JP2012099416A - Redox flow battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a redox flow battery (RF battery) which can detect electrolyte leakage early, an RF battery system, and an RF battery frame and an RF battery cell stack which are suitable for the constituent members of the battery.SOLUTION: The RF battery includes: a cell stack 10A composed of a cell having a membrane interposed between a positive electrode and a negative electrode and a frame 1A having a bipolar plate 121, the cell and the frame 1A alternately laminated one on top of another; and a leakage sensor 20 which detects an electrolyte leaking from the cell stack 10A. The frame 1A, provided on a periphery more outer than a seal member 127, includes a liquid storing groove 2 for collecting an electrolyte leaking over the seal member 127 and a draining groove 3 which is disposed continuously to the liquid storing groove 2 to gather the electrolyte in the liquid storing groove 2 and drain it to the outside of the frame 1A. Since an electrolyte leaking over the seal member 127 is temporarily collected in the liquid storing groove 2 and then collectively drained by the draining groove 3, the RF battery can detect leakage earlier with the leakage sensor 20.

Description

  The present invention relates to a redox flow battery (hereinafter sometimes referred to as an RF battery), a cell stack suitable for a component of the RF battery, a frame, and a system including the RF battery. In particular, the present invention relates to a redox flow battery capable of early detection of leakage of electrolyte.

  It is expected to install large-capacity storage batteries for new energies such as solar power generation and wind power generation to smooth output fluctuations, store surplus power, and level load.

  One of large-capacity storage batteries is an RF battery (see Patent Document 1). The RF battery 100 is typically configured as shown in FIG. 7, and includes a positive electrode cell 102 incorporating a positive electrode 104, a negative electrode cell 103 incorporating a negative electrode 105, and both cells 102, 103 interposed between both cells 102, 103. A cell is provided that includes a diaphragm 101 that separates and transmits ions. In addition, the RF battery 100 is configured to store the electrode electrolytes 106 and 107 used for battery reactions in the electrode cells 102 and 103, and to distribute the electrolyte solution between the electrode cells 102 and 103 and the electrode tanks 106 and 107. It includes conduits 108 to 111 that become roads. The electrode electrolytes are circulated and supplied to the electrode cells 102 and 103 by using pumps 112 and 113 installed in the conduits 108 and 109, respectively. As the electrolytic solution, an aqueous solution containing a metal ion whose valence is changed by oxidation-reduction, for example, vanadium ion is used. Note that the solid line arrow in the cell of FIG. 7 means charging, and the broken line arrow means discharging.

  The RF battery 100 typically uses a form called a cell stack in which a plurality of the cells are stacked. As shown in FIG. 8, the cell stack 200 uses a frame 122 formed on the outer periphery of a bipolar plate 121 on which the electrode electrodes 104 and 105 are arranged on the front and back sides. The cell stack 200 is repeatedly laminated in order of a frame 122 having a bipolar plate 121, a positive electrode 104, a diaphragm 101, a negative electrode 105, a frame 122 having a bipolar plate 121, etc. It is configured by sandwiching between a pair of end plates 210 and tightening the end plate 210 with a tightening member 220 such as a long bolt.

  The above-mentioned frame 122 is provided on one surface with liquid electrolyte supply holes 123, 124 and drain holes 125, 126 penetrating through the front and back thereof, a liquid introduction groove continuous with the liquid supply holes 123, the drain holes 125, and liquid discharge The groove includes a liquid introduction groove and a liquid discharge groove provided on the other surface and continuing to the liquid supply hole 124 and the liquid discharge hole 126. Using the liquid introduction groove / liquid discharge groove, the positive electrode electrolyte is supplied to and discharged from the positive electrode 104 disposed on one surface of the bipolar plate 121, and the negative electrode electrolyte is supplied to the negative electrode 105 disposed on the other surface.・ It is discharged. By laminating a plurality of frames 122, the liquid supply hole 123 (124) and the drainage hole 125 (126) constitute a flow path for each electrolyte solution, and this flow path is appropriately connected to the conduits 108 to 111. .

  In order to prevent leakage of the electrolytic solution from the gaps between the above-described members constituting the cell stack 200, a sealing mechanism is provided in which a sealing member 127 such as an O-ring is disposed between the stacked frames 122.

Japanese Patent Laid-Open No. 2002-367659

  It is desired to have a configuration capable of detecting as early as possible when an electrolyte leaks outside the cell stack.

  By providing the sealing mechanism as described above, the RF battery prevents leakage of the electrolyte. However, there is a possibility that the electrolyte solution leaks from an arbitrary portion of the cell stack due to deformation or damage of the components of the RF battery due to deterioration over time or loosening of the tightened state. Therefore, in order to ensure that the electrolyte that may leak from any part of the cell stack can be received, a drain pan that is large enough to receive the entire area below the cell stack in the installed state is provided below the cell stack. Arrangement is made and a leakage sensor such as a float sensor or conductivity sensor is arranged in the drain pan.

  The electrolyte used in the RF battery is a deleterious substance such as a sulfuric acid solution, so if it leaks in large quantities, it will impair the safety of the worker, affect the environment, and contaminate the surrounding equipment. Since it has conductivity, there is a risk of a ground fault or a short circuit between cells or between an RF battery and peripheral equipment. Therefore, in the unlikely event that a leak occurs, it is desirable to detect it early. However, in the configuration in which the leak sensor is arranged in the drain pan described above, the leak sensor may not operate if the storage amount is not more than a certain amount or if the leak sensor is not arranged at a position where the electrolyte solution reliably contacts. Yes, early detection of leaks can be difficult. For example, it is conceivable that an inclination is provided in the drain pan, and the electrolyte solution is concentrated in a local area to facilitate the operation of the leakage sensor (reducing the time until detection). However, as time passes, the electrolyte in the drain pan dries and the viscosity increases, and it takes a long time for the electrolyte to reach the leakage sensor, which may make early detection difficult.

  Therefore, one of the objects of the present invention is to provide an RF battery and an RF battery system that can detect leakage of an electrolytic solution at an early stage. Another object of the present invention is to provide an RF battery frame and an RF battery cell stack that can contribute to early detection of leakage of an electrolytic solution.

  The present invention includes a region that once collects the electrolyte solution leaking beyond the seal mechanism in the frame, and the electrolyte solution in this region can be collected and discharged to the outside of the frame. Achieve the goal.

  The frame for a redox flow battery of the present invention is provided on the outer periphery of the bipolar plate, and supplies the electrolytic solution to the electrode disposed on the bipolar plate and discharges the electrolytic solution from the electrode. On at least one surface of the frame, there is provided a seal mechanism for sealing the electrolyte mainly in the electrode, and a liquid reservoir provided on the outer periphery of the seal mechanism for storing the electrolyte that has leaked beyond the seal mechanism. A groove and a drainage portion that is provided continuously with the liquid reservoir groove and serves as a flow path when the electrolyte in the liquid reservoir groove is collected and discharged to the outside of the frame.

  The cell stack for a redox flow battery of the present invention is configured by alternately laminating a cell having a diaphragm interposed between a positive electrode and a negative electrode and a frame having a bipolar plate. And each said flame | frame is this invention frame which provides the said liquid storage groove | channel and a drainage part.

  The redox flow battery of the present invention includes a cell stack in which a cell having a diaphragm interposed between a positive electrode and a negative electrode and a frame having a bipolar plate are alternately stacked, and each of the electrodes provided in the cell stack. Each electrode tank storing each electrode electrolyte supplied to each electrode, and a flow path for transferring each electrode electrolyte between the cell stack and each electrode tank. The cell stack is the cell stack for the redox flow battery of the present invention including the frame of the present invention. The RF battery further includes a leakage sensor that detects the electrolyte collected in the liquid storage groove.

  The redox flow battery system of the present invention includes a control unit that controls a supply state of the electrolyte from each of the electrode tanks to the cell stack based on information from the redox flow battery of the present invention and the leakage sensor included in the RF battery. With.

  According to the present invention RF battery or RF battery system including the present invention frame including the above-described liquid reservoir groove and the drainage part or the present cell stack, the sealing mechanism before the electrolyte leaks to the outside of the cell stack. The electrolytic solution is automatically introduced into the liquid reservoir groove whose internal pressure is smaller than that of the inside. That is, according to the present invention, the electrolyte solution that leaks out of the cell stack from an arbitrary position of the sealing mechanism is reliably collected in the liquid storage groove provided on the outer periphery of the sealing mechanism and is retained in the frame. be able to. Then, the electrolytic solution collected in the liquid storage groove is collected in the liquid drainage section using the liquid storage groove as a flow path, and is discharged to the outside of the cell stack. That is, according to the present invention, even if the electrolyte solution leaks from a plurality of positions with different sealing mechanisms, the electrolyte solution is finally collected at the same location (drainage portion), and the discharge location of the electrolyte solution is specified. can do. With this configuration, the RF battery or RF battery system of the present invention can effectively prevent the electrolyte from leaking from any position of the cell stack, and the discharge location of the leaked electrolyte must be determined in advance. Therefore, the leakage can be detected at an early stage by arranging the leakage sensor at an appropriate location (typically near the drainage portion). In addition, since the electrolyte solution leaking from the sealing mechanism can be collected to some extent outside the cell stack, the leakage sensor is easy to detect (it can be detected in a short time). The battery system can detect leakage of the electrolyte at an early stage.

  As an embodiment of the frame of the present invention, the drainage part may include a drainage groove that continues from the liquid reservoir groove to the outer peripheral edge of the frame.

  According to the said form, the electrolyte solution collected by the liquid storage groove | channel can be easily discharged | emitted from the discharge groove | channel branched from the liquid storage groove | channel.

  As an embodiment of the frame of the present invention, the drainage part may include a discharge hole penetrating the front and back of the frame.

  According to the said form, the electrolyte solution collected by the liquid storage groove | channel can be easily discharged | emitted from a discharge hole. In addition, that the discharge hole is continuously provided in the liquid storage groove means that the liquid storage groove and the discharge hole have a portion overlapping.

  As one aspect of the cell stack of the present invention, each frame includes the liquid reservoir groove and a discharge groove that continues from the liquid reservoir groove to the outer peripheral edge of the frame, and the frame includes a plurality of the discharge grooves. The form provided in the position located in a straight line in the state where the said frame was laminated | stacked is mentioned.

  The discharge groove can be provided at an arbitrary position with respect to the liquid storage groove. However, when a plurality of frames constituting the cell stack include frames with different discharge groove formation positions, there are random discharge locations for the electrolyte solution, and thus it is necessary to place a leak sensor at each location. Or it becomes difficult to collect the electrolyte discharged outside the cell stack. On the other hand, according to the said form, since the discharge location of electrolyte solution is located in a straight line, a leak sensor can be easily arrange | positioned along the said discharge location, and also it is easy to collect the electrolyte solution discharged | emitted outside the cell stack. .

  As an embodiment of the cell stack of the present invention, each frame includes the liquid reservoir groove and a discharge groove continuous from the liquid reservoir groove to the outer periphery of the frame, and the discharge groove included in each frame includes the cell In a state in which the stack is installed, a form opened to the lower side of the cell stack can be mentioned.

  According to the above aspect, the electrolyte solution in the liquid storage groove can surely reach the discharge groove due to its own weight, and the electrolyte solution can be automatically discharged from the discharge groove.

  As one form of the cell stack of the present invention, each of the frames is provided with the liquid reservoir groove and a discharge hole penetrating the front and back of each of the frames. And a discharge path in which the discharge holes are continuously formed, and at least one opening of the discharge path is used for discharging the electrolyte stored in the discharge path.

  According to the said form, each flame | frame which comprises a cell stack provides a discharge hole, Therefore The electrolyte solution from a liquid storage groove | channel is efficiently collected in the discharge path where the several discharge hole was comprised continuously. And the electrolyte solution collected by the discharge path can be easily discharged | emitted from the opening part of the one end of a discharge path, or the opening part of both ends. Therefore, according to this embodiment, in the state where the cell stack is installed, it is possible to detect the leakage of the electrolyte even when the installation space for the leakage sensor cannot be secured on the lower side.

  As one form of the cell stack of the present invention, each of the frames is provided with the liquid reservoir groove and a discharge hole penetrating the front and back of each of the frames. The said discharge hole is provided with the discharge path comprised continuously, and the form with which the both ends of the said discharge path were closed is mentioned. In this embodiment, at least one frame of the plurality of frames includes a discharge groove that is continuous from the discharge path to the outer peripheral edge of the frame and discharges the electrolyte stored in the discharge path.

  In the form having the discharge path, in addition to the form in which the electrolyte is discharged from the opening at the end of the discharge path as described above, at least one frame has a discharge groove as in the above form. The electrolyte collected in the discharge path from the liquid storage groove can be easily discharged from the discharge groove. That is, in this embodiment, both the discharge path (discharge hole) and the discharge groove function as a drainage part.

  As one form of the RF battery of the present invention, the discharge groove of each frame constituting the cell stack is open on the lower side as described above, and is disposed below the opening of the discharge groove, and is electrolyzed from the discharge groove. Examples include a liquid receiving bowl that receives the liquid and a leakage sensor that detects the electrolyte collected in the liquid receiving bowl.

  According to the above aspect, the electrolyte solution is automatically discharged from the discharge groove to the outside of the cell stack due to its own weight, and the discharged electrolyte solution is reliably received and collected by the liquid receiver. Therefore, according to the said form, the electrolyte solution collected by the liquid receptacle can be detected easily and reliably by a leak sensor.

  The RF battery of the present invention having the liquid receptacle includes a configuration in which the liquid receptacle has an inclined portion inclined from one side to the other, and the leak sensor is provided at the lowermost portion of the inclined portion.

  According to the above aspect, the electrolyte solution can be efficiently collected at the lowermost portion of the inclined portion by the dead weight of the electrolyte solution, and the leakage sensor is disposed at the lowermost portion so that the electrolyte solution collected in the liquid receiving bowl can be removed. Therefore, it can be detected easily and reliably. In addition, according to this embodiment, even when there are a plurality of discharge locations of the electrolytic solution, the detection location of the leakage sensor can be made one, so that the electrolytic solution that has passed through the liquid catcher can be easily detected with only one leakage sensor. it can. As a more specific form of the above form, the liquid receiving bowl is arranged to be inclined from one side to the other, that is, the liquid receiving bowl as a whole is an inclined part, and is inclined from one and the other to the intermediate part. And a form in which the entire liquid receiving bowl is V-shaped, a form in which a part of the liquid receiving bowl is provided with an inclined portion, and the like.

  As one form of the RF battery of the present invention, the cell stack is provided with a discharge path composed of the discharge holes described above, and is housed in the discharge path provided in the cell stack, The form which provides the leak sensor which detects electrolyte solution is mentioned. In particular, a form in which the leakage sensor is a string sensor can be cited.

  According to the said form, before the electrolyte solution which leaked from the sealing mechanism leaks outside the cell stack, the said electrolyte solution can be detected within a cell stack. That is, it is possible to detect before the electrolyte leaks that the electrolyte solution may leak to the outside of the cell stack. Therefore, according to the said form, a leak (possibility) can be detected earlier. Moreover, according to the said form, in order to detect a leak in a cell stack, it is anticipated that electrolyte solution does not dry substantially and can be detected efficiently. Even in this embodiment, it is necessary to discharge the electrolytic solution. For discharging the electrolytic solution, it is possible to provide at least one frame having a discharge groove as described above and use the discharge groove or use at least one opening of the discharge path.

  The redox flow battery and the redox flow battery system of the present invention can detect leakage of the electrolyte at an early stage. The frame for redox flow battery of the present invention and the cell stack for redox flow battery of the present invention can be suitably used as a component of the above redox flow battery of the present invention, and can contribute to early detection of leakage of the electrolyte.

FIG. 1 is a schematic diagram of a frame according to the first embodiment. FIG. 1 (A) shows an example having one discharge groove, and FIG. 1 (B) shows an example having a plurality of discharge grooves. FIG. 2 is a schematic diagram illustrating a state in which the frames of Embodiment 1 are stacked. FIG. 3 is a schematic diagram of a cell stack including the frame of the first embodiment. FIG. 4 is a functional block diagram of an RF battery system including the frame of the first embodiment. FIG. 5 is a schematic diagram of a frame according to the second embodiment. FIG. 6 is a schematic diagram of a cell stack including the frame of Embodiment 2, FIG. 6 (A) is a form including a string sensor, and FIG. 6 (B) is both a discharge groove and a discharge hole. FIG. 6C shows a form in which the electrolyte solution is discharged from the end plate. FIG. 7 is an explanatory diagram showing the operation principle of the RF battery. FIG. 8 is a schematic configuration diagram of a cell stack included in a conventional RF battery.

  Hereinafter, a redox flow battery (RF battery) frame, cell stack, RF battery, and RF battery system according to an embodiment will be described with reference to the drawings. In the figure, the same reference numeral indicates the same name object.

  The basic configuration of the RF battery of the present invention is the same as that of the conventional RF battery shown in FIGS. That is, a cell in which a diaphragm (typically an ion exchange membrane) is interposed between a positive electrode and a negative electrode, and a frame having a bipolar plate in which electrodes of each electrode are arranged on the front and back are alternately laminated. A cell stack, each electrode tank storing each electrode electrolyte supplied to the electrode of each electrode, and a conduit connected to the cell stack and each electrode tank and serving as a flow path for the electrolyte. Yeah. In addition, the RF battery of the present invention performs a battery reaction by supplying an electrolytic solution such as a sulfuric acid solution containing metal ions such as vanadium ions in the active material from the electrode tanks to the cell stack. The RF battery of the present invention typically has an AC / DC converter through a power generation unit (e.g., a general power plant (thermal power, hydropower, nuclear power, wind power, sunlight, etc.), a general house, (Including distributed generators such as solar power generators and wind power generators installed in various places including apartment buildings) and loads (customers such as ordinary households, plants, factories, etc.) Is charged, and the load is discharged as a power supply target. The RF battery of the present invention is assembled between the power generation unit and the load as described above and used as one element of the power system.

  The RF battery of the present invention is characterized by the structure of the frame as its constituent members and the structure of the cell stack. Hereinafter, the difference from the conventional RF battery: mainly the frame configuration and the cell stack configuration will be described, and detailed description of other configurations will be omitted. In the frames shown in FIGS. 1 to 3, 5, and 6, the liquid supply holes, the liquid discharge holes, the liquid introduction grooves, and the liquid discharge grooves are omitted for easy understanding.

[Embodiment 1]
1 to 4, an RF battery frame of Embodiment 1, an RF battery cell stack formed by stacking a plurality of the frames, an RF battery including the stack, and an RF battery An RF battery system will be described.

(Cell stack)
A frame 1A shown in FIG. 1 (A) is a rectangular frame provided on the outer periphery of the bipolar plate 121, and a sealing mechanism provided to surround the bipolar plate 121 on the outer periphery from a liquid supply hole / drainage hole (not shown). And a liquid storage groove 2 provided on the outer periphery of the seal mechanism and a discharge groove (drainage part) 3 provided continuously to the liquid storage groove 2.

  The sealing mechanism is provided to prevent the electrolyte impregnated in each electrode disposed on the bipolar plate 121 from leaking outside the frame 1A, and is provided so as to surround the bipolar plate 121. For example, the form is not particularly limited. Here, the sealing mechanism is provided on each of the front and back of the frame 1A, and includes a rectangular groove (not shown) surrounding the outer periphery of the rectangular bipolar plate 121 and a sealing member 127 such as an O-ring fitted in the groove. Has been. In addition, the seal mechanism uses a flat packing for the seal member 127 and is configured by a flat packing and a region where the flat packing is arranged in the frame, heat-bonds the stacked frames 1A to each other, or by an adhesive. It can be constituted by a fusion region (including an adhesive used for fusion) or an adhesion region.

  One feature of the present invention is that the frame 1A includes a liquid storage groove 2. The liquid storage groove 2 is a groove that temporarily stores the electrolyte leaking from the arbitrary position of the sealing mechanism and that is used as a flow path to the discharge groove 3 described later. Then, it is provided in a rectangular shape along the outer periphery of the seal mechanism.

  The cross-sectional shape of the liquid reservoir groove 2 is not particularly limited. Typical examples include a semicircular arc shape and a rectangular shape. Further, the volume of the liquid reservoir groove 2 can be appropriately selected according to the amount of electrolytic solution to be circulated. Further, here, an example is shown in which the liquid reservoir groove 2 is provided only on one surface of the frame 1A, but the liquid reservoir groove 2 may be provided on both the front and back surfaces of the frame 1A. In this case, it is easy to increase the volume (electrolyte storage amount) by stacking a plurality of frames 1A.

  In addition, the frame 1A is provided with the discharge groove 3 as one of the features of the present invention. The discharge groove 3 is a groove used as a discharge flow path for collecting the electrolytic solution stored in the liquid storage groove 2 and discharging it to the outside of the frame 1A. Here, the discharge groove 3 extends from the liquid storage groove 2 to the frame 1A. An opening 3o is provided continuously to the outer peripheral edge and opens to the outer peripheral edge. The opening 3o is provided so as to open downward with the frame 1A installed. With this configuration, the electrolytic solution collected in the liquid storage groove 2 is automatically transferred to the discharge groove 3 due to its own weight and discharged to the outside of the frame 1A.

  The shape, size, formation position, and number of the discharge grooves 3 are not particularly limited. The cross-sectional shape of the discharge groove 3 is typically a semicircular arc shape or a rectangular shape. In addition, here, the discharge groove 3 is shown as an example of being provided in a straight line so as to be orthogonal to the outer peripheral edge of the frame 1A from the liquid storage groove 2, but the slanted line shape provided so as to intersect the outer peripheral edge It can be curved. The volume of the discharge groove 3 can be appropriately selected according to the amount of electrolyte solution discharged from one frame 1A at a time.

  The number of the discharge grooves 3 may be one as shown in FIG.1 (A), but if the form is provided with a plurality of discharge grooves 3a, 3b as in the frame 1B shown in FIG.1 (B), at least One drainage groove (for example, the discharge groove 3b) can be used as an air vent hole, preventing negative pressure in the drainage groove 2 and the discharge groove 3a, and easily discharging the electrolyte. In particular, when a plurality of discharge grooves are provided, at least two discharge grooves are formed at different positions. If another one is arranged, the electrolyte can be easily discharged from the discharge groove disposed on the lower side. In the example shown in FIG. 1 (B), the discharge grooves 3a and 3b are provided on the upper side and the lower side, respectively, in the state where the frame 1B is installed, and the upper discharge groove 3b functions as an air vent hole to discharge the lower side. The groove 3a can be used for discharging the electrolytic solution. Further, in the embodiment provided with a plurality of discharge grooves, the electrolyte solution does not accumulate excessively in the liquid storage groove 2, and an increase in internal pressure due to the presence of excessive electrolyte solution can be prevented, and the electrolyte solution can be efficiently discharged outside the frame.

  The frame 1A including the liquid storage groove 2 and the discharge groove 3 can be easily manufactured by using injection molding or the like as in the prior art.

(Cell stack)
Using the frame 1A including the liquid storage groove 2 and the discharge groove 3, for example, a cell stack 10A in which a plurality of frames 1A are stacked as shown in FIG. 2 can be constructed. The cell stack 10A in FIG. 2 shows only the frame 1A having the bipolar plate 121, and omits each electrode and the diaphragm. This also applies to FIGS. 3 and 6. In FIG. 2, the frame 1A is illustrated, but the frame 1B may be used.

By laminating a plurality of frames 1A ₁ , 1A ₂ ,..., 1A ₇ ,..., The liquid storage groove 2 and the discharge groove 3 provided on one surface of a certain frame 1A (for example, the frame 1A ₂ ) The other surface of the frame 1A (for example, the frame 1A ₁ ) covers the substantially closed space. However, the liquid storage groove 2 has an opening continuous with the discharge groove 3, and the discharge groove 3 has an opening 3o on the outer peripheral edge of the frame 1A. This is the same in the second embodiment described later. Further, a plurality of frames 1A stacked _1, 1A _2, ..., 1A _7, ... frame 1A _1, 1A _n placed at both ends of the, by being sandwiched between a pair of end plates shown in FIG. 8, similarly It becomes a closed space (however, it has the above-mentioned opening).

Further, in the example shown in FIG. 2, none of the plurality of frames 1A _x, in installed state of the cell stack 10A, the discharge groove 3 is provided to be the same position. Specifically, the discharge groove 3 of each frame 1A _x is aligned in a straight line along the stacking direction of the cell stack 10A. That is, any opening 3o of the discharge groove 3 of each frame 1A _x are aligned in a straight line, an opening on the same side in the installed state of the cell stack 10A. In the example shown in FIG. 2, the opening is on the lower side.

  Such a cell stack 10A typically has a configuration in which it is sandwiched between a pair of end plates and fastened by a fastening member such as a long bolt as shown in FIG. By this tightening, the seal mechanism (seal member 127) functions sufficiently, and the electrolyte filled in each electrode is prevented from leaking beyond the seal mechanism. However, when the electrolyte solution leaks out of the frame 1A beyond the seal mechanism due to deterioration over time, the electrolyte solution passes through the liquid storage groove 2. Since the pressure in the liquid storage groove 2 is small, the electrolyte that has leaked is positively stored in the liquid storage groove 2, and the electrolytic solution in the liquid storage groove 2 is discharged from the discharge groove 3 to the outside of the cell stack 10A. To be discharged. Therefore, in the cell stack 10A, the electrolyte does not substantially leak from any position of the liquid reservoir groove 2, that is, from the portion other than the discharge groove 3 to the outside of the liquid reservoir groove 2. In particular, in this example, since the opening 3o of the discharge groove 3 is provided on the lower side of the cell stack 10A, the electrolytic solution in the liquid storage groove 2 automatically moves to the discharge groove 3 by its own weight, Further, it passes through the discharge groove 3 and is discharged from the opening 3o.

(RF battery)
Using the cell stack 10A, for example, as shown in FIG. 3, the liquid receiving bowl 15 that receives the electrolytic solution from the discharge groove 3 and the outside of the cell stack 10A is discharged through the opening 3o of the discharge groove 3. Thus, an RF battery including the leakage sensor 20 that detects the electrolyte collected in the liquid receiver 15 can be constructed. The RF battery shown in FIG. 3 shows only the cell stack 10A, the liquid receiver 15 and the leakage sensor 20, and the electrode tanks and conduits are omitted.

  The liquid receptacle 15 provided in the RF battery shown in FIG. 3 has a V-shaped cross section and extends linearly, and can receive the electrolytic solution from all the openings 3o of the discharge grooves 3 arranged in a straight line. It has a sufficient size. Here, below the openings 3o of the discharge grooves 3 aligned in a straight line, as shown in FIG. 3, it decreases from one (left side in FIG. 3) to the other (right side in FIG. 3). Further, the leak sensor 20 is arranged at the lowermost part (right side in FIG. 3).

  The shape, size, number and arrangement form of the liquid receiving bowl 15 are not particularly limited. For example, a cross-section] body may be used, a plurality of discharge grooves 3 may be arranged according to the number of the discharge grooves 3, or they may be arranged horizontally without being inclined. As shown in FIG. 3, because the liquid receiving bowl 15 has an inclined portion (here, the entire liquid receiving bowl 15 is an inclined portion), the liquid receiving bowl 15 has automatically dropped from the opening 3o of the discharge groove 3 by its own weight. Electrolyte can be collected automatically and efficiently at the bottom of the liquid receiver 15.

  As the leakage sensor 20, various commercially available sensors such as a float sensor, a conductivity sensor, and a sensor using a glass electrode method (a sensor including a PH electrode) can be used. When using these leakage sensors 20, a storage tank (not shown) is provided in the vicinity of the lowermost portion to store the electrolyte solution that has passed through the discharge groove 3, and the sensor 20 is disposed in this storage tank. Good. Here, since the liquid receiving bowl 15 has an inclined portion, the electrolytic solution can be efficiently stored in the storage tank, so that the sensor 20 can detect the electrolytic solution reliably and early. The leakage sensor in FIG. 3 is a schematic diagram.

  In addition, a string-like sensor can be used as the leakage sensor 20 and, for example, a string-like sensor can be arranged in the liquid receptacle 15 along the liquid receptacle 15. Commercially available string sensors include, for example, those having a plurality of rod-shaped electrodes and electrode holders for holding these electrodes, and those having a stranded wire formed by twisting a plurality of electrode wires and an exterior. it can. The string-like sensor detects leakage when an electrolyte solution contacts an arbitrary portion of a rod-shaped electrode or an electrode wire and a short circuit occurs between the rod-shaped electrodes or between the electrode wires. Therefore, as shown in FIG. 3, in the form in which there are a plurality of electrolyte discharge locations (here, there can be as many discharge locations as the number of cell frames 1A), the string-shaped sensor is used to identify the discharge locations. That is, it is possible to specify the position of the frame where the defect occurs.

  The example shown in FIG. 3 shows a mode in which there is one liquid receiving bowl 15 and one leakage sensor is arranged at the bottom, but it has a plurality of liquid receiving parts, and each liquid receiving part has a leakage sensor. That is, it is possible to adopt a form having a plurality of detection points. However, if there are too many detection points, the amount of electrolyte collected at each point decreases, so it is preferable to select the number of detection points within a range where early detection is possible.

(RF battery system)
Using the above RF battery, for example, as shown in FIG. 4, leakage is detected from the RF battery and the electrolyte discharged from the liquid storage groove (not shown) through the discharge groove 3 to the outside of the cell stack 10A. Based on the information from the sensor 20 and the leakage sensor 20, an RF battery system including the controller 30 that controls the supply state of the electrolytic solution from each of the electrode tanks 106 and 107 to the cell stack 10A can be constructed. The RF battery shown in FIG. 4 shows a simplified cell stack 10A.

  For example, the control unit 30 compares an input unit 31 that inputs information from the leakage sensor 20, a determination unit 32 that compares the input information with a set threshold value, and determines whether there is leakage of the electrolyte, From the result of the means 32, there may be mentioned one comprising an instruction means 33 for instructing the change of the operating conditions of the pumps 112 and 113 and a storage means 34 for storing various set values (for example, threshold values). As such a control unit 30, a computer including a processing device including the above-described units and a direct input unit 35 such as a keyboard can be preferably used. Further, display means 36 such as a monitor may be provided.

  The RF battery system including the control unit 30 can early detect that the electrolyte has leaked to the outside of the cell stack 10A configured by the cell frame including the liquid storage groove and the discharge groove 3 described above. As soon as it is detected, the supply state of the electrolyte is changed (for example, to reduce leakage, the amount of electrolyte supplied from each of the electrode tanks 106 and 107 to the cell stack 10A is reduced, and in some cases, the supply of the electrolyte is stopped. can do. Therefore, according to this RF battery system, it is possible to reduce the leakage of the electrolyte to the extent that it can be received by the liquid receiving tank 15 or the storage tank, and sufficiently ensure the safety of the worker and protect the environment. Can do.

(effect)
In the case of an RF battery having the above configuration, even if the electrolyte solution leaks out of the cell stack 10A (frame 1A (or 1B)) from any position of the seal mechanism, Once collected in the groove 2, it can be discharged together by the discharge groove 3. Accordingly, since the amount of the electrolyte discharged outside the cell stack 10A is a certain amount, the leakage sensor 20 can operate sufficiently and the leakage can be detected at an early stage.

  Further, in the RF battery system having the above-described configuration, when the leakage of the electrolytic solution is detected by the leakage sensor 20, the leakage of the electrolytic solution can be immediately suppressed by the control unit 30. Therefore, it is possible to effectively prevent damage caused by leakage of the electrolyte solution outside the RF battery. In addition, an electric power system including such an RF battery system is expected to be highly reliable because an abnormality of the RF battery can be detected at an early stage.

[Embodiment 2]
(flame)
In the first embodiment, the embodiment has been described in which the discharge groove 3 is provided as a drainage section that collects the electrolyte solution in the liquid storage groove 2 and discharges it to the outside of the frames 1A and 1B. In addition, as the drainage part, a form including a discharge hole 4 penetrating the front and back of the frame 1C, such as a frame 1C shown in FIG. The basic configuration of the frame of the second embodiment is the same as that of the first embodiment, and the difference is in the discharge hole 4. Therefore, the discharge hole 4 will be mainly described here, and other overlapping configurations and effects will be described in detail. Is omitted.

  Similar to the frames 1A and 1B of the first embodiment, the frame 1C includes a liquid storage groove 2 and a discharge hole 4. Similarly to the discharge groove 3 described in the first embodiment, the discharge hole 4 collects the electrolyte solution leaking beyond the seal mechanism from any position of the seal mechanism and discharges it to the outside of the frame 1C. Used for flow paths.

  Here, the discharge hole 4 has a circular shape, and more specifically, is provided so that the center of the circle is located in the liquid reservoir groove 2 so as to overlap a part of the liquid reservoir groove 2. As the shape of the discharge hole 4, various shapes such as an ellipse and a rectangle can be used in addition to a circular shape. However, if the shape is a circular shape, it is considered that the pressure loss when the electrolyte flows is small. Further, here, the discharge hole 4 is provided so as to be positioned on the lower side in the state where the frame 1C is installed, and the electrolytic solution that has passed through the liquid storage groove 2 is automatically transferred to the discharge hole 4 by its own weight. Be transported. The number of the discharge holes 4 is not particularly limited, but one is considered to be sufficient. The size of the discharge hole 4 is desirably large enough to discharge the maximum amount of electrolyte stored in the liquid storage groove 2.

  The frame 1C having the discharge hole 4 can also be easily manufactured by injection molding or the like.

(Cell stack)
Using the frame 1C having the liquid storage groove 2 and the discharge hole 4, for example, a cell stack 10B in which a plurality of frames 1C are stacked can be constructed as shown in FIG. 6 (A). When a plurality of frames 1C are stacked, the discharge holes 4 of each frame 1C are continuous to form a cylindrical (here, cylindrical) discharge path 11, and the electrolyte from the reservoir groove 2 Collected in 11. That is, by providing the discharge path 11, the electrolyte collected in the liquid storage groove 2 of one frame 1C can be further collected over a plurality of frames 1C. Further, this aggregation can be performed in the cell stack 10B. Accordingly, as shown in FIG. 6 (A), when the above-described string sensor 21 is arranged in the discharge path 11, the electrolyte collected in the discharge path 11 can be detected in the cell stack 10B. In addition, by arranging the end plate 210 (see FIG. 6B) so as to sandwich both sides of the laminated frame 1C, the inside of the discharge path 11 becomes a substantially closed space. The electrolyte is difficult to dry. Therefore, by arranging the string sensor 21 along the discharge path 11 in the discharge path 11, the electrolyte in the discharge path 11 can be detected reliably and at an early stage. In addition, since it is possible to detect that the electrolyte has leaked beyond the seal mechanism before the electrolyte is discharged outside the cell stack 10B, further early detection can be realized. Furthermore, by using the string-like sensor 21 as described above, it is easy to specify the leakage location (exposed frame) of the electrolyte, and it is easy to replace a member such as a frame.

By appropriately discharging the electrolyte stored in the discharge path 11, it is possible to prevent the electrolyte from leaking from an arbitrary position of the frame 1C due to an increase in pressure in the discharge path 11. For example, in the cell stack 10B, the electrolytic solution can be discharged from at least one discharge hole 4 (opening at least one end of the discharge path 11) of the frames 1C ₁ and 1C _n located at both ends thereof. As shown in FIG. 6 (C), when a pair of end plates 210 are arranged on both sides of the stacked frame 1C, in the end plate 210, the discharge path 11 (frames 1C ₁ and ₁ positioned at both ends of the stacked frame 1C, A through hole 210h continuous with the discharge path 11 may be provided at a location where the 1C _n discharge hole 4) contacts, and the electrolyte stored in the discharge path 11 may be discharged through the through hole 210h. In the vicinity of the through hole 210h, a storage tank for storing the discharged electrolyte is provided. Only one of the end plates 210 may have a through hole 210h. In the cell stack 10B, when discharging the electrolyte solution in the discharge channel 11 from the opening (at least one through hole 210h of the end plate 210) of at least one end of the discharge channel 11, the electrolyte collected in the discharge channel 11 Reaches the opening (through hole 210h) after contacting the string sensor 21 in the discharge path 11. Therefore, the string sensor 21 can sufficiently detect the electrolytic solution, and can efficiently discharge after the detection.

  Alternatively, as shown in FIG. 6 (B), as a frame constituting the cell stack 10C, a form including at least one frame 1D having the discharge groove 3 described in the first embodiment together with the discharge hole 4 (in this example) 1). The discharge groove 3 provided in the frame 1D is provided continuously from the discharge path 11 (discharge hole 4) to the outer peripheral edge of the frame 1D. In this embodiment, both ends of the discharge path 11 are closed by the end plate 210, and the electrolyte collected in the discharge path 11 is discharged only from the discharge groove 3 of the frame 1D. Since the discharge groove 3 is formed continuously with the discharge path 11, the electrolyte collected in the discharge path 11 reaches the discharge groove 3 after contacting the string sensor 21 in the discharge path 11. Therefore, the string sensor 21 can sufficiently detect the electrolytic solution, and can efficiently discharge after the detection.

  In the embodiment including the discharge groove 3, in place of arranging the string-like sensor 21 in the discharge path 11, as shown in FIG.6 (B), in the vicinity of the opening of the discharge groove 3 (in FIG.6 (B) A configuration in which a leakage sensor 20 such as a float sensor or a conductivity sensor is arranged (below the opening) can be employed. In this embodiment, since the electrolyte solution collected in the discharge path 11 is collectively discharged from the discharge groove 3, the leak sensor 20 can detect the electrolyte solution efficiently and at an early stage. Further, by using the leak sensor 20 such as a float sensor, the leak sensor can be easily arranged and replaced. As in the first embodiment, a storage tank for storing the discharged electrolyte solution is provided below the opening of the discharge groove 3.

  Further, in the case where a plurality of frames 1D including the discharge grooves 3 and the discharge holes 4 are provided, as described in the first embodiment, a frame provided with a plurality of discharge grooves 3 arranged in a straight line is used. In addition, by arranging the liquid receptacles along the discharge grooves 3, the electrolyte discharged from the respective discharge grooves 3 can be easily collected by the liquid receptacles. In particular, when the opening of each discharge groove 3 is directed downward in a state where the cell stack is installed, the electrolyte can be easily discharged by the weight of the electrolyte as described above.

  As shown in FIG. 6 (C), when the end plate 210 is provided with a through hole 210h, instead of placing the string sensor 21 in the discharge path 11, the vicinity of the through hole 210h ( Here, it is possible to adopt a form in which a leakage sensor 20 such as a float sensor is disposed (below the through-hole 210h). In this embodiment, since the electrolytic solution collected in the discharge path 11 is collectively discharged from the through hole 210h, the leak sensor 20 can detect the electrolytic solution efficiently and early. Moreover, this form can arrange | position the leak sensor 20 easily, when the space for arrange | positioning the leak sensor 20 below a cell stack cannot fully be ensured. Furthermore, since this embodiment easily secures a sufficient space for arranging the leakage sensor 20, it is easy to perform maintenance, inspection, cleaning, and the like.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration. For example, the shape, number, formation position, etc. of the discharge grooves / discharge holes can be appropriately changed.

  The RF battery and RF battery system of the present invention are aimed at stabilizing fluctuations in power generation output, storing electricity when surplus generated power, leveling load, etc., for power generation of new energy such as solar power generation and wind power generation. It can utilize suitably for a use. Further, the RF battery and the RF battery system of the present invention can be suitably used as a large-capacity storage battery that is provided in a general power plant and is intended for measures against instantaneous voltage drop, power failure, and load leveling. The RF battery frame and the RF battery cell stack of the present invention can be suitably used for the constituent members of the RF battery of the present invention.

1A, 1A _n (n = 1,…, k,…), 1B, 1C, 1C _n (n = 1,…, k,…), 1D frame
2 Liquid storage groove 3, 3a, 3b Discharge groove 3o Opening 4 Discharge hole
10A, 10B, 10C, 10D Cell stack 11 Discharge path 15 Liquid receiving tank
20 Leak sensor 21 String sensor
30 Control unit 31 Input means 32 Judgment means 33 Instruction means 34 Storage means
35 Direct input 36 Display
100 Redox flow battery 101 Diaphragm 102 Positive electrode cell 103 Negative electrode cell
104 Positive electrode 105 Negative electrode 106 Positive electrode tank 107 Negative electrode tank
108,109,110,111 Conduit 112,113 Pump
121 Bipolar plate 122 Frame 123 Positive electrode supply hole 124 Negative electrode supply hole
125 Positive electrode drain hole 126 Negative electrode drain hole 127 Seal member
200 Cell stack 210 End plate 210h Through hole 220 Tightening member

Claims (13)

A frame for a redox flow battery, provided on the outer periphery of the bipolar plate, for supplying an electrolytic solution to an electrode disposed on the bipolar plate and discharging the electrolytic solution from the electrode,
On at least one side of this frame,
A sealing mechanism for mainly sealing the electrolyte in the electrode;
A liquid reservoir groove that is provided on an outer periphery than the seal mechanism, and stores an electrolyte that leaks beyond the seal mechanism;
A redox flow battery comprising a drainage portion provided continuously with the liquid reservoir groove and serving as a flow path when the electrolytic solution in the liquid reservoir groove is collected and discharged to the outside of the frame. For frames.   2. The redox flow battery frame according to claim 1, wherein the drainage portion includes a drainage groove that continues from the liquid reservoir groove to an outer peripheral edge of the frame.   3. The redox flow battery frame according to claim 1, wherein the drainage part includes a discharge hole penetrating the front and back of the frame. A cell stack for a redox flow battery in which a cell having a diaphragm interposed between a positive electrode and a negative electrode and a frame having a bipolar plate are alternately stacked,
The redox flow battery cell stack according to any one of claims 1 to 3, wherein each frame is the redox flow battery frame. Each frame includes the liquid reservoir groove and a discharge groove continuous from the liquid reservoir groove to the outer peripheral edge of the frame,
5. The cell stack for a redox flow battery according to claim 4, wherein the discharge groove provided in each frame is provided at a position aligned in a straight line in a state where a plurality of the frames are stacked. Each frame includes the liquid reservoir groove and a discharge groove continuous from the liquid reservoir groove to the outer peripheral edge of the frame,
6. The cell stack for a redox flow battery according to claim 4 or 5, wherein the discharge groove provided in each frame is opened to a lower side of the cell stack in a state where the cell stack is installed. . Each of the frames includes the liquid reservoir groove and a discharge hole provided continuously to the liquid reservoir groove and penetrating the front and back of each frame.
The cell stack includes a discharge path in which a plurality of the discharge holes are continuously formed, and at least one opening of the discharge path is used for discharging an electrolyte stored in the discharge path. The cell stack for a redox flow battery according to claim 4. Each of the frames includes the liquid reservoir groove and a discharge hole provided continuously to the liquid reservoir groove and penetrating the front and back of each frame.
The cell stack includes a discharge path in which a plurality of the discharge holes are continuously formed,
Both ends of the discharge path are closed,
The at least one frame of the plurality of frames includes a discharge groove that continues from the discharge path to an outer peripheral edge of the frame and discharges the electrolyte stored in the discharge path. The cell stack for redox flow batteries according to 4. A cell stack in which a diaphragm is interposed between a positive electrode and a negative electrode, and a frame having a bipolar plate, and each electrode supplied to the electrode of each electrode included in the cell stack A redox flow battery comprising each electrode tank for storing an electrolyte, and a flow path for transferring each electrode electrolyte between the cell stack and each electrode tank,
The cell stack is a cell stack for a redox flow battery according to any one of claims 4 to 8,
A redox flow battery comprising a leakage sensor for detecting an electrolyte collected in the liquid storage groove. A cell stack in which a diaphragm is interposed between a positive electrode and a negative electrode, and a frame having a bipolar plate, and each electrode supplied to the electrode of each electrode included in the cell stack A redox flow battery comprising each electrode tank for storing an electrolyte, and a flow path for transferring each electrode electrolyte between the cell stack and each electrode tank,
The cell stack is a cell stack for a redox flow battery according to claim 6,
A liquid receptacle that is disposed below the opening of the discharge groove and receives the electrolytic solution from the discharge groove;
A redox flow battery comprising: a leak sensor for detecting an electrolyte collected in the liquid receptacle.   11. The redox flow battery according to claim 10, wherein the liquid receptacle has an inclined portion inclined from one side to the other, and the leakage sensor is provided at a lowermost portion of the inclined portion. A cell stack in which a diaphragm is interposed between a positive electrode and a negative electrode, and a frame having a bipolar plate, and each electrode supplied to the electrode of each electrode included in the cell stack A redox flow battery comprising each electrode tank for storing an electrolyte, and a flow path for transferring each electrode electrolyte between the cell stack and each electrode tank,
The cell stack is a cell stack for a redox flow battery according to claim 7 or 8,
A redox flow battery comprising a leak sensor housed in the discharge path provided in the cell stack and detecting an electrolytic solution in the discharge path, wherein the leak sensor is a string sensor. The redox flow battery according to any one of claims 9 to 12,
A redox flow battery system comprising: a control unit that controls a supply state of an electrolyte from each of the electrode tanks to the cell stack based on information from the leakage sensor.

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