WO2019031949A1

WO2019031949A1 - Redox flow battery

Info

Publication number: WO2019031949A1
Application number: PCT/KR2018/009277
Authority: WO
Inventors: 이용희; 이종욱; 강태혁; 신동명; 김보라; 손덕영; 최윤호
Original assignee: 롯데케미칼 주식회사; 아주대학교산학협력단
Priority date: 2017-08-11
Filing date: 2018-08-13
Publication date: 2019-02-14
Also published as: KR20190017498A

Abstract

A redox flow battery is introduced. The redox flow battery according to one embodiment of the present invention comprises a stack for generating a current in an electrolytic solution, which flows into an electrolytic solution inflow line, and discharging the electrolytic solution to an electrolytic solution outflow line, wherein the stack comprises membranes, spacers and electrode plates, which are repeatedly stacked so as to form an inner volume, and a flow frame for accommodating the membranes and the electrode plates, the flow frame comprises a flow channel connected to the electrolytic solution inflow line and the electrolytic solution outflow line through which the electrolytic solution flows into or is discharged from the inner volume, and the flow channel comprises a plurality of discharge holes at one flow channel divided at the final bifurcation point connected to the inner volume.

Description

【Specification Tax

Title of the Invention

Redox flow cell

TECHNICAL FIELD

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a redox flow cell, and more particularly, to a redox flow cell in which an electrolyte is supplied to and discharged from an electrode through an inlet channel and an outlet channel.

BACKGROUND ART [0002]

The zinc bromine redox flow cell is a type of flow cell that produces electricity by redox reaction between the electrolyte and the electrode.

For example, a redox flow cell is formed by repeatedly laminating a bipolar electrode and a membrane, stacking a current collector plate and an end plate in sequence on both sides of the outermost layer, and supplying an electrolyte solution An electrolyte pump for supplying an electrolyte to the stack, piping, and an electrolyte tank for storing an electrolyte solution flowing out after the inside of the stack.

The stack includes a flow frame, i. E., A membrane flow frame incorporating the membrane and an electrode flow frame incorporating the electrode. For example, the stack is formed by centering one electrode flow frame, having a membrane flow frame in a bilaterally symmetrical structure on both sides of the electrode flow frame, and disposing an end plate at the periphery of the membrane flow frame.

1 is a configuration diagram of a flow frame applied to a redox flow cell of the prior art. 1, the flow frame 101 includes an inlet channel 103 for introducing an electrolyte solution into an internal volume 102 provided between the electrode and the membrane, and a flow channel 103 for discharging the electrolyte solution from the internal volume 102 after the reaction. And an outlet channel (104). The inflow channel 103 uniformly supplies the electrolytic solution flowing into the set pressure, and the outflow channel 104 is configured to uniformly discharge the electrolytic solution flowing out to the atmospheric pressure after the countercurrent.

As the flow uniformity evaluation variables, the symmetry coefficient (symmetry coef fi cient), which is the deviation of the flow rate at the branch point, and the maximum velocity of the flowing or flowing electrolyte An absolute value variability range coefficient that is the difference of the lowest speed can be used.

FIG. 2 is a flow chart showing the flow rate of the electrolyte at the fifth branch point of the inlet channel and the outlet channel of the flow frame of FIG. A portion where the electrolyte is supplied from the fifth branch point b51 of the inlet channel 103 to the internal volume 102 and a portion where the electrolyte is supplied from the fifth branch point b52 of the outlet channel 104 A dead-zone (DZ) whose flow rate is close to zero is generated due to the non-uniformity of the flow velocity.

3 is a flow deviation diagram showing a flow rate deviation (mass flow rate) at the first to third branch points of the inflow channel according to the flow velocity distribution in FIG. Fig. 4 is a graph showing the flow rate deviation (mass flow rate) at the fourth branch point to the low 15 branch point of the inflow channel according to the flow velocity distribution of Fig. 2;

For convenience, the outflow channel 104 is omitted and the inflow channel 103 is described as an example. 3 and 4, the symmetric coefficient which is the flow rate deviation at the first to sixth branch points b1 to b3 of the inflow channel 103 is small (see Fig. 3) ) And the symmetry coefficient (symmetry coef ficient), which is a flow rate deviation at the fifth branch point (b5, b51 in Fig. 2), becomes larger.

DETAILED DESCRIPTION OF THE INVENTION

[Technical Problem]

Embodiments of the present invention provide a method and apparatus for equalizing the flow rate (minimizing the variability range coef ficient) with respect to the flow of the electrolyte flowing into the internal volume from the inlet channel and the electrolyte flowing out of the internal volume into the outlet channel, And to provide a redox flow cell that removes the dead zone from the volume, the inlet channel, and the outlet channel.

In addition, embodiments of the present invention are directed to uniformly distributing the electrolytic solution to the left and right at the respective branch points of the inlet channel and the outlet channel with respect to the flow of the electrolytic solution flowing from the inlet channel to the inner volume and the electrolytic solution flowing from the inner volume to the outlet channel (Symmetry coefficient) is minimized). [Technical Solution]

The redox flow cell according to an embodiment of the present invention includes a stack for generating an electric current from an electrolyte flowing into an electrolyte inflow line and discharging an electrolyte solution to an electrolyte outflow line, the stack being repeatedly stacked to form an internal volume And a flow frame for receiving the membrane and the electrode plate, wherein the flow frame is connected to the electrolyte inflow line and the electrolyte outflow line through which the electrolytic solution flows into or flows out from the internal volume And the flow channel includes a plurality of discharge ports in one flow channel divided at a final branch point side connected to the internal volume.

The plurality of ejection openings may be opened to a minimum size at the center and gradually increase in size toward both sides.

The plurality of ejection openings may be spaced apart by a predetermined interval.

The flow channel may be divided into three to five channels and then may have a plurality of outlets.

When the flow channel is divided n times, the flow channel may have a branch deviation reduction unit between the nth branch point and the (n-1) th branch point.

The branching deviation reduction unit of the flow channel is formed by a curve L1 passing through the center of the width of the flow channel and a vertical line L2 passing through the center of the width at a point distributed at the n turn point, May be set to a straight line distance between a first point P1 where the vertical line L2 meets the first line P1 and a second line P2 where the curve L1 and the vertical line L2 meet from above and may be more than zero.

The flow channel may have a flow characteristic of 500 to 2000 Re. 【Effects of the Invention】 .

As described above, the embodiments of the present invention have a plurality of discharge ports partitioned on the side of the final branch point of the flow channel (inlet channel and outlet channel) connected to the internal volume, so that the flow rate of the electrolytic solution, The dead zone can be removed from the internal volume and the inlet and outlet channels by equalizing the flow rate (minimizing the variable range coefficient) for the flow of electrolyte flowing into the inlet and outlet channels. In addition, the embodiments of the present invention can uniformly distribute the electrolytic solution (minimization of the symmetry coefficient) to the left and right at each branch point of the inlet channel and the outlet channel.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of a flow frame applied to a redox flow cell of the prior art

FIG. 2 is a flow diagram showing the flow rate of the electrolyte at the fifth branch point of the inlet channel and the outlet channel of the flow frame of FIG.

3 is a flow deviation diagram showing a flow rate deviation at the first branch point to the third branch point of the inflow channel according to the flow velocity distribution of FIG.

FIG. 4 is a graph showing the flow rate deviation of the flow channel at the fourth to fifth branch points of the inflow channel according to the flow velocity distribution of FIG. 2. FIG.

5 is a perspective view illustrating a stack applied to a redox flow cell according to an embodiment of the present invention.

6 is a sectional view taken along the line VI-VI in Fig.

7 is a cross-sectional view taken along the line Vn -?

FIG. 8 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to the first embodiment of the present invention.

9 is a partial structural view ( _a ) and a transverse sectional view (b) of _a flow frame applied to a redox flow cell according to a modification of the first embodiment of the present invention.

10 is a partial structural view ( _a ) and a transverse sectional view (b) of _a flow frame applied to a redox flow cell according to the second embodiment of the present invention.

11 is a partial structural view ( _a ) and a transverse sectional view (b) of _a flow frame applied to a redox flow cell according to a modification of the second embodiment of the present invention.

12 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to a third embodiment of the present invention.

13 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to a modification of the third embodiment of the present invention.

FIG. 14 is a graph showing the relationship between the pressure loss of the electrolyte, the area-weighted mean outlet velocity, the variable range coefficient, the flow velocity distribution (a) and the flow velocity distribution in the flow frames of the first, second, and third embodiments of FIGS. 8, 10, The cross-sectional flow velocity distribution diagram (b) FIG.

FIG. 15 is a graph showing the relationship between pressure loss, area weighted average outlet velocity, variable range coefficient, flow velocity distribution (a) in the flow frame of the first, second, and third embodiments of FIGS. 9, 11, And a cross-sectional flow velocity distribution diagram (b).

FIG. 16 is a detailed view showing a shape of a branch deviation reducing section of a branch point in the flow frame applied to FIG. 10; FIG.

17 is a graph showing the relationship between the number of Re channels and the symmetry coefficient of the channel channel and the symmetry coefficient immediately before the quadrant.

FIG. 18 is a graph showing the relationship of the variables of the channel channel in the channel just before the fourth branching point optimized for Re.

FIG. 19 is a flow diagram showing a flow rate deviation of a final branch point according to the prior art and a flow rate deviation of a final branch point according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

In the specification, when that any part is "connected" with another part, which includes also a case that is "directly coupled to" as well as, interposed between the other member "indirectly coupled to ¹ '. In addition, When an element is referred to as " comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

It will be understood that when a layer, film, region, plate, or the like is referred to as being "on" or "on" another portion throughout the specification, . And " ¹ over" or The term " on " means located above or below the object portion, and does not necessarily mean that it is located on the upper side with respect to the gravitational direction.

FIG. 5 is a perspective view showing a stack applied to a redox flow cell according to an embodiment of the present invention, FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5, and FIG. 7 is a cross- Fig.

5 to 7, the redox flow cell of the embodiment includes a stack 120 for generating current, and the electrolyte is supplied from the electrolyte tank (not shown) to the stack 120, 120 to store the electrolyte solution in the electrolyte tank.

By way of example, the stack 120 is configured to generate an electric current while circulating the electrolyte. The electrolyte tank is configured to supply the electrolyte solution to the stack 120 and to store the electrolyte solution flowing out of the stack 120, and is connected to the electrolyte solution inflow line and the electrolyte solution outflow line.

For example, the electrolyte tank may include an anode electrolyte tank containing an anode electrolyte containing zinc and a cathode electrolyte tank containing a cathode electrolyte containing bromine (for convenience, a two-phase electrolyte tank containing two phases of the cathode electrolyte, (Not shown).

The electrolyte inflow line connects the anode, the cathode electrolyte tank and the stack 120, and flows the electrolyte solution into the stack 120 by driving the electrolyte pump. The electrolyte effluent line connects the anode and the cathode electrolyte tank with the stack 120, and discharges the electrolyte after the stack 120 from the stack 120 via the stack 120.

The stack 120 includes the membrane 10, the spacer 20 and the electrode plate 30 which are repeatedly stacked, the current collectors 61 and 62 and the end plates 71 and 72 which are sequentially stacked at both ends in the stacking direction, And includes a first flow channel (CH1) and a second flow channel (CH2) through which the electrolyte flows. The electrode plate 30 includes the anode electrode 32 on one side and the cathode electrode 31 on the other side.

The end plates 71 and 72 connect the anode and the cathode electrolyte inlets H21 and H31 connected to the electrolyte inflow line to the first and second flow channel channels CHI and CH2. The end plates 71 and 72 connect the anode and cathode electrolyte outlets H22 and H32 connected to the electrolyte outflow line to the first and second flow channel channels CHI and CH2. The stack 120 may discharge the current generated internally through the bus bars B1 and B2 or may be connected to an external power source to transfer a current to the anode electrolyte tank. .

The stack 120 further includes a flow frame, i.e., a membrane flow frame 40 and an electrode flow frame 50. Since the stack 120 has two unit cells CI and C2, one electrode flow frame 50 is provided at the center and two membrane flow frames 40 and two end plates 71, 72 disposed on the outer periphery of the membrane flow frame 40, respectively.

The membrane 10 is configured to pass ions and is coupled to the membrane flow frame 40 in the thickness direction center of the membrane flow frame 40. The electrode plate 30 is joined to the electrode flow frame 50 at the center in the thickness direction of the electrode flow frame 50.

The end plate 71, the membrane flow frame 40, the electrode flow frame 50, the membrane flow frame 40 and the end plate 72 are disposed, and a spacer 10 is interposed between the membrane 10 and the electrode plate 30, The stack 120 having the two unit cells CI and C2 is formed by joining the membrane flow frame 40, the electrode flow frame 50 and the end plates 71 and 72 to each other via the through- do.

The electrode plate 30 includes a cathode electrode 31 formed on one side and an anode electrode 32 formed on the other side in the portion where the two unit cells CI and C2 are connected and the two unit cells CI and C2 ) Are connected in series.

The membrane flow frame 40, the electrode flow frame 50 and the end plates 71 and 72 are adhered to each other to set the internal volume S between the membrane 10 and the electrode plate 30, (CHI, CH2) for supplying an electrolyte solution to the first and second flow channels (CH1, CH2). The first and second flow channel channels (CHI, CH2) are configured to supply the electrolyte at a uniform pressure and amount, respectively, on both sides of the membrane (10).

5 and 6, the first channel CH1 is connected to the anode electrolyte inlet H21, the internal volume S and the anode electrolyte outlet H22, and is driven by the anode electrolyte pump, 10 and the anode electrode 32, The anode electrolytic solution flows into the internal volume S set between the anode and the cathode.

5 and 7, the second flow channel CH 2 connects the cathode electrolyte inlet H 31, the internal volume S and the cathode electrolyte outlet H 32, and is driven by the cathode electrolyte pump, 10 and the cathode electrode 31 to allow the cathode electrolyte solution to flow out after the catholyte flows.

The anode electrolyte undergoes a redox reaction on the side of the anode electrode 32 of the internal volume S to generate a current and is stored in the anode electrolyte tank. The cathode electrolytic solution is redox-repelled on the side of the cathode electrode 31 of the internal volume S to generate a current and stored in the cathode electrolytic solution tank.

Layer display, between the membrane 10 and the cathode electrode 31,

2Β → 2Br + 2e ^~ (formula 1)

The bromine contained in the cathode electrolyte is produced and stored in the cathode electrolyte tank.

During charging, between the membrane 10 and the anode electrode 32,

Zn ^{2 +} + 2e & ^quot ^; - > Zn (Formula 2)

The zinc contained in the anode electrolyte is deposited on the anode electrode 32 and stored.

During the discharge, inversion between Equation 1 and Equation 1 occurs between the membrane 10 and the cathode electrode 31, and the inverse reaction of Equation 2 occurs between the membrane 10 and the anode electrode 32.

The current collectors 61 and 62 collect the current generated in the cathode electrode 31 and the anode electrode 32 or collect the current generated in the outermost electrode plate 32 30, and 30 to be electrically connected.

8 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to the first embodiment of the present invention. 8, the flow frame (i.e., the membrane flow frame 40, the electrode flow frame 50) in the first embodiment includes an electrolyte inflow line and an electrolyte inflow line that flow in or out of the internal volume S The first and second flow channel channels (CHI, CH2) Respectively.

For convenience, the one-channel channel CH1 will be described so that the anode electrolyte flowing from the anode electrolyte inlet H21 to the internal volume S flows. The first flow channel CH1 has a plurality of discharge ports 0L1 partitioned at the final branch point (fifth branch point b5) side connected to the internal volume S.

The plurality of ejection openings 0L1 are opened to a minimum size at the center and gradually increase in size to both sides (for example, in the width direction of the flow frame (left and right direction in Fig. 8)). This prevents the anode electrolyte from being concentrated in the middle region among the plurality of discharge ports 0L1, thereby enabling a uniform distribution of the anode electrolyte flow.

By way of example, the plurality of ejection openings 0L1 are formed in a rectangular structure, and are spaced apart by a predetermined gap G1. The interval G1 is set to 1 mm. The plurality of discharge ports 0L1 are provided after the fifth branch point b5 after being branched five times from the first one-way channel CH1. That is, the plurality of discharge ports 0L1 are provided on the inner volume S side after the fifth branching point b5 in the first flow channel CH1, and are joined to the inner volume S again. Although not shown, the discharge ports may be formed in a triangular shape, a polygonal shape, a circular shape, an elliptical shape, or the like.

Hereinafter, various embodiments of the present invention will be described. The description of the same configuration as that of the first embodiment and the previously described embodiment will be omitted and different configurations will be described.

9 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to a modification of the first embodiment of the present invention. Referring to FIG. 9, in the first flow channel CH11, the plurality of discharge ports OLL11 are formed in a rectangular shape and are spaced apart by a predetermined gap G11. The gap G11 is set to 0.5 mm. That is, the plurality of discharge ports 0L11 are provided on the inner volume S side after the fifteenth branching point b5 in the first flow channel CH11, and are joined to the inner volume S again.

Therefore, the plurality of discharge ports 0L11 according to the modification of the first embodiment can more uniformly discharge the anode electrolyte into the internal volume S, as compared with the plurality of discharge ports 0L1 according to the first embodiment . 10 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to the second embodiment of the present invention. 10, in the second embodiment, the first flow channel CH3 includes a plurality of discharge ports 0L3 partitioned at the final branch point (fourth branch point b4) connected to the internal volume S Respectively.

The plurality of ejection openings 0L3 are opened to a minimum size at the center and gradually increase in size toward both sides. This prevents the anode electrolyte from being concentrated in the middle region of the plurality of discharge ports 0L3, thereby enabling uniform distribution of the anode electrolyte flow.

By way of example, the plurality of ejection openings 0L3 are formed in a rectangular structure, and are spaced apart by the set gap G3. The interval G3 is set to 1 mm. The plurality of discharge ports 0L3 are provided after the fourth branching point b4 branched four times in the gas flow channel CH3. That is, the plurality of discharge ports 0L3 are provided on the inner volume S side after the brinking point b4 in the first flow channel CH3, and are joined to one another to be connected to the inner volume S again.

In the second embodiment, the plurality of outlets 0L3 are formed in a wider range as compared with the plurality of outlets 0L1 in the first embodiment, so that the anode electrolytic solution is discharged from a larger range of the inner volume S So that uniform discharge can be achieved.

11 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to a modification of the second embodiment of the present invention. Referring to FIG. 11, in the gas channel channel CH31, the plurality of discharge ports 0L31 are formed in a rectangular shape and are spaced apart by a predetermined gap G31. The interval G31 is set to 0.5 mm. That is, the plurality of discharge ports 0L31 are provided on the inner volume S side after the fourth branching point b4 in the first flow channel CH31, and are joined to the inner volume S again.

Accordingly, the plurality of discharge ports 0L31 according to the modification of the second embodiment can more uniformly discharge the anode electrolyte into the internal volume S, as compared with the plurality of discharge ports 0L3 according to the second embodiment.

12 is a partial structural view ( _a ) and a transverse sectional view (b) of _a flow frame applied to a redox flow cell according to the third embodiment of the present invention. Referring to Fig. 12, in the third embodiment, the first flow channel CH4 is connected to the inner volume S And a plurality of discharge ports 0L4 partitioned at the branch point (third branch point b3).

The plurality of ejection openings 0L4 are opened to a minimum size at the center and gradually increase in size to both sides. This prevents the anode electrolyte from being concentrated in the middle region among the plurality of discharge ports 0L4, thereby enabling the anode electrolyte flow and uniform distribution.

By way of example, the plurality of ejection openings 0L4 are formed in a rectangular shape and are spaced apart by the set gap G4. The interval G4 is set to 1 占. The plurality of discharge ports 0L4 are provided after the third branch point b3 branched three times in the first flow channel CH4. That is, the plurality of discharge ports 0L4 are provided on the inner volume S side after the third branching point b3 in the first flow channel CH4, and are combined into one another to be connected to the inner volume (SHI).

In the third embodiment, the plurality of discharge ports 0L4 are formed in a wider range as compared with the plurality of discharge ports 0L3 in the second embodiment, so that the anode electrolyte can be discharged in a wider range of the inner volume S So that uniform discharge can be achieved.

13 is a partial structural view (a) and a transverse sectional view (b) of a flow frame applied to a redox flow cell according to a modification of the third embodiment of the present invention. Referring to FIG. 13, in the system 1 flow channel CH41, the plurality of discharge ports 0L41 are formed in a rectangular structure and are spaced apart by a predetermined gap G41. The gap G41 is set to 0.5 mm. In other words, the plurality of discharge ports 0L41 are connected to the inner volume CH4 after the third branch point b3 in the first flow channel CH41. (S), and are joined together into an internal volume (S).

Accordingly, the plurality of discharge ports 0L41 according to the modified example of the third embodiment can more uniformly discharge the anode electrolyte into the internal volume S, as compared with the plurality of discharge ports 0L4 according to the third embodiment.

Fig. 14 is a graph showing the pressure drop of the electrolyte in the flow frames of the first, second and third embodiments of Figs. 8, 10 and 12, the flow velocity of the area weighted average outlet (ar ea- weighted (a) and (b) of the cross-sectional flow velocity distribution, respectively. The results are shown in Fig. 1 (a) and (b).

Referring to FIG. 14, in the first, second, and third embodiments, the first channel channels CHI, CH3, CH4) can gradually reduce the pressure drop as the branch point decreases to 5, 4, and 3.

In the second and third embodiments, the first channel channels CH3 and CH4 are variable range coefficients for evaluating the uniformity of the area-weighted average outlet velocity according to the number of the branch points being four or three. var iabi 1 ity range coefficient were reduced by 64% and 65%, respectively, from 0.18 m / s to 0.064 m / s and 0.062 m / s, respectively.

The first, second, and third embodiments can remove the dead zone in the internal volume S and the first flow channel CHI, CH3, CH4 due to the minimization of the variability range coefficient.

FIG. 15 is a graph showing the pressure drop of an electrolytic solution in a flow frame of a modified example of the first, second, and third embodiments of FIGS. 9, 11, and 13, area- (a) and the cross-sectional flow velocity distribution (b), as shown in FIG. 3 (b).

Referring to FIG. 15, in the first, second, and third embodiments, the first flow channels CHll, CH31, and CH41 decrease the pressure drop of the electrolyte, The varia- bility constant coefficient for evaluating the uniformity of the area-weighted average outlet velocity is implemented more efficiently than in the first, second, and third embodiments Respectively.

Variable range. Modifications of the first, second, and third embodiments can further remove the dead zone from the internal volume S and the first flow channels CHll, CH31, and CH41 due to further minimization of the coefficients.

FIG. 16 is a detailed view showing a shape of a branch deviation reducing section of a branch point in the flow frame applied to FIG. 10; FIG. Referring to FIG. 16, in the case where the first flow channel CH3 is branched n times (for example, four times), the first flow channel CH3 is divided into nth branch points (for example, four branch points b4) and has a branch deviation reduction section between n-1 branch points (for example, three branch points b3).

The branch deviation reducing section may improve the left and right flow rate deviation at the fourth branch point (b4) Is set according to the length (L) of the music as a variable. When drawing a vertical line L2 passing through the center of the width at a point distributed at the nth branch point (for example, the fourth branch point b4) and the curve L1 passing through the width center of the first flow channel CH3, L is a straight line distance between a first point P1 where the end point of the curve L1 and the perpendicular line L2 meet below and a second point P2 where the curve L1 and the perpendicular line L2 meet from above, And is greater than zero. The branch deviation reduction section of the first flow channel CH3 immediately before the crab quadrature point b4 increases as the length L increases and the branch deviation reduction section does not exist when the length L is zero ).

FIG. 17 is a graph showing the relationship between the Re number and the curvature parameter of the channel channel and the symmetry coef fi cient immediately before the fourth bifurcation point. FIG. 18 is a graph showing the curvature parameter As shown in FIG.

Referring to FIGS. 17 and 18, the analysis according to the curvature was performed for the laminar flow region corresponding to Reynolds Number 250 to 2000. The symmetry coef fi cient decreases as the length L, which is the curvature variable (branch deviation reduction section) between the fourth branch point M and the third branch point b3, increases, . The length of the curvature parameter with which the symmetric coefficient for each Re number is zero converges to 2.5..

FIG. 19 is a flow deviation diagram showing a comparison between the flow rate deviation of the final branch point according to the prior art and the flow rate deviation of the final branch point according to an embodiment of the present invention, and FIG. 19 shows the optimized length L of the curvature As a result, it can be confirmed that the symmetric coefficient according to the branching deviation of the second embodiment is reduced as compared with the conventional technique. That is, the symmetry factor at the fourth branching point b4 of the first-flow channel CH3 of the second embodiment is 0.3%, which is 3.6% improved from the conventional 3.9%. For convenience, the first flow channel of the prior art is shown.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And it goes without saying that the invention belongs to the scope of the invention. - Explanation of symbols -

10: membrane 20: spacer

30 electrode plate 32: anode electrode

31 Cathode electrode 40: Membrane flow

50 Electrode flow frame 61, 62: Collector plate

71 72: End plate 120 ^• ^• - Person -ΪΙ 1

L: length L1:

L2 straight line B1, B2: bus bar

b3 Third branch point b4: Fourth branch point

b5 fifth branch point ci, C2: unit cell

CHI, CH11, CH3, CH31, CH4, CH41: The first channel

CH2: Gage 2 Euro channel G1, Gil, G3, G31, G4, G41: Interval

H21, H31: anode, cathode electrolyte inlet

H22, H32: anode, cathode electrolyte outlet

0L1, OLll, 0L3, 0L31, 0L4, 0L41:

PI, P2: First and second points S: Inner volume

Claims

Claims:

[Claim 1]

And a stack for generating an electric current with an electrolyte flowing into the electrolyte inflow line and discharging the electrolyte to the electrolyte outflow line, wherein the stack is repeatedly stacked to form an internal volume, a spacer, and an electrode plate, A flow frame for receiving the plate,

Wherein the flow frame includes a flow channel connected to the electrolyte inflow line and the electrolyte inflow line through which the electrolyte flows into or flows out from the internal volume,

Wherein the flow channel has a plurality of discharge ports in one flow channel partitioned at a final branch point side connected to the internal volume.

[Claim 2]

In Item 1,

Wherein the plurality of ejection openings are opened to a minimum size at the center and gradually open to both sides of the redox flow cell.

[3]

The method according to claim 1,

Wherein the plurality of discharge ports are spaced apart at a predetermined interval.

Claim 4

In Item 1,

Wherein the flow channel is divided into three to five circuits, and then the plurality of discharge ports are provided.

[Claim 5]

The method according to claim 1,

Wherein when the flow channel is divided n times, the flow channel has a branch deviation reduction section between the n-th branch point and the (n-1) th branch point.

[Claim 6]

In Item 5,

Wherein the branching deviation reducing section of the flow channel The first point P1 where the end point of the curve L1 and the perpendicular line L2 meet from below when the vertical line L2 passing through the center of the width is drawn at the point where the curve passes through the curve LI and the point divided by the n branch point, The redox flow cell being set at a straight line distance between points 12 and P2 where the curve L1 and the vertical line L2 meet from above. 7.

The method according to claim 6,

The channel channel

A redox flow cell having flow characteristics of 500 to 2000 Re.