KR101241814B1 - Bipolar plate having guide vane and electrochemical stack having the same - Google Patents

Abstract

 The present invention relates to an electrochemical cell separator and an electrochemical cell stack including the same, in which a reaction fluid can be uniformly supplied into each channel flow path, and a reaction fluid is prevented from flowing back. The electrochemical cell separator according to the present invention is for separating an electrochemical unit cell in an electrochemical system. The distribution manifold to which the reaction fluid is supplied, the recovery manifold to which the reaction fluid flows out, and the distribution manifold An electrochemical cell separator in which a plurality of channel flow paths are formed, one end of which is connected to a distribution manifold and the other end of which is connected to a distribution manifold so that the reaction fluid flows toward the recovery manifold, wherein the distribution manifold is located in the distribution manifold. Guide vanes are provided for separating the oil into a plurality of independent inflow passages.

Description

Bipolar plate having guide vane and electrochemical stack having the same}

The present invention provides a uniform flow / distribution of high-density, high-viscosity reaction fluid and cooling / heating media provided in an electrochemical cell stack such as a fuel cell, a redox flow battery, a hydrogen generator using an electrodialysis process, an electrolysis device, and the like. To this end, the present invention relates to an electrochemical cell separator having guide vanes and an electrochemical cell stack having the same.

Electrochemical cells, generally composed of electrolytes and electrodes, are used in a generic sense to encompass both galvanic cells and electrolysis devices, thereby electrochemically converting the chemical energy of fuels and oxidants Fuel cells that convert electrical energy by reaction and electrolysis cells that generate hydrogen and oxygen gas through electrolysis of water all fall into the category of electrochemical cells. Such an electrochemical cell is manufactured in the form of a unit cell having two or more conductor electrodes, an aqueous solution, or an electrolyte composed of a polymer material as a basic component. They have a structure of a high density cell stack in which they are connected in series.

In such an electrochemical cell stack, a working fluid that participates in the electrochemical oxidation / reduction reaction is continuously supplied from the outside, and the chemical oxidation / reduction reaction is blocked by direct contact between the oxidation / reduction reaction fluids, and A large number of separators, bipolar plates, and flow-field plates are provided to secure free electrons through chemical oxidation / reduction reactions and to provide structural support for electrodes undergoing oxidation / reduction reactions. A schematic configuration diagram is shown in FIG. 1 to help an understanding of an internal shape and a structure of a separator provided in a conventional electrochemical cell stack.

Referring to FIG. 1, the separator 9 is supplied with a working fluid that participates in an oxidation / reduction reaction to a reaction surface (electrode) or a distribution and recovery for discharging a reaction product by an electrochemical reaction from the reaction surface to the outside. It can be seen that manifolds 2 to 4 and a plurality of fine flow paths 1 are formed. On the other hand, the working fluid which is usually supplied to the electrochemical cell stack is a cooling medium for uniformly controlling the temperature of the cell stack so that a smooth electrochemical reaction can proceed with each of the reaction fluids participating in the oxidation / reduction reaction. material or heating material. The reaction fluid that participates in the oxidation / reduction reaction in the working fluid is supplied into the cell through a distribution manifold 2 having a rectangular cross-sectional shape located at the bottom left of the separator of FIG. 1, and the reaction product and the reaction by the electrochemical reaction. Unreacted fluids which do not participate in are discharged to the outside through the recovery manifold 3 located on the upper right side of the separator plate. In addition, a cooling / heating medium for maintaining a constant reaction temperature of the electrochemical cell stack is formed in the left / right center of the separator plate instead of supplying an additional external device for increasing density and lightening / thinning of the stack. By using the manifold (4) has a structure to supply / discharge directly into the stack.

On the other hand, in the stack 9A in which a plurality of unit cells are connected in series, manifolds 2 to 4 formed at the same positions of the stacked separator plates have a series of supply pipes or discharge pipes. ). In other words, a constant clamping pressure is applied at both ends of the stack to prevent the incorporation and leakage of working fluid between the manifolds formed inside the separator and to minimize contact resistance between components within the stack, typically in the manufacture of electrochemical cell stacks. This process creates a rigid structured oxidation / reduction reaction fluid and cooling / heating medium supply / exhaust tubes within the stack.

Oxidation / reduction reaction fluid transferred from the manifold into the separator plate through the supply pipe is supplied into the electrochemical cell through a plurality of flow paths 1 formed over the active area of the separator plate center. It moves to the electrode reaction surface and participates in the oxidation / reduction reaction or the electrolysis reaction.

However, in the conventional case, the distribution structure of the reaction fluid (or the cooling / heating medium) inside the electrochemical cell stack is distributed jointly through one through hole (manifold) formed on the left side (or right side) of the separator plate. And in the form of recovery. Therefore, in the case of an electrochemical cell stack using a liquid reaction medium and a cooling / heating medium as a working fluid having high density and high viscosity properties, the working fluid is biased in the lower portion of the distribution manifold under the influence of gravity. Therefore, the flow rate distribution deviation per unit cell adjacent to the distribution manifold and the flow rate distribution variation for each microchannel in the unit cell are increased, resulting in a problem that the performance variation between electrochemical cells deepens. This is a major factor that drastically degrades lifespan and durability in terms of stable long-term operation of the electrochemical cell stack.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electrochemical cell stack including a reaction fluid in a liquid form having high viscosity properties and a cooling / heating medium as a working fluid. It is to provide an electrochemical cell separator having an improved structure and an electrochemical cell stack having the same to prevent the bias of the working fluid due to gravity.

In order to achieve the above object, the electrochemical cell separator according to the present invention is for separating an electrochemical unit cell in an electrochemical system, a distribution manifold to which a reaction fluid is supplied, and a recovery manifold to which the reaction fluid is discharged. And a plurality of channel flow paths having one end connected to the distribution manifold and the other end connected to the recovery manifold such that the reaction fluid supplied to the distribution manifold flows toward the recovery manifold. In the cell separating plate, the distribution manifold is characterized in that the guide vane for separating the distribution manifold into a plurality of inflow passages blocked from each other.

According to the present invention, it is preferable that the inflow channel is formed by the number of the channel flow paths so that the inflow flow path of the distribution manifold and the channel flow path correspond one to one.

The electrochemical cell stack according to the present invention is coupled to one end of the plurality of electrochemical cell separators and the plurality of stacked electrochemical cell separators arranged to be stacked on each other, the distribution manifold of the electrochemical cell separator It characterized in that it comprises a reaction fluid distributor for supplying the reaction fluid.

According to the present invention, the distributor is coupled to the distributor, and further comprises a supply pipe for supplying the reaction fluid to the distributor, the inside of the distributor, the flow space in which the reaction fluid supplied from the supply pipe flows to the distribution manifold The dividing wall which is formed and communicates with the distribution manifold in the flow space part and communicates with the distribution manifold is preferably provided with a dividing wall separating the outlet area into a plurality of outlets.

According to the present invention, it is preferable that the outlets are formed as many as the inflow passages so that the outlets of the outlet region and the inflow passages of the distribution manifold correspond one to one.

According to the present invention having the above-described configuration, it is possible to prevent the phenomenon of bias of the working fluid by gravity inside the electrochemical cell stack using the reaction fluid in the liquid form having high density and high viscosity properties and the cooling / heating medium as the working fluid. As a result, the performance and durability of the electrochemical cell stack are finally improved through securing uniform flow rate distribution characteristics of the working fluid per unit cell of the electrochemical cell stack and reducing performance deviations between the unit cells.

1 is a perspective view of a conventional electrochemical cell separator.
2 is a schematic exploded perspective view of an electrochemical cell stack in accordance with one embodiment of the present invention.
FIG. 3A is a plan view of the electrochemical cell separator shown in FIG. 2, and FIG. 3B is a cross-sectional view taken along the line IIIb-IIIb of FIG. 3A.
4 is a schematic perspective view of the dispenser viewed in the direction of arrow A of FIG. 2.
Figure 5 (a) is a plan view of an electrochemical cell separator according to another embodiment of the present invention, Figure 5 (b) is a plan view of a distributor according to another embodiment of the present invention.

Hereinafter, an electrochemical cell stack and an electrochemical cell separator according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a schematic exploded perspective view of an electrochemical cell stack according to an embodiment of the present invention, Figure 3 (a) is a plan view of the electrochemical cell separator shown in Figure 2, Figure 3 (b) is 3A is a cross-sectional view taken along line IIIb-IIIb of FIG. 3, and FIG. 4 is a schematic perspective view of the distributor viewed in the direction of arrow A of FIG. 2, and FIG. 5A is an electrical diagram according to another embodiment of the present invention. 5 is a plan view of a chemical cell separator, and FIG. 5B is a plan view of a dispenser according to another embodiment of the present invention.

2 to 5, the electrochemical cell stack 100 according to the present embodiment includes an electrochemical cell separator 10, a distributor 20, and a supply pipe 30.

The electrochemical cell separator 10 is for separating unit cells from each other in an electrochemical system (electrochemical cell stack). Here, the electrochemical system means a power generation system using an oxidation / reduction reaction fluid, that is, a fuel cell or an electrolysis cell (concentration system) for electrolyzing water.

The electrochemical cell separator 10 is basically formed in a plate shape. In addition, a plurality of channel flow paths 11 for the flow of the reaction fluid are formed in the central portion of the electrochemical cell separator. The channel flow path 11 is formed in a shape that is bent so that the flow path of the reaction fluid is long, and the length of each channel flow path 11 is the same. In the case of this embodiment, the channel flow path 11 is formed in the form shown in Fig. 3A, so-called "multi-channel serpentine type." On the other hand, the channel flow path 11 may be formed on only one side of the inverted chemical cell separator 10, or both sides, in the present embodiment, the channel flow path is only in front of the electrochemical cell separator plate Is formed.

In addition, one side surface of the electrochemical cell separator is formed with a distribution manifold 12 penetrating in the thickness direction. The distribution manifold 12 is an inlet through which the reaction fluid is supplied. A plurality of guide vanes 122 are provided in the distribution manifold, and the distribution manifold is separated into a plurality of independent inflow passages 121 by the guide vanes 122. At this time, it is preferable that the inflow passage 121 is separated into the same number as the number of the channel passage 11 so that the inflow passage 121 and the channel passage 11 correspond one to one.

As illustrated in FIG. 3B, each of the inflow passages 121 and the channel passages 11 communicate with each other through the auxiliary passage 14 formed on the rear surface of the electrochemical cell separator. At this time, in the auxiliary flow passage 14, the flow direction of the reaction fluid flowing in the longitudinal direction of the stack along the distribution manifold is rapidly changed in the vertical direction, and a plurality of inflows of the distribution manifold 12 are introduced in this auxiliary flow path section. Since the flow cross-sectional area is smaller than the flow path 121, the flow resistance is increased. Therefore, it is preferable that the width and depth of the auxiliary flow passage 14 increase the flow cross-sectional area relative to the channel flow passage 11 so as to minimize the flow resistance of the working fluid.

In addition, the recovery manifold 13 is formed in the electrochemical cell separator in the thickness direction. The recovery manifold 13 communicates with each channel flow path 11 through an auxiliary flow path (not shown) formed on the rear surface of the electrochemical cell separator. The reaction fluid introduced into the distribution manifold 12 is supplied to the channel flow path 11 and then discharged to the outside through the recovery manifold 13. In the present embodiment, the recovery manifold 13 is illustrated as one hole, but alternatively, the recovery manifold 13 may be configured to be separated by guide vanes such as the distribution manifold 12.

On the other hand, as shown in Figure 5 (a), the electrochemical cell separation plate may be further formed a common flow path 15 for the supply of cooling fluid (refrigerant) or heating fluid (heat medium). The common flow path 15 may be formed as a single hole like the recovery manifold 13, or may be formed into a plurality of flow paths separated by guide vanes like the distribution manifold 12. And this common flow path 15 communicates with each channel flow path 11.

Electrochemical cell separators configured as described above are stacked on each other, as shown in FIG. In this case, each of the inflow passages 121 of the stacked electrochemical cell separators are connected to each other to form one independent passage, and thus, in the present embodiment, a total of six independent passages are formed, and a reaction fluid is formed along each independent passage. Will flow.

The manifold 20 is for supplying the reaction fluid to the electrochemical cell separator. The distributor 20 is coupled to one end of the plurality of stacked electrochemical cell separators 10. Then, the supply hole 22 for the coupling of the supply pipe 30 to be described later is formed through, the flow space portion 21 is formed inside the distributor. The flow space portion 21 is a space in which the reaction fluid supplied through the supply pipe 30 flows into the distribution manifold 12 of the electrochemical cell separator.

Hereinafter, for convenience of description, the flow space part 21 will be described by being divided into an inflow area 22, an outflow area 23, and an intermediate area 24. The inflow zone 22 is a region in which the reaction fluid is supplied from the supply pipe 30, and the supply hole 22 to which the supply pipe 30 is connected corresponds to the inflow zone. In addition, the outlet area 23 is an area in which the reaction fluid in the flow space 21 flows into the distribution manifold 12 of the electrochemical cell separator, and the distributor 20 is connected to the electrochemical cell separator 10. In the coupled state, the outlet area 23 is arranged to face the distribution manifold 12. A separation wall 231 is provided in the outflow region 23, and the outflow region 23 is separated into a plurality of outlets 232 by the separation wall 231. In this case, the outlets 232 are preferably formed in the same shape and the same number as the number of the inflow passages 121 so that the outlets 232 and the inflow passages 121 correspond one-to-one. The intermediate region 24 is the region between the inlet region 22 and the outlet region 23. The guide wall 241 is provided in the intermediate region 24, and the reaction fluid introduced into the inlet region 22 by the guide wall 241 is divided into a constant ratio and flows to the outlet region 23.

That is, the reaction fluid introduced into the supply hole from the supply pipe is primarily distributed by the guide wall 241, and is secondly distributed by the separation wall 231, and then supplied to each inflow path 121 of the separation plate. .

And, as shown in FIG. 5 (a) described above, when the common flow path for the supply of cooling fluid or heating fluid is formed in the electrochemical cell separator, supplying the fluid to the common flow path as shown in (b) of FIG. Auxiliary flow space 25 for may be formed in the distributor. In this case, the auxiliary flow space 25 of the distributor may be formed as a single space, or the separation wall and the guide wall may be installed like the flow space 21.

The supply pipe 30 is for supplying the reaction fluid, and is coupled to the supply hole 22 of the distributor to supply the reaction fluid to the distributor 20. Here, the reaction fluid is a fluid used for an electrochemical reaction, for example, an oxidation / reduction fluid in a fuel cell and water in an electrolysis cell.

In the electrochemical cell stack 100 configured as described above, the reaction fluid is supplied through the supply pipe 30, and the fluid is divided by a constant (same) ratio by the guide wall 241, so that the outflow region 23 is provided. To flow. In addition, the outlet area 23 is divided by the separating wall 231 at a constant ratio and flows to each outlet 232, and then flows along the inflow passage 121 corresponding to each outlet 232, and then flows in the channel passage ( 11) is supplied. At this time, as described above, each of the inflow passages 121 are separated from each other by guide vanes to form independent spaces, thereby preventing bias of the working fluid due to gravity inside the electrochemical cell stack. As a result, a uniform flow rate distribution characteristic of the working fluid per unit cell of the electrochemical cell stack is ensured, and the performance deviation between unit cells is reduced, thereby finally improving the performance and durability of the electrochemical cell stack.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation in the embodiment in which said invention is directed. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

For example, the shape of the channel flow path need not be limited to the multi meandering shape, and the number can also be changed as necessary.

In addition, the number of distribution manifolds and recovery manifolds, the presence or absence of guide vanes, the position and shape of the dispenser, the position and shape of the guide vanes in the distributor, the shape and number of flow paths in the separator, and the like are required for the electrochemical reaction and cooling. It can be altered based on the physical / chemical properties of the heating medium.

100 ... electrochemical cell stack 10 ... electrochemical cell separator
11 Channel Euro 12 Distribution Manifold
121.Inflow Euro 122 ... Guide Vane
13 ... Recovery Manifold 14 ... Secondary Euro
15 ... common euro 20 ... distributor
21 ... flow space part 22 ... inflow area
23 Outflow area 231 Partition wall
232 ... Outlet 24 ... Intermediate zone
241 ... Guide Wall

Claims (5)

delete delete delete A plurality of electrochemical cell separators disposed to be stacked on each other;
A distributor coupled to one end of the stacked plurality of electrochemical cell separators and supplying a reaction fluid to a distribution manifold of the electrochemical cell separators; And
And a supply pipe coupled to the distributor and supplying the reaction fluid to the distributor.
In the electrochemical cell separator,
A distribution manifold to which a reaction fluid is supplied;
A recovery mani folder in which the reaction fluid flows out;
A plurality of channel flow paths, one end of which is connected to the distribution manifold and the other end of which is connected to the recovery manifold so that the reaction fluid supplied to the distribution manifold flows toward the recovery manifold;
Guide vanes are provided to separate the distribution manifold into a plurality of inflow paths that are blocked from each other.
Inside the distributor, a flow space portion in which the reaction fluid supplied from the supply pipe flows to the distribution manifold is formed, and in the outflow region facing the distribution manifold in the flow space portion, the outlet region is provided. An electrochemical cell stack, comprising: a separating wall for separating into a plurality of outlets. 5. The method of claim 4,
And the outlets are formed in the same shape and the same number as the inflow passage so that the outlet of the outlet region and the inflow passage of the distribution manifold correspond one-to-one.

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