JPH0794215A - Charging degree measuring meter of zinc-bromine battery - Google Patents

Abstract

PURPOSE:To easily measure the charging degree without troublesome operations by making pipes for an electrolytic liquid supply and discharge transparent ones and measuring the light refractive index of the electrolytic liquid by a light receiving unit whose installation angle and installation position can be finely controlled. CONSTITUTION:An electrolytic liquid 5 is circulated from a positive electrode side tank and a negative electrode side tank through a pipeline 12 by an electrolytic liquid pump. The pipeline is composed of a transparent pipe and the alteration of the refractive index of the electrolytic liquid, which corresponds to the charging degree, is measured by refracting laser beam radiated by a laser oscillator 21 of a light emitting unit near the pipeline 12 and receiving the laser beam by laser light receiver 22 of a light receiving unit. For that, the light receiver 22 is supported by a movable body and its installation position and installation angle are finely controlled, so that the charging degree of zinc- bromine batteries is easily measured without toublesome operations, such as temperature correction of the electrolytic liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge depth meter for measuring the charge depth of an electrolytic solution in a zinc-bromine battery.

[0002]

2. Description of the Related Art A zinc-bromine battery is a positive electrode active material containing bromine,
It is a secondary battery that uses zinc as the negative electrode active material. It is a battery for peak cut that stores surplus power at night in the battery to eliminate unbalanced power demand between day and night, and discharges it during daytime when demand is high. Is. Currently, a large capacity battery is being developed for power storage.

The chemical reaction of this zinc-bromine battery is

[0004]

[Chemical Formula 1] During charging: positive electrode: 2Br ⁻ → Br ₂ + 2e ⁻ , negative electrode: Zn ⁺⁺ + 2e ⁻ → Zn During discharging: positive electrode: 2Br ⁻ ← Br ₂ + 2e ⁻ , negative electrode: Zn
It is represented by ⁺⁺ + 2e ⁻ ← Zn.

The electrolyte solution is circulated by a pump at the time of charging / discharging from a positive electrode side tank separately provided from the battery body. Then, the bromine generated at the positive electrode reacts with the bromine complexing agent (quaternary amine) added to the electrolytic solution to form an oil-like precipitate that is returned to the tank and pumped into the cell during discharge. Be reduced. The electrolyte is composed of 3 mol / l ZnBr ₂ with about 2 mol / l salt such as NH ₄ Cl in order to reduce the resistance of the solution, and further prevents the negative electrode zinc dendrite to promote uniform electrodeposition. To this end, Pb, Sn, quaternary ammonium salts, and 1 mol / l of a bromine complexing agent are added. A separator is used between the positive electrode and the negative electrode to prevent bromine generated in the positive electrode from diffusing into the negative electrode and causing self-discharge of zinc.

FIG. 6 is a schematic diagram for explaining the operating principle of the above zinc-bromine battery. In FIG. 6, reference numeral 1 denotes a positive electrode side tank in which a positive electrode electrolyte solution 2 and a bromine complex compound 3 are contained. Are stored. Reference numeral 4 denotes a negative electrode side tank, in which the negative electrode electrolyte solution 5 is stored. The positive electrode electrolyte 2 flows through the four-way switching valve 7 and the pipe 8 from the positive electrode manifold 9 of the battery main body along with the driving of the positive electrode side pump 6 in the unit cell, as shown by the arrow in the figure, and the pipe While flowing back to the positive electrode side tank 1 via 10, the negative electrode electrolyte solution 5 is driven by the negative electrode side pump 11 from the pipe 12 and the negative electrode manifold 13 of the battery body to the separator 14
It flows through the unit cell separated by and flows back from the pipe 15 to the negative electrode side tank 4. Reference numeral 16 is an intermediate electrode constituting the battery main body, 17 is the current collecting electrode, 18 is a positive side electrode terminal, 19
Is a negative electrode terminal.

[0007] Generally, the amount of electric power charged to such a zinc-bromine battery is confirmed by the scale of an electric power meter provided in the charging device. The charging electric energy is obtained by multiplying each average value of current and voltage by the charging time.

The remaining capacity of the zinc-bromine battery at the time of discharging is calculated by multiplying the charging electric energy by the battery efficiency.
From this, the scale of the watt-hour meter of the discharge device is subtracted to obtain the remaining amount of power. On the other hand, there is also known a method of obtaining the charging depth by measuring the conductivity of the electrolytic solution by utilizing the fact that the conductivity of the electrolytic solution changes depending on the charging depth.

[0009]

However, in such a zinc-bromine battery, the means for confirming the amount of charging power and the amount of discharging power depending on the power meter of the usual charging / discharging device is
There is a problem that the depth of charge of the zinc-bromine battery cannot be easily checked, and the remaining capacity of the battery at the time of discharging and the time until the completion of charging at the time of charging cannot be easily obtained.

For example, since the charging power amount at the time of charging or the remaining capacity at the time of discharging is calculated by using the scale of the watt hour meter attached to the charging / discharging device as a reference as described above, the operation and the calculation are complicated. However, particularly when the battery is used based on an irregular charging / discharging operation pattern, it is difficult to calculate the remaining capacity and the charging power amount by calculation. Furthermore, when the zinc-bromine battery is used based on an operation pattern in which the self-discharge amount increases, this self-discharge amount is not counted by the watt-hour meter of the charging / discharging device, and therefore the accurate charging power amount and The remaining capacity cannot be confirmed.

Therefore, since there is no simple method for checking the depth of charge of a zinc-bromine battery, when the battery is exhausted, how much more should be charged to full charge (Full Charge)
There is a possibility that it will be overcharged by continuing to charge as it is, and it will have a great adverse effect on the performance and life of the battery.

Further, when the remaining capacity of the battery is unknown even at the time of discharging, it is not known how long the discharging will end, and therefore, the usable time of the device when the battery is used as the power source for the portable device is determined. However, there is a problem that the work cannot be estimated and a problem occurs in the work.

Further, since the above zinc-bromine battery is not usually provided with a charge depth meter, there is no particular problem in a usage mode in which a predetermined current is charged for a predetermined time as a load standardization battery, but for general users. When diverted as a battery, it is required to attach a charging depth meter that prevents overcharging and allows the user to check the charging state of the battery at a glance.

In response to the above problems, the present applicant previously proposed a charging depth meter shown in FIG. 7 in Japanese Patent Application No. 4-211893. That is, the sending side pipe 12 of the negative electrode electrolyte 5 is made of a transparent vinyl chloride pipe body, and a laser oscillator 21 as a light emitting unit and a laser light receiver 22 as a light receiving unit are arranged on both sides of the pipe 12 sandwiched therebetween. In the illustrated example, an offset amount F having a predetermined length is provided between the center point O ₁ of the pipe 12 and the oscillation center O ₂ of the laser oscillator 21, and the laser oscillator 21 and the laser receiver 22 have a predetermined optical refraction angle. It is placed with θ ₁ . As the above various sensors, Keyence's ultra-small laser discrimination sensor LX2 series is used.

When charging and discharging the battery main body while maintaining such a state, first, in a steady state, the light refraction angle of the laser emitted from the laser oscillator 21 is indicated by the arrow X in the figure. When θ ₁ is set, the above-described light refraction angle gradually changes from θ ₁ as the battery is charged. Along with this, the amount of light received by the laser receiver 22 also decreases, and the analog output from the laser receiver 22 gradually decreases.

That is, as the depth of charge of the electrolytic solution increases, the zinc ions in the negative electrode side electrolytic solution decrease, and the specific gravity of the electrolytic solution decreases as the zinc ion concentration decreases. Then, as the specific gravity decreases, the refractive index of the light passing through the pipe 12 changes.

However, the above-mentioned light refraction angle θ ₁ changes depending on the type of electrolyte and temperature, and the mounting angle and position of the laser receiver 22 are adjusted to an optimum state according to these conditions. There is a need to.

Therefore, the present invention has been made in view of the above points, and makes it possible to easily measure the depth of charge of a zinc-bromine battery without requiring a complicated operation, and to arrange and mount the light receiving unit. An object of the present invention is to provide a charging depth meter whose angle can be easily adjusted.

[0019]

In order to achieve the above-mentioned object, the present invention is to circulate an electrolyte solution by a pump from a positive electrode side tank and a negative electrode side tank separately placed from a battery main body at the time of charging / discharging, and at the positive electrode at the time of charging. The generated bromine reacts with the bromine complexing agent added to the electrolytic solution and is returned to the positive tank,
In a zinc-bromine battery in which the electrolytic solution is pumped into the battery body to be reduced at the time of discharging, first of all, as claimed in claim 1, a transparent tubular body is used as a pipe for supplying and discharging the electrolytic solution to the battery body. A light-receiving unit for arranging the light-emitting unit on one side of the portion close to the pipe and measuring the light refraction angle of the electrolytic solution at a position corresponding to the light-emitting unit on the other side of the portion close to the pipe. The charging depth meter is arranged and is provided with a mechanism for finely adjusting the mounting angle and the mounting position of the light receiving unit depending on the type of the electrolyte.

Further, according to claim 2, a fixed base supporting the light emitting unit, and a mounting base fixed to the fixed base and supporting a transparent pipe for an electrolytic solution,
The movable body is slidably fitted in an annular groove provided on the fixed base and has a light receiving unit supported at its tip, and is inserted from the outside of a through hole formed in the fixed base. Thus, the charging depth meter is configured to include an angle adjusting screw member that moves the movable body and the light receiving unit along the groove by a predetermined length.

Further, according to claim 3, the light emitting unit is arranged on one side of the transparent pipe for the electrolytic solution, and the light receiving unit is arranged on the other side of the transparent pipe at a position corresponding to the light emitting unit. Charging by irradiating the central part of the pipe with parallel light and measuring the depth of charge of the electrolyte according to changes in the refractive index of the pipe, the refractive index of the electrolyte, the width of the parallel light, and the focal length of the light passing through the pipe. Provide a depth meter. or,
The position of the light receiving unit is changed to adjust the output of the depth gauge.

[0022]

According to the charge depth meter of the present invention, the light emitted from the light emitting unit is projected onto the pipe made of a transparent material, and the light is transmitted through the electrolyte solution along a preset refraction path. On the other hand, as the depth of charge of the electrolyte increases, the zinc ions in the negative electrolyte decrease, and the specific gravity of the electrolyte decreases as the zinc ion concentration decreases, and the light that passes through the piping The refractive index of the light is changed, and the refraction angle of the light emitted from the light emitting unit gradually changes as the charging of the battery progresses, and accordingly, the amount of light received by the light receiving unit also decreases. At this time, by finely adjusting the mounting angle and the mounting position on the light receiving unit side according to the type of electrolyte, it is possible to cope with the change in the light refraction angle of the electrolyte by the light emitting unit and the light receiving unit. The charge depth of the battery can be obtained from the change in the amount of received light.

According to the charge depth meter of the second aspect, the light receiving unit can be operated by rotating the angle adjusting screw member in accordance with the light refraction angle which changes depending on the type of electrolyte and the temperature. It moves with the movable body by a certain length, and the mounting angle of the light receiving unit is finely adjusted according to the magnitude of the light refraction angle.

Further, according to the charge depth meter of claim 3,
By irradiating the central part of the pipe with parallel light from the light emitting unit arranged on one side of the transparent pipe for electrolyte, the pipe functions as a kind of lens, and the focal length of the light emitted from the light emitting unit changes. Then, it is received by the light receiving unit, and at this time, the depth of charge of the electrolytic solution can be measured according to changes in the refractive index of the pipe, the refractive index of the electrolytic solution, the width of the parallel light, and the focal length of the light passing through the pipe. The output of the depth meter is adjusted by changing the position where the light receiving unit is arranged.

[0025]

EXAMPLE An example of the depth-of-charge meter for a zinc-bromine battery according to the present invention will be described below. The basic idea of this example is to utilize the property that the photorefractive index of the electrolytic solution changes depending on the charging depth of the battery as described in FIG. 7, and to use the arbitrary position of the electrolytic solution piping system in the zinc-bromine battery. In addition, in a configuration in which an optical sensor for measuring a photorefractive index of an electrolytic solution flowing in the pipe is provided, a charging depth meter capable of easily adjusting an arrangement position and an angle on a light receiver side is realized. That is a major feature.

1A and 1B show a charge depth meter according to the first embodiment of the present invention, and the structure and operation thereof will be described below. That is, 25 is a fixed base, the mounting base 26 to the fixed base 25 is screwed, the pipe 12 for supplying and discharging electrolyte having a center point O ₁ to the screw has been saddle 27 to the mounting base 26 It is supported. And at one end of the fixed base 25 and the pipe 1
A laser oscillator 21 as a light emitting unit is arranged on one side of a portion close to 2.

The fixed base 25 is provided with an annular groove 28 centered on the point O ₁ , and a movable body 29 is slidably fitted in the groove 28. 29
A laser receiver 22 as a light receiving unit is disposed on the other side of the tip end of the and adjacent to the pipe 12 in a state of being supported by the die 30. An elongated hole 29a is opened in the movable body 29, and a pin 31 protruding from the fixed base 25 side is fitted in the elongated hole 29a.
Therefore, the movable body 29 is slidable by the circumference of the slot 29a.

Therefore, the groove 28, the movable body 29 and the screw 32 constitute a fine adjustment mechanism of the laser receiver 22 as a light receiving unit.

As shown in FIG. 2 which is a sectional view taken along the line AA of FIG. 1B, an angle adjusting screw 32 is provided from the outside of the through hole 25a formed in the fixed base 25. Top 33
The spring pin 34, which is inserted under the interposition of the screw 32 and is attached in the middle of the screw 32 in the insertion direction, is locked to the movable body 29. Therefore, by rotating the angle adjusting screw 32, the screw 32 is converted into a linear motion by the action of the top 33, and the movable body 29 and the laser receiver 22 can be moved along the groove 28 by a certain length. It is possible.

According to this structure, when the mounting angle of the laser receiver 22 is changed according to the light refraction angle θ ₁ which changes depending on the type of electrolyte and the temperature, the screw 32 for angle adjustment is used. The screw 32 is converted into a linear motion by the action of the top 33 by the turning operation, and the laser receiver 22 is shown from the solid line to the broken line in FIG. 1A by the movement of the spring pin 34 attached to the screw 32. As described above, the mounting angle of the laser receiver 22 can be finely adjusted according to the magnitude of the light refraction angle θ ₁ by moving the movable body 29 by a certain length and corresponding to the angle α in the figure. The adjustment range is usually 20 ° ± 10 °.

In the above operation, the laser receiver 22 is moved with the electrolyte filled in the pipe 12, and the movement of the laser receiver 22 is stopped at the angle at which the maximum peak appears.

FIG. 3 is a graph plotting the change in the analog output value by the laser receiver 22. According to FIG. 3, the analog output value at the beginning of 5 V gradually decreases as the charging progresses. By charging for 3 hours, the analog output value becomes about 3.5V, and then discharging,
The refraction angle of the laser light gradually returned to the original value, and the output value of the laser light receiver 22 was restored to about 5 V within 3 hours of discharging. Therefore, the charge depth of the battery can be obtained from the refractive index of the light passing through the pipe 12.

FIG. 4 is a schematic diagram for explaining the second embodiment of the present invention. In the case of the second embodiment, the laser beam emitted from the laser oscillator 21 is regarded as the pipe 12 as a kind of lens. The feature is that the depth of charge of the electrolyte is measured according to the change of the focal length of light.

In the illustrated example, the pipe 12 is made of transparent vinyl chloride, and the outer radius r ₀ is 16 mm and the inner radius r _i is 13 mm.
Laser light of m width (2 × B) is applied to the central portion of the pipe 12. If the acceptance angle at this time is θ,

[0035]

[Equation 1]

Here, α _{p is} the refractive index of the pipe 12, α _{E is} the refractive index of the electrolyte solution B, and the laser beam width from the center of the pipe 12 (= 3.5 mm). The refractive index of the electrolytic solution 5 existing in the pipe 12 is 1.45 when the charging depth is 0%, and the charging depth is 100.
It has been experimentally confirmed that it is 1.39 when%, so r ₀ = 16, r _i = 13, α _p = 1.54 in the above equation.
5, α E ₀ = 1.45, α _E100 = 1.39, B = 3.5
Substituting, θ ₀ is about 7.7 when the charging depth is 0%.
Θ, θ ₁₀₀ is about 6.7 ° when the charging depth is 100%.

The focal length L of the laser light passing through the pipe 12 is L = B / sin θ, and the focal length L ₀ when the charging depth is 0% is 26.3.
mm, the focal length L ₁₀₀ when the depth of charge is 100% is 2
It becomes 9.9 mm.

Further, as shown in FIG.
If the width 1 of the light receiving slit of 1 is 1 mm, and the laser receiver 22 is attached to the position of 22.6 mm from the center point O ₁ of the pipe 12, the converging width of the laser light becomes 1 mm as shown by the solid line, When the charging depth is 100%, the light collecting width at this position is about 1.7 m as shown by the broken line in the figure.
m. Therefore, the sensor output is 5v when the charging depth is 0%.
By setting to 1, the output when the charging depth is 100% is (1 / 1.7) × 4 + 1≈3.35V.

Thus, the sensor output can be easily adjusted by appropriately changing the position where the laser receiver 22 is installed.

In this way, in the second embodiment, the pipe 12 is regarded as a kind of lens, and the charge depth of the electrolytic solution can be measured according to the change in the focal length of the laser beam emitted from the laser oscillator 21. .

[0041]

As described above, according to the first aspect of the present invention.
According to the charge depth meter described, the light emitted from the light emitting unit is received by the light receiving unit by passing through the electrolyte along the preset refraction path, and as the charge depth of the electrolyte increases. Since the refraction angle of the light emitted from the light emitting unit gradually changes, the charging depth of the battery can be easily obtained from the change in the amount of light received by the light receiving unit. By finely adjusting the mounting angle and mounting position on the light receiving unit side according to the type of electrolyte, it is possible to easily deal with changes in the photorefractive angle of the electrolyte, and obtain an accurate charging depth. be able to.

According to the second aspect of the present invention, by rotating the angle adjusting screw member, the light receiving unit is fixed according to the type of electrolyte or the light refraction angle that changes depending on the temperature. It is possible to move for a long distance, and it is possible to easily cope with a change in the light refraction angle.

Further, according to the charge depth meter of claim 3,
By irradiating the central part of the pipe with parallel light from the light emitting unit arranged on one side of the transparent pipe for the electrolytic solution, the pipe functions as a kind of lens to change the focal length of the light emitted from the light emitting unit. The output of the depth meter can be adjusted by changing the position where the light receiving unit is placed, and the output of the depth meter can be adjusted. The refractive index of the pipe and the electrolyte, the width of the parallel light, and the focal length of the light passing through the pipe. The charge depth of the electrolytic solution can be determined according to the change of

In the present invention, since an optical sensor is used for determining the depth of charge, it is not necessary to pay attention to insulation measures even when applied to a battery having a high electric potential, and it is troublesome to correct the temperature of the electrolytic solution. No operation is necessary. In particular, since the remaining capacity of the battery can be easily estimated even when the battery is discharged, the usable time of the battery when used as a power source for a portable device becomes clear, and the work can be smoothly performed.

Furthermore, it is possible to measure the charge / discharge state of the battery in real time even while the pump is in operation. When the zinc-bromine battery is diverted as a battery for general users, overcharging is prevented and the user can It is possible to easily attach a charging depth meter that can check the charging status of the battery at a glance.

[Brief description of drawings]

FIG. 1A is a front view of an apparatus showing a first embodiment of the present invention. FIG. 1B is a side view of the same.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a graph in which a change in analog output value by the light receiving unit is plotted.

FIG. 4 is a schematic diagram for explaining a second embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining another embodiment of the second embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating the operating principle of a zinc-bromine battery.

FIG. 7 is a schematic diagram illustrating a principle of measuring a depth of charge of an electrolytic solution using a light emitting unit and a light receiving unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Positive electrode side tank 2 ... Positive electrode electrolytic solution 3 ... Bromine complex compound 4 ... Negative electrode side tank 5 ... Negative electrode electrolytic solution 6 ... Positive electrode side pump 8, 10, 12, 15 ... Piping 9 ... Positive electrode manifold 11 ... Negative side pump 14 ... Separator 16 ... Intermediate electrode 17 ... Current collecting electrode 21 ... Laser oscillator 22 ... Laser receiver 25 ... Fixed base 26 ... Mounting base 27 ... Saddle 28 ... Groove 29 ... Movable body 32 ... Screw 34 ... Spring pin

Claims (4)

[Claims] 1. An electrolyte solution is circulated by a pump from a positive electrode side tank and a negative electrode side tank separately placed from a battery main body during charging / discharging, and bromine generated in the positive electrode during charging reacts with a bromine complexing agent added to the electrolytic solution. And then returned to the positive side tank,
In a zinc-bromine battery in which the electrolytic solution is pumped into the battery body for reduction during discharge, a transparent tube is used as the piping for supplying and discharging the electrolytic solution to the battery body. The light emitting unit is arranged on one side of the adjacent portion, and the light receiving unit for measuring the light refraction angle of the electrolytic solution is arranged on the other side of the portion adjacent to the pipe at a position corresponding to the light emitting unit, and the electrolytic solution is arranged. A charging depth meter for a zinc-bromine battery, which is provided with a fine adjustment mechanism for the mounting angle and mounting position on the light receiving unit side according to the type of the. 2. A fixed base supporting the light emitting unit, a mounting base fixed to the fixed base and supporting a transparent pipe for an electrolytic solution, and an annular groove provided in the fixed base. Is slidably fitted to the movable body, and the light receiving unit is supported at the tip of the movable body, and the movable body and the light receiving unit are inserted along the groove by being inserted from the outside of the through hole formed in the fixed base. A charge depth meter for a zinc-bromine battery, comprising a screw member for adjusting an angle for moving a fixed length. 3. A light emitting unit is arranged on one side of a transparent pipe for an electrolytic solution, and a light receiving unit is arranged on the other side of the transparent pipe at a position corresponding to the light emitting unit, and parallel light is piped from the light emitting unit. It is characterized in that the depth of charge of the electrolytic solution is measured in accordance with changes in the refractive index of the pipe, the refractive index of the electrolytic solution, the width of parallel light, and the focal length of the light passing through the pipe by irradiating the central part of Charge depth meter for zinc-bromine batteries. 4. The charge depth meter for a zinc-bromine battery according to claim 3, wherein the output of the depth meter is adjusted by changing the position where the light receiving unit is arranged.