors are not unusable. The color sensor 17 determines the color of the electrolytic solution, and it is sufficient that the color can be determined as well as the lightness and darkness.
Since the redox flow battery 300 of the present invention includes an LED illumination composed of a white LED 45 that determines the color of the electrolytic solution and a color sensor 17 that detects the color of the electrolytic solution under the LED illumination, the redox flow battery Since the color of the electrolytic solution of 300 is detected by the LED illumination and the color sensor 17 under the LED illumination, it is not affected by the depth of the electrolytic solution and also affects the number of years of use. There is no need for maintenance because it is not received.

Further, in the redox flow battery 300 of the present invention, a float sensor for detecting the liquid level position of the electrolytic solution in the cylinder made of the transparent large diameter tube 86 is further provided in the cylinder made of the transparent large diameter tube 86. It is a thing.
Here, since the float sensor 100 operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.
In the redox flow battery 300 of the present invention, since the float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder is further provided in the cylinder made of the transparent large-diameter tube 86, the transparent diameter Since the float sensor 100 can be managed with a tube body or a tube body having a square cross section and can be moved in the controlled state, the trouble of protecting with a cushioning material or the like can be saved.

Further, since the redox flow battery 300 of the present invention has a breathing hole and a filter 84 attached to the upper part of a cylinder made of a transparent large-diameter tube 92, the outside temperature of the electrolytic solution with respect to a change in the outside air temperature. Since the volume change of the above is offset by the volume change of the electrolytic solution containers 11, 31, 51, 71, the change is small with respect to the original change amount of the breathing air. Further, the amount of air passing through the filter 84 changes with a small amount of air and does not attract dust or the like.
Further, a breathing hole and a filter 84 are attached to the upper part of the tubular body made of the transparent large-diameter tube 92.
Here, the breathing hole in the upper part of the tubular body made of the transparent large-diameter tube 92 is not limited to the upper surface of the tubular body made of the transparent large-diameter tube 92, and may be at the upper position of the side surface. Good. Further, the filter 84 preferably has no hygroscopicity of the electrolytic solution, and a liquid blocking effect can be obtained by repelling the liquid.

The electrolytic solution liquid circulation pumps 12, 32, 52, 71 are arranged on the upper plane side formed by the entire electrolytic solution containers 11, 31, 51, 71.
Here, the upper plane side formed by the entire electrolyte container 11, 31, 51, 71 means a plane on the plane of the upper surface of the electrolyte container 11, 31, 51, 71 or the back surface thereof. The liquid circulation pumps 12 and 32 can be attached to the upper flat or a position below the upper flat, and any position can be used as long as the workability of the electrolytic solution containers 11, 31, 51, 71 can be ensured. .. In particular, the movable part may be in a position where parts can be easily replaced.
Since the liquid circulation pumps 12, 31, 51, 71 of the redox flow battery 300 of the present invention are arranged on the upper plane side formed by the entire electrolytic solution container 11, 31, 51, 71, the electrolytic solution Since the containers 11, 31, 51, and 71 are arranged on the upper surface side formed by the whole, maintenance can be freely performed and the workability thereof can be improved.

The redox flow battery of the present embodiment passes through an output circuit composed of lead wires 26A and 26B and lead wires 27A and 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series and the cell stacks 20 and 60. Passes through the positive electrode side electrolytic solution containers 31 and 71 for accommodating the electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The positive electrode side charge / discharge circulation paths 33 and 73 in which the flow of the electrolytic solution is in the same direction for both charging and discharging, and the negative electrode side in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. The flow velocity between the charge / discharge circulation passages 13, 53 and the electrolytic solution of the positive electrode side charge / discharge circulation passages 13, 33, 53, 73 between the cell stacks 20, 60 and the positive electrode side electrolytic solution containers 31, 71. The positive electrode side liquid circulation pumps 12, 32, 52, 72 and the negative electrode side charge / discharge circulation passages 13, 33, 53, 73 are combined with the cell stacks 20, 60 and the negative electrode side electrolytic solution container. It is provided with a negative electrode side liquid circulation pump 12, 32, 52, 71 that increases the flow velocity between the 11, 31, 51, and 71.

In the redox flow battery 300 of the present embodiment, the output voltage can be determined by an output circuit composed of a lead wire 26A and a lead wire 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series. Further, the output circuit including the lead wire 26A and the lead wire 27B connected in series can be determined in consideration of the fluid resistance of the electrolytic solution passing through the cell stacks 20 and 60.
Further, the positive electrode side electrolytic solution containers 31 and 71 and the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60 accommodate the electrolytic solution, and have a charging capacity for the electrolyzed solution. Determines the amount of electricity charged.

The positive electrode side charge / discharge circulation paths and the negative electrode side charge / discharge circulation paths 11, 31, 51, 71 in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 are in the same direction for both charging and discharging are the electrolytic solutions. Since the flow is unidirectional for both charging and discharging, the positive electrode side electrolytic solution containers 11, 31, 51, 71, the negative electrode side electrolytic solution containers 11, 31, 51, 71, and the positive electrode side charge / discharge circulation path 33. , 73, the negative electrode side charge / discharge circulation passages 31, 51, the positive electrode side liquid circulation pumps 12, 32, 52, 71 and the negative electrode side liquid circulation pumps 12, 32, 52, 72 are charged with the redox flow battery 300. It does not control the discharge, and can be naturally charged and discharged from the outside, for example, from the solar panel 301 or the like by its electromotive force.
That is, for example, even if the charging voltage of a secondary battery such as the redox flow battery 300 is low, the secondary voltage is such that the flow of the electrolytic solutions of one cell stack 20 and 60 is connected in parallel and the outputs are connected in series. By increasing the voltage, the usable input voltage of the inverter 304 can be increased.

Further, the input of the inverter 304 can be naturally converted (modulated) into alternating current by the electromotive force of the solar panel 301 or the like regardless of the charge / discharge of the redox flow battery 300.
The positive electrode side liquid circulation pumps 32, 72 for increasing the electrolyte flow velocity of the positive electrode side charge / discharge circulation passages 33, 73 and the negative electrode side liquid circulation pump for increasing the electrolyte flow velocity of the negative electrode side charge / discharge circulation passages 13, 53. In the positions 12 and 52, the positive electrode side liquid circulation pumps 32 and 72 and the negative electrode side liquid are located at any of the positive electrode side charge / discharge circulation paths 33 and 73 and the negative electrode side charge / discharge circulation paths 13 and 53 for circulating the electrolytic solution. Since the circulation pumps 12 and 52 may be arranged, the degree of freedom in design and maintenance is high.

In the redox flow battery 300 of the present embodiment, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 are single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution. A plurality of positive electrode side charge / discharge circulation paths 33, 73 and a plurality of negative electrode side charge / discharge circulation paths 13, 53 are independently piped to the containers 11 and 51 except for the diaphragms of the cell stacks 20 and 60.
Therefore, the positive electrode side electrolytic solution container 31, 71 or the negative electrode side electrolytic solution container 11, 51 of the redox flow battery 300 is a single positive electrode side electrolytic solution container 31, 71 or the negative electrode side electrolytic solution container 11, Since the plurality of positive electrode side charge / discharge circulation passages 33 and 73 and the plurality of negative electrode side charge / discharge circulation passages 13 and 53 are independently piped to 51 except for the diaphragms of the cell stacks 20 and 60, standardization is possible. On the contrary, the shape and volume of the positive electrode side electrolytic solution container 11,51 or the negative electrode side electrolytic solution container 11,51 can be arbitrary.

The redox flow battery of the present embodiment has positive electrode side electrolytic solution containers 31, 71, negative electrode side electrolytic solution containers 13, 53, positive electrode side charge / discharge circulation paths 33, 73, negative electrode side charge / discharge circulation paths 13, 53, and positive electrode side. Since one or more of the liquid circulation pumps 32 and 72 and the negative electrode side liquid circulation pumps 12 and 52 are provided for the single cell stacks 20 and 60, the liquid pressure rises with respect to the single cell stacks 20 and 60. Live less. Further, since the charge / discharge does not change depending on the location, the temperature of the electrodes 24, 25, 64, 65 does not rise due to the partial current.
Therefore, the positive electrode side electrolytic solution containers 31, 71 and the negative electrode side electrolytic solution containers 11, 51, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 73, 73a, 73b, 73c and the negative electrode side charge / discharge circulation paths. 13, 13a, 13b, 13c, 53, 53a, 53b, 53c, the positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 are one for a single cell stack 20, 60. The above is provided and others.

The above embodiment comprises a flow of an electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. A charge / discharge circulation path consisting of circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive electrode side, and 3 divalent vanadium during or during charging to change trivalent vanadium to divalent vanadium by discharge. The charge / discharge circulation path consisting of the negative electrode side circulation pipelines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c consisting of the flow of the electrolytic solution composed of the divalent vanadium and the trivalent vanadium during the change to the valent vanadium. In the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution, the electrolytic solution is discharged from the liquid circulation pumps 12, 32, 52, 72 that circulate the electrolytic solution. Electrolyte containers 11, 31, 51, 71 accommodating a cylinder made of a transparent large-diameter tube 92 made of synthetic resin to be diffused and a cylinder made of the transparent large-diameter tube 92, and the liquid circulation pumps 12, 32. , 52, 72 The transparent large diameter that discharges the electrolytic solution in the electrolytic solution container 11, 31, 51, 71 to the outside of the electrolytic solution container 11, 31, 51, 71 by the pressing force of the electrolytic solution sent out from It includes a discharge pipe arranged in parallel with a cylinder made of a pipe body 92.

The redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 of the present invention as an electrolytic solution has circulation pipelines 33, 33a, 33b on the positive side, which is composed of a flow of an electrolytic solution composed of tetravalent vanadium and pentavalent vanadium. The charge / discharge circulation path composed of, 33c, 73, 73a, 73b, 73c is the above-mentioned tetravalent vanadium while changing tetravalent vanadium to pentavalent vanadium by charging or changing pentavalent vanadium to tetravalent vanadium by discharging. It consists of a flow of an electrolytic solution composed of pentavalent vanadium and pentadium vanadium.
Further, the charge / discharge circulation path composed of the negative electrode side circulation pipelines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c composed of the flow of the electrolytic solution composed of divalent vanadium and trivalent vanadium is trivalent due to discharge. It is composed of the above-mentioned divalent vanadium and trivalent vanadium while changing vanadium to divalent vanadium or while changing divalent vanadium to trivalent vanadium by charging.

That is, the charge / discharge circulation path including the circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive electrode side forms a positive electrode as a secondary battery and is a terminal for taking out current. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side forms a negative electrode as a secondary battery, and is a terminal through which a current flows. The charge / discharge circulation paths 13, 33, 53, 73 on the positive electrode side and the negative electrode side have charge / discharge circulation paths composed of independent positive electrode side circulation lines 33, 33a, 33b, 33c, 73, 73a, 73b, 73c. A charge / discharge circulation path composed of circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side is formed, and an electromotive force is generated by an electrolytic solution flowing through the charge / discharge circulation line.

The electrolytic solution containers 11, 31, 51, and 71 that accommodate the tubular body made of the transparent large-diameter tube 92 and the tubular body made of the transparent large-diameter tube 92 are liquid circulation pumps 12 that circulate the electrolytic solution. The electrolytic solution containers 11, 31, 51, 71 for accommodating the tubular body made of the transparent large-diameter tubular body 92 are the electrolytic solution accommodating containers for averaging the electrolytic solution delivered from 32. Is.
Further, the discharge pipes 81, 82 electrolyze the electrolytic solution in the electrolytic solution containers 11, 31, 51, 71 by the pressure of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. It is circulated outside the liquid containers 11, 31, 51, 71, that is, through the pipeline, and is preferably arranged in parallel with the cylinder made of the transparent large-diameter pipe 92. is there.

In particular, a charge / discharge circulation path composed of circulation tubes 33, 33a, 33b, 33c, 73, 73a, 73b, 73c on the positive side of the redox flow battery 300 using vanadium sulfate aqueous solutions 15, 35, 55, 75 as an electrolytic solution. Consists of a flow of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing the tetravalent vanadium to the pentavalent vanadium by charging or changing the pentavalent vanadium to the tetravalent vanadium by the discharge. Further, the charge / discharge circulation path composed of the circulation lines 13, 13a, 13b, 13c, 53, 53a, 53b, 53c on the negative electrode side is divided into divalent vanadium while changing trivalent vanadium to divalent vanadium by discharge or by charging. It consists of a flow of an electrolytic solution composed of the divalent vanadium and the trivalent vanadium while changing to trivalent vanadium.
A cylinder made of a transparent large-diameter pipe 92 that circulates the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72 and diffuses the electrolytic liquid and a cylinder made of the transparent large-diameter pipe 92 are housed. The electrolytic solution containers 11, 31, 51, 71 are the electrolytic solutions in the electrolytic solution containers 11, 31, 51, 71 due to the pressing force of the electrolytic solution sent from the liquid circulation pumps 12, 32, 52, 72. Is circulated in the cell stack via the conduit outside the electrolyte containers 11 and 31.

Therefore, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 circulates the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 delivered from the liquid circulation pumps 12, 32, 52, 72. Then, the electrolytic solution circulating in the electrolytic solution containers 11, 31, 51, 71 containing the tubular body made of the transparent large-diameter tubular body 92 and the tubular body made of the transparent large-diameter tubular body 92 is diffused. Therefore, the electrolytic solutions of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20 are uniformly distributed as vanadium having different valences.
Further, the electrolytic solution delivered from the liquid circulation pumps 12, 32, 52, 72 is subjected to the electrolytic solution by the electrolytic solution containers 11, 31, 51, 71 that accommodate the cylinder and the cylinder that are double-stacked. Is a complicated flow, so that vanadium having different valences is mixed well, and as a result of circulating it as the electrolytic solution, the electrolytic solution of the electrolytic solution containers 11, 31, 51, 71 circulating in the cell stack 20. Is uniformly distributed, and the electromotive force of the redox flow battery 300 using the vanadium sulfate aqueous solutions 15, 35, 55, 75 as the electrolytic solution is stable.

The liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 of the above embodiment are attached so as to be housed in the upper part of the cylinder made of the transparent large-diameter tube 92. ..
Here, the liquid circulation pumps 11, 31, 51, 71 for circulating the electrolytic solution of the redox flow battery 300 are housed in the upper part of the tubular body made of the transparent large-diameter tube 92, and the transparent large-diameter tube 92 By integrating it with the upper part of the tubular body made of the above, the outer shape can be summarized into the size of the tubular body made of the transparent large-diameter tube 92.

Since the liquid circulation pumps 12, 32, 52, 72 for circulating the electrolytic solution of the redox flow battery 300 are attached to be housed in the upper part of the cylinder, the cylinder made of the transparent large-diameter pipe 92 is formed. Since the liquid circulation pumps 12, 32, 52, 72 to be accommodated in the upper part of the body are attached, the liquid circulation pumps 12, 32, 52, 72 can be accommodated in the upper part of the cylinder made of the transparent large-diameter tube 92. Then, various parts can be accommodated in the tubular body made of the transparent large-diameter tube 92, and parts can be replaced in the case of failure in the tubular unit made of the transparent large-diameter tube 92.

The LED illumination for determining the color of the electrolytic solution of the redox flow battery 300 of the present invention and the color sensor 17 for detecting the color of the electrolytic solution under the LED illumination composed of the white LED 45 are the ambient light sources. White is preferable, but other colors are not unusable. The color sensor 17 determines the color of the electrolytic solution, and it is sufficient that the color can be determined as well as the lightness and darkness.
Since the redox flow battery 300 of the present invention includes an LED illumination composed of a white LED 45 that determines the color of the electrolytic solution and a color sensor 17 that detects the color of the electrolytic solution under the LED illumination, the redox flow battery Since the color of the electrolytic solution of 300 is detected by the LED illumination and the color sensor 17 under the LED illumination, it is not affected by the depth of the electrolytic solution and also affects the number of years of use. There is no need for maintenance because it is not received.

Further, in the redox flow battery 300 of the present invention, a float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder made of the transparent large diameter tube 92 is further placed in the cylinder made of the transparent large diameter tube 92. It is provided.
Here, since the float sensor 100 operates at a predetermined liquid level, it can be operated by two sensors, a humidity sensor, a water level sensor, or the like.
In the redox flow battery 300 of the present invention, since the float sensor 100 for detecting the liquid level position of the electrolytic solution in the cylinder is further provided in the cylinder made of the transparent large diameter tube 92, the transparent diameter Since the float sensor 100 can be managed with a tube body or a tube body having a square cross section and can be moved in the controlled state, the trouble of protecting with a cushioning material or the like can be saved.

Further, since the redox flow battery 300 of the present invention has a breathing hole and a filter 84 attached to the upper part of a cylinder made of a transparent large-diameter tube 92, the outside temperature of the electrolytic solution with respect to a change in the outside air temperature. Since the volume change of the above is offset by the volume change of the electrolytic solution containers 11, 31, 51, 71, the change is small with respect to the original change amount of the breathing air. Further, the amount of air passing through the filter 84 changes with a small amount of air and does not attract dust or the like.
Further, a breathing hole and a filter 84 are attached to the upper part of the tubular body made of the transparent large-diameter tube 92.
Here, the breathing hole in the upper part of the tubular body made of the transparent large-diameter tube 92 is not limited to the upper surface of the tubular body made of the transparent large-diameter tube 92, and may be at the upper position of the side surface. Good. Further, the filter 84 preferably has no hygroscopicity of the electrolytic solution, and a liquid blocking effect can be obtained by repelling the liquid.

The electrolytic solution liquid circulation pumps 12, 32, 52, 72 are arranged on the upper plane side formed by the entire electrolytic solution containers 11, 31, 51, 71.
Here, the upper plane side formed by the entire electrolyte container 11, 31, 51, 71 means a plane on the plane of the upper surface of the electrolyte container 11, 31, 51, 71 or the back surface thereof. The liquid circulation pumps 12 and 32 can be attached to the upper flat or a position below the upper flat, and any position can be used as long as the workability of the electrolytic solution containers 11, 31, 51, 71 can be ensured. .. In particular, the movable part may be in a position where parts can be easily replaced.
The liquid circulation pumps 12, 32, 52, 72 of the redox flow battery 300 of the present invention are arranged on the upper plane side formed by the entire electrolytic solution container 11, 31, 51, 71. Since the electrolytic solution containers 11, 31, 51, and 71 are arranged on the upper surface side formed by the whole, maintenance can be freely performed and the workability thereof can be improved.

The redox flow battery 300 of the present embodiment includes an output circuit composed of lead wires 26A and 26B and lead wires 27A and 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series, and the cell stacks 20 and 60. Passes through the positive electrode side electrolytic solution containers 31 and 71 for accommodating the passing electrolytic solution, the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60, and the cell stacks 20 and 60. The flow of the electrolytic solution passes through the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the cell stacks 20, 60 in which both charging and discharging are in the same direction. The negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, and the positive electrode side charge / discharge circulation paths 33, in which the flow of the electrolytic solution is in the same direction for both charging and discharging. , 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d, the positive electrode side that increases the flow velocity between the cell stacks 20, 60 and the positive electrode side electrolytic solution containers 31, 71. The liquid circulation pumps 32, 72 and the electrolytic solutions of the negative electrode side charge / discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are applied to the cell stacks 20, 60 and the negative electrode side. It is provided with negative electrode side liquid circulation pumps 12 and 52 that increase the flow velocity between the electrolyte containers 11 and 51.

In the redox flow battery 300 of the present embodiment, the DC output voltage can be determined by an output circuit composed of lead wires 26A and lead wires 27B in which the outputs of two or more cell stacks 20 and 60 are connected in series. Further, the output circuit including the lead wire 26A and the lead wire 27B connected in series can be determined in consideration of the fluid resistance of the electrolytic solution passing through the cell stacks 20 and 60.
Further, the positive electrode side electrolytic solution containers 31 and 71 and the negative electrode side electrolytic solution containers 11 and 51 for accommodating the electrolytic solution passing through the cell stacks 20 and 60 accommodate the electrolytic solution, and have a charging capacity for the electrolyzed solution. Determines the amount of electricity charged.

Then, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d in which the flow of the electrolytic solution passing through the cell stacks 20 and 60 is in the same direction for both charging and discharging. In the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, since the flow of the electrolytic solution is unidirectional for both charging and discharging, the positive electrode side electrolytic solution Containers 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side electrolytic solution containers 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, the positive electrode side. Charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d. The positive electrode side liquid circulation pumps 12, 32, 52, 71 and the negative electrode side liquid circulation pumps 12, 32, 52, 72 do not control the charging and discharging of the redox flow battery 300, and from the outside, for example, It can be charged and discharged naturally from the solar panel 301 or the like by its electromotive force.
That is, for example, even if the charging voltage of a secondary battery such as the redox flow battery 300 is low, the secondary voltage is such that the flow of the electrolytic solutions of one cell stack 20 and 60 is connected in parallel and the outputs are connected in series. By increasing the voltage, the usable input voltage of the inverter 304 can be increased.

Further, the input of the inverter 304 can be naturally converted (modulated) into alternating current by the electromotive force of the solar panel 301 or the like regardless of the charge / discharge of the redox flow battery 300.
The positive electrode side liquid circulation pumps 12, 32, 52, 72 and the negative electrode side charging that increase the flow velocity of the electrolytic solution in the positive electrode side charging / discharging circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d. The negative electrode side liquid circulation pumps 12 and 52 for increasing the flow velocity of the electrolytic solution in the discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are filled with the positive electrode side for circulating the electrolytic solution. The positive electrode side liquid circulation pumps 32, 72 and the negative electrode side liquid circulation pumps 12, 52 may be arranged at any of the discharge circulation paths 13, 33, 53, 73 and the negative electrode side charge / discharge circulation paths 13, 53. Therefore, the degree of freedom in design and maintenance is high.
In particular, the cell stacks 20 and 60 of the redox flow battery 300 can be shortened, and even if the fluid resistance is not increased, the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d And the current capacities of the negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d can be secured.

In the redox flow battery 300 of the present embodiment, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 are single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution container 11. , 51, and a plurality of positive electrode side charge / discharge circulation paths and a plurality of negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d are used as diaphragms of the cell stacks 20, 60. It is an independent pipe except for.
Therefore, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51 of the redox flow battery 300 are combined with the single positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution containers 11, 51. On the other hand, a plurality of positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and a plurality of negative electrode side charge / discharge circulation paths 13, 13a, 13b, 13c, 13d, 53, Since 53a, 53b, 53c, 53d are independently piped except for the diaphragms of the cell stacks 20 and 60, standardization is possible, and conversely, the positive electrode side electrolytic solution containers 31, 71 or the negative electrode side electrolytic solution The shapes and volumes of the containers 11 and 51 can be arbitrary.

The positive electrode side electrolytic solution containers 31, 71 of the redox flow battery 300 of the present invention, the negative electrode side electrolytic solution containers 11, 51, and the positive electrode side charge / discharge circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c. , 73d, the negative electrode side charge / discharge circulation path, the positive electrode side liquid circulation pumps 32, 72, and the negative electrode side liquid circulation pumps 12, 52 are provided at least one for a single cell stack 20, 60. The rise in liquid pressure for a single cell stack 20, 60 lives low. Further, since the charge / discharge does not change depending on the location, the temperature of the electric 15 pole does not rise due to the partial current.
Therefore, the positive electrode side electrolytic solution containers 31, 71 and the negative electrode side electrolytic solution containers 11, 51, the positive electrode side charging / discharging circulation paths 33, 33a, 33b, 33c, 33d, 73, 73a, 73b, 73c, 73d and the negative electrode side charging The discharge circulation passages 13, 13a, 13b, 13c, 13d, 53, 53a, 53b, 53c, 53d, the positive electrode side liquid circulation pumps 32, 71 and the negative electrode side liquid circulation pumps 12, 52 are single cell stacks 20, One or more is provided for 60, and the other is provided.

11, 31, 51, 71 Electrode container 12, 32, 52, 72 Liquid circulation pump 13, 13a, 13b, 13c, 13d Circulation line 15, 35, 55, 75 Vanadium sulfate aqueous solution 33, 33a, 33b, 33c, 33d Circulation pipeline 53, 53a, 53b, 53c, 53d Circulation pipeline 73, 73a, 73b, 73c, 73d Circulation pipeline 17 Color sensor 20, 60 Cell stack 21 Negative electrode side cell path 22 Positive electrode side cell path 61 Negative electrode side cell Road 62 Positive electrode side cell road 44 Color detector 45 White LED
46 Optical fiber 50 Electrolytic solution distributor 92 Transparent large diameter tube 93 Insertion circulation line 100 Float sensor 121 Center moving rod 123 Float 124 Reed switch 300 Redox flow battery 400 Battery storage body

Claims (6)

Charge / discharge circulation on the positive side consisting of the flow of the electrolytic solution composed of the tetravalent vanadium and the pentavalent vanadium while changing the tetravalent vanadium to the pentavalent vanadium by charging or changing the pentavalent vanadium to the tetravalent vanadium by discharging. On the negative side, which consists of a flow of an electrolytic solution composed of the divalent vanadium and the trivalent vanadium, while changing trivalent vanadium to divalent vanadium by discharging or changing divalent vanadium to trivalent vanadium by charging. In a redox flow battery using an aqueous solution of vanadium sulfate having a charge / discharge circulation path as an electrolytic solution,
A cylinder that is sent from a liquid circulation pump that circulates the electrolyte and diffuses the electrolyte, and an electrolyte container that houses the cylinder.
A discharge pipe arranged in parallel with the cylinder for discharging the electrolytic solution in the electrolytic solution container to the outside of the electrolytic solution container by the pressure of the electrolytic solution sent from the liquid circulation pump.
A redox flow battery characterized by being equipped with. The redox flow battery according to claim 1, wherein the liquid circulation pump for circulating the electrolytic solution is attached so as to be housed in an upper portion of the cylinder. The redox flow battery according to claim 1 or 2, further comprising an LED illumination that determines the color of the electrolytic solution and a color sensor that detects the color of the electrolytic solution under the LED illumination. .. The redox flow battery according to any one of claims 1 to 3, wherein a float sensor for detecting the liquid level position of the electrolytic solution in the cylinder is provided in the cylinder. The redox flow battery according to any one of claims 1 to 4, wherein a breathing hole and a filter are assembled on the upper part of the cylinder. The redox flow battery according to any one of claims 1 to 5, wherein the liquid circulation pump is arranged on the upper plane side formed by the entire electrolytic solution container.