JP5423699B2 - Gas flow path forming body and fuel cell - Google Patents

Description

  The present invention relates to a flow path structure for gas and refrigerant that flows along a power generation region of a fuel cell.

A fuel cell is a device that generates electricity by an electrochemical reaction between hydrogen as a fuel gas and oxygen (O ₂ ) as an oxidizing gas. Hereinafter, the fuel gas and the oxidizing gas may be simply referred to as “reaction gas” or “gas” without particular distinction. This fuel cell includes a fuel cell (also simply referred to as “cell”) in which a membrane-electrode assembly (MEA) is sandwiched between separators. MEA has a structure in which a catalyst electrode layer is bonded to both surfaces of a solid polymer electrolyte membrane (hereinafter, also simply referred to as “electrolyte membrane”) having proton (H ⁺ ) conductivity, and a gas diffusion layer is further disposed. have.

  Gas flow for supplying oxidizing gas (also referred to as “cathode gas”) to the catalyst electrode layer on the cathode side and gas flow for supplying fuel gas (also referred to as “anode gas”) to the catalyst electrode layer on the anode side The path is configured by a groove formed on the surface of the separator on the gas diffusion layer side or a gas flow path member separately provided between the gas diffusion layer and the separator.

  FIG. 16 is a schematic configuration diagram showing an example of an anode-side separator having a groove-like gas flow path. The separator SPAa is formed by press-molding a conductive metal plate to form a coolant channel on one side and a gas channel on the other side. The figure shows the surface on which the flow path of the refrigerant is formed. The surface on which the refrigerant flow path is formed is referred to as a “refrigerant flow path forming surface”, and the surface on which the gas flow path is formed is referred to as a “gas flow path forming surface”. In the following description, the direction along the long side of the substantially rectangular shape is described as the horizontal direction or the horizontal direction, and the direction along the short side is described as the vertical direction or the vertical direction.

  As shown in the figure, an oxidizing gas manifold hole constituting an air (Air) manifold (referred to as an “oxidizing gas manifold”) containing oxygen as an oxidizing gas is formed on the upper and lower ends of the rectangular separator SPAa. AMO is arranged. The lower oxidant gas manifold hole is a manifold hole AMOi (also referred to as “inlet oxidant gas manifold hole”) constituting the inlet side oxidant gas manifold (also referred to as “inlet side oxidant gas manifold”), and the upper oxidant gas manifold The manifold hole is a manifold hole AMOo (also referred to as “exit-side oxidant gas manifold hole”) that constitutes an exit-side oxidant gas manifold (also referred to as “exit-side oxidant gas manifold”). A seal line SOi is formed so as to cover the periphery of each inlet-side oxidizing gas manifold hole AMOi, and a seal line SOo is formed so as to cover the periphery of each outlet-side oxidizing gas manifold AMOo. The inner regions of these seal lines SOi, SOo have communication holes and porous members formed in the cathode side separator (not shown) of the adjacent fuel cell stacked on the upper surface of the anode side separator SPAa. It functions as a region for the flow path of the oxidizing gas supplied to the catalyst electrode layer on the cathode side of the adjacent fuel cell.

  Also, a hydrogen manifold (“fuel gas”) is provided at the upper end of the left edge of the separator (abbreviated as “upper left end”) and the lower end of the right edge (abbreviated as “lower right end”). A fuel gas manifold hole AMH (which is referred to as a “manifold”) is disposed, and a fuel gas manifold hole at the upper left end is a manifold hole AMHi (which is also referred to as an “inlet side fuel gas manifold”). The manifold gas hole AMHo (“exit side”) is a fuel gas manifold hole (also called “outlet side fuel gas manifold”) at the lower right end of the fuel gas manifold hole (also called “exit side fuel gas manifold”). Also called “fuel gas manifold hole”. A seal line SHi is formed so as to cover the inlet side fuel gas manifold hole AMHi, and a seal line SHo is formed so as to cover the outlet side fuel gas manifold hole AMHo. The inside of these seal lines SHi and SHo functions as a fuel gas flow path region together with the fuel gas flow path formed on the opposite surface. In addition, communication holes HHi and HHo are formed on the inner side of these seal lines SHi and SHo to connect the fuel gas flow path formed on the opposite surface.

  In addition, refrigerant manifold holes AMW constituting a refrigerant manifold (referred to as “refrigerant manifold”) are arranged above the outlet side fuel gas manifold hole AMHo and below the inlet side fuel gas manifold hole AMHi. The refrigerant manifold hole on the upper side of the outlet side fuel gas manifold hole AMHo is a manifold hole AMWi (also referred to as “inlet side refrigerant manifold hole”) that constitutes an inlet side refrigerant manifold (also referred to as “inlet side refrigerant manifold”). The refrigerant manifold hole on the lower side of the inlet side fuel gas manifold hole is a manifold hole AMWo (“outlet side refrigerant manifold hole”) that constitutes an outlet side refrigerant manifold (“outlet side refrigerant manifold (also referred to as“ exit side refrigerant manifold ”)). The seal line SW is formed so as to surround the area excluding the seal lines SOi, SOo, SHi, and SHo in the area from the inlet side refrigerant manifold hole AMWi to the outlet side refrigerant manifold hole AMWo. The area inside this seal line SW is the flow of the refrigerant. To function as a region.

  Here, hatched portions in the figure are convex portions formed by press molding, and these convex portions become concave portions on the opposite surface. The difference in hatching interval indicates a step. On the refrigerant flow path forming surface, the convex part with a narrow hatching interval has a higher height than the wide convex part, and on the opposite gas flow path forming surface, the narrow part of the hatched part is wider than the wide part. It becomes a deep concave structure.

  Protrusions WHcmi and WHcmo extending in the left-right direction are formed at the upper and lower ends of the area inside the seal line SW. A plurality of convex portions WH extending in the vertical direction are formed between the upper convex portion WHcmi and the lower convex portion WHcmo. The convex portions WH are arranged so that the two convex portions WH1 and WH2 having different heights are arranged so that the first convex portions WH1 and the second convex portions of each convex portion WH are arranged along the left-right direction. It is formed alternately along the direction. As a result, the relatively high second protrusions WH2 arranged along the left-right direction function as a refrigerant flow path wall, and between the relatively low first protrusions WH1 and WH arranged along the left-right direction. The substrate unit WB functions as a refrigerant flow path. Further, the substrate portion WB functions as a refrigerant flow path that causes the refrigerant to flow in the vertical direction and diffuse.

  The plurality of convex portions WH become concave portions on the opposite surface, and these concave portions are groove-shaped plural flow paths (hereinafter referred to as “branches”) for supplying fuel gas to a power generation region where power generation is performed by the membrane electrode assembly. It also functions as a “channel”. The convex portions WHcmi and WHcmo provided on the upper and lower sides also become concave portions on the opposite surface, and these concave portions supply fuel gas to the plurality of branch passages and collect the fuel gas flowing out from the plurality of branch passages ( Hereinafter, it also functions as a “common channel”.

  The convex portions WHcmi and WWHmo whose concave portions on the opposite side serve as a common flow path are connected to the communication holes HHi and HHo across the seal lines SHi and SHo, and the fuel gas flow path surrounded by the seal lines SHi and SHo It is connected to the tunnel structure portions TWi and TWo so as to connect to the region. In these tunnel structure portions TWi and TWo, the concave portion on the opposite surface is constituted by a plurality of convex portions that function as fuel gas flow paths straddling the seal lines SHi and SHo.

  Here, a region GA (indicated by a one-dot chain line in the figure) corresponding to the power generation region on the upper side of the tunnel structure portion TW0 and on the lower side of the tunnel structure portion TWi outside the left and right convex portions WH is surrounded by the seal line SW. The flow of the refrigerant to the convex portion WHcci, which is in the region of the refrigerant flow path, and serves as a flow path wall for regulating the flow of the refrigerant from the inlet side refrigerant manifold hole AMi, and the flow of the refrigerant to the outlet side refrigerant manifold hole AMo are regulated. A convex portion WHcco serving as a flow path wall is formed. As described above, since the convex portions WHcci and WHcco are press-molded, it is difficult to form a fuel gas flow path on the surface opposite to the region GA. For this reason, the fuel gas supplied to the power generation region corresponding to this region only depends on the gas diffusing in the gas diffusion layer, and the power generation performance in this region is significantly lower than the power generation performance in other regions. It becomes an almost unusable area. Therefore, when the separator having such a structure is used, the utilization efficiency of the power generation region is insufficient. That is, the conventional structure has a problem that both the utilization efficiency of the power generation region and the cooling efficiency are insufficient.

Japanese Patent Laid-Open No. 2005-141979 JP 2005-166545 A

  Therefore, an object of the present invention is to provide a structure in which a refrigerant flow path and a gas flow path are integrally formed so that both cooling efficiency and utilization efficiency of a power generation region can be compatible.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A gas flow path forming body that is used in a fuel cell and has a structure in which a groove-like gas flow path on a gas flow path forming surface and a refrigerant flow path on a refrigerant flow path forming surface are formed integrally with each other,
Inside the first region of the gas flow path forming surface corresponding to the substantially rectangular power generation region of the fuel cell,
A first gas flow path formed along the first edge;
A second gas flow path formed along a second end side facing the first end side;
A plurality of third gas passages formed so as to connect between the first gas passage and the second gas passage;
A first gas manifold hole formed on the third end side perpendicular to the first end side outside the first region;
A second gas manifold hole formed on a fourth end side facing the third end side outside the first region;
A first refrigerant manifold hole formed along the fourth end side alongside the fourth gas manifold hole outside the first region; and the third end outside the first region. A second refrigerant manifold hole formed side by side with the first gas manifold hole;
A first seal line covering the first gas manifold hole on the refrigerant flow path forming surface;
A second seal line covering the second gas manifold hole on the refrigerant flow path forming surface;
A first tunnel structure formed so as to straddle the first seal line on the coolant flow path forming surface in order to connect the first gas flow path to the first gas manifold hole;
A second tunnel structure formed so as to straddle the second seal line on the refrigerant flow path forming surface in order to connect the second gas flow path to the second gas manifold hole;
With
Concavities and convexities formed on the refrigerant flow path forming surface side by the first to third gas flow paths form the refrigerant flow path,
The first region corresponding to the portion of the first region surrounded by the first refrigerant manifold hole, the second tunnel structure, and the third gas flow path closest to the fourth end side. The first portion of the refrigerant flow path forming surface is formed with a first refrigerant flow path wall that regulates the flow of the refrigerant from the first refrigerant manifold hole toward the direction of the refrigerant flow path,
Corresponding to a portion of the first region surrounded by the second refrigerant manifold hole, the first tunnel structure, and the third gas flow path closest to the third end side. The second portion of the refrigerant flow path forming surface is formed with a second refrigerant flow channel wall that restricts the flow of the refrigerant from the refrigerant flow channel toward the second refrigerant manifold hole. And
The unevenness on the gas flow path forming surface side formed by the first refrigerant flow path wall and the second refrigerant flow path wall is connected to any one of the first to third gas flow paths. ,
A gas flow path forming body characterized by that.
In this gas flow path forming body, the first refrigerant flow path wall and the second refrigerant flow path wall are formed using the first refrigerant flow path wall and the second refrigerant flow path wall as gas flow paths. Since gas can be supplied to the portion of the power generation region corresponding to the region, the efficiency of use of the power generation region can be improved while maintaining the cooling efficiency by the refrigerant.

[Application Example 2]
A gas flow path forming body according to Application Example 1,
At least one of the first and second tunnel structure portions has a separation structure that separates liquid water and gas.
In this gas flow path forming body, since liquid water and gas can be separated, it is possible to prevent liquid water from staying in the tunnel structure and inhibiting the flow of gas.

[Application Example 3]
The gas flow path forming body according to Application Example 1 or 2, wherein the gas flow path forming body is a separator used in the fuel battery cell.
If the separator is a gas flow path forming body, the configuration of the fuel cell can be simplified.

[Application Example 4]
A fuel cell comprising the gas flow path forming body according to any one of Application Examples 1 to 3.
According to this fuel cell, it is possible to improve the utilization efficiency of the power generation region while maintaining the cooling efficiency by the refrigerant.

  In addition, this invention can be implement | achieved with various forms, for example, can be implement | achieved with various forms, such as a refrigerant flow path formation body, a separator, a fuel cell, a fuel cell.

It is a schematic plan view of the fuel cell FUC in the first embodiment. It is the schematic plan view which looked at the gas flow path formation surface FP of the fuel gas on the opposite side to the refrigerant flow path formation surface WP of the anode separator SPA from the refrigerant flow path formation surface WP side. It is the schematic plan view which looked at the electric power generation body part PB from the anode separator SPA side. It is the schematic plan view which looked at the cathode separator SPC from the electric power generation body part PB side. It is explanatory drawing which shows the A1-A1 cross section and A2-A2 cross section of FIG. It is explanatory drawing which shows the E1-E1 cross section and E2-E2 cross section of FIG. It is explanatory drawing which shows the F1-F1 cross section and F2-F2 cross section of FIG. It is explanatory drawing which shows the D1-D1 cross section of FIG. It is explanatory drawing which expands and shows the fuel gas flow path using recessed part FF2 corresponding to the refrigerant flow path wall WW2 formed in area | region GA1 of FIG. It is explanatory drawing which shows the 1st modification of the fuel gas flow path shown in FIG. It is explanatory drawing which shows the 2nd modification of the fuel gas flow path shown in FIG. It is explanatory drawing which shows the 3rd modification of the fuel gas flow path shown in FIG. It is explanatory drawing which shows the exit side tunnel structure part in 2nd Example. It is explanatory drawing which shows the 1st modification of the exit side tunnel structure part of 2nd Example. It is explanatory drawing which shows the 2nd modification of the exit side tunnel structure part of 2nd Example. It is a schematic block diagram which shows an example of the separator by the side of an anode which has a groove-shaped gas flow path.

Next, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
B. Second embodiment:
C. Variations:

A. First embodiment:
A1. Fuel cell configuration:
FIG. 1 is a schematic plan view of a fuel cell FUC in the first embodiment. In this fuel cell FUC, as shown in FIG. 1, the power generating unit PB includes an anode-side separator SPA (hereinafter also referred to as “anode separator”) and a cathode-side separator SPC (hereinafter referred to as “cathode”). This is a power generation module having a substantially rectangular planar shape sandwiched between separators). FIG. 1 shows a state in which the fuel cell FUC is viewed from the refrigerant flow path forming surface WP side of the anode separator SPA. FIG. 2 is a schematic plan view of the gas flow path forming surface FP of the fuel gas opposite to the refrigerant flow path forming surface WP of the anode separator SPA as viewed from the refrigerant flow path forming surface WP side. FIG. 3 is a schematic plan view of the power generator PB as viewed from the anode separator SPA side. FIG. 4 is a schematic plan view of the cathode separator SPC as viewed from the power generation unit PB side. In the following description, the direction along the long side of the substantially rectangular shape is described as the horizontal direction or the horizontal direction, and the direction along the short side is described as the vertical direction or the vertical direction.

  In the fuel cell FUC, as shown in FIG. 1, an oxidizing gas manifold MO is disposed along the upper and lower edges of the drawing. The lower oxidizing gas manifold MO is the inlet side oxidizing gas manifold MOi, and the upper oxidizing gas manifold MO is the outlet side oxidizing gas manifold MOo. As shown in FIGS. 1 to 4, the inlet-side oxidizing gas manifold MOi includes the inlet-side oxidizing gas manifold hole AMOi of the anode separator SPA, the inlet-side oxidizing gas manifold hole PMOi of the power generation unit PB, and the cathode separator SPC. The inlet side oxidizing gas manifold hole CMOi. Similarly, the outlet side oxidizing gas manifold MOO is defined by the outlet side oxidizing gas manifold hole AMOo of the anode separator SPA, the outlet side oxidizing gas manifold hole PMOo of the power generator PB, and the outlet side oxidizing gas manifold hole CMOo of the cathode separator SPC. It is configured.

  In the fuel cell FUC, as shown in FIG. 1, fuel gas manifolds MH are arranged at the left upper end and right lower end. The fuel gas manifold MH at the upper left end is the inlet side fuel gas manifold MHi, and the fuel gas manifold MH at the lower right end is the outlet side fuel gas manifold MHo. 1 to 4, the inlet side fuel gas manifold MHi includes the inlet side fuel gas manifold hole AMHi of the anode separator SPA, the inlet side fuel gas manifold hole PMHi of the power generator PB, and the cathode separator SPC. The inlet side fuel gas manifold hole CMHi. Similarly, the outlet side fuel gas manifold MHo is defined by the outlet side fuel gas manifold hole AMHo of the anode separator SPA, the outlet side fuel gas manifold hole PMHo of the power generator PB, and the outlet side oxidizing gas manifold hole CMHo of the cathode separator SPC. It is configured.

  In addition, as shown in FIG. 1, the fuel cell FUC is provided with a refrigerant manifold MW along the left and right edges. The refrigerant manifold MW arranged above the right outlet side fuel gas manifold MHo is an inlet side refrigerant manifold MWi, and the refrigerant manifold MW arranged below the left inlet side fuel gas manifold MHi is an outlet side refrigerant manifold MWo. 1 to 4, the inlet side refrigerant manifold MWi includes an inlet side refrigerant manifold hole AMWi of the anode separator SPA, an inlet side refrigerant manifold hole PMWi of the power generator PB, and an inlet side of the cathode separator SPC. The refrigerant manifold hole CMWi is used. Similarly, the outlet side refrigerant manifold MWo is configured by the outlet side refrigerant manifold hole AMWo of the anode separator SPA, the outlet side refrigerant manifold hole PMWo of the power generator PB, and the outlet side refrigerant manifold hole CMWo of the cathode separator SPC. .

  As shown in FIG. 1, a seal line SOi is formed on the refrigerant flow path forming surface WP of the anode separator SPA so as to cover the entire periphery of the inlet side oxidizing gas manifold hole AMOi. A seal line SOo is formed so as to cover the entire periphery of the manifold hole AMOo. Further, a seal line SHi is formed so as to cover the inlet side fuel gas manifold hole AMHi, and a seal line SHo is formed so as to cover the outlet side fuel gas manifold hole AMHo. Further, the seal line SW is formed so as to surround a region excluding the region surrounded by the seal lines SOi, SOo, SHi, and SHo in the region from the inlet side refrigerant manifold hole AMWi to the outlet side refrigerant manifold hole AMWo. . As will be described later, these seal lines SOi, SOo, SHi, SHo, and SW are in contact with cathode separators SPC of other fuel cells stacked on the upper surface, and seal the areas surrounded by the respective seal lines. , Function as part of the region of the fluid flow path through each manifold. However, the region surrounded by the seal lines SOi and SOo is not an own fuel cell but a part of the oxidizing gas flow path of the upper fuel cell FUC.

  As shown in FIG. 1, the anode separator SPA is formed by press-molding a conductive metal plate so that the convex portions (the portions indicated by hatching in the figure) formed on the refrigerant flow path forming surface WP A refrigerant flow path is configured as a road wall. Moreover, as shown in FIG. 2, the recessed part (part shown by hatching in the figure) formed in the gas flow path formation surface FP integrally with the front and back is the fuel gas flow path. The anode separator SPA may be molded using a conductive material such as carbon.

  As shown in FIG. 3, the power generation unit PB has gas diffusion layers (GDL) PB2 and PB3 arranged on the anode side and cathode side surfaces of the membrane electrode assembly (MEA) PB1, and further gas diffusion on the cathode side. It has a structure in which a power generator configured by disposing a porous body flow path portion PB4 on the surface of the layer PB3 is covered with a seal portion PB5. The region in the gas diffusion layers PB2 and PB3 functions as an effective power generation region PA. In FIGS. 1 to 4, the outer shape of the region corresponding to the power generation region PA is indicated by a substantially rectangular broken line. Each manifold hole PMOi, PMOo, PMHi, PMHo, PMWi, and PMWo is formed in the seal portion PB5, that is, outside the edge of the power generation area PA.

  As shown in FIG. 4, the cathode separator SPC is a conductive flat metal plate having communication holes HOi and HOo. These communication holes HOi, HOo are in regions corresponding to regions surrounded by seal lines SOi, SOo formed in the anode separator SPA of the lower-layer fuel cell FUC (indicated by a one-dot chain line in the figure), and In the region corresponding to the power generation region PA (indicated by a broken line frame), the region is formed along the vertical edge of the region corresponding to the power generation region PA. The cathode separator SPC may be molded using a conductive material such as carbon.

  As shown in FIG. 1, on the refrigerant flow path forming surface WP, convex portions WHcmi and WHcmo extending in the lateral direction are formed on the lateral sides of the inlet side fuel gas manifold hole AMHi and the outlet side fuel gas manifold hole AMHo. ing. And these convex part WHcmi and WHcmo become the recessed part FHcmi and FHcmo in the gas flow path formation surface FP of FIG. 2, and comprises the fuel gas flow path which functions as a common flow path.

  A communication hole HHi is formed inside the seal line SHi between the inlet side fuel gas manifold hole AMHi and the first protrusion WHcmi, and corresponds to the communication hole HHi and the first protrusion WHcmi. The entrance side tunnel structure TWi is formed so as to connect the first recesses FHcmi. Similarly, a communication hole HHo is formed inside the seal line SHo between the outlet side fuel gas manifold hole AMHo and the second convex part WHcmo, and the communication hole HHo and the second convex part WHcmo are formed in the communication line HHo. An exit-side tunnel structure TWo is formed so as to connect the corresponding second recesses FHCmo. In these tunnel structures TWi and TWo, a plurality of tunnel convex portions TWi1 and TWo1 are formed so as to straddle the seal lines SHi and SHo on the refrigerant flow path forming surface WP, respectively. A plurality of tunnel recesses TFi1 and TFo1 function as fuel gas flow paths in the FP.

  FIG. 5 is an explanatory diagram showing the A1-A1 cross section and the A2-A2 cross section of FIG. In this figure, for ease of explanation, the cathode separator SPC of the upper fuel cell FUC in contact with the anode separator SPA of one fuel cell FUC and the anode separator SPA of the lower fuel cell FUC in contact with the cathode separator SPC are shown. Including. The same applies to the cross-sectional views shown below.

As shown in the figure, the fuel gas (H ₂ ) flowing through the inlet side fuel gas manifold MHi passes through a plurality of inlet side tunnel concave portions TFi1 of the inlet side tunnel structure portion TWi from the communication hole HHi in the region surrounded by the seal line SHi. Via the first recess FHcmi as a common flow path.

  Although illustration is omitted, the B1-B1 cross section and the B2-B2 cross section in FIG. 1 also have the same structure as the A1-A1 cross section and the A2-A2 cross section. The fuel gas flowing through the second recess FHCmo as the common flow path is discharged from the plurality of outlet-side tunnel recesses TFo1 of the outlet-side tunnel structure TWo to the region surrounded by the seal line SHo through the communication hole HHo. , And discharged to the outlet side fuel gas manifold MHo.

  Further, as shown in FIG. 1, a plurality of third protrusions WH extending in the vertical direction are first between the upper first protrusions WHcmi and the lower second protrusions WHcmo. Are formed so as to be connected to the second convex portion WHcmi and the second convex portion WHcmo. The plurality of third convex portions WH become the third concave portion FH on the gas flow path forming surface FP in FIG. 2 and constitute a fuel gas flow path that functions as a branch flow path.

  6 is an explanatory diagram showing an E1-E1 cross section and an E2-E2 cross section of FIG. The fuel gas flowing in the first recess FHcmi that functions as a common channel flows to the second recess FHcmo that functions as a common channel via the third recess FH that functions as a branch channel. The fuel gas flowing through the third recess FH functioning as a branch channel diffuses in the gas diffusion layer PB2 and is supplied to the catalyst electrode layer (not shown) on the anode side of the membrane electrode assembly PB1.

  As shown in FIGS. 2 and 6, the third recess FH includes a relatively shallow first partial recess FH1 (shown by narrow interval hatching in FIG. 2) and a relatively deep second partial recess FH2 ( In FIG. 2, a wide interval hatching) is alternately arranged. The difference in the depth of the third recess FH is not particularly meaningful for the fuel gas flow path, and as described below, the branch flow path for flowing the fuel gas in the vertical direction on the refrigerant flow path forming surface WP. The structure of the third recess FH as described above and the structure of the refrigerant flow path wall for allowing the refrigerant to flow in the lateral direction are realized in an integrated manner.

  FIG. 7 is an explanatory diagram showing the F1-F1 cross section and the F2-F2 cross section of FIG. The first partial concave portion FH1 and the second partial concave portion FH2 are relatively low first partial convex portions WH1 (in FIG. 1) constituting the third convex portion WH on the refrigerant flow path forming surface WP shown in FIG. And a relatively high second partial protrusion WH2 (indicated by narrowly spaced hatching in FIG. 1). As shown in FIGS. 1 and 7, the first partial convex portions WH <b> 1 and the second partial convex portions are arranged along the horizontal direction in each third convex portion WH. In addition, the first partial protrusions WH1 and the second partial protrusions WH2 are alternately arranged along the vertical direction. As a result, the relatively high second partial projections WH2 arranged along the horizontal direction come into contact with the upper cathode separator SPC, and constitute a refrigerant flow path wall for flowing the refrigerant in the horizontal direction. Further, the substrate portion WB between the relatively low first partial protrusions WH1 and the third protrusions WH arranged in the horizontal direction constitutes a refrigerant flow path for flowing the refrigerant in the horizontal direction. Moreover, the board | substrate part WB comprises the refrigerant | coolant flow path through which a refrigerant | coolant is flowed and diffused in the vertical direction.

FIG. 8 is an explanatory diagram showing a D1-D1 cross section of FIG. As shown in FIG. 8, the oxidizing gas (Air, strictly speaking O ₂ ) flowing through the inlet side oxidizing gas manifold MOi passes through the inlet side oxidizing gas channel surrounded by the seal line SOi formed in the anode separator SPA. The region is led to the communication hole HOi on the lower side of the cathode separator SPC of the upper fuel cell FUC. The lower communication hole HOi functions as an oxidizing gas supply side communication passage for supplying the oxidizing gas to the porous body flow path portion PB4. The oxidizing gas supplied to the porous channel portion PB4 flows while diffusing in the porous channel portion PB4 toward the outlet-side oxidizing gas manifold MOo, and diffuses in the gas diffusion layer PB3 to form a membrane electrode. It is supplied to the catalyst electrode layer (not shown) on the cathode side of the joined body PB1.

  Although not shown, the C1-C1 cross section in FIG. 1 has the same structure as the D1-D1 cross section. Then, the oxidizing gas that has flowed through the porous body flow path portion PB4 and the gas diffusion layer PB3 is guided to the communication hole HOo on the upper side of the cathode separator SPC. The upper communication hole HOo is an oxidant gas flow path sandwiched between the oxidant gas flow path wall WOo in the region of the oxidant gas flow path on the outlet side surrounded by the seal line SOo from the porous body flow path part PB4. Through the outlet side oxidizing gas manifold MOo.

  As shown in FIG. 1, power generation between the inlet-side refrigerant manifold hole AMWi and the third convex portion WH at the right end in the region of the refrigerant flow path surrounded by the seal line SW on the refrigerant flow path forming surface WP. In the area corresponding to the area PA, the refrigerant flowing out from the inlet side refrigerant manifold hole AMWi into the area surrounded by the seal line SW as the refrigerant flow area is the first partial convex portion WH1 of the third convex portion WH. A convex refrigerant flow path wall WW1 (corresponding to the first refrigerant flow path wall of the present invention) along the oblique direction is formed so as to face the direction of the refrigerant flow path constituted by the substrate portion WB. . Similarly, in the region corresponding to the power generation region PA between the outlet side refrigerant manifold hole AMWo and the third convex portion WH at the left end, the first partial convex portion WH1 and the substrate portion of the third convex portion WH are also provided. A refrigerant flow path wall WW2 along the oblique direction is formed so that the refrigerant that has flowed through the refrigerant flow path constituted by WB is directed in the direction of the outlet side refrigerant manifold hole AMWo. Further, as shown in FIG. 2, the refrigerant flow path walls WW1 and WW2 are formed such that corresponding recesses FF1 and FF2 are connected to the recess FH on the gas flow path forming surface FP.

  As described below, the feature of the present embodiment is that the refrigerant flow path walls WW1 and WW2 of the refrigerant flow path forming surface WP and the gas flow of the gas flow path forming surface FP constituted by the refrigerant flow path walls WW1 and WW2 are described. The recesses FF1 and FF2 function as a path.

  FIG. 9 is an explanatory view showing, in an enlarged manner, a fuel gas flow path using a recess FF2 corresponding to the refrigerant flow path wall WW2 formed in the region GA1 of FIG. As shown in FIG. 2, the third concave portion FH functioning as a branch flow path is strictly composed of a first partial concave portion FH1 and a second partial concave portion FH2. Since there is no, it is omitted. The region GA1 is a region surrounded by the outlet side refrigerant manifold hole AMWo, the inlet side tunnel structure portion TWi, and the third concave portion FH corresponding to the third convex portion WH at the left end.

  As shown in FIG. 9, the recess FF2 corresponding to the coolant channel wall WW2 is connected to a third recess FH that functions as a branch channel. Thereby, the fuel gas flowing through the third recess can flow into the recess FF2, and the fuel gas can be supplied to the region of the power generation region PA corresponding to the region GA1, so that the utilization efficiency of the power generation region can be improved. Moreover, since this recessed part FF2 utilizes the refrigerant | coolant flow path wall WW2 as it is, it can maintain the flow of the refrigerant | coolant for efficient cooling. Therefore, it is possible to improve the utilization efficiency of the power generation region while maintaining the cooling efficiency by the refrigerant.

  Although not shown, the recess FF1 corresponding to the refrigerant flow path wall WW1 in the region GA2 is also the same as the recess FF2 corresponding to the refrigerant flow path wall WW2 in the region GA1, while maintaining the cooling efficiency by the refrigerant. It is possible to improve the utilization efficiency of the power generation area. The region GA2 is a region surrounded by the inlet-side refrigerant manifold hole AMWi, the outlet-side tunnel structure portion TWo, and the third concave portion FH corresponding to the third convex portion WH at the right end.

  As described above, in this embodiment, it is possible to improve the utilization efficiency of the power generation region while maintaining the cooling efficiency by the refrigerant, and the cooling efficiency and the utilization of the power generation region, which have been problems in the prior art. It is possible to realize a structure in which the refrigerant flow path and the gas flow path are integrally formed so that both efficiency can be achieved.

  In this embodiment, the region GA1 corresponds to the first part of the invention, and the region GA2 corresponds to the second part of the invention. Further, the refrigerant flow path wall WW1 formed in the area GA1 corresponds to the first refrigerant flow path wall, and the refrigerant flow path wall WW2 formed in the area GA2 corresponds to the second refrigerant flow path wall. Further, the first recess FHcmi, the second recess FHcmo, and the third recess FH correspond to the first to third gas flow paths. Further, the seal line SOi corresponds to the first seal line, and the seal line SOo corresponds to the second seal line. In addition, the entrance-side tunnel structure portion TWi corresponds to the first tunnel structure portion, and the exit-side tunnel structure portion TWo corresponds to the second tunnel structure portion.

A2. Variations:
FIG. 10 is an explanatory view showing a first modification of the fuel gas flow path shown in FIG. The fuel gas flow path for supplying fuel gas to the region of the power generation area PA corresponding to the area GA1 shown in FIG. 9 has one end connected to the third recess FH that functions as a branch flow path, and the other end. It is comprised by several recessed part FF2 by which the part was obstruct | occluded. However, the present invention is not limited to this, and as shown in FIG. 10, the power generation area PA corresponding to the area GA1 is formed by meandering, and both ends are connected to the third recess FH. You may make it do. In the case of this configuration, the depth of the portion indicated by cross hatching in the drawing is shallower than the depth of the other portion, that is, the height of the wall surface of the refrigerant flow path forming surface WP is higher than the other portion. Therefore, it is necessary to secure a flow path through which the refrigerant flows as a structure having a low level.

  Even in this configuration, it is possible to improve the utilization efficiency of the power generation area while maintaining the cooling efficiency by the refrigerant, and it is possible to achieve both the cooling efficiency and the utilization efficiency of the power generation area, which were problems in the prior art. In addition, it is possible to realize a structure in which the refrigerant flow path and the gas flow path are integrally formed.

  Although illustration is omitted, the region GA2 can have the same configuration as that of the first modification.

  FIG. 11 is an explanatory view showing a second modification of the fuel gas flow path shown in FIG. This modification shows a structure in which a recess FHb is formed in a region GA1 along the third recess FH, and a plurality of recesses FF2 corresponding to the refrigerant flow path wall WW2 are connected to the recess FHb. The recess FHb is connected to the second recess FHcmi that functions as a common flow path with the entrance-side tunnel recess TFi1. Note that the connection destination of the recess FHb may be a recess that functions as a common flow path or a tunnel recess, or may be connected across both. Similarly to the third concave portion, the concave portion FHb is also configured by partial concave portions having different depths, and it is necessary to secure a flow path through which the refrigerant flows.

  Even in this configuration, it is possible to improve the utilization efficiency of the power generation area while maintaining the cooling efficiency by the refrigerant, and it is possible to achieve both the cooling efficiency and the utilization efficiency of the power generation area, which were problems in the prior art. In addition, it is possible to realize a structure in which the refrigerant flow path and the gas flow path are integrally formed.

  Although illustration is omitted, the area GA2 can have the same configuration as that of the second modification.

  FIG. 12 is an explanatory view showing a third modification of the fuel gas flow path shown in FIG. This modification shows a structure in which a recess FF2c similar to the recess FF2a of the first modification is connected not to the third recess FH but to the entrance-side tunnel recess TFi1 and the second recess FHcmo as a common channel. ing. The end connected to the entrance-side tunnel recess TFi1 may be connected to the first recess FHcmi as a common flow path, or connected across both the entrance-side tunnel recess TFi1 and the first recess FHcmi. Also good.

  Even in this configuration, it is possible to improve the utilization efficiency of the power generation area while maintaining the cooling efficiency by the refrigerant, and it is possible to achieve both the cooling efficiency and the utilization efficiency of the power generation area, which were problems in the prior art. In addition, it is possible to realize a structure in which the refrigerant flow path and the gas flow path are integrally formed.

  Although illustration is omitted, the area GA2 can have the same configuration as that of the third modification.

  As described above, the structure of the fuel gas channel using the refrigerant channel wall for supplying the fuel gas to the power generation region PA corresponding to the regions GA1 and GA2 is limited to the structure shown in FIG. For example, various structures shown in FIGS. 10 to 12 can be used. That is, the structure of the fuel gas flow path using the refrigerant flow path wall uses the refrigerant flow path wall formed in consideration of the cooling efficiency, and uses the fuel gas flow path in the power generation area PA corresponding to the areas GA1 and GA2. Any structure can be used as long as the structure can be supplied.

B. Second embodiment:
B1. Tunnel structure:
FIG. 13 is an explanatory view showing the exit side tunnel structure in the second embodiment. FIG. 13A shows an enlarged view of the exit side tunnel structure TWoa of the second embodiment, and FIG. 13B shows an enlargement of the exit side tunnel structure TWo of the first embodiment.

  As shown in FIG. 13B, a plurality of outlet-side tunnel recesses TFo1 are formed as concave fuel gas flow paths in the outlet-side tunnel structure TWo of the first embodiment. As described above, these outlet-side tunnel recesses TFo1 have a function of discharging the fuel gas flowing through the second recess FHCmo as a common flow path to the outlet-side fuel gas manifold MHo. Although the enlarged illustration of the inlet-side tunnel structure TWi of the first embodiment is omitted, similarly, the function of supplying the fuel gas from the inlet-side fuel gas manifold MHi to the first recess FHcmi as a common flow path is provided. It has a plurality of entrance-side tunnel recesses TFi1.

The fuel gas flowing through the tunnel recesses TFi1, TFi1 is prehumidified or contains water (H ₂ O) due to power generation. If this water stays in the tunnel recesses TFo1 and TFi1 as liquid water (hereinafter referred to as “liquid water”), the tunnel recesses TFo1 and THi1 are blocked and the flow of fuel gas is obstructed. As a result, the power generation performance of the fuel cell is reduced. Further, if the liquid water staying in the tunnel recesses TFo1, TFi1 freezes in the sub-freezing environment when the fuel cell is stopped, the tunnel recess TFo1 is blocked and the flow of the fuel gas is obstructed. Normally, when the operation is stopped, purging is performed to remove the liquid water staying in the fuel cell. However, when the flow rate of the purge gas is low or the time is short, the force for removing the liquid water is weak or insufficient. In some cases, liquid water will remain. As a result, the startability is lowered at the time of subsequent operation start, and the start cannot be performed. The above problem is caused by the fact that the liquid water and fuel gas flow paths are the same.

  On the other hand, as shown in FIG. 13A, in the outlet side tunnel structure portion TWoa of the present embodiment, the direction perpendicular to the flow direction of the fuel gas flowing in the outlet side tunnel concave portion TFo1 (vertical direction in the figure) is vertical. Assume that the fuel cells are arranged in the direction. A gap TMa is provided in the partition wall of the exit-side tunnel recess TFo1, and a groove TMb is provided in a side surface of the partition wall at the lowest end in the vertical direction so that the fuel gas flow path has a substantially mesh structure. Although the enlarged illustration of the entrance-side tunnel structure portion TWia of this embodiment is omitted, similarly, a gap TMa is provided in the partition wall of the entrance-side tunnel recess TFi1, and a groove TMb is formed on the side surface of the partition wall at the lowest end in the vertical direction. The fuel gas channel is provided with a substantially mesh structure.

  In the structure of the present embodiment, the liquid water flowing through the tunnel recesses TFi1, TFi1 can be moved to the lower end via the gap TMa by gravity and collected in the groove TMb. As a result, it is possible to separate the liquid water staying in the tunnel recesses TFo1 and TFi1 through which the fuel gas flows and to secure the fuel gas passage, and to suppress the inhibition of the flow of the fuel gas. .

B2. Variations:
FIG. 14 is an explanatory view showing a first modification of the exit side tunnel structure of the second embodiment. As shown in the figure, the tunnel structure portion TWob of the first modified example has a capillary structure TC that generates a capillary phenomenon in one outlet-side tunnel recessed portion TFo1. As a result, of the outlet-side tunnel recess TFo, one recess is secured as a fuel gas passage across the capillary structure TC, and the other recess is secured as a liquid water passage to separate liquid water and fuel gas. It is possible to suppress the flow of the fuel gas from being hindered.

  The entrance-side tunnel structure TWia of the second embodiment may also have a structure having a capillary structure TC in one entrance-side tunnel recess TFi1, as in the structure of the first modification.

  FIG. 15 is an explanatory view showing a second modification of the exit side tunnel structure portion of the second embodiment. As shown in the figure, in the tunnel structure portion TWoc of the second modified example, a porous body TPa having a relatively large pore diameter and a porous body TPb having a relatively small pore diameter are alternately arranged in one outlet-side tunnel recessed portion TFo1. The porous body portion TP is provided. Since water passes through relatively small holes and gas passes through relatively large holes, the above structure ensures a porous body TPa having a relatively large pore diameter as a fuel gas passage, It is possible to secure the porous body TPb having a small pore diameter as a passage for liquid water and to separate the liquid water and the fuel gas, and it is possible to suppress the obstruction of the flow of the fuel gas.

  In addition, the entrance-side tunnel structure TWia of the second embodiment also has a relatively large pore body TPa and a relatively large pore diameter in one entrance-side tunnel recess TFi1, as in the structure of the second modification. It is good also as a structure in which the porous part TP in which the small porous bodies TPb are alternately arranged is provided.

  As described above, the structure of the tunnel structure portion is not limited to the structure shown in FIG. 13 and can be various structures shown in FIGS. 14 and 15, for example. That is, the structure of the tunnel structure may be any structure that can separate the fuel gas and the liquid water and secure the passage of the fuel gas.

C. Variations:
In addition, elements other than the elements claimed in the independent claims among the constituent elements in the above embodiment are additional elements and can be omitted as appropriate. The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the scope of the invention.

(1) Modification 1:
In the above embodiment, the structure in which one surface of the anode separator is the fuel gas flow path forming surface and the other surface is the refrigerant flow path forming surface has been described as an example. However, the anode separator is also a flat separator, and the anode separator and power generator A gas flow path forming body in which a fuel gas flow path and a refrigerant flow path wall are integrally formed between the first and second surfaces, with one surface being a fuel gas flow path forming surface and the other surface being a refrigerant flow path forming surface. And the present invention may be applied.

(2) Modification 2:
In the above-described embodiment and the first modification, the structure in which the fuel gas flow path on the fuel gas flow path forming surface and the refrigerant flow path wall on the refrigerant flow path forming surface are integrally formed is shown as an example. You may make it apply this invention to the structure which formed the oxidizing gas flow path of the oxidizing gas flow path formation surface, and the refrigerant flow path wall of the refrigerant flow path formation surface integrally.

FUC ... Fuel cell SPA SPA ... Anode separator SPC ... Cathode separator PB ... Power generation unit PA ... Power generation area MH ... Fuel gas manifold MO ... Oxidizing gas manifold MW ... Refrigerant manifold MHi ... Inlet side fuel gas manifold MHo ... Outlet side fuel gas manifold MOi ... Inlet side oxidizing gas manifold MOo ... Outlet side oxidizing gas manifold MWi ... Inlet side refrigerant manifold MWo ... Outlet side refrigerant manifold AMOi ... Inlet side oxidizing gas manifold hole PMOi ... Inlet side oxidizing gas manifold hole CMOi ... Inlet side oxidizing gas manifold hole AMOo ... Outlet side oxidizing gas manifold hole PMOo ... Outlet side oxidizing gas manifold hole CMOo ... Outlet side oxidizing gas manifold hole AMHi ... Inlet side fuel gas manifold hole PMHi ... Inlet side Gas manifold hole CMHi ... Inlet side fuel gas manifold hole AMHo ... Outlet side fuel gas manifold hole PMHo ... Outlet side fuel gas manifold hole CMHo ... Outlet side oxidizing gas manifold hole AMWi ... Inlet side refrigerant manifold hole PMWi ... Inlet side refrigerant manifold hole CMWi ... Inlet side refrigerant manifold hole AMWo ... Outlet side refrigerant manifold hole PMWo ... Outlet side refrigerant manifold hole CMWo ... Outlet side refrigerant manifold hole WP ... Refrigerant flow path forming surface FP ... Gas flow path forming surface WHcmi ... First convex part FHcmi ... 1st recessed part WHcmo ... 2nd convex part FHCmo ... 2nd recessed part WH ... 3rd convex part FH ... 3rd recessed part WH1 ... 1st partial convex part WH2 ... 2nd partial convex part FH1 ... 1st 1 partial recessed part FH2 ... 2nd partial recessed part WB ... board | substrate part TWi ... entrance Tunnel structure portion TWo ... exit side tunnel structure portion GA1 ... region GA2 ... region PB1 ... membrane electrode assembly PB2 ... gas diffusion layer PB3 ... gas diffusion layer PB4 ... porous body flow passage portion PB5 ... sealing portion SW ... sealing line SH ... sealing Line SOi ... Seal line SOo ... Seal line SHo ... Seal line HHi ... Communication hole HHo ... Communication hole HOi ... Communication hole HOo ... Communication hole WOi ... Oxidation gas channel wall WOo ... Oxidation gas channel wall WWi ... Refrigerant channel wall WWo ... Refrigerant channel wall WW1 ... Refrigerant channel wall WW2 ... Refrigerant channel wall TWia ... Inlet side tunnel structure TWoa ... Exit side tunnel structure part TWob ... Exit side tunnel structure part TWoc ... Outlet side tunnel structure part TWi1 ... Inlet side tunnel Convex part TFi1 ... Entrance side tunnel concave part TWo1 ... Outlet side tunnel convex part TFo1 ... Out Side tunnel recess FF1 ... recess FF2 ... recess FF2a ... recess FF2c ... recess TC ... capillary structure TP ... porous body FHB ... recess TMa ... void TMb ... groove TP ... porous body TPa ... porous body TPb ... porous body

Claims (4)

A gas flow path forming body that is used in a fuel cell and has a structure in which a groove-like gas flow path on a gas flow path forming surface and a refrigerant flow path on a refrigerant flow path forming surface are formed integrally with each other,
Inside the first region of the gas flow path forming surface corresponding to the substantially rectangular power generation region of the fuel cell,
A first gas flow path formed along the first edge;
A second gas flow path formed along a second end side facing the first end side;
A plurality of third gas passages formed so as to connect between the first gas passage and the second gas passage;
A first gas manifold hole formed on the third end side perpendicular to the first end side outside the first region;
A second gas manifold hole formed on a fourth end side facing the third end side outside the first region;
A first refrigerant manifold hole formed along the fourth end side alongside the fourth gas manifold hole outside the first region; and the third end outside the first region. A second refrigerant manifold hole formed side by side with the first gas manifold hole;
A first seal line covering the first gas manifold hole on the refrigerant flow path forming surface;
A second seal line covering the second gas manifold hole on the refrigerant flow path forming surface;
A first tunnel structure formed so as to straddle the first seal line on the coolant flow path forming surface in order to connect the first gas flow path to the first gas manifold hole;
A second tunnel structure formed so as to straddle the second seal line on the refrigerant flow path forming surface in order to connect the second gas flow path to the second gas manifold hole;
With
Concavities and convexities formed on the refrigerant flow path forming surface side by the first to third gas flow paths form the refrigerant flow path,
The first region corresponding to the portion of the first region surrounded by the first refrigerant manifold hole, the second tunnel structure, and the third gas flow path closest to the fourth end side. The first portion of the refrigerant flow path forming surface is formed with a first refrigerant flow path wall that regulates the flow of the refrigerant from the first refrigerant manifold hole toward the direction of the refrigerant flow path,
Corresponding to a portion of the first region surrounded by the second refrigerant manifold hole, the first tunnel structure, and the third gas flow path closest to the third end side. The second portion of the refrigerant flow path forming surface is formed with a second refrigerant flow channel wall that restricts the flow of the refrigerant from the refrigerant flow channel toward the second refrigerant manifold hole. And
The unevenness on the gas flow path forming surface side formed by the first refrigerant flow path wall and the second refrigerant flow path wall is connected to any one of the first to third gas flow paths. ,
A gas flow path forming body characterized by that. The gas flow path forming body according to claim 1,
At least one of the first and second tunnel structure portions has a separation structure that separates liquid water and gas.   The gas flow path forming body according to claim 1 or 2, wherein the gas flow path forming body is a separator used in the fuel battery cell.   A fuel cell comprising the gas flow path forming body according to any one of claims 1 to 3.

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