KR101678550B1 - End plate and wire clamping for fuel cell stack - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a fuel cell stack wire fastening method, and aims to lighten the fuel cell stack, to provide uniform fastening force to the stack, and to alleviate the problem of reducing the tightening pressure. By this means, there is provided a fuel cell stack wire fastening method comprising an end plate including a thin plate shaped base plate, a structural grating and a wire mounting ring, and a high strength aramid fiber or carbon fiber wire and a wire stick.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an end plate for a fuel cell stack,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end plate of a fuel cell stack and a method for fastening a stack wire including the end plate, and more particularly, to a fuel cell stack having a fuel cell stack End plate and a stack wire fastening method including the end plate.

The unit cell of the polymer electrolyte membrane fuel cell generally includes an anode in which hydrogen is oxidized, a cathode in which oxygen is supplied to cause a reduction reaction, and a polymer electrolyte in which hydrogen ions are transferred therebetween. Is referred to as a membrane-electrode assembly (MEA).

The output voltage of the above-mentioned unit cell is practically used in the range of 0.6V to 1V. In this case, the output of the unit cell is not suitable. In order to obtain a practical output, a fuel cell stack in which fuel cell unit cells are stacked in series And is used as a power supply device in various fields.

The fuel cell stack generally comprises a separator plate having a plurality of electrode membrane composites stacked therebetween, a support for supporting the electrode membrane composites therebetween and having a passage for fluid entry and exit, a current collecting plate provided at both ends of the separator plate, And an end plate for supporting the end plate.

If the size and distribution of the surface pressure acting on the fuel cell stack is not proper, leakage of the reaction gas and increase of the contact resistance cause loss of electric energy. Therefore, it is essential to tighten the stack by applying appropriate tightening pressure and tightening force to be.

A plurality of apparatuses and methods for fastening a fuel cell stack have been disclosed in the prior art. For example, Korean Patent Laid-Open Publication No. 10-2011-0054604 discloses a method for improving assemblability of a fuel cell stack using a steel wire rope and a ratchet And a fuel cell stack fastening apparatus which firmly holds the fuel cell stack.

Korean Patent Laid-Open Publication No. 10-2014-0121730 discloses a fuel cell capable of improving the fastening force by forming a fixing member on the outer circumferential surface of the fuel cell stack and engaging with an I-shaped fastening member.

Prior art techniques including the above-described techniques have been used for fastening a fuel cell stack, including a heavy-weight fastening rod, a bolt, a nut, and a spring in a fuel cell stack fastening.

Meanwhile, as researches for applying a polymer electrolyte fuel cell as a propulsion power source for a UAV and a portable power source have recently been activated, there is a growing need for a lightweight technology for a fuel cell stack.

Therefore, it is necessary to develop a technique for efficiently stacking the fuel cell stack while reducing the weight of the fuel cell stack, in addition to the uniform tightening pressure and gas leakage required in the conventional stacking method.

In order to solve the problems of the prior art, the present invention has been made to solve the problems of the prior art by eliminating massive elements such as a fastening rod, a thick metal end plate and a spring in a fuel cell stack fastening, Lt; / RTI >

The present invention also provides an efficient fuel cell stack wire fastening method capable of reducing the weight of the fuel cell stack, and maintaining the size and distribution of the surface pressure acting on the stack appropriately and uniformly.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

In order to achieve the above object, an embodiment of the present invention provides an end plate including a base plate having a thin plate shape, a structure grating coupled on the base plate, and a wire holding ring coupled to one surface of the structure grating.

In addition, in the embodiment of the present invention, the bottom plate of the end plate may be provided with a plurality of manifolds for entering and exiting the fluid, and the manifold is a protruding structure.

Also, in the embodiment of the present invention, the structural lattice is characterized by being provided with a rectangular or honeycomb type partition wall.

At this time, a plurality of manifolds can be fastened to the workpiece provided in the partition wall.

In an embodiment of the present invention, a plurality of first grooves for engaging with the structural grating are formed at the lower end of the wire holder ring, and a plurality of second grooves for receiving the wires are formed at the upper end.

Further, in another embodiment of the present invention, the fuel cell stack-wire structure includes a fuel cell stack in which a plurality of unit cells are stacked, a first end plate provided on one side thereof, a second end plate provided on the opposite side, And a wire stick which imparts tension to the wire and prevents the wire from being unwound.

In this case, the first end plate and the second end plate are characterized by including a base plate in the form of a thin plate, a structural grating, and a wire holder ring, wherein the structural grating is provided with a rectangular or honeycomb type partition wall .

Further, the wire holder ring included in the first end plate and the second end plate may be characterized in that a plurality of grooves are provided.

In an embodiment of the present invention, the wire included in the fuel cell stack-wire structure is an aramid fiber comprising at least one of Kevlar, Twaron, Technora, Heracron, Or a high-strength carbon fiber comprising at least one of polyacrylonitrile-based carbon fiber and pitch-based carbon fiber.

According to another aspect of the present invention, there is provided a fuel cell stack wire fastening method.

In an embodiment of the present invention, a fuel cell stack is prepared by laminating a fuel cell unit cell, a current collecting plate and an end plate, pressing the fuel cell stack to apply a fastening force, And releasing the pressure.

Further, in the fuel cell stack wire fastening method of the present invention, the step of winding a wire on the stack to form a knot includes winding a wire on a side of the stack, inserting a wire stick by tying the wire end, A step of applying a predetermined tension, and a step of laminating the wire stick and winding the wires at both ends to fix the fuel cell stack in a non-releasable manner.

According to the embodiment of the present invention, the structural lattice included in the end plate for a fuel cell contributes to the weight reduction of the fuel cell and can provide a uniform tightening force to the stack, while minimizing bending deformation of the end plate.

Further, the wire according to the embodiment of the present invention can contribute to weight reduction of the fuel cell by using high strength aramid fiber or carbon fiber which hardly stretches when stretched.

In addition, the method for fastening a fuel cell stack wire according to an embodiment of the present invention is that a tightening force is reduced by maintaining a necessary tension because there is no unnecessary extra portion in a wire even after the wire is tightened by pressing the wire, Can be minimized.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is an exploded perspective view showing a conventional fuel cell stack fastening structure.
2 is a perspective view illustrating an end plate of a fuel cell stack according to an embodiment of the present invention.
3 is an exploded perspective view showing an end plate of a fuel cell stack according to an embodiment of the present invention.
4 is a perspective view showing a bottom plate of an end plate according to an embodiment of the present invention.
5 is a perspective view showing a structural grating of an end plate according to an embodiment of the present invention.
6 is a perspective view showing a wire holder ring of an end plate according to an embodiment of the present invention.
7 is a perspective view illustrating a stack-wire structure according to one embodiment of the present invention.
8 is a schematic view showing a method of fastening a fuel cell stack wire according to an embodiment of the present invention.
9 is a schematic view showing a step of knotting a fuel cell stack wire according to an embodiment of the present invention.
10 is an enlarged schematic view showing a portion of a fuel cell stack wire knot according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" (connected, connected, coupled) with another part, it is not only the case where it is "directly connected" "Is included. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The same reference numerals are used for the same constituent elements in the following description, and redundant explanations for the same constituent elements are omitted.

FIG. 1 is a view showing a fastening structure of a conventional fuel cell stack. Referring to FIG. 1, a conventional fuel electric stack fastening apparatus includes a thick and thick thick metal end plate 2 for reducing bending deformation, Or a bolt (3) and a nut (4) for fastening a steel connecting rod (1) to a metal plate provided separately therefrom, and their weight proportion in the fuel cell stack is not small.

Also, the fastening method using the fastening rods is a structure in which the fastening rods are positioned at the edges of the end plates and nonuniform fastening pressure is transmitted to the end plates. This causes a decrease in surface pressure and an increase in contact resistance at the center portion of the stack, It can act as a main cause of deterioration.

In order to overcome the disadvantages of the prior art, a fuel cell stack fastening method using a wire or a band has been disclosed. However, a separate device for applying a tension to a steel wire or a band and fixing the steel wire or band such as a tightening mechanism, a ratchet, And may be unsuitable if weight is an important design variable, such as a small propulsion power source for UAVs, including.

Alternatively, the present invention provides an end plate of a lightweight structure, a fuel cell stack-wire fastening structure using the same, and a fuel cell stack wire fastening method by removing elements having a large mass such as a fuel cell fastening rod, a thick end plate, and a spring do.

Hereinafter, preferred embodiments of the present invention will be described with reference to Figs. 2 to 10. Fig.

First, an end plate of a lightweight structure designed for fastening a fuel cell stack wire will be described with reference to Figs. 2 to 7. Fig.

The end plate 110 of the fuel cell stack according to the present invention includes a base plate 10 having a thin plate shape, a structural lattice 20 coupled to the base plate 10 and a wire mount ring 30 provided on the structural lattice 20. [ And a control unit.

At this time, at least one manifold 11 including a first work 5 is provided on one side of the bottom plate 10 for the entry and exit of hydrogen gas, oxygen gas, and product water used as fuel. can do.

5, the structure grating 20 may be formed as a partition wall in the form of a quadrangle 20a or a honeycomb 20b. The structure grating may include a plurality of workpieces 6 and 7 And contributes to weight reduction of the stack, and it has an advantage that the applied force can be evenly distributed while the wire is fastened and the bending deformation of the material due to the fastening pressure can be minimized. At this time, the study provided in the square structure grid is referred to as the second study (6), and the study provided in the honeycomb structure grid is referred to as the third study (7).

The manifold 11 may be coupled to the plurality of second workpieces 6 provided between the partitions of the structural grating 20. The manifold 11 may be a protruding structure, It is preferable to prepare it in the form of a column.

In the embodiment of the present invention, the wire holder ring 30 included in the end plate 110 is formed with a plurality of grooves. At the lower end of the wire holder ring 30, And a second groove (32) for receiving the wire is formed on the upper end of the wire holder ring (30).

At this time, the wire holder ring 30 may be configured to transmit the pressing force by the wire holder to the stack uniformly.

Hereinafter, the fuel cell stack-wire structure utilizing the end plate will be described.

First, the fuel cell stack has a structure in which a plurality of unit cells 40 are stacked. More specifically, the fuel cell stack includes an oxidizing electrode oxidizing hydrogen, a reducing electrode supplied with oxygen to cause a reducing reaction, and a polymer electrolyte membrane disposed therebetween A gas diffusion layer on both sides of the electrode membrane composite to prevent deformation due to diffusion of gas, a separator plate on both sides of which a flow path for fluid flow is formed, and a collecting plate for collecting the generated electric energy And at least one or more unit cells 40 arranged in layers may be connected in series.

 Further, the fuel cell stack may include a current collecting plate 140 for collecting current generated in the fuel cell on both sides thereof and supplying the current to the external circuit, and an end plate 110 for supporting the fuel cell stack.

At this time, it is specified that the above-described components and arrangements of the fuel cell stack are deformable and can be omitted.

The fuel cell stack-wire structure according to an embodiment of the present invention includes a stack of a plurality of fuel cell unit cells 40, a first end plate 110a provided on one side of the stack, a second end A wire 110 that covers the first end plate 110a and the second end plate 110b and a wire stick 130 that applies tension to the wire 120 and prevents loosening of the wire 120 .

In the present invention, the wire may be an aramid fiber or a polyacrylonitrile-based carbon fiber including at least one of Kevlar, Twaron, Technora and Heracron, a pitch-based carbon fiber Or a high-strength carbon fiber including at least one of the carbon fibers.

In a preferred embodiment of the present invention, the wire may be an aramid fiber, which is excellent in heat resistance and has a strength of 5 to 10 times higher than that of steel.

Hereinafter, a method of fastening a fuel cell stack wire according to an embodiment of the present invention will be described in detail with reference to FIGS. 8 to 10. FIG.

8 to 10, a fuel cell stack wire fastening method includes stacking a fuel cell unit cell 40, a current collecting plate 140, a first end plate 110a, and a second end plate 110b, A step of providing a stack, a step of applying a fastening force by pressing the fuel cell stack, a step of forming a knot by winding the wire 120 in a state where the fastening force is applied, and the step of releasing the pressure.

The step of wrapping the wire 120 includes winding the wire 120 on the fuel cell stack, inserting the wire stick 130 by tying the end of the wire 120, Applying a predetermined tension to all of the wires wound on the fuel cell stack by rotating the wires, and winding and fixing the wires 120 at both ends by laying the wire sticks, so that the distribution and size of the surface pressure applied to the fuel cell stack And the like.

This does not include a spring, a bolt, a nut, and a heavy weight tightening mechanism as compared with the prior art, and the fuel cell stack is tightened by a simple operation of applying a tension to the wire 120 by using the wire stick 130 and fixing it And it is possible to minimize the reduction of the fastening pressure because there is no unnecessary excess in the wire 120 after fastening.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: Fuel cell stack
110: end plate
110a: first end plate
110b: second end plate
120: wire
130: Wire stick
140: House front plate
10: Base plate
11: Manifold
20: Structural grating
20a: square structure grid
20b: Honeycomb type structure lattice
30: Wire mounting ring
40: Unit cell
31: First Home
32: 2nd home
1: Connecting rod
2: End plate
3: Bolt
4: Nut
5: Study 1
6: The second study
7: Third study

Claims (16)

In a fuel cell stack-wire structure,
A fuel cell stack in which a plurality of unit cells are stacked;
A first end plate provided at one side of the stack;
A second end plate provided on the opposite side of the stack;
A wire surrounding the stack and the end plate; And
A wire stick that applies tension to the wire and prevents loosening; / RTI >
Wherein the end plate comprises a structural grid capable of applying a uniform clamping force to the stack and being lightweight,
Wherein the wire is a lightweight material that can maintain a tensile force even after fastening the stack to minimize a reduction in the fastening force applied to the stack.
The method according to claim 1,
Wherein the end plate comprises:
A bottom plate of a thin plate shape, a structure grating provided on the bottom plate, and a wire holding ring provided on the structure grating.
3. The method of claim 2,
Wherein the base plate is provided with a plurality of manifolds for entering and exiting the fluid.
The method of claim 3,
Wherein the manifold is a protruding structure.
The method according to claim 1,
Wherein the structural grid is provided in a square or honeycomb type barrier.
6. The method of claim 5,
And at least one manifold is fastened to the plurality of openings provided in the partition wall.
3. The method of claim 2,
And a plurality of first grooves for engaging with the structural lattice are formed at the lower end of the wire holder ring.
3. The method of claim 2,
And a plurality of second grooves for receiving the wires are formed on the upper end of the wire holder ring.
The method according to claim 1,
Wherein the fuel cell stack includes at least one collector plate for collecting electric energy.
delete delete delete The method according to claim 1,
Wherein the wire is an aramid fiber comprising at least one of Kevlar, Twaron, Technora, and Heracron.
The method according to claim 1,
Wherein the wire is a high-strength carbon fiber including at least one of polyacrylonitrile-based carbon fiber and pitch-based carbon fiber.
A method for fastening a fuel cell stack-wire structure according to claim 1,
Stacking a fuel cell unit cell, a current collecting plate and an end plate to form a fuel cell stack;
Pressing the fuel cell stack to apply a fastening force;
Winding a wire to form a knot while the fastening force is applied; And
Releasing the pressure;
Wherein the fuel cell stack wire is fastened to the fuel cell stack.
16. The method of claim 15,
The step of winding the wire to form a knot comprises:
Winding a wire on a side surface of the fuel cell stack;
Inserting a wire stick by bundling an end of the wire;
Rotating the wire stick to apply tension to the wire wound on the fuel cell stack; And
Laying the wire stick down and fixing the wires at both ends thereof;
Wherein the fuel cell stack wire is fastened to the fuel cell stack.

Images