JP2021128900A - Separator for fuel cell - Google Patents

Abstract

To provide a separator for a fuel cell that can easily set a distribution amount of a reaction gas to be distributed from an inlet to each flow path groove as intended.SOLUTION: Separators 15 and 16 include reaction gas flow paths 28 and 29 having a plurality of recessed streaks through which a reaction gas flows, gas inlets 31 and 41 having an opening dimension smaller than a total flow path width of the reaction gas flow paths 28 and 29, inlet side manifolds 35 and 45 for guiding the reaction gas from the gas inlets 31 and 41 to the reaction gas flow paths 28 and 29, and a pair of gas distribution members 71 and 81 which has a plurality of integrated gas distribution grooves 72 and 82 being arranged in the inlet side manifolds 35 and 45 for radially distributing the reaction gas flowing from the gas inlets 31 and 41 to the reaction gas flow paths 28 and 29, and in which release portions of the plurality of gas distribution grooves 72 and 82 are blocked by inner surfaces of the inlet side manifolds 35 and 45.SELECTED DRAWING: Figure 3

Description

The present invention relates to a separator for a fuel cell.

A separator structure for a fuel cell is known in which a membrane electrode assembly in which a negative electrode and a positive electrode are bonded via a solid polymer membrane which is an electrolyte is sandwiched between a gasket and a separator. The separator is provided at an inlet for supplying a reaction gas (fuel gas or an oxidant gas), a plurality of flow path grooves, and a connecting portion connecting the inlet and the plurality of flow path grooves to support the solid polymer membrane. It has a department. A part of the connecting part of the flow path from the inlet to the plurality of flow path grooves is on the surface of the plurality of flow path grooves (the surface facing the membrane electrode assembly and corresponding to the bottom of the flow path groove). On the other hand, the flow path of the reaction gas is dug down so as to be inclined (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-342342

A conventional fuel cell separator includes an inlet having an opening width similar to the total flow path width of a plurality of flow path grooves. Therefore, the amount of the reaction gas distributed from the inlet to each channel groove is affected by the flow of the reaction gas at the inlet.

On the other hand, the total flow path width of the plurality of flow path grooves and the opening size of the reaction gas inlet may be significantly different. For example, the opening size of the reaction gas inlet may be smaller than the total flow path width of the plurality of flow path grooves. In such a case, a manifold for distributing the reaction gas is provided between the inlet and the plurality of flow path grooves.

Then, the distance between the inlet communicated via the manifold and each flow path groove is not constant and becomes non-uniform. For example, when the inlet is biased toward one end in the width direction of a plurality of flow paths, the distance between the inlet and each flow path groove is far from the flow path groove near the inlet. It becomes continuously long to the flow path groove. Such a difference in distance causes an unintended difference in the amount of reaction gas distributed in the plurality of channel grooves.

By the way, the flow amount of the reaction gas in each channel groove may be intentionally different. For example, the flow rate of the reaction gas may differ between the flow path groove passing through the end portion of the membrane electrode assembly and the flow path groove passing through the central portion of the membrane electrode assembly. In such a case, the difference in the distance between the inlet and each channel groove may impair the difference in the intentional flow amount of the reaction gas in each channel groove.

Therefore, an object of the present invention is to provide a fuel cell separator in which the distribution amount of the reaction gas distributed from the inlet to each flow path groove can be easily set as intended.

In order to solve the above problems, the fuel cell separator according to the present invention has a reaction gas flow path having a plurality of recesses through which the reaction gas flows, and an opening size smaller than the total flow path width of the reaction gas flow path. A plurality of inlets of the reaction gas, a manifold for guiding the reaction gas from the inlet to the reaction gas flow path, and a plurality of manifolds arranged in the manifold and radially distributing the reaction gas flowing from the inlet to the reaction gas flow path. The gas distribution groove is provided, and the release portion of the plurality of gas distribution grooves is closed by the inner surface of the manifold.

According to the present invention, it is possible to provide a separator for a fuel cell capable of suppressing a difference in the distribution amount of the reaction gas due to a difference in the distance between the inlet and each flow path groove.

The schematic perspective view of the fuel cell which concerns on embodiment of this invention. An exploded perspective view of a fuel cell according to an embodiment of the present invention. FIG. 3 is a partial cross-sectional view of a fuel cell according to an embodiment of the present invention. The schematic diagram of the separator on the anode electrode side seen from the membrane electrode joint side of the fuel cell which concerns on embodiment of this invention. The schematic diagram of the separator on the cathode electrode side seen from the membrane electrode joint side of the fuel cell which concerns on embodiment of this invention. The perspective view of the gas distribution member of the separator which concerns on embodiment of this invention. The perspective view of the gas distribution member of the separator which concerns on embodiment of this invention. An enlarged perspective view of the oxygen inlet side manifold of the separator according to the embodiment of the present invention. The perspective view of another example of the gas distribution member of the separator which concerns on embodiment of this invention.

An embodiment of the fuel cell separator according to the present invention will be described with reference to FIGS. 1 to 9. In the plurality of drawings, the same or corresponding configurations are designated by the same reference numerals.

FIG. 1 is a schematic perspective view of a fuel cell according to an embodiment of the present invention.

As shown in FIG. 1, the fuel cell 1 according to the present embodiment reacts hydrogen gas as a fuel gas with oxygen as an oxidant gas (oxygen contained in air) to generate power. The fuel cell 1 is a laminated body of a plurality of stacked fuel cell cells 5, a pair of end plates 6 sandwiching the plurality of fuel cell cells 5 from the outside in the stacking direction L, and a pair of end plates 6 of the fuel cell 5. It is provided with a fastening member 8 for fixing to.

The fuel cell 1 includes a large number of fuel cell 5s that are stacked along the stacking direction L. Therefore, the fuel cell 1 is also called a fuel cell stack. The fuel cell 1 has a fuel cell 5 as a minimum unit, and includes several tens to several hundreds of stacked fuel cell cells 5. The number of stacked fuel cell cells 5 depends on the power generation capacity required of the fuel cell 1.

The pair of end plates 6 have a rectangular shape larger than the fuel cell 5. The pair of end plates 6 are connected by a fastening member 8 bridged between them.

The fastening member 8 applies an inward load in the stacking direction L to the plurality of fuel cell cells 5 via the pair of end plates 6.

FIG. 2 is an exploded perspective view of the fuel cell according to the embodiment of the present invention.

As shown in FIG. 2, the fuel cell 5 of the fuel cell 1 according to the present embodiment has a membrane electrode assembly 11 (MEA) and a pair of gas diffusion layers 12 sandwiching the membrane electrode assembly 11 (Membrane Electrode Assembly, MEA). It includes a Gas Diffusion Layer (GDL) and a pair of separators 15 and 16 that sandwich the membrane electrode assembly 11 from the front and back via a pair of gas diffusion layers 12.

Further, the fuel cell 5 has a refrigerant flow passage (not shown) for passing air as a refrigerant for cooling the fuel cell 1 between the separators 15 and 16 adjacent to each other in the stacking direction.

FIG. 3 is a partial cross-sectional view of the fuel cell according to the embodiment of the present invention.

FIG. 4 is a schematic view of a separator on the anode electrode side as viewed from the membrane electrode joint side of the fuel cell according to the embodiment of the present invention.

FIG. 5 is a schematic view of a separator on the cathode electrode side as viewed from the membrane electrode joint side of the fuel cell according to the embodiment of the present invention.

In addition to FIG. 2, as shown in FIGS. 3 to 5, the membrane electrode assembly 11 of the fuel cell 1 includes a solid polymer membrane 17 (electrolyte), an anode electrode 18 (fuel electrode), and a cathode electrode 19 ( Air electrode) and. The pair of electrodes 18 and 19 sandwich the solid polymer membrane 17 from the front and back.

A pair of sub-gaskets 22 are arranged around the pair of gas diffusion layers 12. The pair of sub-gaskets 22 are thin films of, for example, polyethylene naphthalate (PEN) resin having a gas permeability coefficient smaller than that of the gas diffusion layer 12.

Further, each fuel cell 5 has a hydrogen gas flow path 28 (reaction gas flow path) for supplying hydrogen gas to the anode pole 18 and an air flow path 29 (reaction gas flow path) for supplying air to the cathode pole 19. And have. The hydrogen gas flow path 28 is partitioned between the anode pole 18 and the separator 15 facing the anode pole 18. The air flow path 29 is partitioned between the cathode pole 19 and the separator 16 facing the cathode pole 19.

The hydrogen gas flow path 28 is connected to the hydrogen gas inlet 31 and the hydrogen gas outlet 32. The hydrogen gas flow path 28 has, for example, a plurality of linear and concave flow path grooves between a plurality of convex portions 33 extending parallel to the long side of the rectangular fuel cell 5. In other words, the hydrogen gas flow path 28 has a plurality of recesses through which hydrogen gas as a reaction gas is circulated. The plurality of flow path grooves may meander from one long side of the fuel cell 5 to the other long side, and from the other long side to one long side.

The hydrogen gas inlet 31 and the hydrogen gas outlet 32 have an opening dimension smaller than the total flow path width of the hydrogen gas flow path 28, that is, the total flow path width of the plurality of flow path grooves. The opening dimensions of the circular hydrogen gas inlet 31 and the hydrogen gas outlet 32 correspond to the opening diameter. The hydrogen gas inlet 31 is arranged at one end in the flow path width direction of the hydrogen gas flow path 28, and the hydrogen gas outlet 32 is arranged at the other end in the flow path width direction of the hydrogen gas flow path 28. Has been done. In the flow path width direction of the hydrogen gas flow path 28, the flow path groove near one end is close to the hydrogen gas inlet 31 and far from the hydrogen gas outlet 32. In the flow path width direction of the hydrogen gas flow path 28, the flow path groove near the other end is close to the hydrogen gas outlet 32 and far from the hydrogen gas inlet 31. Therefore, the straight line connecting the hydrogen gas inlet 31 and the hydrogen gas outlet 32 at the shortest distance crosses the hydrogen gas flow path 28 diagonally (diagonally).

A hydrogen gas inlet side manifold 35 is provided between the hydrogen gas inlet 31 and the hydrogen gas flow path 28. The hydrogen gas inlet side manifold 35 guides the hydrogen gas flowing from the hydrogen gas inlet 31 to the hydrogen gas flow path 28. The hydrogen gas inlet side manifold 35 branches the hydrogen gas flowing from the hydrogen gas inlet 31 into the respective flow path grooves. A hydrogen gas outlet side manifold 36 is provided between the hydrogen gas outlet 32 and the hydrogen gas flow path 28. The hydrogen gas outlet side manifold 36 guides the hydrogen gas flowing out of the hydrogen gas flow path 28 to the hydrogen gas outlet 32. The hydrogen gas outlet side manifold 36 collects the hydrogen gas flowing out of the hydrogen gas flow path 28 into the hydrogen gas outlet 32 from each flow path groove.

The air flow path 29 is connected to the air inlet 41 and the air outlet 42. The air flow path 29 has, for example, a plurality of linear and concave flow path grooves between a plurality of convex portions 43 extending parallel to the long side of the rectangular fuel cell 5. In other words, the air flow path 29 has a plurality of recesses through which air as a reaction gas flows. The plurality of flow path grooves may meander from one long side of the fuel cell 5 to the other long side, and from the other long side to one long side.

The air inlet 41 and the air outlet 42 have an opening dimension smaller than the total flow path width of the air flow path 29, that is, the total flow path width of the plurality of flow path grooves. The opening dimensions of the circular air inlet 41 and the air outlet 42 correspond to the opening diameter. The air inlet 41 is arranged at one end in the flow path width direction of the air flow path 29, and the air outlet 42 is arranged at the other end in the flow path width direction of the air flow path 29. In the flow path width direction of the air flow path 29, the flow path groove near one end is close to the air inlet 41 and far from the air outlet 42. In the flow path width direction of the air flow path 29, the flow path groove near the other end is close to the air outlet 42 and far from the air inlet 41. Therefore, the straight line connecting the air inlet 41 and the air outlet 42 at the shortest distance crosses the air flow path 29 diagonally (diagonally).

An air inlet side manifold 45 is provided between the air inlet 41 and the air flow path 29. The air inlet side manifold 45 guides the air flowing from the air inlet 41 to the air flow path 29. The air inlet side manifold 45 branches the air flowing from the air inlet 41 into the respective flow path grooves. An air outlet side manifold 46 is provided between the air outlet 42 and the air flow path 29. The air outlet side manifold 46 guides the air flowing out of the air flow path 29 to the air flow path 29. The air outlet side manifold 46 collects the air flowing out of the air flow path 29 from each flow path groove to the air outlet 42.

Note that FIG. 3 is a cross-sectional view of the fuel cell 5 in the vicinity of the air inlet 41 as shown in lines III-III of FIG. The air outlet 42, the hydrogen gas inlet 31, and the hydrogen gas outlet 32 have similar structures. Therefore, the cross-sectional view of the fuel cell 5 in the vicinity of the air outlet 42, the cross-sectional view of the fuel cell 5 in the vicinity of the hydrogen gas inlet 31, and the cross-sectional view of the fuel cell 5 in the vicinity of the hydrogen gas outlet 32 are omitted.

The separators 15 and 16 are made of, for example, carbon fiber reinforced plastic, conductive resin, or metal.

The separator 15 facing the anode electrode 18 has an air inlet 51 for supplying air to the separator 16 facing the cathode electrode 19 of the membrane electrode assembly 11, and an air outlet 52 for discharging air from the separator 15. There is.

A hydrogen gas side seal 59 projecting toward the membrane electrode assembly 11 is provided on the surface 15a of the separator 15.

The hydrogen gas side seal 59 orbits the outer peripheral edge portion of the surface 15a of the separator 15. The hydrogen gas side seal 59 goes around the outer periphery of the hydrogen gas flow path 28, the hydrogen gas inlet 31, the hydrogen gas inlet side manifold 35, the hydrogen gas outlet 32, and the hydrogen gas outlet side manifold 36, and forms a continuous space around them. It has a first part 59a to be stored inside. Further, the hydrogen gas side seal 59 has a second portion 59b that individually orbits the air introduction port 51 and a third portion 59c that individually orbits the air outlet 52. That is, the air introduction port 51 is a space through which hydrogen gas flows (hydrogen gas flow path 28, hydrogen gas inlet 31, hydrogen gas inlet side manifold 35, hydrogen gas outlet 32, and hydrogen gas outlet side manifold 36), and air conduction. It is cut off from each of the exits 52 and is independent. The air outlet 52 is independent of the space through which hydrogen gas flows and the air inlet 51, respectively.

The first part 59a, the second part 59b, and the third part 59c may be connected in succession as shown in FIG. 5 and may have a shared part, and the respective parts 59a, 59b, and 59c are independent of each other. You may be doing it.

The separator 16 facing the cathode electrode 19 includes a hydrogen gas introduction port 61 for supplying hydrogen gas to the separator 15 facing the anode electrode 18 of the membrane electrode assembly 11, and a hydrogen gas outlet 62 for discharging hydrogen gas from the separator 15. have.

An air-side seal 69 projecting toward the membrane electrode assembly 11 is provided on the surface 16a of the separator 16.

The air side seal 69 orbits the outer peripheral edge portion of the surface 16a of the separator 16. The air side seal 69 is a first portion that goes around the outer circumferences of the air flow path 29, the air inlet 41, the air inlet side manifold 45, the air outlet 42, and the air outlet side manifold 46 and stores them in a continuous space. It has 69a. Further, the air side seal 69 has a second portion 69b that individually orbits the hydrogen gas introduction port 61, and a third portion 69c that individually orbits the hydrogen gas outlet 62. That is, the hydrogen gas introduction port 61 is a space through which air flows (air flow path 29, air inlet 41, air inlet side manifold 45, air outlet 42, and air outlet side manifold 46), and a hydrogen gas outlet 62, respectively. It is cut off from and independent. The hydrogen gas outlet 62 is independent of the space through which air flows and the hydrogen gas inlet 61, respectively.

The first part 69a, the second part 69b, and the third part 69c may be connected in succession as shown in FIG. 6 and may have a shared part, or the respective parts 69a, 69b, and 69c are independent of each other. You may be doing it.

The separator 15 includes an integrated hydrogen gas distribution member 71 arranged on the hydrogen gas inlet side manifold 35. The hydrogen gas distribution member 71 has a plurality of hydrogen gas distribution grooves 72 that radially distribute the hydrogen gas flowing from the hydrogen gas inlet 31 to the hydrogen gas flow path 28. The open portions of the plurality of hydrogen gas distribution grooves 72 do not penetrate the hydrogen gas inlet side manifold 35 and are closed by the inner surface of the hydrogen gas inlet side manifold 35. This inner surface is connected to the bottom of the flow path groove of the hydrogen gas flow path 28. The hydrogen gas distribution member 71 extends in an arc shape along the edge of the circular hydrogen gas inlet 31.

Further, the separator 16 includes an integrated air distribution member 81 arranged in the air inlet side manifold 45. The air distribution member 81 has a plurality of air distribution grooves 82 that radially distribute the air flowing from the air inlet 41 to the air flow path 29. The open portions of the plurality of air distribution grooves 82 do not penetrate the air inlet side manifold 45 and are closed by the inner surface of the air inlet side manifold 45. This inner surface is connected to the bottom of the flow path groove of the air flow path 29. The air distribution member 81 extends in an arc shape along the edge of the circular air inlet 41.

6 and 7 are perspective views of the gas distribution member of the separator according to the embodiment of the present invention.

FIG. 6 is a perspective view of the hydrogen gas distribution member 71 as viewed from the hydrogen gas inlet side manifold 35 side, and FIG. 7 is a perspective view of the air distribution member 81 as viewed from the membrane electrode assembly 11 side. The configuration of the hydrogen gas distribution member 71 viewed from the membrane electrode joint side is the same as that shown in FIG. 7, and is omitted. The configuration of the air distribution member 81 as viewed from the air inlet side manifold 45 side is the same as that shown in FIG. 6, and is omitted.

FIG. 8 is an enlarged perspective view of the oxygen inlet side manifold of the separator according to the embodiment of the present invention.

For convenience of explanation, the hydrogen gas inlet side manifold 35 and the air inlet side manifold 45 are collectively referred to as the inlet side manifolds 35 and 45. Further, the hydrogen gas distribution member 71 and the air distribution member 81 are collectively referred to as gas distribution members 71 and 81. Further, the hydrogen gas distribution groove 72 and the air distribution groove 82 are collectively referred to as gas distribution grooves 72 and 82. Further, the hydrogen gas inlet 31 and the air inlet 41 are collectively referred to as gas inlets 31 and 41. Further, the hydrogen gas flow path 28 and the air flow path 29 are collectively referred to as reaction gas flow paths 28 and 29.

As shown in FIGS. 6 to 8, the gas distribution members 71 and 81 of the separators 15 and 16 according to the present embodiment have a plurality of gas distribution grooves 72 and 82. The plurality of gas distribution grooves 72 and 82 are all grooves opened in the same direction. The open portions of the plurality of gas distribution grooves 72 and 82 are closed by the inlet side manifolds 35 and 45. The flow path defined by the plurality of gas distribution grooves 72 and 82 and the inlet-side manifolds 35 and 45 is a distribution flow path for distributing the reaction gas. The gas distribution members 71 and 81 are integral parts made of, for example, carbon fiber reinforced plastic, conductive resin, or metal. That is, the gas distribution members 71 and 81 integrate the plurality of gas distribution grooves 72 and 82 and the plurality of inter-groove convex portions 85 and the arc-shaped plate portion 86 that integrates the plurality of inter-groove convex portions 85. Be prepared for.

Further, the plurality of gas distribution grooves 72 and 82 extend radially outward in the direction away from the gas inlets 31 and 41, that is, in the radial direction of the arc-shaped gas distribution members 71 and 81.

Further, the flow path cross-sectional areas of the gas distribution grooves 72 and 82 expand from the gas inlets 31 and 41 toward the reaction gas flow paths 28 and 29, respectively. Therefore, the inlets 72i and 82i of the respective gas distribution grooves 72 and 82 are smaller than the outlets 72o and 82o of the corresponding gas distribution grooves 72 and 82.

As shown in FIGS. 4 to 8, the plurality of gas distribution grooves 72 and 82 of the separators 15 and 16 according to the present embodiment are smaller than the plurality of flow path grooves of the reaction gas flow paths 28 and 29. That is, a plurality of flow path grooves are arranged on the extension lines of the gas distribution grooves 72 and 82, respectively. In other words, the gas distribution grooves 72 and 82 face a plurality of flow path grooves, respectively. Therefore, the respective gas distribution grooves 72 and 82 are not directly connected to any of the flow path grooves, but are connected to the reaction gas flow paths 28 and 29 via a continuous space of the inlet side manifolds 35 and 45. Has been done.

The outlet area of the gas distribution grooves 72 and 82 is larger as the distance between the gas distribution grooves 72 and 82 and the plurality of flow path grooves located on the extensions of the gas distribution grooves 72 and 82 is longer. .. That is, the magnitude relationship of the outlet areas of the plurality of gas distribution grooves 72 and 82 is smaller as the distance to the corresponding flow path groove is shorter, and is larger as the distance to the corresponding flow path groove is longer.

Further, the distance between the outlets 72o and 82o of the respective gas distribution grooves 72 and 82 and the outlets 72o and 82o of the adjacent gas distribution grooves 72 and 82 is the distance between the respective gas distribution grooves 72 and 82 and the respective gas distribution grooves 72. , The farther the distance to the plurality of flow path grooves located on the extension of 82, the smaller. The distance between the outlets 72o and 82o of the respective gas distribution grooves 72 and 82 and the outlets 72o and 82o of the gas distribution grooves 72 and 82 adjacent to the outlets 72o and 82o corresponds to the width dimension on the outer peripheral side of each of the inter-groove protrusions 85. That is, the magnitude relationship of the width dimension on the outer peripheral side of the plurality of inter-groove convex portions 85 is larger as the distance to the corresponding flow path groove is shorter, and is smaller as the distance to the corresponding flow path groove is longer.

Further, the inlet area of the gas distribution grooves 72 and 82 is larger as the distance between the gas distribution grooves 72 and 82 and the flow path groove located on the extension of the gas distribution grooves 72 and 82 is longer. .. That is, the magnitude relationship of the inlet areas of the plurality of gas distribution grooves 72 and 82 is smaller as the distance to the corresponding flow path groove is shorter, and is larger as the distance to the corresponding flow path groove is longer.

Further, the distance between the inlets 72i and 82i of the respective gas distribution grooves 72 and 82 and the inlets 72i and 82i of the gas distribution grooves 72 and 82 adjacent thereto is the distance between the respective gas distribution grooves 72 and 82 and the respective gas distribution grooves 72. , The farther the distance to the plurality of flow path grooves located on the extension of 82, the smaller. The distance between the inlets 72i and 82i of the respective gas distribution grooves 72 and 82 and the inlets 72i and 82i of the adjacent gas distribution grooves 72 and 82 corresponds to the width dimension on the inner peripheral side of the respective inter-groove protrusions 85. .. That is, the magnitude relationship of the width dimension on the inner peripheral side of the plurality of inter-groove convex portions 85 is larger as the distance to the corresponding flow path groove is shorter, and smaller as the distance to the corresponding flow path groove is longer.

Returning to FIG. 4, the separator 15 facing the anode pole 18 is provided on the hydrogen gas inlet side manifold 35 side, and fits into each hydrogen gas distribution groove 72 of the hydrogen gas distribution member 71 to fit each hydrogen gas distribution groove. A second gas distribution groove 88 that extends 72 is provided.

The hydrogen gas side flow path (hydrogen gas inlet side manifold 35, hydrogen gas flow path 28, and hydrogen gas outlet side manifold 36) is the air side flow path (air inlet side manifold 45, air flow path 29, and air outlet). The flow path height in the stacking direction L of the fuel cell 5 is lower than that of the side manifold 46), that is, the flow path height in the out-of-plane direction of the separator 15. Therefore, the thickness dimension of the hydrogen gas distribution member 71 arranged in the hydrogen gas inlet side manifold 35 must be smaller than the thickness dimension of the air distribution member 81 arranged in the air inlet side manifold 45. That is, the hydrogen gas distribution member 71 is thinner than the air distribution member 81. Therefore, the hydrogen gas distribution groove 72 cannot have a groove depth like the air distribution groove 82, and it may be difficult to secure a sufficient flow path cross-sectional area. In such a case, a desired flow path cross-sectional area can be easily obtained by forming a second gas distribution groove 88 on the hydrogen gas inlet side manifold 35 side and combining this with the hydrogen gas distribution groove 72. ..

The second gas distribution groove 88 preferably extends further toward the hydrogen gas flow path 28 than the outer peripheral edge of the hydrogen gas distribution member 71. The width of the extended portion of such a second gas distribution groove 88 is preferably extended toward the hydrogen gas flow path 28, similarly to the hydrogen gas distribution groove 72. The extension portion of the second gas distribution groove 88 alleviates the discontinuous expansion of the flow path cross-sectional area at the outlet of the hydrogen gas distribution groove 72, and suppresses the increase in pressure loss in and around the portion.

The separator 15 facing the anode electrode 18 is provided on the side of the hydrogen gas outlet side manifold 36, and is a second gas that fits into each hydrogen gas distribution groove of the hydrogen gas distribution member and expands each hydrogen gas distribution groove. It may be provided with a distribution groove.

By the way, the hydrogen gas side seal 59 and the air side seal 69 face each other in the stacking direction L of the fuel cell 1 with the membrane electrode assembly 11 and the gas diffusion layer 12 sandwiched between them. Therefore, the hydrogen gas side seal 59 and the air side seal 69 are pressed against each other by the load applied to the fuel cell 1 in the stacking direction L inward.

However, the second portion 59b of the hydrogen gas side seal 59 surrounds the air introduction port 51 without interruption, while the first portion 69a of the air side seal 69 connects the air inlet 41 and the air inlet side manifold 45 in order to connect the air inlet 41 and the air inlet side manifold 45. It does not surround the entire circumference of the air inlet 41. The third portion 59c of the hydrogen gas side seal 59 surrounds the air outlet 52 without interruption, while the first portion 69a of the air side seal 69 is an air outlet for connecting the air outlet 42 and the air outlet side manifold 46. It does not surround the entire circumference of 42. The second portion 69b of the air side seal 69 surrounds the hydrogen gas introduction port 61 without interruption, while the first portion 59a of the hydrogen gas side seal 59 is for connecting the hydrogen gas inlet 31 and the hydrogen gas inlet side manifold 35. , Does not surround the entire circumference of the hydrogen gas inlet 31. The third portion 69c of the air side seal 69 surrounds the hydrogen gas outlet 62 without interruption, while the first portion 59a of the hydrogen gas side seal 59 is for connecting the hydrogen gas outlet 32 and the hydrogen gas outlet side manifold 36. , Does not surround the entire circumference of the hydrogen gas outlet 32.

Here, the portion where the air inlet 41 and the air inlet side manifold 45 are connected and the portion where the hydrogen gas inlet 31 and the hydrogen gas inlet side manifold 35 are connected are referred to as an inlet side distribution communication unit 91. In the distribution communication unit 91 on the entrance side, since the seals 59 and 69 do not face each other, the seals 59 and 69 cannot be pressed against each other.

Therefore, the gas distribution members 71 and 81 are provided in the corresponding inlet side distribution communication unit 91. The arcuate plate portion 86 of the gas distribution members 71 and 81 extends over the entire circumference of the gas inlets 31 and 41 not surrounded by the corresponding seals 59 and 69.

That is, in one of the seals 59 and 69, the reaction gas flow paths 28 and 29, the gas inlets 31 and 41, the gas outlets 32 and 42, the inlet side manifolds 35 and 45, and the outlet side manifolds 36 and 46 are collectively enclosed. One part 59a, 69a, the fourth part 59d, 69d which is a part of the second part 59b, 69b surrounding the gas inlets 51, 61, and a part of the third part 59c, 69c surrounding the gas outlets 52, 62. The fifth portions 59e and 69e face the other seals 59 and 69 with the sub-gasket 22 in between. Therefore, the first sites 59a and 69a, the fourth sites 59d and 69d, and the fifth sites 59e and 69e can transfer and receive loads between the seals 59 and 69.

Further, in one of the seals 59 and 69, the sixth portions 59f and 69f, which are the rest of the second portions 59b and 69b surrounding the gas introduction ports 51 and 61, and the third portions 59c and 69c surrounding the gas outlets 52 and 62. The seventh portions 59g and 69g along the rest of the seal do not face the other seals 59 and 69. Therefore, the sixth sites 59f and 69f, and the seventh sites 59g and 69g cannot transfer and receive loads between the two seals 59 and 69. Therefore, the sixth portions 59f and 69f, which are the remaining portions of the second portions 59b and 69b surrounding the gas introduction ports 51 and 61, load a load between the second portions 59f and 69f and the corresponding gas distribution members 71 and 81 with the sub-gasket 22 sandwiched between them. Give and receive each other. That is, the sixth portion 59f of the hydrogen gas side seal 59 transfers a load to and from the air distribution member 81 arranged in the air inlet side manifold 45. The sixth portion 69f of the air side seal 69 transfers a load to and from the hydrogen gas distribution member 71 arranged in the hydrogen gas inlet side manifold 35.

The portion where the air outlet 42 and the air outlet side manifold 46 are connected and the portion where the hydrogen gas outlet 32 and the hydrogen gas outlet side manifold 36 are connected are referred to as an outlet side distribution communication unit 92. Even in these outlet-side distribution communication units 92, since the seals 59 and 69 do not face each other, the seals 59 and 69 cannot be pressed against each other. Therefore, a gas distribution member (not shown) may be provided in the outlet side distribution communication unit 92 as in the inlet side distribution communication unit 91. That is, the gas distribution member may be provided on the outlet side manifolds 36 and 46 as well as the inlet side manifolds 35 and 45. In that case, the seventh portion 59g of the hydrogen gas side seal 59 can transfer a load to and from the air distribution member (not shown) arranged in the air outlet side manifold 46. Further, the seventh portion 69g of the air side seal 69 transfers a load to and from a hydrogen gas distribution member (not shown) arranged in the hydrogen gas outlet side manifold 36.

Next, another example of the gas distribution members 71 and 81 will be described.

FIG. 9 is a perspective view of another example of the gas distribution member of the separator according to the embodiment of the present invention.

FIG. 9 is a perspective view of the air distribution member 81 as viewed from the membrane electrode joint side.

As shown in FIG. 9, the separator 16 according to the present embodiment may include a second seal 95 sandwiched between the air distribution member 81 and the gas diffusion layer 12. The second seal 95 is provided on the arcuate plate portion 86 of the air distribution member 81. The second seal 95 transfers a load to and from the sixth portion 59f of the hydrogen gas side seal 59.

Similar to the separator 16, the separator 15 may also include a sealing material (not shown) sandwiched between the hydrogen gas distribution member 71 and the gas diffusion layer 12. Similarly, the distribution member provided in the outlet-side distribution communication unit 92 may also have a second seal (not shown) sandwiched between the distribution member and the gas diffusion layer 12.

As described above, the separators 15 and 16 of the fuel cell 1 according to the present embodiment are arranged on the inlet side manifolds 35 and 45, and the reaction gas flowing from the gas inlets 31 and 41 radiates to the reaction gas flow paths 28 and 29. An integral gas distribution member 71, 81 having a plurality of gas distribution grooves 72, 82 for distribution and having the open portions of the plurality of gas distribution grooves 72, 82 closed on the inner surfaces of the inlet-side manifolds 35, 45. I have. Therefore, the separators 15 and 16 of the fuel cell 1 radiately diffuse the reaction gas from the gas inlets 31 and 41 to the respective flow path grooves of the reaction gas flow paths 28 and 29, and the reaction gas is diffused into the respective flow path grooves. Can be easily distributed as intended. For example, the separators 15 and 16 can diffuse the reaction gas radially and uniformly distribute the reaction gas to the respective flow path grooves. Further, the separators 15 and 16 can also diffuse the reaction gas radially to intentionally and non-uniformly distribute the reaction gas to the respective flow path grooves. That is, when the inlet of the reaction gas is directly connected to a plurality of channel grooves as in the conventional separator, the distribution amount of the reaction gas distributed from the inlet to each channel groove is at the inlet. While being affected by the flow of the reaction gas, the separators 15 and 16 according to the present embodiment can diffuse the reaction gas radially, and the amount of the reaction gas distributed to the respective flow path grooves can be easily and intentionally set. ..

Further, the separators 15 and 16 according to the present embodiment are different from the conventional separators in which the inlet and the flow path groove are directly connected, and are between the gas distribution members 71 and 81 and the reaction gas flow paths 28 and 29. It also has inlet-side manifolds 35, 45 having a continuous space. That is, like the reinforcing member that connects the inlet and the flow path groove without interruption in the conventional separator, the gas distribution grooves 72 and 82 according to the present embodiment fill the entire area of the inlet side manifolds 35 and 45. There is no need to stretch to. Therefore, the separators 15 and 16 can reduce the radial dimensions of the gas distribution members 71 and 81 (dimensions in the direction from the gas inlets 31 and 41 toward the reaction gas flow paths 28 and 29). Further, the separators 15 and 16 may have a simple structure having a smaller number of gas distribution grooves 72 and 82 than the plurality of flow path grooves of the reaction gas flow paths 28 and 29.

Further, the separators 15 and 16 according to the present embodiment can support the sixth portions 59f and 69f of the seals 59 and 69 facing each other by the integrated gas distribution members 71 and 81. Further, since the separators 15 and 16 support the sixth portions 59f and 69f of the seals 59 and 69 facing each other by the integrated gas distribution members 71 and 81, a plurality of loads received from the sixth portions 59f and 69f of the seals 59 and 69 are applied. It can be supported by the inter-groove convex portion 85 of the above. Therefore, the gas distribution members 71 and 81 distribute the load received from the sixth portions 59f and 69f of the seals 59 and 69 to the inter-groove convex portion 85 having a width smaller than the groove width of the plurality of gas distribution grooves 72 and 82. Can be supported. Further, the integrated gas distribution members 71 and 81 are extremely high as compared with the case where the inter-groove convex portions 85 are individually provided on the separators 15 and 16 in view of the number of fuel cell cells 5 mounted on the fuel cell 1 in large numbers. Has manufacturability.

The separators 15 and 16 according to the present embodiment include a plurality of gas distribution grooves 72 and 82 having a flow path cross-sectional area extending from the gas inlets 31 and 41 toward the reaction gas flow paths 28 and 29. Therefore, the separators 15 and 16 can start the diffusion of the reaction gas flow toward the reaction gas flow paths 28 and 29 in the gas distribution grooves 72 and 82, respectively.

Further, the separators 15 and 16 according to the present embodiment have a plurality of outlet areas proportional to the distances to the respective gas distribution grooves 72 and 82 and the flow path grooves located on the extensions of the respective gas distribution grooves 72 and 82, respectively. The gas distribution grooves 72 and 82 of the above are provided. Further, in the separators 15 and 16, the distance between the outlets 72o and 82o of the gas distribution grooves 72 and 82 and the outlets 72o and 82o of the gas distribution grooves 72 and 82 adjacent thereto is different from that of the gas distribution grooves 72 and 82, respectively. A plurality of gas distribution grooves 72, 82 are provided, which are inversely proportional to the distance to the flow path groove located on the extension of each of the gas distribution grooves 72, 82. Further, the separators 15 and 16 according to the present embodiment have a plurality of inlet areas proportional to the distances between the gas distribution grooves 72 and 82 and the flow path grooves located on the extensions of the gas distribution grooves 72 and 82, respectively. The gas distribution grooves 72 and 82 of the above are provided. Further, in the separators 15 and 16, the distance between the inlets 72i and 82i of the gas distribution grooves 72 and 82 and the inlets 72i and 82i of the gas distribution grooves 72 and 82 adjacent thereto is different from that of the gas distribution grooves 72 and 82, respectively. A plurality of gas distribution grooves 72, 82 are provided, which are inversely proportional to the distance to the flow path groove located on the extension of each of the gas distribution grooves 72, 82.

Due to the gas distribution grooves 72 and 82 having these relationships, the separators 15 and 16 have a distance between the gas distribution grooves 72 and 82 and the flow path groove rather than a portion where the distance between the gas distribution grooves 72 and 82 and the flow path groove is closer. It is possible to easily equalize the distribution amount of the reaction gas in the reaction gas flow paths 28 and 29 by allowing a larger amount of the reaction gas to flow through the parts separated from each other.

Further, the separators 15 and 16 according to the present embodiment include metal gas distribution members 71 and 81. Therefore, the separators 15 and 16 firmly support the sixth portions 59f and 69f of the seals 59 and 69 to suppress the bending of the membrane electrode assembly 11 at the contact portion between the membrane electrode assembly 11 and the seals 59 and 69. It is possible to reliably prevent the leakage of the reaction gas between the membrane electrode assembly 11 and the seals 59 and 69 and the blockage of the flow path in the inlet side flow connecting portion 91.

Further, the separators 15 and 16 according to the present embodiment include a second seal 95 sandwiched between the gas distribution members 71 and 81 and the gas diffusion layer 12. Therefore, the separators 15 and 16 press the sixth portions 59f and 69f of the seals 59 and 69 against each other with the seals in the same manner as the other portions 59a, 69a, 59d and 69d and the portions 59e and 69e to join the membrane electrodes. It is possible to reliably prevent leakage of the reaction gas between the body 11 and the seals 59 and 69 and blockage of the flow path at the inlet side distribution communication unit 91.

Further, the separator 15 facing the anode electrode 18 is provided on the hydrogen gas inlet side manifold 35 side, and fits into each hydrogen gas distribution groove 72 of the hydrogen gas distribution member 71 to expand each hydrogen gas distribution groove 72. A second gas distribution groove 88 is provided. Therefore, the separator 15 facing the anode pole 18 generally has a lower flow path height of the reaction gas flow path than the separator 16 facing the cathode pole 19, but has a radial flow path (hydrogen) sufficient for diffusion of the reaction gas. The gas distribution groove 72 and the second gas distribution groove 88) can be formed.

Therefore, according to the separators 15 and 16 of the fuel cell 1 according to the present invention, the distribution amount of the reaction gas distributed from the gas inlets 31 and 41 to the respective flow path grooves of the reaction gas flow paths 28 and 29 can be easily determined. Can be set as intended.

1 ... Fuel cell, 5 ... Fuel cell, 6 ... End plate, 8 ... Fastening member, 11 ... Membrane electrode joint, 12 ... Gas diffusion layer, 15 ... Separator, 15a ... Surface, 16 ... Separator, 16a ... Surface, 17 ... solid polymer film, 18 ... anode pole, 19 ... cathode pole, 22 ... sub gasket, 28 ... hydrogen gas flow path, 29 ... air flow path, 31 ... hydrogen gas inlet, 32 ... hydrogen gas outlet, 33 ... hydrogen Convex part of gas flow path, 35 ... Hydrogen gas inlet side manifold, 36 ... Hydrogen gas outlet side manifold, 41 ... Air inlet, 42 ... Air outlet, 43 ... Convex part of air flow path, 45 ... Air inlet side manifold, 46 ... Air outlet side manifold, 51 ... Air inlet, 52 ... Air outlet, 59 ... Hydrogen gas side seal, 59a ... First part, 59b ... Second part, 59c ... Third part, 59d ... Fourth part, 59e ... 5th part, 59f ... 6th part, 59g ... 7th part, 61 ... Hydrogen gas inlet, 62 ... Hydrogen gas outlet, 69 ... Air side seal, 69a ... 1st part, 69b ... 2nd part, 69c ... Third part, 69d ... Fourth part, 69e ... Fifth part, 69f ... Sixth part, 69g ... Seventh part, 71 ... Hydrogen gas distribution member, 72 ... Hydrogen gas distribution groove, 72i ... Hydrogen gas distribution groove Inlet, 72o ... Hydrogen gas distribution groove outlet, 81 ... Air distribution member, 82 ... Air distribution groove, 82i ... Air distribution groove inlet, 82o ... Air distribution groove outlet, 85 ... Inter-groove protrusion, 86 ... Arc Shape plate part, 88 ... second gas distribution groove, 91 ... inlet side distribution communication part, 92 ... outlet side distribution communication part, 95 ... second seal.

Claims (9)

A reaction gas flow path having a plurality of recesses through which the reaction gas flows,
An inlet of the reaction gas having an opening dimension smaller than the total flow path width of the reaction gas flow path, and an inlet of the reaction gas.
A manifold that guides the reaction gas from the inlet to the reaction gas flow path,
It has a plurality of gas distribution grooves arranged in the manifold and radially distributes the reaction gas flowing from the inlet to the reaction gas flow path, and the open portion of the plurality of gas distribution grooves is closed on the inner surface of the manifold. A separator for a fuel cell, comprising an integrated gas distribution member. The fuel cell separator according to claim 1, wherein the flow path cross-sectional area of each of the gas distribution grooves expands from the inlet toward the reaction gas flow path. The fuel cell according to claim 1 or 2, wherein the farther the distance between each gas distribution groove and the recess located on the extension of each gas distribution groove is, the larger the outlet area of each gas distribution groove is. Separator for. The farther the distance between each gas distribution groove and the recess located on the extension of each gas distribution groove is, the distance between the outlet of each gas distribution groove and the outlet of the gas distribution groove adjacent to the gas distribution groove. The separator for a fuel cell according to any one of claims 1 to 3, wherein the fuel cell separator is small. One of claims 1 to 4, the farther the distance between each of the gas distribution grooves and the recess located on the extension of each of the gas distribution grooves is, the larger the inlet area of each of the gas distribution grooves is. Separator for fuel cell described in. The farther the distance between each gas distribution groove and the recess located on the extension of each gas distribution groove is, the distance between the inlet of each gas distribution groove and the inlet of the gas distribution groove next to it. The separator for a fuel cell according to any one of claims 1 to 5, wherein the size is small. The fuel cell separator according to any one of claims 1 to 6, wherein the gas distribution member is made of metal. The separator for a fuel cell according to any one of claims 1 to 7, further comprising a seal sandwiched between the gas distribution member and the diffusion layer. Claims 1 to 8 provided on the manifold side, having a second gas distribution groove that fits into each of the gas distribution grooves of the gas distribution member and expands each of the gas distribution grooves, and faces the anode pole. The separator for a fuel cell according to any one of the above items.

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