KR20110013054A - Metal seperator for fuel cell including convex coolant guideline and fuel cell stack having the same - Google Patents

Abstract

PURPOSE: A metal separator for a fuel cell including convex coolant guideline is provided to secure cooling performance and reactive gas flow path while minimizing the size of the metal separator and to facilitate the flow of cooling water and reaction gas. CONSTITUTION: A metal separator(100) for a fuel cell including convex coolant guideline includes: a channel part including a reactive gas channel(140) and a coolant channel(145), wherein the reactive gas channel protrudes from a first side to a second side and the coolant channel is formed between the reactive gas channels; manifolds formed at both sides of the channel part; a coolant flow channel terminal part formed in a region between the channel part and manifold; and convex coolant guidelines(170,180,185) formed form the first side to the second side.

Description

TECHNICAL SEPERATOR FOR FUEL CELL INCLUDING CONVEX COOLANT GUIDELINE AND FUEL CELL STACK HAVING THE SAME}

The present invention relates to a fuel cell metal separator including a protruding coolant guide portion in a coolant flow path terminal and a fuel cell stack including the same.

A fuel cell is a power generation device which converts chemical energy into electrical energy generally by oxidizing and reducing hydrogen and oxygen. Hydrogen is oxidized at the anode and separated into hydrogen ions and electrons, and the hydrogen ions move through the electrolyte to the cathode. At this time, the electrons move to the anode through the circuit. In addition, a reduction reaction occurs in which the hydrogen ions, electrons, and oxygen react to form water at the anode.

Among the fuel cells having the above-described structure, the amount of water contained in the polymer electrolyte membrane is particularly important in determining the performance of the fuel cell in a polymer electrolyte membrane fuel cell (PEMFC). This is because water acts as a medium for transferring hydrogen ions to the anode.

On the other hand, the fuel cell is composed of several parts. First, the MEA (membrane-electrode assembly) where the electrochemical reaction takes place and the GDL, a porous medium for evenly dispersing the reaction gas to the surface of the MEA, and the MEA and GDL are supported. Transporting the coolant and collecting and delivering the generated electricity. Dozens or hundreds of these parts form a fuel cell stack.

Here, during fuel cell power generation, hydrogen, oxygen, and cooling water are continuously supplied to each side of the MEA, GDL, and separator plates. Is one of the parts.

Conventional fuel cells use separator plates made of graphite and metal. The graphite separator is milled and the metal separator is pressed to form cooling water channels. At this time, not only the width of the cooling water channel is narrow, but also has a curved structure, the flow of the cooling water was not smooth. In other words, the existing graphite separation plate can be made differently the flow path between the reaction surface and the cooling surface, but in particular, the metal separation plate is a flow path for the coolant flow because the shape of the channel is projected on the opposite side as the stamping process of the reaction gas channel as it is It is difficult to secure separately.

In order to solve this problem, in order to smoothly flow the coolant in the metal divider plate which is difficult to make a separate coolant inflow structure, a structure in which a coolant flow path terminal part is formed between the manifold and the channel is used to allow the coolant to flow therein. Was used. However, when the coolant flowing through the coolant flow path terminal part hits the gasket, the flow thereof is not smooth, and thus, the inflow of the coolant does not occur well in the middle part where heat is accumulated most in the separator.

On the other hand, most polymer electrolyte fuel cells adopt a method of securing a gas tight structure by installing gaskets on both sides of the separator plate. When a gas gasket is installed to secure the airtightness, the fuel cell stack is installed to improve airtightness and electrical conductivity. The tightening pressure of hand pressure is applied. Most of the deformation occurs in the GDL and the gasket when such a load is applied, and in the case of the metal-based separator plate manufactured by sheet molding, a part of the metal separator plate is deformed together with the deformation of the gasket at the clamping pressure of the hand pressure. Particularly, in the case of a couple in which the reaction gas and the coolant are introduced, the structure is easily deformed due to the absence of the supporting structure in the portion where the gasket is present and the portion where the fluid must pass.

When this deformation occurs, it is difficult to smoothly introduce the reaction gas and the cooling water, which causes a large load on the peripheral devices, especially the blower or the pump, thereby reducing the efficiency of the system.

As described above, the fuel cell separator according to the prior art has a difficulty in solving the problem of forming an efficient cooling water flow path and preventing deformation of the separator. In particular, the root cause of the two problems is the cooling water flow path terminal portion of the separator. In the coolant flow path terminal part, it refers to the area between the channel part and the manifold part, and rectification occurs when the coolant coming out of the channel hits the gasket part, which causes the coolant to not flow normally to the coolant discharge manifold. Occurs. In addition, since the flow path terminal portion tends to be formed as a relatively empty space for the flow of cooling water or reaction gas, there is a problem that is very vulnerable to deformation such as distortion, but there is no special solution yet.

It is an object of the present invention to provide a fuel cell metal separator body for a fuel cell that can secure cooling performance and a reaction gas flow path while minimizing the size of the metal separator plate.

In addition, the present invention by providing a separate coolant flow guideline in the flow path terminal portion that is the portion where the coolant rectification occurs in order to facilitate the flow of the coolant, while smoothing the flow of the coolant, protruding the guideline like the channel portion It is an object of the present invention to provide a fuel cell metal separator plate and a fuel cell stack having the same, which include a protruding coolant guideline capable of reliably preventing deformation of the separator plate.

The metal separator plate body for a fuel cell according to the present invention includes a channel portion including a reaction gas channel protruding from a first surface to a second surface and a coolant channel formed between the reaction gas channel protruding from the second surface. And protruding from the first surface to the second surface of the manifold formed on both sides of the channel portion, the cooling water flow path terminal portion and the cooling water flow path terminal portion formed in the region between the manifold and the channel portion. Including a bar-shaped protruding coolant guidelines, characterized in that the angle (θ) formed by the direction in which the coolant flows into the coolant flow path terminal portion and the protruding coolant guideline is 80 ° to 100 °. .

The coolant channel may be formed to protrude from the second surface of the metal separator body to the first surface, and the manifold may include a reaction gas inlet and a coolant outlet. And a reaction gas outlet hole formed in a portion adjacent to the manifold of the cooling water flow path terminal part, wherein the protruding coolant guide line has a length corresponding to the reaction gas outlet part. The protruding coolant guideline is a drawbead, and is used as an anti-wrinkle means and anti-spring means when forming a metal separator body.

In addition, the metal separator plate for fuel cells according to the present invention requires a metal separator plate body including the above-described protruding coolant guideline and a channel portion of the metal separator plate body and an edge portion around the manifold and other sealings. It characterized in that it comprises a gasket formed on the site.

Here, a reaction gas outlet hole formed in a portion of the metal separator plate adjacent to the manifold of the region between the channel portion and the manifold, and is formed in the first surface of the metal separator body, the manifold And a first guide gasket formed in the region between the reaction gas inlet and outlet holes toward the channel portion, and formed on the second surface of the main body of the metal separator plate, wherein the reaction gas inlet and the protruding coolant guides are formed. And further comprising a second guide gasket formed in an open area toward the manifold in an area between the lines.

In addition, the fuel cell stack according to an embodiment of the present invention is characterized in that a plurality of junction structures of the aforementioned metal separator and membrane-electrode assembly (MEA) are stacked.

In addition, the fuel cell stack according to another embodiment of the present invention is a stack structure in which the two metal separator plates are joined to each other in a form in which the first surfaces thereof face each other, and a membrane-electrode assembly formed on the stack structure. It is characterized by including.

The metal separator plate body according to the present invention forms a protruding guide line in the region between the channel portion and the manifold, thereby securing a flow path of the cooling water. Therefore, it is possible to improve the cooling performance of the fuel cell without increasing the thickness, area, and volume of the separator, and to provide an effect of increasing the production efficiency.

In addition, the protruding coolant guideline of the metal separation plate according to the present invention can increase the coolant flow-through efficiency by adjusting the forming angle or adjusting the division size.

In addition, since the protruding coolant guideline of the metal separator according to the present invention may be formed at the same time using a stamping process for forming a reaction gas channel or a coolant channel in the channel portion, the manufacturing time of the metal separator may be shortened. In addition, the manufacturing cost also provides an effect that can be lowered.

Finally, since the protruding coolant guideline of the metal separator according to the present invention serves as a frame for supporting the empty space portion of the metal separator, it is excellent in resistance to deformation of the space and prevents deformation of the metal separator and the gasket. By more reliably preventing, the lamination between the separators is facilitated, and the effect of forming the fuel cell stack more efficiently is provided.

Hereinafter, a fuel cell metal separator including a protruding coolant guideline according to the present invention and a fuel cell stack including the same will be described in detail.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments and drawings described in detail below. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims.

1 is a plan view showing a first surface of a metal separator plate for a fuel cell according to the present invention, Figure 2 is a plan view showing a second surface of a metal separator plate for a fuel cell according to the present invention. Here, the middle part with respect to the longitudinal direction of the separator is omitted.

1 and 2, first, a reaction gas channel 140 and a coolant channel 145 are formed in a central portion of a metal separator body 100 that is provided in a rectangular shape and surrounds four sides of the gasket ( 130) is formed. The first reaction gas inlet manifold 120, the coolant inlet manifold 124, the second reaction gas inlet manifold 128, the first reaction gas outlet manifold 160, and the coolant outlet manifold are provided at both sides of the channel part. The fold 164 and the second reaction gas discharge manifold 168 are respectively provided. In this case, the reaction gas channel 140 has a shape protruding to the rear surface (second surface) of the illustrated surface (first surface), the cooling water channel 140 is formed by utilizing the region between the reaction gas channel 140. It may also be formed in a form protruding from the second surface to the first surface. In addition, each manifold may be formed by a manifold formed in the metal separator body, and in another embodiment according to the present invention, after forming a metal separator body formed of one manifold, a gasket-like structure May be divided into respective manifold regions.

In addition, in order to facilitate structural understanding, the respective inflow manifolds and the discharge manifolds are separately displayed, but the directions of inflow and outflow may be made in reverse according to the situation. It is not always limited by

Next, the reaction gas inlet hole 125 and the reaction gas outlet hole 150 are respectively formed in the region between the channel part and the manifold. The reaction gas inlet and outlet holes as described above may be formed in the metal separator body, and when the gasket is formed as an independent structure constituting the manifold, it may be formed integrally with the gasket. In this case, a gas outflow structure is formed in which the first and second surfaces of the gasket are connected in an 'S' shape.

Here, the illustrated first surface is a surface through which reaction gases flow, and may be defined as a reaction gas surface, in which case the second surface becomes a cooling water surface. Accordingly, the reaction gas is introduced through the second surface, guided to the first surface through the reaction gas inlet hole 125, and toward the reaction gas discharge hole 150 through the reaction gas channel 140 of the first surface. Will be discharged. At this time, in order to facilitate the inflow and outflow of the reaction gas, a guide gasket is formed in a region between the manifold and the reaction gas inflow hole of the metal separation plate main body 100. The first guide gasket 135A is formed on the first surface and is opened toward the channel portion, and the second guide gasket 135B is formed on the second surface and is opened toward the manifold. .

Here, it can be seen that the cooling water flowing through the channel part is formed in a structure in which the second guide gasket 130B collides with the second surface as the cooling water surface. In this case, the second guide gasket 130B may generate rectification that prevents the cooling water from flowing, and thus, the cooling water may not flow into the cooling water inflow and out manifolds 124 and 164. Accordingly, in the present invention, protruding coolant guidelines 170, 175, and 180 are provided at a portion adjacent to the channel portion among regions between the channel portion on which the reaction gas channel 140 and the coolant channel 145 are formed and the manifold on which the outlet manifolds are formed. , 185).

Here, the area between the channel portion and the manifold is referred to as the euro terminal portion when the coolant surface is referred to, and the protruding coolant guide lines 170, 175, 180, and 185 are formed in the flow path terminal portion. At this time, the protruding coolant guide line 170, 175, 180, 185 should be a shape protruding from the first surface to the second surface, the shape is shown as a bar (Bar), as described above As long as the coolant does not hit the two guide gasket 130B, it may be in any form. Therefore, hereinafter, the protrusion type cooling water guideline according to various embodiments of the present invention will be described in detail.

3 is a schematic view showing a cooling water flow of the metal separator plate for fuel cells according to the present invention.

3 illustrates a second surface of the metal separator body 200, and includes a reaction gas channel 240 and a cooling water channel 245 protruding from the second surface to the first surface. 230 is formed. In this case, as part of the gasket 230, a second guide gasket 235 is formed between the second reaction gas discharge manifold 228 and the channel part.

Here, the second guide gasket 235 is in the direction of the second guide gasket 235 so that the reaction gas discharged through the reaction gas discharge hole 225 may be naturally induced to the second reaction gas discharge manifold 228. It must be in a form that can be opened. Therefore, the coolant hits the second guide gasket 235. In the conventional case, rectification occurs in the X ₁ and X ₂ portions, and thus the coolant may not flow to the coolant discharge manifold 224. However, in the present invention, the rectification problem as described above is solved by the protruding coolant guideline 270. The protruding coolant guideline 270 may prevent the cooling water from hitting the second guide gasket 235 or rectifying the cooling water flowing into the second guide gasket 235. Here, the reason why the rectification does not occur is that the width of the cooling water flow path is reduced by the second guide gasket 235, so that the flow rate is faster, so that rectification does not occur. Therefore, the line width or length of the protruding coolant guide line 270 may be appropriately adjusted according to the size of the flow path terminal portion. In addition, depending on the situation, the protruding coolant guidelines 270 may be formed in two rows, and the plurality of protruding coolant guidelines 270 divided into small bars may be connected in a line. have.

Figure 4 is a schematic diagram showing a metal separator plate for a fuel cell according to an embodiment of the present invention.

Referring to FIG. 4, a gasket 330 is formed in the metal separator body 300, and a second guide gasket 335 is formed as part of the gasket 330. Next, the reaction gas discharge hole 325 and the first reaction gas discharge manifold 320 are formed in the direction in which the second guide gasket 335 is opened. In addition, the reaction gas discharge hole 325 may be formed directly in the metal separator body 300, or after forming a gasket covering the metal separator body, the reaction gas discharge hole 325 in the gasket. This can be done in one piece.

Next, protruding coolant guidelines 370a and 370b are formed in a region between the reaction gas channel 340, the coolant channel 345, and the second guide gasket 335. In this case, various types of protruding coolant guide lines 370a and 370b may be formed according to the size or length of the coolant flow path terminal, and the first condition is a direction in which the coolant flows and a length of the bar type. It is preferable to make the angle to be made vertical or near vertical.

In addition, the length of the bar is not particularly limited, but may be formed to have a length corresponding to the length of the reaction gas outlet holes such as the first reaction gas discharge manifold 320.

Preferably, the minimum angle θ ₁ is 80 °, and the maximum angle θ ₂ is preferably 110 °. If it is out of the range, the protruding coolant guidelines 370a and 370b come into contact with the second guide gasket 335 or the channel part, and thus may impede the flow of the coolant. It is desirable to be able to form.

5 is a cross-sectional view showing a fuel cell stack according to the present invention.

FIG. 5 illustrates a fuel cell stack formed by combining three metal separator plates for fuel cell of FIG. 4.

The cooling water surface (second surface) of the second metal separator plate body 500 and the third metal separator plate body 600 are joined to face each other to form a cooling water flow path. In this case, the second protruding coolant guide line 570 and the third protruding coolant guide line 670 are bonded to each other.

The second membrane-electrode assembly 580 is formed on the reaction gas surface (first surface) of the second metal separator body 500, and the membrane-electrode assembly 480 formed in the first metal separator body 400. And to be bonded to each other.

As described above, the metal separator for fuel cells according to the present invention may form a stable cooling water discharge line, and may naturally cause problems such as warpage deformation of the protruding coolant guidelines 470, 570, and 670 metal fuel cell body. I can solve it.

As described above, the metal separator plate body, the metal separator plate, and the fuel cell stack including the same according to the present invention are formed of a manifold, a reaction gas channel, and a cooling gas channel constituting a reaction gas, a coolant inlet and outlet manifold. By forming the protruding coolant guideline in the region between the channel portions, it is possible to efficiently improve the performance of the fuel cell without changing the thickness, area, and volume of the separator.

In addition, by forming a protruding coolant guideline in a region where space deformation is vulnerable, it is possible to increase the reaction gas inlet and outlet efficiency, and is more resistant to space deformation than in the case of the conventional metal separation plate having the reaction gas inlet and outlet integrally. In addition, it is possible to manufacture a metal separation plate for a fuel cell that can reduce the pressure drop by reducing the flow resistance of the reaction gas. That is, the protruding coolant guideline according to the present invention serves as a drawbead when forming the metal separating plate, thereby reducing spring back to prevent wrinkles and reduce deformation after forming the metal separating plate. Perform the function.

In addition, the membrane-electrode assembly (MEA) is bonded to one sheet of the metal separator plate for fuel cell of the present invention as described above, or the reaction gas surfaces of the metal separator plate are joined to face each other, and then the membrane-electrode assembly (MEA) is bonded. By stacking), a fuel cell stack having a high efficiency and having various types of manifolds can be manufactured.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be modified in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a plan view showing a first surface of a metal separator plate for fuel cell according to the present invention.

Figure 2 is a plan view showing a second surface of the metal separator plate for fuel cells according to the present invention.

Figure 3 is a schematic diagram showing the cooling water flow of the metal separator plate for fuel cells according to the present invention.

Figure 4 is a schematic diagram showing a metal separator plate for a fuel cell according to an embodiment of the present invention.

5 is a sectional view showing a fuel cell stack according to the present invention;

Claims (7)

A channel part including a reaction gas channel protruding from the first surface to the second surface and a coolant channel formed between the reaction gas channel protruding from the second surface; A manifold formed on both sides of the channel portion; A cooling water flow channel terminal portion formed in an area between the manifold and the channel portion; And And a bar-shaped protruding coolant guide line formed to protrude from the first surface to the second surface of the coolant flow path terminal part, wherein the coolant flows out to the coolant flow path terminal part and the protruding coolant. An angle (θ) formed by the guideline is a metal separator plate body for a fuel cell, characterized in that 80 ° to 100 °. The method of claim 1, The coolant channel is formed to protrude from the second surface of the metal separator body to the first surface, and further comprises a reaction gas inlet and outlet hole formed in a portion adjacent to the manifold of the cooling water flow path terminal portion. Metal separator plate body for fuel cells. The method of claim 1, The protruding coolant guideline is a drawbead, and the metal separator plate body for a fuel cell, which is used as an anti-wrinkle means and a spring back prevention means during molding of the metal separator body. Claims 1 to 3 of the metal separating plate body comprising the protruding coolant guidelines; And And a gasket formed on a channel portion of the metal separator plate body, an edge portion around the manifold, and a portion requiring sealing. The method of claim 4, wherein A reaction gas outlet hole formed in a portion of the main body of the metal separator adjacent to the manifold among the region between the channel part and the manifold; A first guide gasket formed on the first surface of the metal separation plate body, the first guide gasket being opened toward the channel part in a region between the manifold and the reaction gas outlet hole; And And a second guide gasket formed on the second surface of the metal separation plate body, the second guide gasket being opened toward the manifold in a region between the reaction gas inflow hole and the protruding coolant guide line. A metal separator plate for fuel cells. A fuel cell stack comprising a plurality of junction structures of the metal separator of claim 4 and a membrane-electrode assembly (MEA). A laminated structure in which two metal separator plates of claim 4 are joined to each other such that their first surfaces face each other; And And a membrane-electrode assembly formed on the stack structure.

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