KR101118666B1 - Separator and fuel cell stack using thereof - Google Patents

Abstract

The fuel cell stack according to the present invention includes a membrane-electrode assembly (MEA) and a separator disposed on both sides of the membrane-electrode assembly so as to prevent condensate from flowing into the reaction gas flow path. The electricity generating unit includes a reaction gas inlet manifold through which the reaction gas is introduced and a reaction gas outlet manifold through which the reaction gas is discharged, and the reaction gas inlet manifold and the reaction gas outlet manifold are formed. The fold communicates with a reaction gas flow path formed in the separator, and a protrusion is formed in the reaction gas inlet manifold, and the reaction gas inlet manifold is connected with the reaction gas flow path in the protrusion.

Fuel cell, flow path, resistance member, protrusion, groove

Description

Separator and fuel cell stack using same {SEPARATOR AND FUEL CELL STACK USING THEREOF}

The present invention relates to a fuel cell stack and a separator for a fuel cell stack, and more particularly, to a fuel cell stack and a separator for a fuel cell stack having improved structures of a reaction gas inlet manifold.

A fuel cell is a device that produces electricity electrochemically by using fuel (hydrogen or reformed gas) and oxidant (oxygen or air), and converts fuel and oxidant continuously supplied from outside into electric energy directly by electrochemical reaction. Device.

The oxidant of the fuel cell uses pure oxygen or air containing a large amount of oxygen, and the fuel contains a large amount of hydrogen by reforming pure hydrogen, hydrocarbon fuels (LNG, LPG, CH ₃ OH), or hydrocarbon fuels. Use the reformed gas.

These fuel cells are largely divided into polymer electrolyte fuel cells (PEMFC), direct oxidation fuel cells (DMFC), and direct methanol fuel cells (DMFC). Can be.

The polymer electrolyte fuel cell includes a fuel cell body called a stack, which generates electrical energy through an electrochemical reaction of hydrogen gas supplied from the reformer and air supplied by the operation of an air pump or fan. It is made as a structure. Here, the reformer functions as a fuel treatment apparatus for reforming fuel to generate hydrogen gas from the fuel, and supplying the hydrogen gas to the stack.

Unlike the polymer electrolyte type fuel cell, the direct oxidation type fuel cell is directly supplied with alcohol, which is a fuel, without using hydrogen gas. The direct energy fuel cell is supplied by the electrochemical reaction of hydrogen contained in the fuel and separately supplied air. It is made as a structure for generating a. The direct methanol fuel cell refers to a cell using methanol as a fuel in a direct oxidation fuel cell.

Hereinafter, for convenience of description, the polymer electrolyte fuel cell will be described. The polymer electrolyte fuel cell has excellent output characteristics compared to other fuel cells, has a low operating temperature, fast start-up and response characteristics, as well as mobile power sources such as automobiles, as well as distributed power supplies and electronic devices such as houses and public buildings. There is a wide range of applications such as power supply for small devices.

The membrane-electrode assembly used in a polymer electrolyte fuel cell is formed on both sides of a hydrogen ion conductive polymer electrolyte membrane and includes a catalyst layer mainly composed of a carbon powder carrying a metal catalyst such as a platinum group metal, and an outer surface of the catalyst layer. It consists of a gas diffusion layer having a gas diffusion layer is generally made of carbon paper or carbon nonwoven fabric.

Outside the membrane-electrode assembly, a separator having electrical conductivity for mechanically supporting the membrane-electrode assembly and electrically connecting adjacent membrane-electrode assemblies to each other is provided to form a unit cell. The separator forms a flow path for supplying the reaction gas to the electrode surface and transporting the surplus gas and the reaction product to the portion in contact with the membrane-electrode assembly. The flow path may be provided separately from the separator, but is generally formed in a groove shape on the surface of the separator.

A plurality of unit cells are arranged in a stack and a current collector plate for extracting current and an insulation plate for insulation from the outside are sequentially stacked on the outermost side of the unit cell, and are fixed through the fastening plate and the fastening means.

The fuel and oxidant supplied to the fuel cell are converted to water through an electrochemical reaction in the membrane-electrode assembly, which generates electricity and heat. Unreacted fuel and oxidant are discharged out of the fuel cell stack. The ratio of the amount of reactant gas to the amount of feed gas used in the electrochemical reaction is called gas utilization.

In order to discharge heat generated in the electrochemical reaction, a cooling unit in which a cooling medium flows is installed every one or several unit cells. The cooling unit includes a fuel separator having a fuel gas flow path on one side and a cooling flow path for the cooling medium on the opposite side, and an oxidant having a cooling flow path for the cooling medium on the opposite side and an oxidant gas flow path on the opposite side. Many methods for attaching the separators to each other are used.

In order to supply the reaction gas and the cooling medium from the outside of the fuel cell to the flow path of the separator and to discharge the surplus gas, the reaction product and the cooling medium, at least two through holes are formed in each separator for each fuel gas, the oxidant gas and the cooling medium. . The inlet and outlet of the flow path are connected to their through holes, respectively, to supply the reaction gas or the cooling medium from each of the through holes to each of the flow paths, and to discharge the surplus gas and the reaction product or the cooling medium into the other through holes. The through hole for supplying the reaction gas and the cooling medium and discharging the surplus gas, the reaction product and the cooling medium is commonly referred to as a manifold hole.

In the manifold hole formed in the separator, a plurality of unit cells are stacked to form a manifold in the stacking direction. This reaction gas and cooling medium supply method is called an internal manifold method.

In addition to the internal manifold method, a method of supplying a reaction gas or a cooling medium to each unit cell by forming a pipe or a structure for gas distribution outside the separator without forming a manifold hole in the separator is called an external manifold method.

In general, a polymer electrolyte fuel cell is humidified to a predetermined level or more when a reaction gas (a fuel and an oxidant) is supplied to improve conductivity of hydrogen ions in an electrolyte membrane. On the other hand, since the water is generated by the electrochemical reaction on the cathode side, when the dew point temperature of the reaction gas is higher than the operating temperature of the fuel cell, water droplets due to water vapor condensation are generated in the gas flow path or the electrode.

This is called flooding, which causes uneven flow of reactant gas and deficiency of reactant gas at the electrode, thereby causing deterioration of fuel cell performance. Flooding can occur at the anode electrode as well as at the cathode electrode due to the water transferred through the electrolyte membrane. In particular, when the clogging phenomenon of the gas oil by the condensate occurs on the anode side, it causes a deficiency of fuel gas, which causes irreversible damage of the electrode.

This is because when the load current is forcibly applied due to the lack of fuel gas, the carbon carrying the catalyst of the anode reacts with water to make electrons and protons in the absence of fuel. As a result of this reaction, a loss of the anode side catalyst occurs, leading to a reduction in the effective electrode area, thereby degrading fuel cell performance.

Conventionally, in order to prevent flooding and to stabilize the performance of a fuel cell, a method of humidifying and supplying a dew point temperature of a reaction gas slightly lower than a fuel cell operating temperature has been used. However, even in this case, since the insulation of the reaction gas inlet pipe cannot be perfect, condensate is generated in the inlet pipe during long time operation, and the condensate is intermittently introduced into the manifold with the reaction gas and mixed into the gas flow path. The condensate entering the gas passage blocks the flow path and obstructs the flow of the reaction gas into the flow path, which causes the fuel cell to run out of gas. In addition, the electrode in the vicinity of the condensed water is further accelerated condensation of the water vapor, the reaction product, deepening the flooding phenomenon.

In particular, in the case of a fuel cell stack in which several unit cells are stacked, condensed water is concentrated in a cell adjacent to the inlet pipe, and thus deterioration of the electrode is accelerated. The entire stack is inoperable.

In order to solve the clogging and flooding of the gas flow path by the water flowing into the unit cell, a method of discharging the condensed water by increasing the flow rate in the separator flow path portion of the feed gas is usually used.

However, in order to increase the feed gas flow rate, it is necessary to supply the gas at a high pressure. For this purpose, since the power of the gas supply blower or the compressor must be extremely increased, a system efficiency decreases.

In addition, condensate does not flow evenly into all unit cells, but rather tends to enter the unit cell adjacent to the inlet side due to the nature of the two-phase flow. In this situation, even if the flow rate of the reaction gas is increased, There is a problem that does not efficiently discharge the water present.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a fuel cell stack and a separator used therein that can suppress condensed water from flowing into the flow path.

A fuel cell stack according to an embodiment of the present invention includes an electricity generation unit including a membrane-electrode assembly (MEA) and a separator disposed on both sides of the membrane-electrode assembly, the separator being in close contact with each other. The generating unit includes a reaction gas inlet manifold through which the reaction gas is introduced and a reaction gas outlet manifold through which the reaction gas is discharged, and the reaction gas inlet manifold and the reaction gas outlet manifold are formed in the separator. And a protrusion is formed in the reaction gas inlet manifold, and the reaction gas inlet manifold is connected to the reaction gas flow path in the protrusion.

The reaction gas inlet manifold may be provided with a groove in which condensate is located, and the protrusion may be located at the center of the lower surface of the reaction gas inlet manifold, and the groove may be located at both sides of the reaction gas inlet manifold. In addition, the protrusion may be formed to extend along the longitudinal direction of the reaction gas inlet manifold.

The reaction gas flow path may include a flow path introduction part formed on a surface facing the neighboring separator, and a flow path reaction part communicating with the flow path introduction part and formed on the surface facing the membrane-electrode assembly, wherein the reaction gas flow path includes the flow path introduction part. The flow path connecting part may further include a flow path connecting part formed in the thickness direction of the separator.

In addition, the protrusion may be formed in the separator, and the reaction gas may be a fuel or an oxidizing agent. A front side of the reaction gas inlet manifold may be provided with a resistance member that interrupts the flow of the reaction gas, the resistance member in any one shape selected from cylindrical, rectangular columnar, elliptical columnar, streamlined columnar. Can be done. In addition, the reaction gas inlet manifold may be located above the reaction gas outlet manifold based on the direction of gravity.

A fuel cell stack according to an embodiment of the present invention includes an electricity generation unit including a membrane-electrode assembly and a separator disposed on both surfaces of the membrane-electrode assembly, and the reaction gas is introduced into the electricity generation unit. A reaction gas inlet manifold and a reaction gas outlet manifold through which the reaction gas is discharged are formed, and the reaction gas inlet manifold and the reaction gas outlet manifold are in communication with a reaction gas flow path formed in the separator. Includes a flow path introduction portion formed on a surface facing the neighboring separator and a flow path reaction portion communicating with the flow path introduction portion and formed on the surface facing the membrane-electrode assembly.

The separator for a fuel cell according to an embodiment of the present invention includes a reaction gas flow path hole forming a reaction gas inlet manifold into which a reaction gas is introduced, and a reaction gas outlet hole forming a reaction gas outlet manifold from which the reaction gas is discharged; It has a reaction gas flow path connecting the reaction gas inlet manifold hole and the reaction gas outlet manifold hole, the reaction gas inlet manifold hole is formed with a projection, it is connected to the reaction gas flow path.

The reaction gas flow path may include a flow path introduction part formed on a surface facing the neighboring separator, and a flow path reaction part communicated with the flow path introduction part and formed on the surface toward the membrane-electrode assembly, wherein the reaction gas flow path is the flow path. A flow path connecting part may be further connected to an introduction part and the flow path reaction part in a thickness direction of the separator.

A groove in which condensate is located may be formed next to the protrusion, and the reaction gas may be a fuel or an oxidant.

As described above, according to the present invention, condensed water is prevented from flowing into the reaction gas flow path, thereby suppressing flooding, thereby stably producing electric energy without deteriorating power generation performance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is an exploded perspective view illustrating a fuel cell stack according to a first embodiment of the present invention.

Referring to FIG. 1, the fuel cell stack 100 according to the first exemplary embodiment includes an electricity generation unit 30 in a cell unit that generates electrical energy by electrochemically reacting fuel and an oxidant. It is configured by.

Each of the electricity generating units 30 refers to a unit cell for generating electricity, and includes a membrane electrode assembly (MEA) 31 for oxidizing / reducing oxygen in fuel and oxidant, and a fuel which is a reaction gas. Separators (also known in the art as bipolar plates) for supplying oxidant to the membrane-electrode assembly 31.

The fuel cell stack 100 having a stack structure of the electricity generation unit 30 is formed by providing a plurality of such electricity generation units 30 and continuously disposing these electricity generation units 30.

The fuel cell stack 100 according to the present invention may use hydrogen cracked from liquid or gaseous fuel as a fuel through conventional reformers. In this case, the fuel cell stack 100 may be configured as a polymer electrolyte fuel cell system that generates electrical energy by reaction of hydrogen and oxygen by the electricity generating unit 30.

Alternatively, the fuel used in the fuel cell stack 100 may include a liquid or gaseous fuel containing hydrogen, such as methanol, ethanol, LPG, LNG, gasoline, butane gas, and the like. In this case, the fuel cell stack 100 according to the present invention is a direct oxidation fuel cell method for generating electrical energy through the direct reaction of liquid or gaseous fuel and oxygen by the electricity generating unit 30. Can be configured.

The fuel cell stack 100 may use pure oxygen stored in a separate storage means as an oxidant reacting with the fuel, or may use air containing oxygen as it is.

The membrane-electrode assembly 31 includes a polymer electrolyte membrane formed of a solid polymer electrolyte and an anode electrode and a cathode electrode disposed on both sides of the polymer electrolyte membrane.

The separators 32 and 33 are closely arranged with the membrane-electrode assembly 31 interposed therebetween to form a fuel passage 36 and an oxidant passage 34 on both sides of the membrane-electrode assembly 31, respectively. At this time, the anode separator 32 on which the fuel flow path 36 is formed is disposed on the anode electrode side of the membrane-electrode assembly 31, and the cathode separator 33 on which the oxidant flow path 34 is formed is the membrane-electrode assembly 31. ) Is disposed on the cathode electrode side. The electrolyte membrane then transfers the hydrogen ions generated at the anode to the cathode, thereby enabling ion exchange to combine with oxygen at the cathode to produce water.

The plurality of electricity generating units 30 as described above are continuously arranged to constitute the fuel cell stack 100. Here, the outermost end of the fuel cell stack 100 is provided with an end plate 60 which integrally fixes the fuel cell stack 100.

An oxidant inlet 62 for supplying an oxidant to the fuel cell stack 100, a fuel inlet 64 for supplying fuel to the fuel cell stack 100, and a cooling medium are injected into an upper portion of the one end plate 60. Cooling medium inlet (63) is formed. On the other hand, the lower portion of the one end plate 60 discharges the water and the unreacted air generated by the combined reaction of hydrogen and oxygen at the fuel outlet 67 and the cathode electrode for discharging the remaining unreacted fuel from the anode electrode An oxidant outlet 69 for cooling, and a cooling medium outlet 68 through which the cooling medium is discharged.

The separators 32 and 33 have channel-shaped reaction gas flow paths 36 and 34 formed on one surface thereof, and the reaction gas made of fuel or oxidant flows through the reaction gas flow paths 36 and 34. Here, the reaction gas flow path is a concept including an oxidant flow path and a fuel flow path.

The separators 32 and 33 may be divided into an anode separator 32 and a cathode separator 33. In the cathode separator 33, an oxidant flow path 34 is formed on one surface facing the membrane-electrode assembly 31, and an oxidant gas containing oxygen flows into the oxidant flow path 34. The anode separator 32 is formed with a fuel flow passage 36 on one surface facing the membrane-electrode assembly 31, and a fuel gas containing hydrogen flows into the fuel flow passage 36.

The separators 32 and 33 may have a cooling channel formed on a rear surface corresponding to the opposite side of the separator, thereby removing reaction heat generated together with electrical energy.

In the fuel cell stack 100, an oxidant inlet manifold 41 into which an oxidant is introduced, a cooling medium inlet manifold 42 into which a cooling medium is introduced, and a fuel inlet manifold 43 into which fuel is introduced. In addition, an oxidant outlet manifold 46 through which the oxidant is discharged, a fuel outlet manifold through which the fuel is discharged, and a cooling medium outlet manifold through which the cooling medium is discharged are formed in the fuel cell stack 100.

An oxidant inlet manifold 41 is formed at the upper one corner of the fuel cell stack 100, and an oxidant outlet manifold 46 is formed at the diagonal corner of the one corner at the bottom of the fuel cell stack 100. In the present description, the upper means that the upper side is based on the direction of gravity, and the lower means that the lower side is based on the direction of gravity. In addition, the fuel inlet manifold 43 is formed at the upper other corner of the fuel cell stack 100, and the fuel outlet manifold is formed at the diagonal corner of the other corner. Thus, the oxidant inlet manifold 41 and fuel inlet manifold 43 are located above in the direction of gravity relative to the oxidant outlet manifold 46 and the fuel outlet manifold.

The oxidant inlet manifold 41 and the fuel inlet manifold 43 are formed by successive holes formed in the electrical generators arranged in a stack.

The oxidant inlet manifold 41 and oxidant outlet manifold 46 communicate with the oxidant flow path 34 formed in the cathode separator, and the fuel inlet manifold 43 and fuel outlet manifold are fuel formed in the anode separator 32. It communicates with the flow path 36.

In the oxidant inlet manifold 41 according to the present embodiment, a protrusion 71 is formed, and the oxidant flow path 34 and the oxidant inlet manifold communicate with the protrusion 71.

On the other hand, the grooves 73 are formed on both sides of the protrusions 71 so that the condensed water can be located.

In addition, a projection 81 is also formed in the fuel inlet manifold 43, and is connected to the fuel passage 36 in the projection 81. In addition, grooves 83 are formed at both sides of the protrusion 81 so that the condensed water can be located.

In the present embodiment, the protrusions 71 and 81 are formed only in the separators 32 and 33 and are not formed in the membrane-electrode assembly 31. However, the present invention is not limited thereto, and the protrusion may be formed in the membrane-electrode assembly so that the protrusion may be formed along the longitudinal direction of the oxidant or the flow path.

FIG. 2 is a perspective view showing a part of the fuel cell stack shown in FIG. 1, FIG. 3 is a partial cross-sectional view of the fuel cell stack taken along line III-III in FIG. 2, and FIG. 4 is IV-IV in FIG. 2. Partial longitudinal sectional view of the fuel cell stack taken along a line.

Referring to the drawings, the oxidant inlet manifold 41 is described as an example in the present embodiment, but the present invention is not limited thereto, and the fuel inlet manifold 43 may be formed in the same manner.

A protrusion 71 is formed at the center of the lower end of the oxidant inlet manifold 41, and grooves 73 for condensate discharge are formed at both edges of the oxidant inlet manifold 41 which are both sides of the protrusion 71. In the present embodiment, the oxidant inlet manifold 41 is configured as an internal manifold method as an example, but the present invention is not limited thereto, and the oxidant inlet manifold may be configured as an external manifold method.

The oxidant inlet manifold 41 communicates with the oxidant flow path 34 formed in the cathode separator 33 to supply oxidant to the membrane-electrode assembly through the oxidant flow path 34.

The oxidant flow passage 34 communicates with the flow path introduction portion 34b formed on the surface facing the anode separator 32 disposed to be in contact with the flow path introduction portion 34b and is formed on the surface toward the membrane-electrode assembly 31. 34a) and a flow path connecting part 34c connecting the flow path introduction part 34b and the flow path reaction part 34a.

The flow path introduction portion 34b is formed in the form of a channel on the surface facing the anode separator 32 in contact with the cathode separator 33, and leads to the protrusion 71 to communicate with the oxidant inlet manifold 41 at the protrusion 71.

The flow path connecting portion 34c is formed in the form of a passage extending in the thickness direction of the cathode separator 33 to connect the flow path introduction part 34b and the flow path reaction part 34a. However, the flow path connecting part 34c is not necessarily required, and the flow path introduction part 34b and the flow path reaction part 34a may be directly connected.

On the other hand, the flow path reaction part 34a is formed in a channel shape on the surface facing the membrane-electrode assembly 31 and continues in a meandering shape to supply an oxidant to the membrane-electrode assembly 31.

As shown in FIGS. 3 and 4, the oxidant introduced into the oxidant inlet manifold 41 through the oxidant inlet 62 is distributed and supplied to each of the electricity generating units 30 as shown by the arrow. At this time, the condensed water is also introduced into the oxidant inlet manifold 41. Since the protrusion 71 formed at the lower end of the oxidant inlet manifold 41 is formed higher than the periphery, the water is not directly introduced into the oxidant flow path 34. The oxidant, which is in a gaseous state, may be easily introduced into the oxidant flow path 34. In addition, the condensed water flows through the grooves 73 formed on the left and right sides of the protrusion. The groove 73 preferably has a sufficient volume to accommodate intermittent condensed water.

As shown in the present embodiment, when the protrusion 71 is formed at the portion connected to the oxidant flow path 34 in the oxidant inlet manifold 41, the oxidant and the condensate are separated from each other, and only the oxidant is distributed to each of the electricity generating units 30. Since it is guided to the groove 73, it is possible to prevent the inflow of condensate into the electricity generating unit 30 installed in front of the oxidant inlet manifold 41.

In addition, since the internal temperature of the oxidant inlet manifold 41 is maintained higher than the temperature of the oxidant inlet 62 during the operation of the fuel cell stack 100, the water present in the groove 73 gradually evaporates and reacts with the reaction gas. It is supplied to the electricity generating unit 30. Therefore, according to the present exemplary embodiment, the condensed water may not only be prevented from being introduced into the electricity generating unit 30 positioned in front of the condensed water, but may further humidify the reaction gas.

In addition, in the case of a general fuel cell stack, an outer gasket (not shown) for sealing between the separators 32 and 33 and the membrane-electrode assembly 31 is installed at the outer circumference of the membrane-electrode assembly 31, and the cathode electrode, And the anode electrode includes a catalyst layer in contact with the electrolyte membrane and a gas diffusion layer (GDL) provided outside the catalyst layer, respectively.

It is also common for the thickness of the gas diffusion layer to be thicker than the thickness of the outer gasket. This causes a gap between the membrane electrode assembly and the anode separator or between the membrane electrode assembly and the cathode separator. Condensed water accumulated in the groove 73 may be partially introduced into the gap, and in this case, the condensed water may flow into the oxidant flow path 34 or the fuel flow path 36.

In this embodiment, in order to prevent such a problem, the flow path introduction part 34b is formed in the surface which faces the adjacent separator. When the flow path introduction portion 34b is formed in this manner, even if condensed water flows through the gap, the flow path introduction portion 34b does not flow into the flow path introduction portion formed on the opposite surface. Since the gap is very small and exists only in the portion where the outer gasket is installed, condensed water may not move to the flow path reaction part 34a located below the gasket, thereby preventing condensed water in the groove 73 from flowing into the oxidant flow path. In the present description, only the oxidant flow path is described, but the fuel flow path may also have the same structure as the oxidant flow path. In addition, unlike the present embodiment, the flow path structure can stably prevent the water accumulated in the manifold from flowing into the reaction gas flow path even when the protrusion and the groove are not formed.

5 is a perspective view illustrating a cathode separator and an anode separator according to a modification of the first embodiment of the present invention. Referring to FIG. 5, the cathode separator 200 according to the present exemplary embodiment has a rectangular plate structure, and includes an oxidant inlet manifold hole 241 forming an oxidant inlet manifold thereon and a cooling medium flow path. Cooling medium inlet manifold apertures 242 and fuel inlet manifold apertures 243 forming a fuel inlet manifold.

Further, a lower portion of the cathode separator 200 includes a fuel outlet manifold hole 248 for forming a fuel outlet manifold, a cooling medium outlet manifold hole 247 for forming a cooling medium outlet manifold, and an oxidant outlet manifold. An oxidant outlet manifold aperture 246 is formed.

In addition, an oxidant flow path 230 connecting the oxidant inlet manifold hole 241 and the oxidant outlet manifold hole 246 is formed on the surface of the cathode separator 200. The oxidant flow path 230 is formed of a groove-shaped channel in the cathode separator 200, and a plurality of channels are arranged in a group. Channels are divided into a plurality of ribs.

The oxidant flow path 230 has flow paths extending in the height direction of the plate at random intervals, and both ends thereof are alternately connected to each other to form a meandering path.

In addition, the oxidant flow path 230 communicates with the flow path introduction part 232 formed on the surface facing the anode separator 300 disposed to be in contact with the flow path introduction part 232 and is formed on the surface toward the membrane-electrode assembly 31. The unit 231 includes a flow path connecting part 235 connecting the flow path introduction part 232 and the flow path reaction part 232.

An oxidant inlet manifold hole 241 is formed with a protrusion 271, in which the oxidant inlet manifold hole 241 and the flow path introduction part 232 communicate with each other. In addition, the protrusion 271 is formed at the center thereof, and a groove 272 is formed at the edge of the oxidant inlet manifold hole 241 in which the condensate 278 is located.

A projection 281 is also formed in the fuel inlet manifold hole 243, and a groove 282 is formed at the edge of the fuel inlet manifold hole 243 in which the condensed water is located.

As shown in the present embodiment, a protrusion 281 is formed in the oxidant inlet manifold hole 243, and when the oxidant inlet manifold hole 243 and the oxidant flow path 230 communicate with each other, condensate flows into the oxidant flow path 230. Can be reliably prevented.

6 is a partial cross-sectional view of a fuel cell stack according to a second embodiment of the present invention, and FIG. 7 is a partial longitudinal cross-sectional view of a fuel cell stack according to a second embodiment of the present invention. Referring to FIGS. 6 and 7, the fuel cell stack according to the present exemplary embodiment includes a resistance member 80 installed in the oxidant inlet manifold 41 to prevent the flow of the oxidant.

The resistance member 80 is installed in front of the oxidant inlet manifold 41 to facilitate the separation of the oxidant and the condensate. The resistance member 80 is installed in the space between the fuel injection port 64 and the first electricity generation unit 30 and may be installed inside the end plate 60 as in the present embodiment. The resistance member 80 is formed in a substantially cylindrical shape and extends from the bottom of the oxidant inlet manifold 41 to the top surface.

The oxidant supplied through the oxidant inlet 62 is struck by the resistance member 80 as shown by the arrow, and the inertia to flow forward is suppressed, and the resistance member 80 turns left and right to flow into the oxidant flow path 34. In this process, the water contained in the oxidant hits the resistance member 80 and falls down to be guided to the lower groove 73 of the oxidant inlet manifold 41. The resistance member 80 according to the present embodiment is formed in a cylindrical shape, but the present invention is not limited thereto, and the resistance member 80 may be formed in various forms such as a square pillar, a streamlined pillar, and an elliptical pillar. In this way, if the resistance member 80 is installed, the moisture contained in the reaction gas may be separated at an early stage to prevent excessive moisture from flowing into the electricity generating unit.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

1 is an exploded perspective view illustrating a fuel cell stack according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a part of the fuel cell stack illustrated in FIG. 1.

3 is a partial cross-sectional view of the fuel cell stack taken along line III-III in FIG. 2.

4 is a partial longitudinal cross-sectional view of the fuel cell stack taken along line IV-IV in FIG. 2.

5 is a perspective view illustrating a cathode separator and an anode separator according to a modification of the first embodiment of the present invention.

6 is a partial cross-sectional view of a fuel cell stack according to a second embodiment of the present invention.

7 is a partial longitudinal cross-sectional view of a fuel cell stack according to a second embodiment of the present invention.

-Explanation of symbols for the main parts of the drawing-

100: fuel cell stack 30: electricity generating unit

31 membrane-electrode assembly 32 anode separator

36: fuel euro 33: cathode separator

34: oxidant flow path 41: oxidant inlet manifold

43: fuel inlet manifold 60: end plate

71: protrusion 73: groove

Claims (18)

And a plurality of electricity generating units including a membrane-electrode assembly (MEA), a separator disposed on both sides of the membrane-electrode assembly, and an end plate installed at an outer surface of the electricity generating units. , In the electricity generating unit, a reaction gas inlet manifold through which a reaction gas is introduced and a reaction gas outlet manifold through which the reaction gas is discharged are formed, and the reaction gas inlet manifold and the reaction gas outlet manifold are formed in the separator. In communication with the gas flow path The reaction gas inlet manifold is formed with a protrusion, and the reaction gas inlet manifold is connected with the reaction gas flow path in the protrusion, The reaction gas inlet manifold is provided with a resistance member that interrupts the flow of the reaction gas, The resistance member is installed in the end plate and the fuel cell stack having a columnar shape formed extending from the bottom of the reaction gas inlet manifold to the top surface. The method of claim 1, And a groove formed in the reaction gas inlet manifold to allow condensate to be located. The method of claim 2, Wherein the protrusion is formed at the center of the reaction gas inlet manifold, and the groove is formed at both sides of the protrusion. The method of claim 1, The reaction gas flow path includes a flow path introduction part formed on a surface facing the neighboring separator, and a flow path reaction part communicating with the flow path introduction part and formed on the surface facing the membrane-electrode assembly. The method of claim 4, wherein The reaction gas flow path is connected to the flow path introduction portion and the flow path reaction portion, the fuel cell stack including a flow path connecting portion formed in the thickness direction of the separator. The method of claim 1, The protrusion is formed along the longitudinal direction of the reaction gas inlet manifold. The method of claim 1, The protrusion is formed in the separator fuel cell stack. The method of claim 1, And the reaction gas is a fuel or an oxidant. delete The method of claim 1, The resistance member is a fuel cell stack made of any one shape selected from cylindrical, rectangular columnar, elliptic columnar, streamlined columnar. The method of claim 1, And the reaction gas inlet manifold is located above the reaction gas outlet manifold with respect to the direction of gravity. delete delete delete delete delete delete delete

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