JP2020047483A - Fuel cell - Google Patents

Abstract

To provide a fuel cell capable of reducing pressure loss of a cooling medium.SOLUTION: A fuel cell includes a first separator in which a plurality of first channel grooves through which an oxidizing gas flows are provided on one surface thereof, and a plurality of second channel grooves through which a cooling medium flows are provided between the plurality of first channel grooves on the other surface thereof, and a second separator in which a plurality of third channel grooves through which a fuel gas flows are provided on one surface thereof, and a plurality of fourth channel grooves through which the cooling medium flows are provided between the plurality of third channel grooves are provided on the other side thereof. The first and second separators are overlapped with each other so that the surface provided with the second channel grooves and the surface provided with the fourth channel grooves confront each other, and the respective bottom portions of the first and third channel grooves confront each other with an interval therebetween so that the cooling medium flows between the respective bottom portions of the first and third channel grooves at some intersection portions of a plurality of intersection portions where the first and third channel grooves intersect each other in plan view.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a fuel cell.

  For example, a fuel cell is provided with a separator in which a flow channel for a fuel gas or an oxidizing gas is provided on one surface and a flow channel for a cooling medium is provided on the other surface (for example, see Patent Document 1). . The separator is formed in an uneven shape by, for example, press working so that the flow grooves for the fuel gas or the oxidizing gas and the flow grooves for the cooling medium are alternately arranged.

  The separator on the anode side has a flow groove for fuel gas, and the separator on the cathode side has a flow groove for oxidant gas. The anode-side separator and the cathode-side separator are overlapped so that the surfaces provided with the flow channels of the cooling medium face each other across a MEGA (Membrane Electrode Gus diffusion layer Assembly).

JP 2007-165257 A

  In the region where the fuel gas flow grooves and the oxidizing gas flow grooves intersect in plan view of the separator, the cooling medium flow grooves of the anode-side and cathode-side separators merge, so that the cooling medium flow grooves Has a net-like form as a whole. Since the cooling medium flows in a zigzag manner in the mesh-shaped flow channel grooves and changes its traveling direction frequently, the pressure loss becomes higher than when the cooling medium travels in a certain direction. For this reason, the cooling efficiency of the fuel cell may decrease.

  The present invention has been made in view of the above problems, and has as its object to provide a fuel cell that can reduce pressure loss of a cooling medium.

  In the fuel cell described in the present specification, a plurality of first flow grooves through which an oxidizing gas flows are provided on one surface, and a plurality of second flow paths through which a cooling medium flows between the plurality of first flow grooves. A first separator provided with a passage groove on the other surface, and a plurality of third passage grooves through which fuel gas flows are provided on one surface, and the cooling medium flows between the plurality of third passage grooves. A plurality of fourth flow passage grooves have a second separator provided on the other surface, and the first separator and the second separator are provided on the surface provided with the plurality of second flow passage grooves and the plurality of second flow passage grooves. Of the plurality of intersections where the plurality of first flow channels and the plurality of third flow channels intersect in plan view, At some intersections, the cooling medium passes between the bottom of the first flow channel and the bottom of the third flow channel. The bottom of the bottom portion and the third flow channel of the first channel groove faces at intervals.

  ADVANTAGE OF THE INVENTION According to this invention, the pressure loss of the cooling medium of a fuel cell can be reduced.

FIG. 2 is an exploded perspective view showing an example of a fuel cell. It is a top view which shows an example of each channel groove | channel of an oxidizing gas and a fuel gas. It is a top view showing an example of a channel of cooling water of a cathode separator. It is a top view which shows an example of the flow channel of the cooling water of an anode separator. FIG. 7 is a plan view illustrating a path of cooling water in a comparative example. It is sectional drawing of the cathode separator and the anode separator along the AA line. It is a top view showing a course of cooling water in an example. It is sectional drawing of the cathode separator and the anode separator along the BB line. It is sectional drawing which shows an example of the flow-path groove | channel along DD line. It is sectional drawing of the cathode separator and the anode separator along CC line. It is sectional drawing of the cathode separator and the anode separator along the BB line in other Example.

  FIG. 1 is an exploded perspective view showing an example of a fuel cell. The fuel cell stack is configured by stacking a plurality of fuel cells, disposing end plates at both ends thereof, and fastening between the end plates.

  The fuel cell includes a cathode separator 1, an anode separator 2, a frame 3, and a MEGA 5. Reference symbol P1 indicates a cross section of the MEA 50. The MEGA 5 includes a membrane electrode assembly (MEA: Membrane Electrode Assembly) 50 and a pair of gas diffusion layers 51 and 52 sandwiching the MEA 50. The MEA 50 includes an electrolyte membrane 50a, a cathode electrode catalyst layer 50c, and an anode electrode catalyst layer 50b.

  The electrolyte membrane 50a includes, for example, an ion-exchange resin membrane that exhibits good proton conductivity in a wet state. As such an ion exchange resin membrane, for example, a fluororesin type having a sulfonic acid group as an ion exchange group, such as Nafion (registered trademark), may be mentioned.

  Each of the anode electrode catalyst layer 50b and the cathode electrode catalyst layer 50c is formed as a gas-diffusing porous layer containing catalyst-carrying conductive particles and a proton-conductive electrolyte. For example, the anode electrode catalyst layer 50b and the cathode electrode catalyst layer 50c are formed as a dry coating film of a catalyst ink which is a dispersion solution containing platinum-supported carbon and a proton conductive electrolyte.

  A fuel gas such as hydrogen gas is supplied to the anode electrode catalyst layer 50b via one gas diffusion layer 52, and an oxidizing gas such as air is supplied to the cathode electrode catalyst layer 50c via the other gas diffusion layer 51. . The gas diffusion layers 51 and 52 are formed, for example, by laminating a water-repellent microporous layer on a base material such as carbon paper. The microporous layer is formed to contain a water-repellent resin such as PTFE (polytetrafluoroethylene) and a conductive material such as carbon black.

  The MEA 50 generates power by an electrochemical reaction using an oxidizing gas and a fuel gas. The oxidant gas is supplied from the cathode separator 1 to the MEA 50 via the gas diffusion layer 51, and the fuel gas is supplied from the anode separator 2 of another fuel cell adjacent to the fuel cell stack to the MEA 50 via the gas diffusion layer 52. Is done.

  The cathode separator 1 is arranged on the cathode side of the fuel cell, and the anode separator 2 is arranged on the anode side of the fuel cell. In the fuel cell stack, the cathode separator 1 sandwiches the frame 3 and the MEGA 5 between the anode separator 2 of another fuel cell adjacent to the MEGA 5 and the anode separator 2 is a cathode of another fuel cell adjacent to the anode separator 2. The fuel cell frame 3 and the MEGA 5 are sandwiched between the separator 1 and the fuel cell. Note that the cathode separator 1 is an example of a first separator, and the anode separator 2 is an example of a second separator.

  The cathode separator 1 and the anode separator 2 are made of, for example, a metal plate and have a rectangular outer shape. Note that the cathode separator 1 and the anode separator 2 are not limited to metal, and may be formed by, for example, carbon molding. The cathode separator 1 and the anode separator 2 are joined to each other by an adhesive or welding, and the cathode separator 1 is adhered to the frame 3 by, for example, an adhesive.

  The frame 3 is made of, for example, a resin sheet having a rectangular outer shape. Examples of the material of the frame 3 include a polyethylene terephthalate (PET) resin, a syndiotactic polystyrene (SPS) resin, and a polypropylene (PP) resin.

  A rectangular opening 30 is provided at the center of the frame 3. The opening 30 is provided at a position corresponding to the MEGA 5, and an outer end of the MEA 50 is bonded to the edge thereof. Thereby, the MEGA 5 is fixed to the frame 3.

  The cathode separator 1 is provided so that through holes 11 to 13 are arranged along one end, and the through holes 14 to 16 are arranged along the other end on the opposite side. The anode separator 2 is provided so that the through holes 21 to 23 are arranged along one end, and the through holes 24 to 26 are arranged along the other end on the opposite side. The frame 3 is provided so that the through holes 31 to 33 are arranged along one end, and the through holes 34 to 36 are arranged along the other end on the opposite side.

  The through holes 11, 21, 31 constitute a fuel gas supply manifold by overlapping each other when the fuel cells are stacked. The fuel gas is supplied to each fuel cell by flowing in the fuel gas supply manifold in the stacking direction of the fuel cell stack as indicated by an arrow Hin.

  The through holes 16, 26, and 36 constitute a fuel gas exhaust manifold by overlapping each other when the fuel cells are stacked. The fuel gas used for power generation flows from each fuel cell through the fuel gas discharge manifold in the stacking direction of the fuel cell stack and is discharged, as indicated by an arrow Hout.

  The through holes 12, 22, and 32 constitute a cooling water supply manifold by overlapping each other when the fuel cells are stacked. The cooling water is supplied to each fuel cell by flowing in the cooling water supply manifold in the stacking direction of the fuel cell stack, as indicated by an arrow Cin. The cooling water is an example of a cooling medium that cools the fuel cell.

  The through holes 15, 25, and 35 constitute a cooling water discharge manifold by overlapping each other when the fuel cells are stacked. The cooling water used for cooling the fuel cells is discharged from each fuel cell by flowing in the cooling water discharge manifold in the stacking direction of the fuel cell stack, as indicated by an arrow Cout.

  The through holes 14, 24, and 34 constitute an oxidizing gas supply manifold by overlapping each other when the fuel cells are stacked. The oxidizing gas is supplied to each fuel cell by flowing in the oxidizing gas supply manifold in the stacking direction of the fuel cell stack, as indicated by an arrow Ain.

  The through holes 13, 23, and 33 constitute an oxidant gas discharge manifold by overlapping each other when the fuel cells are stacked. The oxidizing gas used for power generation is discharged from each fuel cell by flowing in the oxidizing gas discharge manifold in the stacking direction of the fuel cell stack, as indicated by an arrow Aout.

  The cathode separator 1 has a cathode channel portion 1c in which a channel groove for oxidizing gas is provided on one surface 1a and a channel groove for cooling water is provided on the opposite surface 1b. The anode separator 2 has an anode flow channel portion 2c in which a fuel gas flow channel is provided on one surface 2a and a cooling water flow channel is provided on the opposite surface 2b.

  The cathode separator 1 and the anode separator 2 are overlapped so that the surfaces 1b and 2b provided with the cooling water flow grooves face each other. The cooling water flows from the supply-side through-hole 12 into the discharge-side through-hole 15 through the flow passage grooves of the cathode flow passage 1c and the anode flow passage 2c.

  The cathode separator 1 is laminated such that the surface 1 a provided with the oxidant gas flow channel faces the gas diffusion layer 51 of the MEGA 5. The oxidizing gas flows from the supply-side through-hole 14 through the flow channel into the discharge-side through-hole 13.

  The anode separator 2 is stacked such that the surface 2a provided with the fuel gas flow channel faces the gas diffusion layer 52 of the MEGA 5 of another fuel cell adjacent to the fuel cell stack. The fuel gas flows from the supply side through hole 21 through the flow channel into the discharge side through hole 26.

  Next, the configuration of each flow channel will be described.

  FIG. 2 is a plan view showing an example of each flow channel groove of the oxidizing gas and the fuel gas. More specifically, FIG. 2 shows each flow path of the oxidizing gas and the fuel gas when the surface 1a of the cathode separator 1 and the surface 2a of the anode separator 2 are overlapped and viewed in plan according to the direction V shown in FIG. It is a figure showing a groove.

  On the surface 1a side of the cathode flow channel portion 1c, an upstream flow channel groove group 10b, a middle flow channel groove group 10a, and a downstream flow channel group 10c including a plurality of flow grooves are formed. The upstream flow channel group 10b, the middle flow channel groove group 10a, and the downstream flow channel group 10c communicate with each other, and the upstream flow channel groove group 10b is connected to the supply-side through hole 14, and the downstream flow channel The road groove group 10c is connected to the through hole 13 on the discharge side. As indicated by the arrows, the oxidant gas is discharged from the supply-side through-hole 14 through the upstream flow channel groove group 10b, the middle flow channel groove group 10a, and the downstream flow channel groove group 10c in this order. Flows into the through-hole 13 on the side.

  On the surface 2a side of the anode flow channel portion 2c, an upstream flow channel groove group 20b, a middle flow channel groove group 20a, and a downstream flow channel group 20c including a plurality of flow grooves are formed. The upstream flow channel group 20b, the middle flow channel groove group 20a, and the downstream flow channel group 20c communicate with each other, and the upstream flow channel groove group 20b is connected to the supply-side through-hole 21, and the downstream flow channel The road groove group 20c is connected to the through hole 26 on the discharge side. As shown by the arrows, the fuel gas flows through the upstream side flow channel group 20b, the middle flow channel groove group 20a, and the downstream flow channel group 20c from the supply side through hole 21 in this order to the discharge side. Flows into the through hole 26.

  The middle flow channel grooves 10a and 20a of the oxidizing gas and the fuel gas overlap the MEA 50 in plan view. The oxidizing gas is transferred between the middle flow channel groove group 10a and the MEA 50, and the fuel gas is transferred between the middle flow channel groove group 20a and the MEA 50. For this reason, the middle flow path groove groups 10a and 20a correspond to a power generation region in which power is generated.

  The middle flow path groove groups 10a and 20a include, for example, a plurality of parallel flow grooves along the long sides of the cathode separator 1 and the anode separator 2, but are not limited thereto. For example, they are arranged in a serpentine shape. A plurality of formed flow grooves may be included. Also, the upstream region flow groove groups 10b and 20b include a plurality of parallel flow grooves inclined with respect to the long side so as to be connected to the middle flow region flow groove groups 10a and 20a. The flow groove groups 10c and 20c include a plurality of parallel flow grooves inclined with respect to the long side so as to be connected to the middle flow region flow groove groups 10a and 20a.

  The oxidant gas through-holes 13 and 14 are located in the vicinity of one set of diagonal corners of the cathode separator 1, and the fuel gas through-holes 21 and 26 are formed in another set that does not overlap with the above-described one set of the anode separator 2. Located near the diagonal of the set. For this reason, the flow grooves of the oxidizing gas and a part of the flow grooves of the fuel gas, which are inclined with respect to the long sides, intersect in plan view as indicated by reference numerals P2 and P3.

  Next, the flow channel of the cooling water will be described.

  FIG. 3 is a plan view illustrating an example of a flow channel of the cooling water of the cathode separator 1. FIG. 3 is a plan view of the surface 1b, in which the cooling water flow channel is formed, viewed through the opposite surface 1a according to the direction V of FIG. 1 so as to facilitate comparison with FIG. Are shown.

  On the surface 1b side of the cathode flow channel portion 1c, an upstream flow channel groove group 19b, a middle flow channel groove group 19a, and a downstream flow channel group 19c including a plurality of flow grooves are formed. The upstream channel groove group 19b, the middle flow channel groove group 19a, and the downstream channel groove group 19c communicate with each other, and the upstream channel groove group 19b is connected to the supply-side through-hole 12, and the downstream flow channel The road groove group 19c is connected to the through hole 15 on the discharge side. As shown by an arrow, the cooling water passes through the upstream side flow channel group 19b, the middle flow channel groove group 19a, and the downstream flow channel group 19c in this order from the supply side through hole 12 to the discharge side. Flows into the through hole 15.

  The cathode flow channel portion 1c is formed in an uneven shape by, for example, press working so that the flow channels of the cooling water are alternately arranged on the plane. For this reason, the cooling water flow grooves are provided between the oxidizing gas flow grooves on the opposite surface 1a. In other words, the cooling water flow channel functions as a wall of the oxidizing gas flow channel, and conversely, the oxidizing gas flow channel functions as a wall of the cooling water flow channel.

  FIG. 4 is a plan view illustrating an example of a flow channel of the cooling water of the anode separator 2. FIG. 4 shows the cooling water flow grooves when the surface 2b on which the cooling water flow grooves are formed is viewed in a plan view in the direction V of FIG.

  On the surface 2b side of the anode flow channel portion 2c, an upstream flow channel groove group 29b, a middle flow channel groove group 29a, and a downstream flow channel group 29c including a plurality of flow grooves are formed. The upstream channel groove group 29b, the middle flow channel groove group 29a, and the downstream channel groove group 29c communicate with each other, and the upstream channel groove group 29b is connected to the supply-side through-hole 22, and the downstream flow channel The road groove group 29c is connected to the through hole 25 on the discharge side. As shown by the arrow, the cooling water passes through the upstream-side channel groove group 29b, the middle-stream region channel groove group 29a, and the downstream-side channel groove group 29c in this order from the supply-side through-hole 22 to the discharge side. Flows into the through hole 25.

  The anode flow path portion 2c is formed in an uneven shape by, for example, press working so that the flow grooves of the cooling water are alternately arranged on the plane. For this reason, the cooling water flow grooves are provided between the fuel gas flow grooves on the opposite surface 2a. That is, the cooling water passage groove functions as a wall of the fuel gas passage groove, and conversely, the fuel gas passage groove functions as a wall of the cooling water passage groove.

  Next, the path through which the cooling water flows will be described.

  FIG. 5 is a plan view showing the path of the cooling water in the comparative example. In FIG. 5, the flow path groove 100 for the oxidizing gas, the flow groove 200 for the fuel gas, and the flow grooves 101 and 201 for the cooling water when the area P3 in FIGS. Is shown. The right direction in FIG. 5 is the manifold side, and the left direction in FIG. 5 is the power generation area side.

  FIG. 6 is a cross-sectional view of the cathode separator 1 and the anode separator 2 along the line AA. More specifically, FIG. 6 shows a part of a cross section when viewed from the cathode separator 1 side. Note that the line AA is along a part of the path of the cooling water indicated by the arrow.

  In the region denoted by reference numeral P3, the oxidizing gas used for power generation flows through the flow channel 100 from the power generating region toward the oxidizing gas discharge manifold. Further, the fuel gas flows through the flow channel 200 from the fuel gas supply manifold toward the power generation area. At the intersection P where the oxidant gas flow groove 100 and the fuel gas flow groove 200 intersect, the bottom of each flow groove 100, 200 is formed so that the support rigidity between the cathode separator 1 and the anode separator 2 is obtained. 100a and 200a are in contact with each other. Therefore, the cooling water cannot pass through the intersection P.

  The cooling water flows from the cooling water supply manifold to the power generation region through the flow channel 201 of the anode separator 2 and the flow channel 101 of the cathode separator 1. At the intersection P ′ between the flow grooves 201, 101, since the bottoms 101a, 201a of the flow grooves 101, 201 face each other with a space therebetween, the cooling water flowing through each flow groove 101, 201 Join. In FIG. 5, only the intersection P 'on the line AA is indicated by a reference numeral.

  The cooling water partially flows from one of the flow channels 101 and 201 to the other at the intersection P ′. In FIG. 6, the path through which the cooling water flows from the flow channel 201 to the flow channel 101 is indicated by an arrow. On the contrary, there is also a path through which the cooling water flows from the flow channel 101 to the flow channel 201. I do. For this reason, the flow grooves 101 and 201 of the cooling water have a net-like form as a whole.

  As shown by an arrow in FIG. 5, for example, the cooling water crosses the cooling water flow grooves 101 and 201 so as to avoid the intersection P of the oxidizing gas and fuel gas flow grooves 100 and 200. It flows zigzag while changing the traveling direction at the section P '. As described above, since the traveling direction of the cooling water changes frequently, the pressure loss becomes higher than when the cooling water proceeds in a fixed direction. For this reason, the cooling efficiency of the fuel cell may decrease.

  Therefore, in the fuel cell of the embodiment, the oxidizing gas flow channel 100 and the fuel gas flow at some intersections P so that the cooling water flows between the bottoms 100a and 200a of the flow channels 100 and 200. At least one of the channel grooves 200 is formed shallow. Thereby, the frequency of the cooling water changing the traveling direction is reduced, so that an increase in the pressure loss of the cooling water is suppressed.

  FIG. 7 is a plan view showing cooling water paths Ka and Kb in the embodiment. FIG. 7 shows the flow grooves 110 and 111 of the oxidizing gas, the flow grooves 210 and 211 of the fuel gas, and the flow groove 112 of the cooling water when the area indicated by reference numeral P3 in FIGS. , 212 are partially shown.

  In addition, the right direction on the paper surface of FIG. 7 is the respective manifold side, and the left direction of the paper surface of FIG. 7 is the power generation region side. The oxidant gas flow grooves 110 and 111 are examples of a first flow groove, and the cooling water flow groove 112 is an example of a second flow groove. The fuel gas flow grooves 210 and 211 are examples of a third flow groove, and the cooling water flow groove 212 is an example of a fourth flow groove.

  FIG. 8 is a cross-sectional view of the cathode separator 1 and the anode separator 2 along the line BB. More specifically, FIG. 8 shows a part of a cross section when viewed from the cathode separator 1 side. In addition, the BB line is along a part of the path Ka of the cooling water indicated by the arrow.

  In this example, the depth of the flow channel 112 of the cooling water of the cathode separator 1 is constant as in the comparative example, but the depth of the flow channels 110 and 111 of the oxidizing gas is different. The flow grooves 110 and 111 are alternately arranged with the cooling water flow groove 112 interposed therebetween, and one flow groove 110 is formed shallower than the other flow groove 111.

  The depth of the cooling water channel groove 212 of the anode separator 2 is constant as in the comparative example, but the depth of the fuel gas channel grooves 210 and 211 is different. The flow grooves 210 and 211 are alternately arranged with the cooling water flow groove 212 interposed therebetween, and one flow groove 211 is formed shallower than the other flow groove 210. The depths of the flow grooves 111 and 210 are the same as those of the flow grooves 100 and 200 of the comparative example.

  Therefore, at the intersection Q where the shallow flow grooves 110 and 211 intersect, there is a gap L between the bottoms 110a and 211a of the flow grooves 110 and 211 through which the cooling water can pass. That is, the bottoms 110a and 211a of the flow grooves 110 and 211 face each other at an interval. On the other hand, at the intersection R where the deep flow grooves 111 and 210 intersect, the bottom portions 111a and 210a of the flow grooves 111 and 210 are in contact with each other so as to obtain support rigidity between the cathode separator 1 and the anode separator 2. doing. Therefore, the cooling water cannot pass through the intersection R.

  At the intersection P ′ where the flow grooves 112 and 212 intersect with each other, the bottoms 112a and 212a of the flow grooves 112 and 212 face each other at intervals, as in the comparative example. The cooling water flowing through the flow channels 112 and 212 joins. In FIG. 7, only the intersection P 'on the line BB is indicated by reference numerals.

  The intersections P 'of the cooling water flow grooves 112 and 212 are adjacent to each other via the intersection Q of the shallow flow grooves 110 and 211. As shown by arrows in FIG. 8, the cooling water passes through the gap L between the bottoms 110a and 211a of the shallow flow grooves 110 and 211 from the intersection P 'on the cooling water supply manifold side, and the cooling water on the power generation area side. It flows into the intersection P '.

  As shown by an arrow in FIG. 8, as an example, the cooling water flows into the gap L from the flow channel 212 at the intersection P ′ on the cooling water supply manifold side, and the flow channel 112 at the intersection P ′ on the power generation region side. Flow into However, although not shown, there is a cooling water path that flows into the gap L from the flow channel 112 at the intersection P ′ on the cooling water supply manifold side and flows into the flow channel 212 at the intersection P ′ on the power generation region side. I do.

  As described above, since the bottom portions 110a and 211a of the oxidant gas flow channel 110 and the fuel gas flow channel 211 face each other with a space therebetween, the cooling water flows through the flow channel on the cooling water supply manifold side. It can flow from the gaps L from the channels 112 and 212 into the flow channels 112 and 212 on the power generation area side.

  Therefore, the cooling water travels at the intersection P ′ of the cooling water flow grooves 112 and 212 so as to avoid the intersection R between the deep flow grooves 111 and 210 like the path Ka shown in FIG. However, at the intersection Q between the shallow flow channel grooves 110 and 211, the flow can flow straight toward the power generation region. Therefore, the frequency of changing the traveling direction of the cooling water is reduced as compared with the comparative example, so that an increase in the pressure loss of the cooling water is suppressed.

  As shown in FIG. 8, step portions 111b and 210b are provided at both ends of the bottom portions 111a and 210a of the deep flow channels 111 and 210 so that a step is formed with respect to the bottom portions 111a and 210a. As described below, since the deep channel groove 111 has the step portion 111b, the difference in pressure loss of the oxidizing gas between the deep channel groove 111 and the shallow channel groove 110 is reduced.

  FIG. 9 is a cross-sectional view showing an example of the flow channel 111 along the line DD (see FIG. 8). More specifically, FIG. 9 shows a cross section along the direction in which the oxidizing gas flows in the flow channel 111. In FIG. 9, the same components as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

  In the flow channel 111, for example, convex portions 111c are provided at regular intervals along the direction in which the oxidizing gas flows. The upper portion of the convex portion 111c corresponds to, for example, the height of the step portion 111b.

  In the space defined by the convex portion 111c, the step portion 111b, and the bottom portion 111a, a vortex of the oxidizing gas is generated as indicated by a dotted arrow. The oxidant gas vortex does not substantially impede the flow of the oxidant gas at the top, and therefore does not contribute to the pressure loss. Therefore, by adjusting the height position of the step portion 111b to the position of the bottom portion 110a of the shallow flow channel 110, the difference in flow cross-sectional area between the deep flow channel 111 and the shallow flow channel 110 is reduced.

  Thereby, the difference in pressure loss of the oxidizing gas between the deep channel groove 111 and the shallow channel groove 110 is reduced. Since the fuel gas flow channel 210 is provided with the same configuration as described above, the fuel gas vortex is generated at the bottom portion 210a, so that the pressure loss of the oxidizing gas between the flow channel 210 and the flow channel 211 is reduced. Is reduced.

  As described above, since the difference in pressure loss between the deep flow grooves 111 and 210 and the shallow flow grooves 110 and 211 is reduced, the unevenness in the flow rates of the oxidizing gas and the fuel gas flowing in the power generation region is reduced. Thus, the power generation efficiency of the fuel cell is improved.

  As shown in a path Kb shown in FIG. 7, the cooling water flows through an intersection T where the deep flow groove 111 intersects with the shallow flow groove 211, and a deep flow groove 210 intersects with the shallow flow groove 110. Even at the intersection S, it can flow straight toward the power generation area, so that the pressure loss is further reduced.

  FIG. 10 is a cross-sectional view of the cathode separator 1 and the anode separator 2 along the line CC. More specifically, FIG. 10 shows a part of a cross section when viewed from the cathode separator 1 side. Note that the line CC follows the path Kb of the cooling water indicated by the arrow. 10, the same reference numerals are given to the same components as those in FIG. 8, and the description will be omitted.

  At the intersection S, a gap M through which cooling water flows exists between the bottom 110a of the shallow flow channel 110 and the bottom 210a of the deep flow channel 210. That is, the bottoms 110a and 210a of the flow channels 110 and 210 face each other at an interval. At the intersection T, a gap N through which cooling water flows exists between the bottom 211 a of the shallow flow channel 211 and the bottom 111 a of the deep flow channel 111. That is, the bottom portions 111a and 211a of the flow channel grooves 111 and 211 are opposed to each other at an interval.

  Therefore, the cooling water can flow straight through the gaps M and N at the intersections S and T from the cooling water supply manifold toward the power generation area along the route Kb. Accordingly, the frequency of changing the course of the cooling water is reduced as compared with the comparative example, so that the pressure loss of the cooling water is reduced.

  As described above, a part of the intersections Q, R, S, and T where the plurality of flow grooves 110 and 111 through which the oxidizing gas flows and the plurality of flow grooves 210 and 211 through which the fuel gas flows intersects. At the intersections Q, S, and T, the cooling water passes between the bottoms 110a, 111a, 210a, 211a of the bottoms 110a, 111a of the flow grooves 110, 111 and the bottoms 210a, 211a of the flow grooves 210, 211. As shown in FIG. For this reason, since the cooling water flows through the gaps between the bottoms 110a, 111a, 210a, and 211a, the frequency of changing the traveling direction of the cooling water is reduced as compared with the comparative example, and the increase in the pressure loss of the cooling water is suppressed. Is done.

  In this example, the shallow flow grooves 110 and 211 are provided in each of the cathode separator 1 and the anode separator 2, but the shallow flow grooves 110 and 211 are provided in only one of the cathode separator 1 and the anode separator 2. Is also good.

  FIG. 11 is a cross-sectional view of the cathode separator 1 and the anode separator 2 along the line BB in another example. 11, the same components as those in FIGS. 6 and 8 are denoted by the same reference numerals, and description thereof will be omitted.

  In this example, the anode separator 2 has the same flow channels 200 and 201 as the comparative example. For this reason, the depth of the fuel gas passage groove 200 is uniform. The flow channel 200 is an example of a third flow channel, and the flow channel 201 is an example of a fourth flow channel.

  At the intersection R where the flow channel 200 and the deep flow channel 111 intersect, the bottom portions 111a and 200a of the flow channels 111 and 200 are in contact with each other so as to obtain support rigidity between the cathode separator 1 and the anode separator 2. I do. Further, at an intersection Q where the flow channel 200 and the shallow flow channel 110 intersect, a gap K through which cooling water flows exists between the bottom portions 110a and 200a of the flow channels 110 and 200. That is, the bottoms 110a and 200a of the flow channels 110 and 200 are opposed to each other with an interval.

  Therefore, like the route Ka shown in FIG. 7, the cooling water changes its traveling direction at the intersection P ′ of the cooling water flow grooves 112 and 201 so as to avoid the intersection R of the flow grooves 111 and 200. However, at the intersection Q between the flow channels 110 and 200, the gas can flow straight toward the power generation region. Thereby, the frequency of changing the traveling direction of the cooling water is reduced as compared with the comparative example, so that an increase in pressure loss of the cooling water is suppressed.

  As described above, at some of the intersections Q and R where the plurality of flow grooves 110 and 111 where the oxidizing gas flows and the plurality of flow grooves 200 where the fuel gas flows intersect, The bottom 110a of the passage groove 110 and the bottom 200a of the passage groove 200 face each other at an interval so that the cooling water passes between the bottoms 110a and 200a. For this reason, the cooling water flows through the gap K between the bottoms 110a and 200a, so that the frequency of changing the traveling direction of the cooling water is reduced as compared with the comparative example, so that an increase in the pressure loss of the cooling water is suppressed.

  In this example, the anode separator 2 is provided with the channel groove 200 having a uniform depth. Instead, the cathode separator 1 is provided with the channel groove 100 having the same depth as the comparative example. May be provided. In this case, since the flow channel 211 is shallower than the other flow channels 210, the cooling water can flow between the flow channel 211 and the bottom portions 211 a and 100 a of the flow channel 100, and the pressure of the cooling water The increase in loss is suppressed.

  In addition, the above configuration can be applied to the area indicated by reference numeral P2 in FIGS. In this case, the pressure loss of the cooling water from the power generation area to the cooling water discharge manifold is reduced, and the cooling water discharge performance is improved.

  Further, in each embodiment, the middle flow channel grooves 10a and 20a each have a straight flow groove in the cathode separator 1 and the anode separator 2, but the present invention is not limited thereto. May have. In this case, even if the same configuration as described above is applied to a part of the intersection where the oxidizing gas flow groove and the fuel gas flow groove intersect in plan view in the middle flow region flow groove groups 10a and 20a. Good.

  Further, in the above embodiment, the depth differs for each of the flow grooves 110, 111, 210, and 211, but the depth changes along the flow direction of the oxidizing gas or the fuel gas in one flow groove. You may. In this case, among the intersections of the respective flow grooves of the oxidizing gas and the fuel gas, at the intersection where at least one of the flow grooves is shallow, there is a gap between the bottoms of the respective flow grooves. It can flow through the intersection, and the same effect as above can be obtained.

  The above embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Cathode separator 2 Anode separator 1a, 1b, 2a, 2b Surface 100, 101, 110-112 Flow groove 200, 201, 210-212 Flow groove 100a, 101a, 110a-112a Bottom 200a, 201a, 210a-212a Bottom P ~ T, P 'intersection

Claims (1)

A plurality of first flow grooves through which the oxidizing gas flows are provided on one surface, and a plurality of second flow grooves through which the cooling medium flows between the plurality of first flow grooves are provided on the other surface. A first separator;
A plurality of third flow grooves through which the fuel gas flows are provided on one surface, and a plurality of fourth flow grooves through which the cooling medium flows are provided between the plurality of third flow grooves on the other surface. A second separator,
The first separator and the second separator are overlapped so that a surface provided with the plurality of second flow channels and a surface provided with the plurality of fourth flow channels face each other,
Among a plurality of intersections where the plurality of first passage grooves intersect with the plurality of third passage grooves in plan view, at some intersections, the bottom of the first passage groove and the third flow passage A fuel cell, wherein the bottom of the first flow path groove and the bottom of the third flow path groove face each other at an interval so that the cooling medium passes between the bottoms of the path grooves.

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