JP4899339B2 - Fuel cell separator - Google Patents

Description

  The present invention relates to a fuel cell separator, and more particularly, to a cooling medium distribution structure.

  In a fuel cell, for example, a polymer electrolyte fuel cell, a fuel gas containing hydrogen and an oxidizing gas containing oxygen are respectively supplied to two electrodes (an oxygen electrode and a fuel electrode) facing each other with an electrolyte membrane interposed therebetween. Thus, an electrochemical reaction is performed, and the chemical energy of the substance is directly converted into electrical energy. As a main structure of such a fuel cell, a so-called stack structure has been developed in which a substantially flat membrane electrode assembly (MEA) and a separator are stacked and fastened in the stacking direction.

  By the way, the fuel cell generates heat due to the thermal energy generated in the above-described electrochemical reaction and the electrical resistance of the constituent materials. An increase in temperature due to heat generation may reduce the performance of the fuel cell. For example, in a polymer electrolyte fuel cell, the amount of water contained in the electrolyte membrane may decrease as the temperature rises, causing a problem called dry-up. For this reason, in order to improve the performance of the fuel cell, it is required to cool the fuel cell efficiently.

  Here, as a fuel cell separator, a separator having a three-layer structure including an anode side plate, a cathode side plate, and an intermediate plate sandwiched between both plates is known (Patent Document 1). . In this three-layered separator, a cooling medium supply manifold and a discharge manifold that penetrate the separator are provided at two diagonal portions of the quadrangular separator. The intermediate plate has a meandering power generation region of the fuel cell, and is provided with a single coolant flow path whose both ends communicate with the supply manifold and the discharge manifold.

JP 2004-6104 A

  However, in the above conventional technique, the cooling medium flow path is formed by punching the intermediate plate and the cooling medium is distributed, so that the degree of freedom of the arrangement of the cooling medium flow path is reduced, and the cooling medium is efficiently performed. Could not be distributed. Specifically, in the above prior art, since the manifold area is narrow, a single cooling medium is meandered, and the pressure loss of the cooling medium may increase and the cooling efficiency may deteriorate.

  The present invention has been made to solve the above-described problems, and an object thereof is to efficiently distribute a cooling medium in a separator of a fuel cell.

In order to solve the above problems, an aspect of the present invention provides a separator that is alternately stacked with membrane electrode assemblies to constitute a fuel cell. The separator according to the aspect of the present invention includes a cathode plate that contacts the cathode side of the membrane electrode assembly, an anode plate that contacts the anode side of the membrane electrode assembly, and an intermediate sandwiched between the cathode plate and the anode plate. An intermediate plate having a cooling medium flow part that penetrates in the thickness direction and flows a cooling medium in at least a part of a region that overlaps the membrane electrode assembly when viewed from the stacking direction; and the cooling medium Distributing portion that is disposed in a flow portion and formed by a non-porous body that is separate from the intermediate plate, and is disposed on a substrate parallel to the intermediate plate, on both sides or one side of the substrate, and and a distribution unit and a plurality of elastic portion is elastically deformed in the direction of lamination, the distribution unit, the cooling medium in the cooling medium flowing section Distributed in the plane direction of the serial separator, the direction of the width of the stack of the distribution unit may be greater than the thickness of said intermediate plate.

The separator which concerns on the aspect of this invention has a cooling-medium flow part between two plates which clamp an intermediate | middle plate. Then, by disposing a distribution part formed of a non-porous body separate from the intermediate plate in the cooling medium flow part, the cooling medium is distributed in the surface direction of the separator in the cooling medium flow part. As a result, it is possible to cool the fuel cell efficiently with a higher degree of freedom in arranging the distribution structure than in the case where the cooling medium is distributed by the cooling medium flow path provided by punching the intermediate plate. In addition, since the distributor and the cathode plate and the distributor and the anode plate are in reliable contact, the contact resistance inside the separator can be reduced. Further, the cooling medium is distributed by the plurality of elastic portions, and the elastic portions enhance the contact between the distribution portion and the cathode plate and between the distribution portion and the anode plate. As a result, it is possible to achieve both the distribution of the cooling medium and the reduction of the contact resistance inside the separator.

  The fuel cell according to an aspect of the present invention further includes a cooling medium supply manifold that penetrates the separator in the thickness direction, a cooling medium discharge manifold that penetrates the separator in the thickness direction, the cooling medium supply manifold, and the cooling You may provide the cooling medium supply flow path which connects a medium flow part, and the cooling medium discharge flow path which connects the said cooling medium discharge manifold and the said cooling medium flow part. The cooling medium flowing through the cooling medium flow section can be supplied / discharged via the cooling medium supply / discharge manifold.

  The separator which concerns on the aspect of this invention WHEREIN: The said some elastic part may be arrange | positioned so that it may be distributed to the whole said cooling-medium flow part. By so doing, the cooling medium is distributed to the entire cooling medium flow part by the elastic part, so that the fuel cell can be efficiently cooled.

  In the separator according to the aspect of the present invention, the elastic portion extends from the substrate at a predetermined angle and has a plurality of first plate members whose end portions contact the cathode plate, and extends from the substrate at a predetermined angle. It may be a plurality of second plate-like members whose parts are in contact with the anode plate. In such a case, the first plate-like member and the second plate-like member function as a leaf spring, so that the contact between the distribution portion and the cathode plate and between the distribution portion and the anode plate is performed. Power to strengthen is generated. Furthermore, since the first plate-like member and the second plate-like member diffuse the cooling medium in the cooling medium flowing portion, the cooling performance of the fuel cell can be improved.

  The separator which concerns on the aspect of this invention WHEREIN: The edge part of the said 1st and 2nd plate-shaped member may be bent in parallel with the said board | substrate, The edge of the said 1st and said 2nd plate-shaped member The part may be bent perpendicularly to the substrate. By adjusting the shape of the end portions in contact with the cathode plate and the anode plate, it is possible to adjust the magnitude of the pressure that enhances the contact between the distribution portion and the cathode plate and between the distribution portion and the anode plate.

  In the separator according to the aspect of the present invention, a distance between the substrate and the cathode plate may be larger than a distance between the substrate and the anode plate. By so doing, the amount of flow on the cathode plate side is larger than that on the anode plate side in the cooling medium flow portion, so that the cathode plate side with a large amount of heat generation can be efficiently cooled.

  The separator which concerns on the aspect of this invention WHEREIN: The said distribution part may be produced by carrying out the plastic working of the board | plate material thinner than the said intermediate | middle plate. In this way, the distribution unit can be easily manufactured.

  Hereinafter, a separator according to the present invention will be described based on examples with reference to the drawings.

A. First embodiment:
With reference to FIGS. 1-2, schematic structure of the fuel cell stack containing the separator based on 1st Example of this invention is demonstrated. FIG. 1 is an explanatory diagram showing the configuration of the fuel cell stack in the first embodiment. FIG. 2 is an explanatory diagram showing the configuration of the unit 200 of the stack of fuel cell stacks.

  The fuel cell stack 100 is configured by stacking a plurality of stack units 200. The fuel cell stack 100 includes an oxidizing gas supply manifold 110, an oxidizing gas discharge manifold 120, a fuel gas supply manifold 130, a fuel gas discharge manifold 140, a cooling medium supply manifold 150, and a cooling medium discharge manifold 160. Is provided. Note that air is generally used as the oxidizing gas, and hydrogen is generally used as the fuel gas. Further, both the oxidizing gas and the fuel gas are also called reaction gases. As the cooling medium, water, antifreeze water such as ethylene glycol, air, or the like can be used.

  As shown in FIG. 2, the unit 200 of the stack includes a separator 1000 and a seal-integrated membrane electrode assembly 2000.

  The separator 1000 includes an anode plate 300, a cathode plate 400, an intermediate plate 500, and a distribution member 600. The intermediate plate 500 is provided with a through portion 550 penetrating the intermediate plate 500 in the thickness direction as shown by a broken line at a substantially central portion. The distribution member 600 is disposed in the through portion 550 of the intermediate plate 500. The anode plate 300 and the cathode plate 400 are joined to both sides of the intermediate plate 500 so as to sandwich the intermediate plate 500. As a method of joining the three plates, for example, thermocompression bonding, brazing, welding, or the like can be used. 2 is a direction in which the stacking units 200 are stacked in the fuel cell stack 100, and is also a direction in which the three plates 300, 400, 500 are stacked in the separator 1000. Hereinafter, the direction indicated by the arrow R is referred to as a stacking direction.

  The seal-integrated membrane electrode assembly 2000 includes a seal member 700 and a membrane electrode assembly 800. The seal member 700 is made of a material having gas impermeability, elasticity, and heat resistance, such as silicone rubber. A hole 750 for arranging the membrane electrode assembly 800 is provided at the center of the seal member 700 as indicated by a broken line. The membrane electrode assembly 800 includes an electrolyte membrane 820, an anode 840, and a cathode 860. The electrolyte membrane 820 is an ion exchange membrane having good conductivity in a wet state formed of a fluorine resin material such as Nafion (trademark of DuPont). The anode 840 and the cathode 860 are formed of a porous material having gas diffusibility and conductivity such as a metal porous body. The anode 840 and the cathode 860 carry platinum or an alloy made of platinum and other metals as a catalyst for the fuel cell reaction.

  With reference to FIG. 3 and FIG. 4, the structure of the separator 1000 is further demonstrated. FIG. 3 is a front view of the anode plate, the cathode plate, and the intermediate plate in the present embodiment. FIG. 4 is an explanatory view showing the structure of the distribution member in the first embodiment. FIG. 4A shows a front view of the distribution member 600. FIG. 4B shows a bottom view of the distribution member 600. FIG. 4 (e) shows a side view of the distribution member 600. 4 (c) and 4 (d) show a CC cross section and a DD cross section in FIG. 4 (a), respectively. In FIG. 3, a region DA indicated by a broken line at the center of each plate 400, 300, 500 is a region that overlaps with the membrane electrode assembly 800 described above when viewed from the stacking direction R when the fuel cell stack 100 is formed (hereinafter, This is referred to as a power generation area DA.).

  The cathode plate 400 is made of stainless steel. The cathode plate 400 includes six manifold forming portions 422 to 432, a plurality of oxidizing gas supply holes 440, and a plurality of oxidizing gas discharge holes 444. The manifold forming portions 422 to 432 are through holes that form the various manifolds described above when configuring the fuel cell stack 100, and are provided outside the power generation area DA. The plurality of oxidizing gas supply holes 440 are arranged side by side at the upper end of the power generation area DA. The plurality of oxidizing gas discharge holes 444 are arranged side by side at the lower end of the power generation area DA.

  Like the cathode plate 400, the anode plate 300 is formed of stainless steel and includes six manifold forming portions 322 to 332, a plurality of fuel gas supply holes 350, and a plurality of fuel gas discharge holes 354. The manifold forming portions 322 to 332 are through-holes that form the various manifolds described above when configuring the fuel cell stack 100, and are provided outside the power generation area DA, like the cathode plate 400. The plurality of fuel gas supply holes 350 are arranged side by side at the right end of the power generation area DA. The plurality of fuel gas discharge holes 354 are arranged side by side at the left end of the power generation area DA.

  The intermediate plate 500 is formed of a heat resistant resin. In the case of using a heat-resistant resin, the temperature at the time of joining the three plates (for example, thermocompression bonding) can be suppressed lower than that in the case of using a metal material. is there. The intermediate plate 500 includes six manifold forming parts 522 to 532, supply flow path forming parts 542 and 546 for supplying / discharging reaction gas (oxidizing gas or fuel gas), in addition to the above-described through part 550, and Discharge flow path forming portions 544 and 548, a plurality of cooling medium supply flow paths 534, and a plurality of cooling medium discharge flow paths 536 are provided.

  The through portion 550 is formed over most of the power generation area DA. The through portion 550 forms a space in which the cooling medium flows between the anode plate 300 and the cathode plate 400 when the three plates are joined. For this reason, in the following, the penetration part 550 is referred to as a cooling medium flow part 550. As described above, the distribution member 600 is disposed in the cooling medium flow portion 550.

  The manifold forming portions 522 to 532 are through holes that form the various manifolds described above when configuring the fuel cell stack 100, and are provided outside the power generation area DA, like the cathode plate 400 and the anode plate 300. Yes.

  The cooling medium supply channel 534 communicates the cooling medium flow part 550 and the cooling medium supply manifold forming part 530. The cooling medium discharge channel 536 communicates the cooling medium flow part 550 and the cooling medium discharge manifold forming part 532. These flow paths 534 and 536 penetrate the inside of the intermediate plate 500 in the surface direction.

  One end of each of the oxidizing gas and fuel gas supply flow path forming portions 542 and 546 and the discharge flow path forming portions 544 and 548 communicates with the corresponding manifold forming portions 522 to 532. The other ends of the flow path forming portions 542 to 548 communicate with the corresponding gas supply / discharge holes 350, 354, 440, and 444, respectively, when the three plates are joined.

  As is clear from FIG. 2, the distribution member 600 is a separate member from the three plates 300, 400, and 500, and as shown in FIG. 4, the substrate 650 and a plurality of first plate-like members. 610 and a plurality of second plate-like members 620. The distribution member 600 performs plastic processing (for example, press processing) on a single plate material (hereinafter, referred to as a base material), whereby the substrate 650, the first plate member 610, and the second plate member 620 are combined. It is produced by molding. The base material is a plate material thinner than the intermediate plate 500, and in this embodiment, dense stainless steel that is not a porous body is used.

  The first plate-like member 610 and the second plate-like member 620 have a substantially U-shaped base material in press molding, as illustrated for the second plate-like member 620 at the lower left in FIG. After cutting along the cutting line NL, the substantially U-shaped part is bent by two bending lines VL1 and VL2. The substantially U-shaped portion bent by the bending line VL1 corresponds to the first plate-like member 610 and the second plate-like member 620. An unprocessed portion other than the substantially U-shaped portion corresponds to the substrate 650. More specifically, these plate-like members 610 and 620 are bent at a predetermined angle α along the bending line VL1 and extend at a predetermined angle α with respect to the substrate 650. The predetermined angle α is determined in accordance with the width of the distribution member 600 to be formed in the stacking direction, the required repulsive force (described later), and the like. However, the negative angle α can be easily formed by pressing. It is preferable that it is 90 degrees or less which does not produce.

  The first plate-like member 610 is bent at the bend line VL2 so that the end portion (the tip portion from the bend line VL2) is parallel to the substrate 650. When the first plate member 610 is assembled together with the three plates 300, 400, and 500 to form the separator 1000 (hereinafter referred to as assembling), the anode plate 300 side (see FIG. 4B) when viewed from the substrate 650. Formed on the lower side). On the other hand, the second plate member 620 is formed on the cathode plate 400 side (the upper side in FIG. 4B) when viewed from the substrate 650 when assembled.

  Since the first plate-like member 610 and the second plate-like member 620 have a general plate spring shape as shown in FIG. 4, they are elastically deformed in the stacking direction R when assembled. That is, when compressed in the vertical direction in FIG. 4, a repulsive force is generated to restore the shape in the direction of arrow R in FIG.

  The width of the distribution member 600 in the stacking direction is larger than the thickness t of the intermediate plate 500 (t + a). Therefore, the distribution member 600 comes into contact with the anode plate 300 and the cathode plate 400 during assembly and is compressed in the stacking direction. Therefore, at the time of assembly, the contact between the distribution member 600 and the anode plate 300 and the contact between the distribution member 600 and the cathode plate 400 are strengthened by the repulsive force against the compression described above. In FIG. 4A, the cross-hatched portion S1 of the first plate-like member 610 indicates a portion that contacts the anode plate 300 during assembly. A portion S2 hatched by a broken line of the second plate-shaped member 620 indicates a portion that contacts the cathode plate 400 during assembly.

  As shown in FIG. 4A, a plurality of first plate members 610 and second plate members 620 are formed. The plurality of first plate members 610 and second plate members 620 are regularly arranged over the entire distribution member 600. In the example shown in FIG. 4, a row in which the first plate members 610 are arranged (CC row in FIG. 4A) and a row in which the second plate members 620 are arranged (FIG. 4). (DD row in (a)) are alternately arranged in the vertical direction in FIG.

  With reference to FIG. 5, the flow of the reaction gas (oxidizing gas and fuel gas) and the cooling medium in the present embodiment will be described. FIG. 5 is an explanatory diagram showing the flow of the reaction gas and the cooling medium of the fuel cell stack 100 in the present embodiment. FIG. 5A shows a front view of the separator 1000. FIGS. 5B and 5C are cross-sectional views of the fuel cell stack 100 corresponding to the lines BB and CC in FIG. 5A, respectively.

  The flow of the reaction gas will be described taking the flow of the fuel gas as an example. The fuel gas is supplied from the fuel gas supply manifold 130 to the anode 840 through the fuel gas supply channel 930 as indicated by the broken arrow in FIG. The fuel gas supply channel 930 is formed by the fuel gas supply channel forming part 546 of the intermediate plate 500 and the fuel gas supply hole 350 of the anode plate 300 at the time of assembly. The fuel gas supplied to the anode 840 is used in the fuel cell reaction while flowing through the porous anode 840. Then, the used fuel gas is discharged from the anode 840 to the fuel gas discharge manifold 140 through the fuel gas discharge flow path 940 as indicated by the dashed arrow in FIG. The fuel gas discharge channel 940 is formed by the fuel gas discharge channel forming part 548 of the intermediate plate 500 and the fuel gas discharge hole 354 of the anode plate 300 at the time of assembly. In the DD cross section in FIG. 5A, the oxidizing gas supply channel 950 and the oxidizing gas discharge channel 960 have the same structure as the fuel gas supply channel 930 and the fuel gas discharge channel 940 described above. It is formed. The oxidizing gas is supplied from the oxidizing gas supply manifold 110 through the oxidizing gas supply flow path 950 to the cathode 860 and is discharged through the oxidizing gas discharge flow path 960 to the oxidizing gas discharge manifold 120.

  The cooling medium is supplied from the cooling medium supply manifold 150 to the above-described cooling medium flow section 550 through the cooling medium supply flow path 534 of the intermediate plate 500, as indicated by solid arrows in FIG. . The cooling medium supplied to the cooling medium flow section 550 is diffused in the surface direction of the separator 1000 (direction perpendicular to the stacking direction R) by the distribution member 600 described above, and distributed to the entire cooling medium flow section 550. After flowing in the cooling medium flow part 550, the cooling medium is discharged to the cooling medium discharge manifold 160 through the cooling medium discharge channel 536 of the intermediate plate 500 as shown by the solid line arrow in FIG. Is done. The cooling medium absorbs the thermal energy of the fuel cell stack 100 and cools the fuel cell stack 100 while mainly flowing through the cooling medium flow part 550.

  According to the separator according to the first embodiment described above, the cooling medium is distributed by the distribution member 600 arranged in the cooling medium flow section 550, so that the fuel cell stack 100 can be efficiently cooled.

  In addition, since the first plate-like member 610 and the second plate-like member 620 of the distribution member 600 are in contact with the anode plate 300 and the cathode plate 400 at the end portions as described above, electrical conductivity within the separator 1000 is ensured. Is done. The contact area between the distribution member 600 and the anode plate 300 and the cathode plate 400 can be adjusted by the shape of the end portions of the first plate member 610 and the second plate member 620. That is, in the conventional separator, since the cooling medium flow path is formed by punching the intermediate plate, there is a problem that the cooling medium flow path becomes narrower when the contact area is increased. 1000 can secure a space in which the cooling medium flows, and can increase the contact area relatively freely. Therefore, it is possible to realize both cooling performance and electrical conductivity.

  Further, since the width of the distribution member 600 in the stacking direction is larger than the width of the intermediate plate 500, the distribution member 600 can reliably contact the anode plate 300 and the cathode plate 400 during assembly.

  Further, since the distribution member 600 is pressed against the anode plate 300 and the cathode plate 400 by a repulsive force against compression during assembly, the distribution member 600 is disposed between the distribution member 600 and the anode plate 300 and between the distribution member 600 and the cathode plate 400. The contact resistance between them can be reduced, and the electrical conductivity in the separator 1000 can be increased.

  In addition, the rigidity of the separator 1000 is improved by disposing the distribution member 600.

  Further, since the distribution member 600 is manufactured by pressing a single base material, it can be easily manufactured.

-Modification of the first embodiment:
・ Modification 1:
A separator 1000 according to the first modification of the first embodiment will be described with reference to FIG. FIG. 6 is an explanatory view showing the structure of the distribution member in this modification. In this modified example and modified example 2 described later, the difference from the first example is the shapes of the first plate-like member and the second plate-like member in the distribution member. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

  In the distribution member 600a in this modification, the end portions of the first plate member 610a and the second plate member 620a are perpendicular to the substrate 650a (parallel to the stacking direction R) along the bending line VL shown in FIG. 6a. Is bent like so. That is, when the first plate member 610a and the second plate member 620a are formed, the cut surfaces cut from the base material come into contact with the anode plate 300 and the cathode plate 400 during assembly. Therefore, the first plate-like member 610a contacts the anode plate 300 and the cathode plate 400 at the time of assembly with a smaller area (S1 and S2 in FIG. 6) than the distribution member 600 in the first embodiment.

  According to the separator 1000 according to this modification, the contact area between the first plate-like member 610a and the anode plate 300 is reduced. As a result, the contact pressure between the first plate-like member 610a and the anode plate 300 increases. Therefore, the effect of breaking through the oxide film formed on the surface of the anode plate 300 is enhanced by the end portion of the first plate-like member 610a, and the contact resistance can be further reduced. The same effect can be obtained for the contact between the second plate-shaped member 620a and the cathode plate 400.

・ Modification 2
With reference to FIG. 7, the separator 1000 which concerns on the modification 2 of 1st Example is demonstrated. FIG. 7 is an explanatory view showing the structure of the distribution member in this modification.

  In the distribution member 600b in this modification, the first plate member 610b and the second plate member 620b have different shapes. Specifically, the distance hc from the end of the second plate member 620b to the substrate 650 is larger than the distance ha from the end of the first plate member 610b to the substrate 650. As a result, during assembly, the distance between the substrate 650 of the distribution member 600 and the cathode plate 400 is larger than the distance between the substrate 650 of the distribution member 600 and the anode plate 300.

  In the separator 1000 according to this modification, the flow rate of the cooling medium in the cooling medium flow unit 550 is larger on the cathode plate 400 side of the substrate 650 than on the anode plate 300 side of the substrate 650. As a result, the cathode 860 that generates a large amount of heat can be efficiently cooled.

B. Second embodiment:
With reference to FIG. 8, the separator 1000 which concerns on 2nd Example is demonstrated. FIG. 8 is an explanatory view showing the structure of the distribution member in the second embodiment. FIG. 8B shows a front view of the distribution member 600c. FIG. 8A shows a left side view of the distribution member 600c (viewed from the left side of FIG. 8B). FIG. 8C shows a right side view of the distribution member 600c (viewed from the right side of FIG. 8B). FIG.8 (d) shows sectional drawing (DD cross section in FIG.8 (b)) of the distribution member 600c. The second embodiment differs from the first embodiment in that a distribution member 600c shown in FIG. 8 is used in the second embodiment instead of the distribution member 600 according to the first embodiment. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

  The distribution member 600c is manufactured by pressing a plate material thinner than the intermediate plate 500. As with the distribution member 600 in the first embodiment, the distribution member 600c is made of a conductive material, for example, a metal material such as stainless steel or titanium.

  A portion IN indicated by a broken line in the left side view (FIG. 8A) is a portion (hereinafter referred to as an inlet portion) adjacent to the cooling medium supply flow path 534 of the intermediate plate 500 at the time of assembly. A portion OT indicated by a broken line in the right side view (FIG. 8C) is a portion (hereinafter referred to as an outlet portion) adjacent to the cooling medium discharge channel 536 of the intermediate plate 500 at the time of assembly.

  The distribution member 600 has a corrugated shape with a continuous cross section as shown in FIG. Due to this corrugated shape, a plurality of grooves are formed on both surfaces of the distribution member 600 to form cooling medium flow paths when assembled. As shown in FIG. 8B, the plurality of grooves reach the outlet portion OT from the inlet portion IN while being bent at portions indicated by broken lines L1 to L4. A solid line EL in FIG. 8B indicates a ridge line (a point EL in FIGS. 8A, 8 </ b> C, and 8 </ b> D corresponds) where a plurality of grooves formed on one surface of the distribution member 600 are adjacent to each other. ing. A broken line BL in FIG. 8B indicates the bottoms of the plurality of grooves formed on one surface of the distribution member 600 (corresponding to the points BL in FIGS. 8A, 8C, and 8D). In the groove formed on the other surface side of the distribution member 600, the back side of the ridge line EL described above corresponds to the bottom of the groove, and the back side of the bottom BL described above corresponds to the ridge line.

  At the time of assembly, the distribution member 600c divides the cooling medium flow part 550 into a plurality of cooling medium flow paths. That is, as shown in FIG. 8D, a plurality of anode-side cooling medium channels 601 are formed between the distribution member 600 and the anode plate 300, and a plurality of cathodes are disposed between the distribution member 600 and the cathode plate 400. A side cooling medium flow path 602 is formed. In FIG. 8D, for convenience of explanation, the anode plate 300 and a part of the cathode plate 400 assembled together with the distribution member 600 are also illustrated.

  The cooling medium that has flowed into the cooling medium flow section 550 from the cooling medium supply flow path 534 flows in the surface direction of the separator 1000 through the cooling medium flow paths 601 and 602 from the inlet portion IN described above, and the cooling medium flow section 550 is distributed throughout. The distributed cooling medium is guided to the above-described outlet OT, and is discharged from the cooling medium discharge channel 536 to the cooling medium discharge manifold 160.

  Further, the width of the distribution member 600 in the stacking direction is a value (t + a) larger than the thickness t of the intermediate plate 500. Therefore, at the time of assembly, the distribution member 600c and the plates 300 and 400 are surely in contact with each other at the ridgeline EL of 600c described above. For example, the ridgeline EL portion of the distribution member 600c may be slightly crushed during assembly so that the contact area is ensured. Alternatively, the distribution member 600c may be made of a highly elastic material, and the contact between the distribution member 600c and the plates 300 and 400 may be strengthened by the repulsive force of the distribution member 600c as in the first embodiment.

  As described above, according to the separator 1000 according to the second embodiment, the cooling medium flow path is arranged over the entire cooling medium flow part 550 while ensuring the contact between the distribution member 600c and the plates 300 and 400. it can. Therefore, as in the separator 1000 according to the first embodiment, both cooling performance and electrical conductivity can be realized.

-Modification of the second embodiment:
A separator 1000 according to a modification of the second embodiment will be described with reference to FIG. FIG. 9 is an explanatory view showing the structure of the distribution member in the present modification. FIG. 9 corresponds to the DD cross section in FIG.

  The distribution member 600d in this modification is different from the distribution member 600c in the second embodiment described above in the waveform shape of the cross section. The other parts are the same as those in the second embodiment, and the description thereof is omitted.

  In the distribution member 600d in this modification, as shown in FIG. 9, the cross-sectional area of the anode-side cooling medium flow path 601 and the cross-sectional area of the cathode-side cooling medium flow path 602 are different due to the distorted waveform of the cross section. ing. Specifically, the cross-sectional area of the cathode-side cooling medium flow path 602 formed on the cathode plate 400 side of the distribution member 600d is the same as that of the anode-side cooling medium flow path 601 formed on the anode plate 300 side of the distribution member 600d. It is larger than the area.

  By doing so, the flow rate of the cooling medium flowing through the cathode-side cooling medium flow channel 602 becomes larger than the flow rate of the cooling medium flowing through the anode-side cooling medium flow channel 601. As a result, as in the second modification of the first embodiment, the cathode 860 that generates a large amount of heat can be efficiently cooled.

C. Third embodiment:
With reference to FIG. 10 and FIG. 11, the separator which concerns on 3rd Example is demonstrated. FIG. 10 is an explanatory diagram showing the configuration of the separator in the third embodiment. FIG. 11 is an explanatory view showing the structure of the anode plate in the third embodiment. FIG. 11A shows a front view of the anode plate 300e. FIGS. 11B and 11C are cross-sectional views of the separator 1000e corresponding to the lines BB and CC in FIG. 11A.

  As in the first embodiment, the separator 1000e according to this embodiment includes an anode plate 300e, a cathode plate 400e, and an intermediate plate 500e. However, unlike the first embodiment, a separate distribution member is not provided.

  Since the cathode plate 400e and the intermediate plate 500e have the same configuration as the cathode plate 400 and the intermediate plate 500 in the first embodiment, description thereof is omitted.

  As shown in FIG. 11A, the anode plate 300e is different from the first embodiment in that a plurality of convex portions 390 are provided at a substantially central portion. Since the other configuration of the anode plate 300e is the same as that of the anode plate 300 in the first embodiment described with reference to FIG. 3B, the same reference numerals as those in FIG. Description is omitted.

  The plurality of convex portions 390 are regularly arranged so as to be distributed over the entire range within the cooling medium flow portion 550 of the intermediate plate 500e when assembled. Accordingly, at the time of assembly, each convex portion 390 is positioned in the cooling medium flow portion 550 of the intermediate plate 500, and the convex portions 390 are regularly arranged over the entire cooling medium flow portion 550. In the example shown in FIG. 11A, they are arranged at equal intervals in the horizontal direction and the vertical direction in FIG. These convex portions 390 are formed by pressing one sheet of material so that it protrudes from the side in contact with the membrane electrode assembly 800 toward the intermediate plate 500e and is depressed.

  Further, as shown in FIG. 10, the plurality of convex portions 390 protrude from the other portion of the anode plate 300e toward the intermediate plate 500e by a thickness (T + a) larger than the thickness T of the intermediate plate 500e. Therefore, at the time of assembly, the convex portion 390 and the cathode plate 400e are reliably in contact with each other at the top P of the convex portion 390. For example, the top portion P of the convex portion 390 may be slightly crushed during assembly, thereby ensuring a contact area. Alternatively, the cathode plate 400e may be made of a highly elastic material, and the contact between the convex portion 390 and the cathode plate 400e may be strengthened by the repulsive force of the convex portion 390.

  The cooling medium that has flowed into the cooling medium flow part 550 from the cooling medium supply flow path 534 is diffused in the surface direction of the separator 1000 by the convex part 390 and distributed to the entire cooling medium flow part 550. The distributed cooling medium is discharged from the cooling medium discharge channel 536 to the cooling medium discharge manifold 160. In FIG. 11B and FIG. 11C, the cooling medium flows in the space indicated by the symbol 301.

  As described above, according to the separator 1000e according to the third embodiment of the younger brother, both the cooling performance and the electrical conductivity can be realized, as in the first and second embodiments.

  Furthermore, the separator 1000e according to the third embodiment does not require a separate distribution member, so that the number of parts does not increase.

  Further, the convex portion 390 is provided on the anode plate 300, and the power generation area DA of the cathode plate 400 is flat. Accordingly, as indicated by reference numeral 301 in FIGS. 11B and 11C, the space in which the cooling medium flows has a larger volume near the cathode 860 side. As a result, as in the second modification of the first embodiment, the cathode 860 that generates a large amount of heat can be efficiently cooled.

Furthermore, since the cathode plate 400 is flat, the contact pressure with respect to the cathode 860 becomes uniform, so that unevenness of electric reaction on the cathode 860 side is unlikely to occur. The electrochemical reaction of a fuel cell is generally limited by the reaction (2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O) at the three-phase interface on the cathode side because the diffusion rate of oxygen molecules is slow. The For this reason, the convex portion 390 is provided on the anode plate 300 with an emphasis on the electrical reaction on the cathode 860 side.

D. Other variations:
In the above-described embodiment, stainless steel is used for the cathode plate 400, the anode plate 300, and the distribution member 600, but other materials may be used. The cathode plate 400 and the anode plate 300 may be made of various materials having gas impermeability and conductivity, for example, titanium or a titanium alloy. The distribution member 600 may be made of various materials having conductivity and a certain degree of elasticity, for example, metal materials such as titanium and titanium alloys. Further, the cathode plate 400, the anode plate 300, and the distribution member 600 may be subjected to a surface treatment (for example, corrosion-resistant plating) in order to reduce contact resistance or improve corrosion resistance.

  In the above embodiment, the intermediate plate 500 is made of a heat-resistant resin capable of suppressing the bonding temperature to suppress thermal deformation. However, a metal material such as stainless steel or titanium can be used instead. .

  Moreover, in the said Example, you may perform joining processes, such as welding, in the contact part of a distribution member, an anode plate, and a cathode plate as needed. By doing so, the strength and conductivity of the separator 1000 can be increased.

  Further, the arrangement of the structure for distributing the cooling medium in each embodiment including the first plate-like member 610 and the second plate-like member 620 in the distribution member 600 in the first embodiment and the modification is implemented. Various arrangements can be adopted without being limited to examples. For example, the convex portions 390 in the third embodiment may be arranged in a staggered pattern on the cathode plate 400.

  In addition to the distribution members 600 to 600d shown as the above-described embodiments and modifications, distribution members having various structures can be used. Specifically, as in the distribution member 600 in the first embodiment, if the width in the stacking direction is thicker than the thickness of the intermediate plate 500 and has elasticity in the stacking direction, the same action as in the first embodiment.・ Effects can be obtained. Moreover, it is preferable that the distribution member does not have a negative angle in the stacking direction and has a shape that can be easily manufactured by pressing a single plate. For example, in the distribution member 600 described above, the plate-like members 610 and 620 are arranged on both sides of the substrate 650, respectively, but a structure in which the plate-like members are arranged only on one side may be employed. In such a case, the width in the stacking direction is made larger than that of the intermediate plate 500 by using only the plate-like member and the substrate on one side.

  As mentioned above, although the Example and modification of this invention were demonstrated, this invention is not limited to these Example and modification at all, and implementation in a various aspect is possible within the range which does not deviate from the summary. It is.

Explanatory drawing which shows the structure of the fuel cell stack in 1st Example. Explanatory drawing which shows the structure of the unit of the lamination | stacking of a fuel cell stack. The front view of the various plates in 1st Example. Explanatory drawing which shows the structure of the distribution member in 1st Example. Explanatory drawing which shows the flow of the reaction gas and cooling medium of the fuel cell stack in 1st Example. Explanatory drawing which shows the structure of the distribution member in the modification 1 of 1st Example. It is explanatory drawing which shows the structure of the distribution member in the modification 2 of 1st Example. Explanatory drawing which shows the structure of the distribution member in 2nd Example. Explanatory drawing which shows the structure of the distribution member in the modification of 2nd Example. Explanatory drawing which shows the structure of the separator in 3rd Example. Explanatory drawing which shows the structure of the anode plate in 3rd Example.

Explanation of symbols

100 ... Fuel cell stack 110 ... Oxidation gas supply manifold 120 ... Oxidation gas discharge manifold 130 ... Fuel gas supply manifold 140 ... Fuel gas discharge manifold 150 ... Coolant supply manifold 160 .. Cooling medium discharge manifold 200 ... Stacking unit 300, 300e ... Anode plate 322, 324, 326, 328, 330, 332 ... Manifold forming part 350 ... Fuel gas supply hole 354 ... Fuel Gas exhaust hole 390 ... Convex part 400, 400e ... Cathode plate 422, 424, 426, 428, 430, 432 ... Manifold formation part 440 ... Oxidation gas supply hole 444 ... Oxidation gas discharge Hole 500, 500e ... Intermediate plate 522, 524, 526, 528, 530, 532 ... Manifold forming part 534 ... Cooling medium supply flow Channel 536 ... Cooling medium discharge channel 542, 546 ... Reaction gas supply channel formation unit 544, 548 ... Reaction gas discharge channel formation unit 550 ... Cooling medium flow unit 600, 600a, 600b, 600c, 600d ... distribution member 601, 602 ... cooling medium flow path 610, 610a, 610b ... first plate member 620, 620a, 620b ... second plate member 650 ... Substrate 700 ... Sealing member 800 ... Membrane electrode assembly 820 ... Electrolyte membrane 840 ... Anode 860 ... Cathode 930 ... Fuel gas supply channel 940 ... Fuel gas discharge channel 950 ... Oxidation gas supply channel 960 ... Oxidation gas discharge channel 1000, 1000e ... Separator 2000 ... Membrane electrode assembly with integrated seal

Claims (8)

A separator that is alternately stacked with membrane electrode assemblies to constitute a fuel cell,
A cathode plate in contact with the cathode side of the membrane electrode assembly;
An anode plate in contact with the anode side of the membrane electrode assembly;
An intermediate plate that is sandwiched between the cathode plate and the anode plate, and penetrates in the thickness direction and flows through at least a part of a region overlapping the membrane electrode assembly when viewed from the stacking direction. An intermediate plate having a cooling medium flow section;
A distribution unit that is disposed in the cooling medium flow unit and is formed of a non-porous body separate from the intermediate plate, and is disposed on a substrate parallel to the intermediate plate and on both sides or one side of the substrate. together, and a distributor having a plurality of elastic portion is elastically deformed in the direction of the lamination,
The distribution unit distributes the cooling medium in the surface direction of the separator in the cooling medium flow unit ,
The width of the stacking direction of the distributor is larger than the thickness of the intermediate plate,
Separator. The separator according to claim 1, further comprising:
A cooling medium supply manifold penetrating the separator in the thickness direction;
A cooling medium discharge manifold penetrating the separator in the thickness direction;
A cooling medium supply channel communicating the cooling medium supply manifold and the cooling medium flow section;
A separator comprising: the cooling medium discharge manifold and a cooling medium discharge channel communicating the cooling medium flow part. The separator according to claim 1 ,
The plurality of elastic portions are separators arranged so as to be distributed throughout the cooling medium flow portion. In the separator according to any one of claims 1 to 3,
The elastic part is
A plurality of first plate-like members extending from the substrate at a predetermined angle and having an end portion in contact with the cathode plate;
A separator that is a plurality of second plate-like members that extend from the substrate at a predetermined angle and whose end portions are in contact with the anode plate. The separator according to claim 4 ,
Ends of the first and second plate-like members are separators bent in parallel with the substrate. The separator according to claim 4 ,
Ends of the first and second plate-like members are separators that are bent perpendicular to the substrate. In the separator according to any one of claims 1 to 6,
The distance between the substrate and the cathode plate is a separator larger than the distance between the substrate and the anode plate. In the separator according to any one of claims 4 to 7 ,
The distributor is a separator manufactured by plastic processing a plate material thinner than the intermediate plate.

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