KR101907521B1 - Separator and fuel cell having the same - Google Patents

Abstract

A separator plate and a fuel cell including the same are disclosed. The separator according to one aspect of the present invention is a separator provided inside the fuel cell to separate the fuel or the oxidizer supplied from the inlet manifold and discharge the oxidizer to the outlet manifold. The separator includes at least one inlet manifold and an outlet manifold A flat plate portion connected thereto; At least one first multi-branched flow path portion inclinedly disposed on the surface of the flat plate portion and divided into a plurality of portions to form a passage through which the fuel or the oxidant flows; And a plurality of second fuel passages which are disposed on the surface of the flat plate portion so as to be staggered with the first multi-passage passage portion and are divided into a plurality of portions so as to intersect with and communicate with the first multi- And at least one second multi-branched flow path portion that forms a flow path through which air flows and flows.

Description

TECHNICAL FIELD [0001] The present invention relates to a separation plate and a fuel cell including the separator,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a separator plate for distributing fuel in a fuel cell, and more particularly, to a separator plate for uniformly distributing fuel of a fuel cell to improve power generation efficiency and a fuel cell including the separator .

Generally, a fuel cell is a power generation system that converts the chemical energy of a fuel into electric energy, for example, hydrogen fuel is supplied to the anode side, air is injected to the cathode, Energy is converted into electrical energy.

This type of fuel cell can be classified into low-temperature type and high-temperature type depending on the operating temperature and electrolyte type. PEMFC (Proton Exchange Membrane Fuel Cell), which is mainly used for automobiles, is a representative example, and high temperature type is Molten Carbonate Fuel Cell ), SOFC (Solid Oxide Fuel Cell), and SOEC (solid oxide electrolysis cell) using the reverse reaction of SOFC.

Fuel cells are capable of continuous power generation in the process of continuously injecting fuel (hydrogen) and air. In the case of fuel, it is necessary to increase the utilization rate in consideration of power generation efficiency and economical efficiency to increase the commercial value.

The conventional separator for a fuel cell is provided with a manifold for supplying fuel, a hole through which the fuel passes, and a channel through which the fuel is distributed, thereby improving the design of factors such as manifold, hole, Can be increased.

In the conventional separation plate for a fuel cell, a flow path through which a fuel or an oxidant passes is linear, and is provided in a bent form for an increase in contact area. Such flow paths have limitations in distributing fuel, and accordingly, techniques for improving uniformity of fuel distribution through the design of manifolds and holes have been developed.

Conventionally, however, the distribution of the fuel depends on the design of the manifold and the hole. When the fuel is unevenly distributed between the manifold and the hole, the flow of the fuel becomes uneven, and improvement is required.

In one embodiment of the present invention, there is provided a separator improved in structure so that fuel passing between a manifold and a hole is dispersed and mixed in a process of passing through the passage, thereby enabling active fuel distribution, and a fuel cell including the separator. The purpose is to provide.

The separator according to one aspect of the present invention is a separator provided inside the fuel cell to separate the fuel or the oxidizer supplied from the inlet manifold and discharge the oxidizer to the outlet manifold. The separator includes at least one inlet manifold and an outlet manifold A flat plate portion connected thereto; A first flow path portion for forming a plurality of rows of first flow paths on the surface of the flat plate portion with respect to the traveling direction of the fuel or the oxidant; And a plurality of heat exchangers arranged in the downstream of the first flow path portion and arranged in a staggered manner between the first flow path portion and the downstream end of the first flow path portion, Or a portion of the oxidant is mixed and flows and forms a second flow path through which the oxidant flows.

Here, the first flow path of the first flow path portion and the second flow path portion of the second flow path portion each include a valley portion which is a region through which the fuel or the oxidizer passes, and an acid portion which is provided to divide both sides of the valley portion, The acid portion may be disposed between the valley portions of the first flow path.

Further, the acid portion of the first flow path and the second flow path may be formed at both ends in a streamline or curved shape with respect to the traveling direction.

Further, the separator plate may be provided in one or both surfaces.

Preferably, the separator plate may be provided on both sides with the upper and lower sides being symmetrical.

According to another aspect of the present invention, there is provided a fuel cell in which at least one unit cell unit is stacked, the unit cell unit comprising: a unit cell; A frame fixed to an edge of the unit cell to support the unit cell; The above-described separation plate disposed on both sides of the unit cell and the frame; And a separation membrane provided to shield the separator plate and partitioning the space inside the frame into a fuel supply space and an oxidant supply space.

Here, the oxidant includes oxygen gas, the fuel includes hydrogen gas, and the separation membrane may include an electrolyte through which oxygen ions separated from oxygen gas or hydrogen ions separated from hydrogen gas are transmitted.

According to an embodiment of the present invention, since the fuel or the oxidizer can be uniformly distributed in a short period of time in the process of passing through the separator plate after the supply, the reactivity of the fuel or the oxidizer can be improved, Can be improved. In addition, the separator of this embodiment can reduce design constraints of the manifolds for the supply of fuel or oxidant because the fuel or oxidant is uniformly distributed.

1 is a perspective view of a separation plate according to an embodiment of the present invention;
2 is a plan view of a separation plate according to an embodiment of the present invention;
Fig. 3 is an enlarged view of a portion A in Fig. 2; Fig.
FIG. 4 is a view showing a process of reducing the oxidizing agent supplied to a general separation plate in a chronological order; FIG.
FIG. 5 is a diagram illustrating a process of reducing the oxidizing agent supplied to the separator according to an embodiment of the present invention in chronological order; FIG.
6 is a sectional view of a fuel cell to which a separator according to an embodiment of the present invention is applied.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The shape and the size of the elements in the drawings may be exaggerated for clarity and the same elements are denoted by the same reference numerals in the drawings.

FIG. 1 is a perspective view of a separation plate according to an embodiment of the present invention, and FIG. 2 is a plan view of a separation plate according to an embodiment of the present invention. 3 is an enlarged view of a portion A in Fig.

Referring to Figs. 1 to 3, the separator plate 10 of this embodiment is provided inside the fuel cell and can be provided to guide the movement of the fuel or oxidizer.

In this embodiment, the fuel cell may be provided by stacking at least one unit cell unit. This unit cell unit includes at least one separator plate 10 and can produce electricity by oxidation and reduction reactions of the fuel and the oxidizer supplied to the separator plate 10.

To this end, the separation plate 10 may be provided with an inlet manifold 12 and an outlet manifold 14 for supplying or discharging fuel and an oxidant.

Here, the separator 10 can guide the movement of the fuel or the oxidizer, and can be provided to be uniformly mixed and distributed in the process of moving the fuel or the oxidizer.

To this end, the separator plate 10 may include a flat plate portion 16 associated with at least one inlet manifold 12 and the outlet manifold 14.

For example, the inlet manifold 12 and the outlet manifold 14 may be positioned on both sides with respect to the center line, and the inlet manifold 12 and the outlet manifold 14 may be located at staggered positions.

That is, the output manifold 14 can be positioned on a line extending from an intermediate position between the inlet manifolds 12.

In addition, the flat plate portion 16 may be formed integrally with the step portion 18 protruding to shield the peripheral portion. The stepped portion 18 provided at the periphery of the inlet side manifold 12 and the outlet side manifold 14 minimizes the flow resistance of the fuel or the oxidant and is bent in a bent shape to guide the flow direction of the fuel or the oxidant Can be provided.

The surface of the flat plate portion 16 may be provided with a first flow path portion 20 for the movement of a fuel or an oxidant and a second flow path portion 30 disposed to intersect with the first flow path portion 20.

Here, the first flow path portion 20 may include a plurality of rows of first flow paths 22 formed on the surface of the flat plate portion with respect to the traveling direction.

The second flow path portion 30 is connected to the rear end of the first flow path portion 20 so that a part of the fuel or the oxidant passing through the first flow path portion 22 of the first flow path portion 20 is cross- And a second flow path 32 passing therethrough.

Here, the second flow path portion 30 may be provided in a plurality of rows with respect to the advancing direction of the fuel or the oxidant at the rear end of the first flow path portion 20, and the second flow path portion 32 of the second flow path portion 30, May be staggered between the first flow paths (22) of the first flow path portion (20) so that a part of the fuel or the oxidant may be mixed and introduced into the flow path.

That is, the first flow path 22 of the first flow path portion 20 can be connected to the second flow path 32 of the two adjacent second flow path portions 30 at the rear end portion, A portion of the fuel or the oxidant passing through the first passage 22 may be crossed and mixed with the second passage 32. The fuel or the oxidant may be uniformed as the passage of the fuel or the oxidant is repeated.

3, in the present embodiment, the first flow path 22 of the first flow path portion 20 and the second flow path 32 of the second flow path portion 30 are formed by passing fuel or oxidizing agent And the mountain portions 22b and 32b provided to divide both sides of the valley portions 22a and 32a.

The acid portion 32b of the second flow path 32 may be disposed between the valley portions 22a of the first flow path 22.

At this time, the acid portions 22b and 32b of the first flow path 22 and the second flow path 32 may be formed at both ends in a streamline or curved shape with respect to the traveling direction. Therefore, the fuel or the oxidant supplied or introduced through the first flow path 22 or the second flow path 32 can be supplied with the flow path resistance with the acid portions 22b, 32b being minimized.

The fuel or the oxidant supplied from the first flow path 22 of the first flow path portion 20 distributes the fuel or the oxidizer in association with the adjacent two second flow paths 32 of the second flow path portion 30 Can supply.

For example, in the present embodiment, the fuel or the oxidant that has passed through any one of the first flow paths 22 of the first flow path portion 20 partially flows into any one of the second flow paths 32 of the second flow path portion 30 And the remainder may be distributed to and supplied to the other adjacent second flow path 32. [

The first passage portion 20 may be disposed at the rear end of the second passage portion 30 so that the fuel or the oxidant that has passed through the second passage portion 30 may partially pass through the first passage portion 20 and the remainder is distributed and supplied to the adjacent one of the first flow paths 22, so that the fuel or the oxidizer can be uniformly redistributed.

For example, when it is assumed that the fuel amount X ₁₁ supplied from any one of the first flow paths 22 of the first flow paths 20 is '100', the second flow path portion 30, Only _one fuel amount x ₁ is supplied to any one of the second flow paths 32 of the first flow path 32 and the remaining amount of fuel 50 is supplied to the other second flow path 32. [ (x ₁ ) may be supplied.

On the other hand, the fuel amount X ₂₂ of '100' supplied from the first one of the first flow paths 22 of the first flow path portion 20 is supplied to one of the second flow paths 32 of the second flow path portion 30 supplying a quantity of fuel (x ₂₎ of '50', and thus can be supplied to any one of the second amount of fuel ₍₁₂ x), the total amount of the "100" channel 32.

The remaining fuel amount x ₂ supplied from the other one of the first flow paths 22 of the first flow path portion 20 may be supplied to another second flow path 32. The other second flow path 32 of the second flow path portion 30 is configured such that the fuel amount x ₃ of '50' supplied from the other first flow path 22 of the first flow path portion 20 is mixed So that the fuel amount X ₂₃ of the total amount of 100 can be passed.

FIG. 4 is a view illustrating a process of reducing the oxidizing agent supplied to a separating plate in a chronological order, and FIG. 5 is a view showing a process of reducing the oxidizing agent supplied to the separating plate according to an embodiment of the present invention in chronological order .

The separator 10 of the present embodiment repeatedly crosses the first flow path portion 20 and the second flow path portion 30 in the process of flowing the fuel or the oxidant flowing through the inlet manifold 12 to the downstream side, .

4, which is a diagram showing a process of reducing oxidizing agent supplied to a general separating plate 10, a general separating plate 10 has a structure in which a 5% It can be seen that the gas is uniformly diffused and supplied but is not uniformly supplied to the portion far from the inlet manifold 12.

It can be seen that it takes about 30 minutes for the general separation plate 10 to uniformly supply the oxidizing agent as a whole.

5 is a sectional view of the separator 10 according to the present embodiment in which 5% of the oxidant is supplied to the inlet manifold 12 and then passes through the first flow path 22 of the first flow path portion 20, Distribution and mixing are performed in the process of being supplied to the second flow path 32 of the flow path portion 30, and thus, it can be understood that the whole is uniformly supplied.

As described above, it is found that about 5 minutes is required for the separation plate 10 of the present embodiment to uniformly supply the oxidizing agent after 5% of the oxidizing agent is supplied.

Such a separator plate 10 may be provided in a cross-section or on both sides depending on the structure to be laminated on the unit cell unit. That is, the separation plate 10 may be provided with a first flow path portion 20 and a second flow path portion 30 on one or both surfaces thereof, and the inlet manifold 12 or the outlet manifold 14 may be provided Can be linked.

Preferably, the separator plate 10 may be provided on both sides, and the upper and lower surfaces may be provided symmetrically. Accordingly, as the separator 10 is provided symmetrically, fuel can be supplied, for example, to the upper surface, and oxidant can be supplied to the lower surface of the separator 10. For this purpose, the inlet manifold 12 and the outlet manifold 14 It is preferable to design such that the position is properly arranged.

6 is a cross-sectional view of a fuel cell to which a separation plate 10 according to an embodiment of the present invention is applied.

6, the fuel cell 100 may be provided by stacking at least one unit cell unit 110, wherein the unit cell unit 110 includes a unit cell 120, And a pair of separation plates 10 disposed on both sides of the unit cell 120 and the frame 130. The frame 130 supports the unit cell 120,

The fuel cell 100 of the present embodiment may include, for example, a solid oxide fuel cell 100 (SOFC).

The unit cell units 110 used in the fuel cell 100 may be stacked and connected to increase the supplied voltage.

The unit cell 120 may include a separator 121, an air electrode 122 formed on one surface of the separator 121, and a fuel electrode 123 formed on the other surface of the separator 121. An air electrode collector 124 and a separator plate 10 or a first separator plate 10a are positioned outside the air electrode 122 and a fuel electrode collector 125 and a separator plate 10 are disposed outside the fuel electrode 123. [ That is, the second separation plate 10b.

An air passage is formed on one surface of the first separator plate 10a facing the air electrode collector 124 to transmit air to the air electrode 122. [ A fuel flow path is formed on one surface of the second separation plate 10b facing the fuel electrode collector 125 to transfer fuel to the fuel electrode 123. [

In this embodiment, the fuel may include hydrogen gas. Further, the oxidizing agent may include oxygen gas.

In addition, it is also possible that pure oxygen is used as the oxygen gas, and in this embodiment, it is also possible to use an atmosphere containing oxygen gas, that is, air.

In addition, the separator 121 may include an electrolyte that is dense and configured to shut off the permeation of fuel and air, and which is not electronically conductive but can transmit oxygen ions.

The air electrode 122 and the fuel electrode 123 may be formed of a porous material so that air and fuel gas are diffused and supplied, and may be formed of a material having high electron conductivity.

The air electrode 122 can be charged with a cathode or can be provided with a catalyst so that the oxidant contained in the surrounding air, that is, oxygen, is separated from the electrons by the reduction reaction and converted into oxygen ions by the air electrode 122 . The oxygen ions pass through the separation membrane 121, move to the fuel electrode 123, and generate water (H ₂ O) by an oxidation reaction with hydrogen gas, which is a fuel gas. In this process, electrons are generated. This reaction process is represented by the following formula (1).

On the other hand, the air electrode current collector 124 enhances mechanical strength of the air electrode 122 and reinforces the contact performance of the air electrode 122 and the first separator 10a so as to allow electricity to pass through. The anode current collector 125 also enhances the mechanical strength of the anode electrode 123 and reinforces the contact performance of the anode electrode 123 and the second separator 10b so as to allow electricity to flow well. The cathode current collector 124 and the anode current collector 125 may be metal foams and the first and second separation plates 10a and 10b may be made of metal.

The frame 130 may be attached to the edge of the unit cell 120 by the bonding layer 132 to support the unit cell 120. The frame 130 may be made of metal and the bonding layer 132 may comprise a glass-based material, for example, glass frit. A sealing material 134 is disposed between the frame 130 and the first separator 10a and between the frame 130 and the second separator 10b to prevent leakage of air and fuel gas Can be prevented. The sealing material 134 may be provided with the same material as the bonding layer 132, i.e., as a glass frit.

The air electrode 122 and the air electrode collector 124 of the unit cell 120 are formed to be smaller in size than the fuel electrode 123 and the fuel electrode collector 125 and the air electrode 122 and the periphery of the air electrode collector 124 Accordingly, the bonding layer 132 may be positioned above the separation membrane 121. The frame 130 may form a cutout 131 that receives the entirety of the bonding layer 132, a part of the separation membrane 121, and a part of the fuel electrode 123 on one side toward the unit cell 120. The frame 130 may be divided into a fixing portion 130a which is fixedly attached to the bonding layer 132 and a supporting portion 130b which supports the fixing portion 130a.

The fixing portion 130a overlaps the bonding layer 132 along the thickness direction of the unit cell 120 and has a _first thickness t1. The support portion 130b may be located between the pair of sealing materials 134 on the outer side of the fixing portion 130a and may have a _second thickness t2 larger than the thickness of the fixing portion 130a.

At this time, the distance between the side surfaces of the support portion 130b facing each other may be larger than the width of the fuel electrode 123 so that the fuel electrode 123 does not contact the frame 130. The vertical height of the cutout portion 131, that is, the side height of the support portion 130b facing the unit cell 120 is set to a value smaller than the sum of the thicknesses of the bonding layer 132, the separation membrane 121 and the fuel electrode 123 So that the frame 130 and the anode current collector 125 are not in contact with each other.

The unit cell 120, the bonding layer 132, the frame 130, the sealing material 134, and the pair of separation plates 10 are stacked in the order shown in Fig. 6, pressed at a high temperature, . At this time, the sealing material 134 has a function of blocking gas permeation while having a predetermined viscosity at a high temperature.

In this process, the first flow path portion 20 and the second flow path portion 30 may be formed on the inner surface of the first partition plate 10a so as to facilitate the bonding of the unit electrons and the frame 130. [

The projecting portion may be formed to face the fixed portion 130a of the frame 130 and a part of the support portion 130b. Therefore, when the pressure is strongly applied to the portion where the protrusion is formed on the outer side of the first separator 10a, the protrusion transmits pressure to the frame 130 and the bonding layer 132, It can be fixed firmly.

However, the present invention is not limited thereto. Depending on the kind of the electrolyte of the separation membrane, etc., as the hydrogen ions pass through the separation membrane, It is also possible to occur.

The reaction formula generated in the fuel cell at this time is represented by the general formula (2).

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It will be clear to those who have knowledge.

10: separator plate 12: inlet manifold
14: output manifold 16: flat plate section
18: step portion 20: first flow portion
22: first flow path 22a:
22b: acid portion 30: second flow path portion
32: second flow path 32a:
32b: Mountain portion

Claims (7)

A separation plate provided on the inside of the fuel cell for separating the fuel or the oxidizer supplied from the inlet manifold and discharging the fuel or the oxidizer to the outlet manifold,
A flat plate portion connected to at least one of the inlet manifold and the outlet manifold;
A step portion protruding to shield the peripheral portion of the flat plate portion;
A first flow path portion forming a plurality of rows of first flow paths on the surface of the flat plate portion with respect to a traveling direction of the fuel or the oxidant; And
Wherein the first flow path is provided in a plurality of rows with respect to a traveling direction of the fuel or the oxidant at the rear end of the first flow path portion and the first flow path is disposed staggered between the first flow path of the first flow path portion and the rear end of the first flow path portion, A second flow path forming a second flow path through which a part of the passed fuel or the oxidizing agent is mixed and flows;
Lt; / RTI >
Wherein the step portion provided at the periphery of the inlet manifold and the outlet manifold is provided in a bent shape to minimize the flow resistance of the fuel or the oxidant and guide the flow direction,
Wherein the separating plate is provided on both sides whose upper and lower surfaces are symmetrical.
The method according to claim 1,
Wherein the first flow path of the first flow path portion and the second flow path portion of the second flow path portion each include a valley portion that is a region through which the fuel or oxidizer passes and an acid portion that is provided to partition both sides of the valley portion,
And the acid portion of the second flow path is disposed between the valley portions of the first flow path.
The method of claim 2,
Wherein the mountain portion of the first flow path and the second flow path are formed at both ends in a streamlined or curved shape with respect to the traveling direction.
delete delete 1. A fuel cell in which at least one unit cell unit is stacked,
The unit cell unit
A unit cell;
A frame fixed to an edge of the unit cell to support the unit cell;
A separation plate according to any one of claims 1 to 3 disposed on both sides of the unit cell and the frame; And
A separation membrane provided for shielding the separator plate and dividing the space inside the frame into a fuel supply space and an oxidant supply space;
. ≪ / RTI >
The method of claim 6,
Wherein the oxidant comprises an oxygen gas,
Wherein the fuel comprises hydrogen gas,
Wherein the separation membrane comprises an electrolyte through which oxygen ions separated from the oxygen gas or hydrogen ions separated from the hydrogen gas permeate.

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