JP5227680B2 - Fuel cell - Google Patents

Description

  The present invention provides an electrolyte / electrode assembly in which electrodes are provided on both sides of an electrolyte, and are sandwiched between separators, and fluid communication holes that pass through at least a reaction gas or a cooling medium through the lamination direction, and separator surfaces The present invention relates to a fuel cell having a fluid flow path for flowing the fluid along a direction.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane is sandwiched by separators. A unit cell is provided. This type of fuel cell is normally used as a fuel cell stack by stacking a predetermined number of unit cells.

  In the fuel cell described above, a fuel gas flow path (fluid flow path) for flowing fuel gas to the anode side electrode and an oxidant gas flow path (flow path for flowing oxidant gas to the cathode side electrode) (in the plane of the separator) Fluid flow path). Further, a cooling medium flow path (fluid flow path) for flowing a cooling medium is provided along the surface direction of the separator for each power generation cell or for each of the plurality of power generation cells.

  This type of fuel cell has a fluid communication hole penetrating in the stacking direction of the separator, specifically, an oxidant gas inlet communication hole, an oxidant gas outlet communication hole, a fuel gas inlet communication hole, a fuel gas outlet communication hole, a cooling In some cases, the medium inlet communication hole and the cooling medium outlet communication hole constitute a so-called internal manifold provided inside the fuel cell.

  For example, the fuel cell disclosed in Patent Document 1 includes a main body 1 and a spacer 2 as shown in FIG. 22, and penetrates in the stacking direction to form first through holes 3 a and 3 b and second through holes. 4a and 4b and 3rd through-holes 5a and 5b are provided up and down. The first through holes 3a and 3b communicate with the guide spaces 6a and 6b, and are provided with fin-shaped guide portions 7a and 7b protruding from the guide spaces 6a and 6b.

  Between the guide spaces 6a and 6b, a reaction portion (space) 8 is formed having a flow direction indicated by an arrow. For example, hydrogen gas introduced into the guide space 6a from the first through hole 3a is guided to the guide portion 7a protruding into the guide space 6a and supplied to the reaction portion 8. The hydrogen gas subjected to the reaction in the reaction portion 8 moves through the guide space 6b under the guide action of the guide portion 7b, and is discharged to the first through hole 3b.

JP-A-11-283636

  In the above-mentioned Patent Document 1, guide spaces 6a and 6b serving as buffer portions are provided between the first through holes 3a and 3b and the reaction portion 8. For this reason, even if the guide portions 7a and 7b are provided in the guide spaces 6a and 6b, the hydrogen gas introduced from the first through hole 3a can be uniformly supplied to the entire width direction of the reaction portion 8. Have difficulty. Therefore, there is a problem in that the flow rate distribution in the reaction section 8 is likely to vary, and the gas distribution becomes non-uniform, resulting in a decrease in power generation reaction, a decrease in fuel utilization rate, and the like. Further, a structure in which the buffer portion is eliminated and the plurality of flow channel grooves are directly connected to the communication holes is conceivable, but there is a problem that the gas distributed to the plurality of flow channel grooves is not uniform.

  The present invention solves this type of problem, and fluid can be uniformly and reliably supplied from a fluid communication hole to a plurality of channel grooves constituting a fluid channel, thereby improving the uniformity of fluid distribution. Another object of the present invention is to provide a fuel cell capable of ensuring desired power generation performance.

  The present invention provides an electrolyte / electrode assembly in which electrodes are provided on both sides of an electrolyte, and are sandwiched between separators, and fluid communication holes that pass through at least a reaction gas or a cooling medium through the lamination direction, and separator surfaces The present invention relates to a fuel cell having a fluid flow path for flowing the fluid along a direction.

In this fuel cell, the fluid flow path has a plurality of flow path grooves, and the fluid communication holes and the predetermined number of flow path grooves are in direct communication with each other through the plurality of connection flow paths. Then, the connecting flow path, the flow path cross-sectional area is set to be constant with respect to the fluid flow direction, a constant region that is provided at a portion communicating with the fluid passage, the flow path cross-sectional area to the fluid flow direction Is reduced, a reduced portion provided at a portion communicating with the predetermined number of the flow channel grooves, and a cross-sectional area of the flow channel is expanded with respect to the fluid flow direction, and the fixed portion and the reduced portion are communicated with each other. that provided Te and a extended portion.

Further, in this fuel cell, the fluid flow path has a plurality of flow path grooves, and the plurality of fluid communication holes and the predetermined number of flow path grooves communicate directly with each other through the connection flow path. , the flow path cross-sectional area is set to be constant with respect to the fluid flow direction, a constant region that is provided at a portion communicating with the fluid passage, the flow path cross-sectional area is expanded to the fluid flow direction, a predetermined number and a extended portion that is provided at a portion of communication with the flow path groove.

In this fuel cell, the fluid channel has a plurality of channel grooves, and the fluid communication hole and the predetermined number of channel grooves communicate directly with each other through the plurality of connection channels, and the connection channel the flow path cross-sectional area is set to be constant with respect to the fluid flow direction, a constant region that is provided at a portion communicating with the fluid passage, the flow path cross-sectional area to the fluid flow direction is reduced, a predetermined and a reduction portion that is provided at a portion communicating with the flow path groove number.

  According to the present invention, the fluid introduced into the connection channel from the fluid communication hole is distributed to the channel groove after the flow rate and the flow direction are changed from a certain part through the expansion part and / or the reduction part. Yes. For this reason, the fluid is uniformly and satisfactorily distributed and supplied from the connection channel to the predetermined number of channel grooves, and the uniformity of the fluid distribution in the fluid channel is effectively improved, and the desired power generation performance, durability performance and fuel are provided. It becomes possible to secure the utilization rate.

  FIG. 1 is an exploded perspective view of the fuel cell 10 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the fuel cell 10.

  In the fuel cell 10, an electrolyte membrane / electrode structure (electrolyte / electrode assembly) 14 is sandwiched between a first separator 16 and a second separator 18. The first and second separators 16 and 18 are made of, for example, a carbon separator, but are made of a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal separator whose surface has been subjected to anticorrosion treatment. It may be configured.

  An oxidant gas (reactive gas), for example, an oxygen-containing gas is supplied to one edge of the fuel cell 10 in the direction of arrow B (horizontal direction in FIG. 1) in communication with the direction of arrow A, which is the stacking direction. An oxidant gas inlet communication hole (fluid communication hole) 20a for supplying a cooling medium, a cooling medium inlet communication hole (fluid communication hole) 22a for supplying a cooling medium, and a fuel gas (reactive gas), for example, a hydrogen-containing gas are discharged. Fuel gas outlet communication holes (fluid communication holes) 24b are arranged in the direction of arrow C (vertical direction).

  The other end edge of the fuel cell 10 in the direction of arrow B communicates with each other in the direction of arrow A, a fuel gas inlet communication hole (fluid communication hole) 24a for supplying fuel gas, and a cooling medium for discharging A cooling medium outlet communication hole (fluid communication hole) 22b and an oxidant gas outlet communication hole (fluid communication hole) 20b for discharging the oxidant gas are arranged in the arrow C direction.

  The electrolyte membrane / electrode structure 14 includes, for example, a solid polymer electrolyte membrane 26 in which a perfluorosulfonic acid thin film is impregnated with water, and a cathode side electrode 28 and an anode side electrode 30 that sandwich the solid polymer electrolyte membrane 26. With. The solid polymer electrolyte membrane 26 is set to have a larger surface area than the cathode side electrode 28 and the anode side electrode 30.

  The cathode side electrode 28 and the anode side electrode 30 are uniformly coated with a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface thereof. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 26.

  An oxidant gas flow path (fluid flow path) 32 is provided on the surface 16 a of the first separator 16 facing the electrolyte membrane / electrode structure 14. As shown in FIG. 3, the oxidant gas channel 32 has a plurality of linear channel grooves 34 extending in the arrow B direction. The oxidant gas inlet communication hole 20 a and the predetermined number of flow channel grooves 34 communicate directly with each other through the connection flow channel 36.

  Describing schematically, for example, of the 16 flow channel grooves 34, the ends of the four flow channel grooves 34 merge (communicate) with the connection flow channel 36, and the oxidant gas inlet communication hole 20a. The four connecting flow paths 36 that communicate with each other are arranged in the direction of arrow C. Similarly, the oxidant gas outlet communication hole 20b and a predetermined number (for example, four) of the channel grooves 34 are directly communicated with each other through the connection channel 36.

  Each of the connection channels 36 has a first part (constant part) 36a in which the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and the channel cross-sectional area is expanded with respect to the oxidant gas flow direction. A second portion (expanded portion) 36b and a third portion (reduced portion) 36c whose flow path cross-sectional area is reduced with respect to the oxidant gas flow direction.

  Specifically, in each connection flow path 36 on the oxidant gas inlet communication hole 20a side, the first part 36a is provided at a part directly communicating with the oxidant gas inlet communication hole 20a, while the third part 36c is The second portion 36b is provided at a portion communicating with a predetermined number (for example, four) of the channel grooves 34, and the second portion 36b is provided so as to smoothly communicate between the first portion 36a and the third portion 36c. .

  Similarly, each connection flow path 36 on the side of the oxidant gas outlet communication hole 20b has a first portion 36a that directly communicates with the oxidant gas outlet communication hole 20b and a predetermined number (for example, four) of flow path grooves 34. A third portion 36c provided in a portion communicating with the second portion 36b, and a second portion 36b provided smoothly communicating the first portion 36a and the third portion 36c.

  As shown in FIG. 4, a fuel gas flow path (fluid flow path) 38 is provided on the surface 18 a of the second separator 18 facing the electrolyte membrane / electrode structure 14. The fuel gas flow path 38 has a plurality of flow path grooves 40, and the fuel gas inlet communication holes 24 a and a predetermined number (for example, four) of the flow path grooves 40 communicate directly with each other through the connection flow paths 42. Similarly, the fuel gas outlet communication hole 24 b and a predetermined number (for example, four) of the flow channel grooves 40 are directly communicated with each other through the connection flow channel 42.

  The connection flow path 42 includes a first part 42a in which the flow path cross-sectional area is set constant with respect to the fuel gas flow direction, and a second part 42b in which the flow path cross-sectional area is expanded in the fuel gas flow direction. , And a third portion 42c whose flow path cross-sectional area is reduced with respect to the fuel gas flow direction.

  In the connection flow path 42 on the fuel gas inlet communication hole 24a side, the first part 42a, the second part 42b, and the third part 42c are connected to the inlet side end portions of the predetermined number of flow channel grooves 40 from the fuel gas inlet communication hole 24a. It continues and smoothly communicates toward The connection flow path 42 on the fuel gas outlet communication hole 24b side includes a first part 42a communicating with the fuel gas outlet communication hole 24b, a third part 42c communicating with a predetermined number of flow channel grooves 40, and the first part. 42a and the 3rd site | part 42c have the 2nd site | part 42b which connects continuously smoothly.

  As shown in FIGS. 1 and 5, a cooling medium flow path (fluid flow path) 44 is provided on the surface 18 b of the second separator 18. The cooling medium flow path 44 has a plurality of flow path grooves 46, and the cooling medium inlet communication holes 22 a and the cooling medium outlet communication holes 22 b and the predetermined number of flow path grooves 46 are directly communicated by the connection flow paths 48.

  The connection channel 48 includes a first part 48a in which the channel cross-sectional area is set constant with respect to the cooling medium flow direction, and a second part 48b in which the channel cross-sectional area is expanded in the cooling medium flow direction. And a third portion 48c whose flow path cross-sectional area is reduced with respect to the cooling medium flow direction.

  The surface 16b of the first separator 16 may be flat, or the cooling medium flow path 44 may be formed in the same manner as the surface 18b of the second separator 18.

  As shown in FIG.1 and FIG.3, the 1st sealing members 50, such as a gasket, are provided in the outer peripheral edge part of the surfaces 16a and 16b of the 1st separator 16. As shown in FIG. The first seal member 50 communicates the oxidant gas inlet communication hole 20a and the oxidant gas outlet communication hole 20b on the surface 16a side with the oxidant gas flow path 32, while the cooling medium inlet communication hole 22a and the oxidant gas outlet communication hole 22b on the surface 16b side. The cooling medium outlet communication hole 22 b communicates with the cooling medium flow path 44.

  As shown in FIGS. 1 and 4, a second seal member 52 such as a gasket is provided on the outer peripheral edge portion of the surfaces 18 a and 18 b of the second separator 18. The second seal member 52 communicates the fuel gas inlet communication hole 24a and the fuel gas outlet communication hole 24b to the fuel gas flow path 38 on the surface 18a side, while the cooling medium inlet communication hole 22a and the cooling medium outlet on the surface 18b side. The communication hole 22 b communicates with the cooling medium flow path 44.

  The operation of the fuel cell 10 configured as described above will be described below.

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 20a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 24a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 22a.

  For this reason, the oxidant gas is introduced into the connection flow path 36 of the first separator 16 from the oxidant gas inlet communication hole 20a as shown in FIG. The oxidant gas moves along the connection channel 36 and is then distributed and supplied to a predetermined number of channel grooves 34 communicating with the connection channel 36. The oxidant gas moves in the direction of arrow B along each flow channel 34 and is supplied to the cathode electrode 28 of the electrolyte membrane / electrode structure 14.

  On the other hand, as shown in FIG. 4, the fuel gas is introduced into the connection channel 42 of the second separator 18 from the fuel gas inlet communication hole 24 a. After the fuel gas moves along the connection flow path 42, it is distributed and supplied to a predetermined number of flow path grooves 40 communicating with the connection flow path 42. The fuel gas moves in the direction of arrow B along each flow channel 40 and is supplied to the anode electrode 30 of the electrolyte membrane / electrode structure 14.

  Therefore, in each electrolyte membrane / electrode structure 14, the oxidant gas supplied to the cathode side electrode 28 and the fuel gas supplied to the anode side electrode 30 are consumed by an electrochemical reaction in the electrode catalyst layer, Power generation is performed.

  As shown in FIG. 3, the oxidant gas flowing along each flow channel groove 34 is discharged to the oxidant gas outlet communication hole 20 b through the connection flow channel 36. Further, the fuel gas flowing along each flow channel groove 40 is discharged from the connection flow channel 42 to the fuel gas outlet communication hole 24b as shown in FIG.

  Further, as shown in FIG. 5, the cooling medium is introduced from a cooling medium inlet communication hole 22 a into a connection channel 48 formed between the first separator 16 and the second separator 18. The cooling medium moves along the connection channel 48 and then is supplied to a predetermined number of channel grooves 46 communicating with the connection channel 48. The cooling medium moves in the direction of arrow B along each flow channel groove 46, cools the power generation surface of the electrolyte membrane / electrode structure 14, and then is discharged from the connection flow channel 48 to the cooling medium outlet communication hole 22 b.

  In this case, in the first embodiment, as shown in FIG. 3, the oxidant gas inlet communication hole 20 a and the predetermined number of flow channel grooves 34 are directly communicated with each other through the connection flow channel 36. The connection channel 36 includes a first portion 36a in which the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and a second portion 36b in which the channel cross-sectional area is expanded in the fluid flow direction. And a third portion 36c whose flow path cross-sectional area is reduced with respect to the fluid flow direction, and these are continuously provided.

  For this reason, the oxidant gas flowing through the connection flow path 36 has a fluid velocity under the expansion action of the second part 36b before reaching the third part 36c, which is a distribution part distributed to each predetermined number of flow path grooves 34. descend. As the fluid velocity decreases, the dynamic pressure decreases, the flow rate to the flow path (34c, 34d in FIG. 7) outside the third portion 36c decreases, and the flow path to the inner flow path (in FIG. 7, The flow rate to 34a, 34b) increases.

  Further, in the third part 36c, the flow direction of the oxidant gas changes as the flow path width is reduced, and the oxidant gas is uniformly distributed in a predetermined number of flow path grooves 34 communicating with the third part 36c. It becomes possible to distribute to. As a result, the oxidant gas can be uniformly and satisfactorily distributed from the connection flow path 36 to the predetermined number of flow path grooves 34, and the uniformity of the oxidant gas distribution over the entire oxidant gas flow path 32 is improved. At the same time, the desired power generation performance, durability performance and fuel utilization rate can be ensured.

  Here, in the case where the normal connection flow path 9 shown in FIG. 6 is used and the case where the connection flow path 36 according to the first embodiment shown in FIG. 7 is used, each flow path groove 34a, 34b, 34c. And a fluid simulation experiment to detect a distributed flow rate of 34d.

  As a result, as shown in FIG. 8, in the conventional connection channel 9 in which the channel cross-sectional area is set to be constant with respect to the fluid flow direction, the flow rate of the channel groove 34d located on the outside is significantly increased. The flow rate of the flow channel groove 34a located at the innermost position is considerably reduced, and a large flow rate difference is generated between the flow channel grooves 34a and 34d.

  On the other hand, when the connection flow path 36 according to the first embodiment is used, the flow rate difference between the gas flow rates flowing through the flow path grooves 34a to 34d is greatly reduced. Therefore, the result that the oxidant gas can be uniformly supplied to the entire oxidant gas flow path 32 was obtained.

  Similarly, in the fuel gas channel 38 and the cooling medium channel 44, the fuel gas and the cooling medium can be supplied uniformly and reliably over the entire separator surface. Thereby, the improvement of the power generation property of the fuel cell 10, the improvement of a distribution property, and the improvement of a fuel utilization factor can be aimed at. In addition, as shown in FIG. 7, the oxidant distributed to the flow channel grooves 34a to 34d by changing the tip positions of the ribs 35a to 35c that determine the inlet side end positions of the flow channel grooves 34a to 34d. It becomes possible to adjust the gas flow rate.

  FIG. 9 is an exploded perspective view of a fuel cell 60 according to the second embodiment of the present invention. Note that the same components as those of the fuel cell 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the following third to sixth embodiments, detailed description thereof is omitted.

  The fuel cell 60 is configured by sandwiching an electrolyte membrane / electrode structure (electrolyte / electrode assembly) 62 between a first separator 64 and a second separator 66. An oxidant gas inlet communication hole 20a, a coolant inlet communication hole 22a, and an oxidant gas outlet communication hole 20b are arranged in the arrow B direction at one end edge (upper edge) in the arrow C direction of the fuel cell 60. .

  A fuel gas inlet communication hole 24a, a cooling medium outlet communication hole 22b, and a fuel gas outlet communication hole 24b are arranged in the arrow B direction at the other end edge (lower edge) in the arrow C direction of the fuel cell 60.

  As shown in FIGS. 9 and 10, a plurality of flow channel grooves 34 constituting the oxidant gas flow channel 32 are formed on the surface 16 a of the first separator 64. The oxidant gas inlet communication hole 20a and the oxidant gas outlet communication hole 20b communicate with both ends of the predetermined number of flow channel grooves 34 via the connection flow channel 36. The oxidant gas inlet communication hole 20a and the oxidant gas outlet communication hole 20b are provided on the same side.

  As shown in FIG. 11, the fuel gas flow path 38 is provided on the surface 18 a of the second separator 66. The plurality of channel grooves 40 constituting the fuel gas channel 38 extend in parallel with each other in the direction of arrow B, and both ends of a predetermined number of the channel grooves 40 are connected to the fuel gas inlet via the connection channel 42. It communicates with the communication hole 24a and the fuel gas outlet communication hole 24b. The fuel gas inlet communication hole 24a and the fuel gas outlet communication hole 24b are provided on the same side.

  As shown in FIG. 9, the cooling medium flow path 44 is formed on the surface 18 b of the second separator 66. The cooling medium flow path 44 has a plurality of flow path grooves 46 extending in the arrow C direction. Both ends of the predetermined number of channel grooves 46 in the direction of arrow C communicate with the cooling medium inlet communication hole 22a and the cooling medium outlet communication hole 22b via the connection channel 48.

  In the second embodiment configured as described above, the oxidant gas flowing through the oxidant gas inlet communication hole 20a flows vertically downward along the connection flow path 36 formed in the first separator 64. After that, it is distributed to a predetermined number of flow channel grooves 34 and supplied in the horizontal direction (arrow B direction). Then, the oxidant gas introduced from the flow channel 34 into the connection flow channel 36 flows vertically upward, and then is discharged to the oxidant gas outlet communication hole 20b.

  Therefore, in the second embodiment, the connection flow path 36 is provided, and the connection flow path 36 includes the first portion 36a, the second portion 36b, and the third portion 36c, and the first embodiment described above. The same effect as the form can be obtained.

  FIG. 12 is an exploded perspective view of a fuel cell 70 according to the third embodiment of the present invention.

  The fuel cell 70 is configured by sandwiching the electrolyte membrane / electrode structure 14 between a first separator 72 and a second separator 74. As shown in FIGS. 12 and 13, a plurality of flow channel grooves 34 constituting the oxidant gas flow channel 32 are formed on the surface 16 a of the first separator 72 facing the electrolyte membrane / electrode structure 14. The oxidant gas inlet communication hole 20 a and the oxidant gas outlet communication hole 20 b communicate with both ends of the predetermined number of flow channel grooves 34 via the connection flow channel 76.

  The connection channel 76 has a first part (constant part) 76a where the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and the channel cross-sectional area is expanded with respect to the oxidant gas flow direction. And a second part (expansion part) 76b.

  In each connection flow path 76 on the oxidant gas inlet communication hole 20a side, the first part 76a is provided at a part that directly communicates with the oxidant gas inlet communication hole 20a, while the second part 76b has a predetermined number of flow paths. It is provided at a portion communicating with the road groove 34. Similarly, each connection flow path 76 on the oxidant gas outlet communication hole 20b side is provided in a first part 76a that directly communicates with the oxidant gas outlet communication hole 20b and a part that communicates with a predetermined number of flow channel grooves 34. And a second portion 76b.

  As shown in FIG. 14, the surface 18 a of the second separator 74 is provided with a plurality of flow channel grooves 40 that constitute the fuel gas flow channel 38. The fuel gas inlet communication hole 24 a and the fuel gas outlet communication hole 24 b communicate with both ends of the predetermined number of flow channel grooves 40 through the connection flow channel 78.

  The connection channel 78 includes a first part (constant part) 78a in which the channel cross-sectional area is set constant with respect to the fuel gas flow direction, and a first part (constant part) 78a in which the channel cross-sectional area is expanded with respect to the fuel gas flow direction. 2 parts (expansion part) 78b. The connection channel 78 is configured in the same manner as the connection channel 76 described above.

  As shown in FIG. 15, the surface 18 b of the second separator 74 is provided with a plurality of flow channel grooves 46 that constitute the cooling medium flow channel 44. The cooling medium inlet communication hole 22 a and the cooling medium outlet communication hole 22 b and the predetermined number of flow channel grooves 46 are in direct communication with each other through the connection flow channel 80.

  The connection channel 80 includes a first part (constant part) 80a where the channel cross-sectional area is set constant with respect to the cooling medium flow direction, and a first part (a constant part) 80a where the channel cross-sectional area is expanded with respect to the cooling medium flow direction. 2 parts (expansion part) 80b.

  In the third embodiment configured as described above, for example, as shown in FIG. 13, the oxidant gas introduced from the oxidant gas inlet communication hole 20a into each connection channel 76 flows from the first part 76a. The road cross-sectional area is supplied to the second portion 76b to be expanded. As a result, the oxidant gas has a reduced fluid velocity and is uniformly and satisfactorily distributed to each predetermined number of flow channel grooves 34. Therefore, the same effects as those of the first and second embodiments described above can be obtained, such as the uniformity of the oxidant gas distribution in the entire oxidant gas flow path 32 being made possible.

  FIG. 16 is an explanatory front view of the first separator 84 constituting the fuel cell according to the fourth embodiment of the present invention.

  A plurality of flow channel grooves 34 constituting the oxidant gas flow channel 32 are formed on the surface 16 a of the first separator 84. At both ends of the predetermined number of flow channel grooves 34, a predetermined number of connection flow paths 86 communicating with the oxidant gas inlet communication hole 20a and the oxidant gas outlet communication hole 20b are provided.

  Each connection channel 86 has a first part (constant part) 86a where the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and a channel cross-sectional area with respect to the oxidant gas flow direction. And a second part (expansion part) 86b to be expanded. In the fourth embodiment, although not shown, a connection channel configured similarly is also provided in the fuel gas channel and the cooling medium channel.

  In the fourth embodiment, the oxidant gas introduced from the oxidant gas inlet communication hole 20a into each connection flow path 86 passes through the second part 86b whose flow path cross-sectional area is expanded from the first part 86a. It is distributed to a predetermined number of flow channel grooves 34. For this reason, the effect similar to the 1st-3rd embodiment is acquired, such as the uniformity of oxidant gas distribution in the oxidant gas flow path 32 whole region being improved.

  FIG. 17 is an exploded perspective view of a fuel cell 90 according to the fifth embodiment of the present invention.

  In the fuel cell 90, the electrolyte membrane / electrode structure 14 is sandwiched between a first separator 92 and a second separator 94. As shown in FIGS. 17 and 18, the surface 16 a of the first separator 92 is provided with a plurality of flow channel grooves 34 constituting the oxidant gas flow channel 32. On both sides of the predetermined number of flow channel grooves 34, there are provided connection flow channels 96 communicating with the oxidant gas inlet communication hole 20a and the oxidant gas outlet communication hole 20b.

  Each connection channel 96 has a first part (constant part) 96a in which the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and the channel cross-sectional area is reduced with respect to the oxidant gas flow direction. A second portion (reduced portion) 96b. In each connection channel 96 on the oxidant gas inlet communication hole 20a side, the first part 96a is provided in a part that directly communicates with the oxidant gas inlet communication hole 20a, while the second part 96b has a predetermined number of flow paths. It is provided at a portion communicating with the road groove 34.

  As shown in FIG. 19, a plurality of flow channel grooves 40 constituting the fuel gas flow channel 38 are provided on the surface 18 a of the second separator 94. On both sides of the predetermined number of flow channel grooves 40, connection flow channels 98 that communicate with the fuel gas inlet communication hole 24a and the fuel gas outlet communication hole 24b are provided.

  The connection channel 98 includes a first part (constant part) 98a in which the channel cross-sectional area is set constant with respect to the fuel gas flow direction, and a first part (constant part) 98a in which the channel cross-sectional area is reduced with respect to the fuel gas flow direction. 2 sites (reduced sites) 98b.

  As shown in FIG. 20, the surface 18 b of the second separator 94 is provided with a plurality of flow channel grooves 46 that constitute the cooling medium flow channel 44. The predetermined number of channel grooves 46, the cooling medium inlet communication hole 22 a, and the cooling medium outlet communication hole 22 b communicate directly with the connection channel 100.

  Each of the connection channels 100 has a first part (a constant part) 100a in which the channel cross-sectional area is set constant with respect to the cooling medium flow direction, and the channel cross-sectional area is reduced with respect to the cooling medium flow direction. And a second part (reduced part) 100b.

  In the fifth embodiment configured as described above, for example, as shown in FIG. 18, the oxidant gas introduced from the oxidant gas inlet communication hole 20a into each connection channel 96 flows from the first part 96a. It is supplied to the second portion 96b where the road cross-sectional area is reduced. For this reason, the flow direction of the oxidant gas changes, and it becomes possible to uniformly distribute the oxidant gas to the predetermined number of flow channel grooves 34 communicating with the second portion 96b. The same effect as the embodiment can be obtained.

  FIG. 21 is an explanatory front view of the first separator 110 constituting the fuel cell according to the sixth embodiment of the present invention.

  A plurality of flow channel grooves 34 constituting the oxidant gas flow channel 32 are provided on the surface 16 a of the first separator 110. The predetermined number of channel grooves 34 communicate with the oxidant gas inlet communication hole 20 a and the oxidant gas outlet communication hole 20 b through the connection channel 112.

  Each connection channel 112 has a first part (constant part) 112a in which the channel cross-sectional area is set constant with respect to the oxidant gas flow direction, and the channel cross-sectional area is reduced with respect to the oxidant gas flow direction. And a second portion (reduced portion) 112b. Although not shown in the figure, a connection channel configured similarly to the connection channel 112 is also provided in the fuel gas channel and the cooling medium channel.

  In the sixth embodiment, the oxidant gas introduced into each connection flow path 112 from the oxidant gas inlet communication hole 20a is supplied from the first part 112a to the second part 112b where the cross-sectional area of the flow path is reduced. The flow direction of the oxidant gas changes. Therefore, the oxidant gas can be uniformly and satisfactorily distributed from each connection channel 112 to the predetermined number of channel grooves 34, and the same effect as in the first to fifth embodiments described above can be obtained. It is done.

1 is an exploded perspective view of a fuel cell according to a first embodiment of the present invention. 2 is a cross-sectional explanatory view of the fuel cell. FIG. It is front explanatory drawing of the 1st separator which comprises the said fuel cell. It is explanatory drawing of one surface of the 2nd separator which comprises the said fuel cell. It is explanatory drawing of the other surface of the 2nd separator which comprises the said fuel cell. It is explanatory drawing of the general connection flow path used for the flow volume detection. It is explanatory drawing of the connection flow path which concerns on 1st Embodiment used for flow volume detection. It is explanatory drawing of a flow volume detection result. FIG. 6 is an exploded perspective view of a fuel cell according to a second embodiment of the present invention. It is front explanatory drawing of the 1st separator which comprises the said fuel cell. It is explanatory drawing of one surface of the 2nd separator which comprises the said fuel cell. It is a disassembled perspective explanatory drawing of the fuel cell which concerns on the 3rd Embodiment of this invention. It is front explanatory drawing of the 1st separator which comprises the said fuel cell. It is explanatory drawing of one surface of the 2nd separator which comprises the said fuel cell. It is explanatory drawing of the other surface of the 2nd separator which comprises the said fuel cell. It is front explanatory drawing of the 1st separator which comprises the fuel cell which concerns on the 4th Embodiment of this invention. It is a disassembled perspective explanatory drawing of the fuel cell which concerns on the 5th Embodiment of this invention. It is front explanatory drawing of the 1st separator which comprises the said fuel cell. It is explanatory drawing of one surface of the 2nd separator which comprises the said fuel cell. It is explanatory drawing of the other surface of the 2nd separator which comprises the said fuel cell. It is front explanatory drawing of the 1st separator which comprises the fuel cell which concerns on the 6th Embodiment of this invention. 2 is an explanatory diagram of a fuel cell disclosed in Patent Document 1. FIG.

Explanation of symbols

10, 60, 70, 90 ... Fuel cell 14, 62 ... Electrolyte membrane / electrode structure 16, 18, 64, 66, 72, 74, 84, 92, 94, 110 ... Separator 20a ... Oxidant gas inlet communication hole 20b ... oxidant gas outlet communication hole 22a ... cooling medium inlet communication hole 22b ... cooling medium outlet communication hole 24a ... fuel gas inlet communication hole 24b ... fuel gas outlet communication hole 26 ... solid polymer electrolyte membrane 28 ... cathode side electrode 30 ... anode Side electrode 32 ... Oxidant gas channel 34, 40, 46 ... Channel groove 36, 42, 48, 76, 78, 80, 86, 96, 98, 100, 112 ... Connection channel 36a-36c, 42a-42c 48a-48c, 76a, 76b, 78a, 78b, 80a, 80b, 86a, 86b, 96a, 96b, 98a, 98b, 100a, 100b, 112a, 112 ... site 38 ... fuel gas flow path 44 ... coolant flow

Claims (3)

An electrolyte / electrode assembly in which electrodes are provided on both sides of the electrolyte is sandwiched between separators, and has fluid communication holes that pass through at least a reaction gas or a cooling medium through the stacking direction, along the separator surface direction. A fuel cell having a fluid flow path for flowing the fluid,
The fluid channel has a plurality of channel grooves,
The fluid communication hole and the predetermined number of the flow channel grooves communicate directly with each other through a plurality of connection flow channels,
Each coupling passage, the flow passage cross-sectional area to the fluid flow direction is set to be constant, and a constant region that is provided at a portion communicating with the fluid passage,
The flow path cross-sectional area is reduced with respect to the fluid flow direction, and a reduced part provided in a part communicating with a predetermined number of the flow path grooves;
It said fluid flow path cross-sectional area to the flow direction is extended, and the extended portion that is provided in communication between the reduced portion and the fixed portion,
Fuel cell comprising: a. An electrolyte / electrode assembly in which electrodes are provided on both sides of the electrolyte is sandwiched between separators, and has fluid communication holes that pass through at least a reaction gas or a cooling medium through the stacking direction, along the separator surface direction. A fuel cell having a fluid flow path for flowing the fluid,
The fluid channel has a plurality of channel grooves,
The fluid communication hole and the predetermined number of the flow channel grooves communicate directly with each other through a plurality of connection flow channels,
The connecting passage, the flow passage cross-sectional area to the fluid flow direction is set to be constant, and a constant region that is provided at a portion communicating with the fluid passage,
The flow path cross-sectional area is expanded to the fluid flow direction, and the extended portion that is provided at a portion communicating with the flow path grooves of a predetermined number,
A fuel cell comprising: An electrolyte / electrode assembly in which electrodes are provided on both sides of the electrolyte is sandwiched between separators, and has fluid communication holes that pass through at least a reaction gas or a cooling medium through the stacking direction, along the separator surface direction. A fuel cell having a fluid flow path for flowing the fluid,
The fluid channel has a plurality of channel grooves,
The fluid communication hole and the predetermined number of the flow channel grooves communicate directly with each other through a plurality of connection flow channels,
The connecting passage, the flow passage cross-sectional area to the fluid flow direction is set to be constant, and a constant region that is provided at a portion communicating with the fluid passage,
Wherein the reduced flow path cross-sectional area to the fluid flow direction, reducing the portion that is provided at a portion communicating with the flow path grooves of a predetermined number,
A fuel cell comprising:

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