JP5829565B2 - Fuel cell system - Google Patents

Description

  The present invention includes a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidant gas, and includes a fuel cell stack in which a plurality of the fuel cells are stacked, and a housing that houses the fuel cell stack therein. The present invention relates to a fuel cell system provided.

  For example, a polymer electrolyte fuel cell is a power generation cell in which an electrolyte membrane / electrode structure (MEA) in which an anode electrode and a cathode electrode are arranged on both sides of an electrolyte membrane made of a polymer ion exchange membrane is sandwiched by separators. It has. This type of fuel cell is usually used as an in-vehicle fuel cell stack, for example, by stacking a predetermined number of power generation cells.

  In the fuel cell stack, particularly when used for in-vehicle use, it is necessary to stack a large number of power generation cells. Therefore, in order to ensure the rigidity of the entire fuel cell stack, a configuration is adopted in which the fuel cell stack is accommodated in a housing.

  At that time, a ventilation device is provided in the housing in order to maintain the hydrogen concentration below a certain value. For example, in the fuel cell system disclosed in Patent Document 1, as shown in FIG. 6, a case ventilation means 3 for ventilating the inside of the case 2 in which the fuel cell stack 1 is stored is provided.

  The casing ventilation means 3 ventilates a part of the blown air from the air supply device 5 supplied through the branch pipe 4 and the running wind of the fuel cell vehicle supplied through the running wind introduction pipe 6. It is introduced into the housing 2 while being appropriately switched by the switching unit 7. Thereby, an increase in the hydrogen concentration in the housing 2 can be surely prevented.

JP 2004-186029 A

  However, in the above-mentioned Patent Document 1, the case ventilation means 3 including the ventilation switching unit 7 is provided, and there is a problem that the configuration of the entire fuel cell system becomes complicated and large, and is not economical.

  An object of the present invention is to solve this type of problem, and to provide a fuel cell system capable of satisfactorily ventilating a casing with a simple and compact configuration.

  The present invention includes a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidant gas, and includes a fuel cell stack in which a plurality of the fuel cells are stacked, and a housing that houses the fuel cell stack therein. The present invention relates to a fuel cell system provided.

  In this fuel cell system, the fuel cell stack includes a first end plate disposed at one end of the fuel cell in the stacking direction, a second end plate disposed at the other end of the fuel cell in the stacking direction, and A fuel gas system device is disposed on the opposite side of the second end plate from the fuel cell stack.

The housing houses a fuel cell stack and is fixed to one end of the second end plate, and a second housing that houses the fuel gas device and is fixed to the other end of the second end plate. And a housing part. The second end plate is formed with a through hole for communicating the first housing portion and the second housing portion with each other , and the first housing portion is provided with a first ventilation port. The second housing part is provided with a second ventilation port .

Further, in this fuel cell system, the opening cross-sectional area of the second vent or first vent Ru inlet port side vent der is preferably set to be smaller than the opening cross-sectional area of the through-hole.

Furthermore, in this fuel cell system, the second end plate is set to have an outer dimension larger than that of the first end plate, and the first end plate has a first end between the first end plate and the first housing portion. while the seal member is interposed, the other end of the second end plate is provided between the second housing part, the second seal member is via instrumentation, and the first sealing member and said second sealing member Are preferably arranged at the same position in the stacking direction across the second end plate.

  According to the present invention, the fuel cell stack is housed in the first housing portion, while the fuel gas system device is housed in the second housing portion, the first housing portion and the second housing portion. And communicate with each other through a through hole formed in the second end plate. For this reason, it is not necessary to provide a separate ventilation mechanism for each of the first housing part and the second housing part, and it is only necessary to form a single ventilation line in the housing.

  Thus, it is possible to perform ventilation in the housing satisfactorily with a simple and compact configuration, and it is economical.

1 is a schematic exploded perspective view of a fuel cell system according to an embodiment of the present invention. It is a cross-sectional side view of the fuel cell system. FIG. 3 is a cross-sectional view of the fuel cell system taken along line III-III in FIG. 2. It is a principal part disassembled perspective explanatory drawing of the fuel cell which comprises the said fuel cell system. It is a schematic perspective view from the rear of the fuel cell system. 1 is a schematic explanatory diagram of a fuel cell system disclosed in Patent Document 1. FIG.

  As shown in FIGS. 1 and 2, a fuel cell system 10 according to an embodiment of the present invention constitutes an in-vehicle fuel cell system mounted on a fuel cell vehicle (not shown) such as a fuel cell electric vehicle. To do. The fuel cell system 10 includes a fuel cell stack 12 and a casing 14 that houses the fuel cell stack 12 therein.

  The fuel cell stack 12 includes a plurality of fuel cells 16 stacked in a horizontal direction (arrow B direction) or a gravitational direction (arrow C direction), and a first terminal plate 20a, The first insulating plate 22a and the first end plate 24a are sequentially arranged outward. At the other end of the fuel cell 16 in the stacking direction, a second terminal plate 20b, a second insulating plate 22b, and a second end plate 24b are sequentially arranged outward.

  A first output terminal 26a connected to the first terminal plate 20a extends outward from the center of the first end plate 24a. A second output terminal 26b connected to the second terminal plate 20b extends outward from the center of the second end plate 24b.

  Between the sides of the first end plate 24a and the second end plate 24b, both ends of the connecting bar 28 are fixed by screws 30, and a tightening load in the stacking direction (arrow B direction) is applied to the plurality of stacked fuel cells 16. Give.

  As shown in FIG. 4, the fuel cell 16 has a horizontally long rectangular shape, and the electrolyte membrane / electrode structure 32 is sandwiched between the first separator 34 and the second separator 36. The 1st separator 34 and the 2nd separator 36 are comprised by metal separators and carbon separators, such as a steel plate, a stainless steel plate, an aluminum plate, or a plating treatment steel plate, for example.

  One end edge of the fuel cell 16 in the direction of arrow A (horizontal direction in FIG. 4) communicates with each other in the direction of arrow B, which is the stacking direction, and oxidant for supplying an oxidant gas, for example, an oxygen-containing gas An agent gas inlet communication hole 38a and a fuel gas outlet communication hole 40b for discharging a fuel gas, for example, a hydrogen-containing gas, are arranged in an arrow C direction (vertical direction).

  The other end edge of the fuel cell 16 in the direction of arrow A communicates with each other in the direction of arrow B, a fuel gas inlet communication hole 40a for supplying fuel gas, and an oxidant gas for discharging oxidant gas. Outlet communication holes 38b are arranged in the direction of arrow C.

  A pair of cooling medium inlet communication holes 42a for supplying a cooling medium is provided at the upper end edge in the arrow C direction of the fuel cell 16, and the lower end edge in the arrow C direction of the fuel cell 16 is A pair of cooling medium outlet communication holes 42b for discharging the cooling medium is provided.

  An oxidant gas flow path 44 communicating with the oxidant gas inlet communication hole 38a and the oxidant gas outlet communication hole 38b is provided on the surface 34a of the first separator 34 facing the electrolyte membrane / electrode structure 32.

  A fuel gas passage 46 communicating with the fuel gas inlet communication hole 40a and the fuel gas outlet communication hole 40b is provided on the surface 36a of the second separator 36 facing the electrolyte membrane / electrode structure 32.

  A cooling medium that connects the cooling medium inlet communication hole 42a and the cooling medium outlet communication hole 42b between the surface 34b of the first separator 34 and the surface 36b of the second separator 36 that constitute the fuel cells 16 adjacent to each other. A flow path 48 is provided.

  The first separator 34 and the second separator 36 are respectively provided with seal members 50 and 52 integrally or individually. For the seal members 50 and 52, for example, a seal material such as EPDM, NBR, fluoro rubber, silicon rubber, fluorosilicon rubber, butyl rubber, natural rubber, styrene rubber, chloroplane, or acrylic rubber, a cushion material, or a packing material is used. To do.

  The electrolyte membrane / electrode structure 32 includes, for example, a solid polymer electrolyte membrane 54 in which a perfluorosulfonic acid thin film is impregnated with water, and a cathode electrode 56 and an anode electrode 58 sandwiching the solid polymer electrolyte membrane 54. Prepare.

  The cathode electrode 56 and the anode electrode 58 are an electrode catalyst formed by uniformly applying a gas diffusion layer made of carbon paper or the like and porous carbon particles carrying a platinum alloy supported on the surface of the gas diffusion layer. And having a layer. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 54.

  As shown in FIGS. 1 and 2, the second end plate 24b has a larger surface area (outer dimension) than the first end plate 24a. As shown in FIGS. 1 and 3, the second end plate 24b communicates with the oxidant gas inlet communication hole 38a, the oxidant gas outlet communication hole 38b, the fuel gas inlet communication hole 40a, and the fuel gas outlet communication hole 40b. An oxidant gas supply manifold 60a, an oxidant gas discharge manifold 60b, a fuel gas supply manifold 62a, and a fuel gas discharge manifold 62b are attached.

  A through hole 64 is formed in the second end plate 24b at a position spaced below the lower part of the fuel cell stack 12 in the stacking direction. As will be described later, the through-hole 64 communicates the first housing part 70a and the second housing part 70b constituting the housing 14. The through hole 64 is not limited to the lower side of the fuel cell stack 12, and may be provided at a position separated from the fuel cell stack 12. For example, the second end plate 24b may be provided away from the fuel cell stack 12 in the upward direction or the left-right direction.

  As shown in FIGS. 2 and 5, the first end plate 24a includes a cooling medium supply manifold 66a and a cooling medium discharge manifold that are integrally connected to the pair of cooling medium inlet communication holes 42a and the pair of cooling medium outlet communication holes 42b. 66b is attached.

  A fuel gas system device 68 connected to the fuel gas supply manifold 62a and the fuel gas discharge manifold 62b is attached to the second end plate 24b on the side opposite to the fuel cell stack 12 (see FIGS. 1 to 3).

  The fuel gas system device 68 includes at least one of an ejector 68a, a hydrogen pump 68b, a gas-liquid separation tank 68c, a purge valve, a scavenging valve, and a hydrogen heat exchanger, and is directly attached to the second end plate 24b.

  Here, the ejector 68a has a function of sucking the discharged fuel gas discharged from the fuel gas outlet communication hole 40b and supplying it again to the fuel gas inlet communication hole 40a as fuel gas. The gas-liquid separation tank 68c has a function of removing liquid water contained in the discharged fuel gas, and the purge valve has a function of discharging impurities present in the fuel gas circulation system out of the system. The scavenging valve has a function of scavenging the fuel gas passage 46, and the hydrogen pump 68 b has a function of supplying (pressure feeding) fuel gas to the fuel gas passage 46. The hydrogen heat exchanger has a function of preheating the fuel gas before being supplied to the fuel gas channel 46.

  As shown in FIGS. 1, 2, and 5, the housing 14 includes a first housing portion 70 a that houses the fuel cell stack 12 and is fixed to one end of the second end plate 24 b, and a fuel gas system device 68. And a second housing part 70b fixed to the other end of the second end plate 24b.

  As shown in FIG. 5, the first output terminal 26a is exposed to the bottom end of the first casing 70a through the seal member 72a, and the cooling medium supply manifold 66a and the cooling medium The medium discharge manifold 66b is exposed to the outside through the seal members 74a and 74b.

  A flange portion 76a is provided at the opening-side end portion of the first housing portion 70a. As shown in FIGS. 1 and 2, a first seal member 78a is interposed between the flange portion 76a and one end of the second end plate 24b, and a plurality of screws inserted into the flange portion 76a. 80 is screwed into each screw hole 82a of the second end plate 24b. A first ventilation port 84a is provided at the lower part of the first housing part 70a. In addition, the 1st ventilation port 84a is not limited to the lower part of the 1st housing | casing part 70a, It can provide in the arbitrary positions of the said 1st housing | casing part 70a.

  As shown in FIG. 1, the second output terminal 26b is exposed to the outside through the seal member 72b at the bottomed end of the second casing 70b, and the oxidizing gas supply manifold 60a and The oxidant gas discharge manifold 60b is exposed to the outside through the seal members 86a and 86b. A fuel gas supply pipe 88a and a fuel gas discharge pipe 88b connected to the fuel gas system device 68 are exposed to the outside through the seal members 90a and 90b at the bottomed end of the second housing part 70b. To do.

  A second ventilation port 84b is integrally provided on the side portion of the second casing 70b. The second ventilation port 84b forms, for example, an inlet side ventilation port, and is connected to the air pump 92 as shown in FIG. The 1st ventilation port 84a comprises an exit side ventilation port, for example.

  The opening diameter D1 of the first ventilation opening 84a is set larger than the opening diameter D2 of the second ventilation opening 84b (D2 ≦ D1), and the opening diameter D3 of the through hole 64 is the opening diameter D2 of the second ventilation opening 84b. (D2 ≦ D3). The opening diameter D1 is preferably set larger than the opening diameter D3 (D3 ≦ D1). In addition, while the 1st ventilation port 84a comprises an entrance side ventilation port, the 2nd ventilation port 84b may comprise an exit side ventilation port. At that time, the relationship between the opening diameters is set to be opposite to the above.

  A flange portion 76b is provided at the opening side end portion of the second housing portion 70b. A second seal member 78b is interposed between the flange portion 76b and the other end of the second end plate 24b, and a plurality of screws 80 inserted into the flange portion 76b are connected to the second end plate 24b. Are screwed into the respective screw holes 82b. The first seal member 78a and the second seal member 78b are disposed at the same position in the stacking direction with the second end plate 24b interposed therebetween.

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

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied from the oxidant gas supply manifold 60a to the oxidant gas inlet communication hole 38a, and from the fuel gas supply pipe 88a to the fuel gas system device 68. The supplied fuel gas such as a hydrogen-containing gas is supplied from the fuel gas supply manifold 62a to the fuel gas inlet communication hole 40a.

  Further, as shown in FIG. 5, a coolant such as pure water, ethylene glycol, or oil is supplied from the coolant supply manifold 66a to the pair of coolant supply passages 42a.

  Therefore, as shown in FIG. 4, the oxidant gas is introduced into the oxidant gas flow path 44 of the first separator 34 from the oxidant gas inlet communication hole 38 a. The oxidant gas is supplied to the cathode electrode 56 constituting the electrolyte membrane / electrode structure 32 while moving in the arrow A direction.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 46 of the second separator 36 from the fuel gas inlet communication hole 40a. The fuel gas is supplied to the anode electrode 58 constituting the electrolyte membrane / electrode structure 32 while moving in the arrow A direction.

  Therefore, in the electrolyte membrane / electrode structure 32, the oxidizing gas supplied to the cathode electrode 56 and the fuel gas supplied to the anode electrode 58 are consumed by an electrochemical reaction in the electrode catalyst layer, and power generation is performed. Is called.

  Next, the oxidant gas supplied and consumed to the cathode electrode 56 flows in the direction of arrow B along the oxidant gas outlet communication hole 38b, and is discharged from the oxidant gas discharge manifold 60b (see FIG. 1). On the other hand, the consumed fuel gas supplied to the anode electrode 58 flows in the direction of arrow B along the fuel gas outlet communication hole 40b, and is introduced into the fuel gas system device 68 from the fuel gas discharge manifold 62b. The fuel gas is further discharged from the fuel gas discharge pipe 88b.

  The cooling medium supplied to the pair of cooling medium inlet communication holes 42 a is introduced into the cooling medium flow path 48 between the first separator 34 and the second separator 36 and then circulates in the direction of arrow C. After cooling the electrolyte membrane / electrode structure 32, the cooling medium flows through the pair of cooling medium outlet communication holes 42b and is discharged from the cooling medium discharge manifold 66b (see FIG. 5).

  In this case, in the present embodiment, as shown in FIGS. 1 and 2, the first housing part 70a is fixed to one end of the second end plate 24b and the other end of the second end plate 24b. The second housing part 70b is fixed. The fuel cell stack 12 is housed in the first housing portion 70a, while the fuel gas system device 68 is housed in the second housing portion 70b.

  And the 1st housing | casing part 70a and the 2nd housing | casing part 70b are mutually connected via the through-hole 64 formed in the 2nd end plate 24b. For this reason, it is not necessary to provide a separate ventilation mechanism for each of the first casing 70a and the second casing 70b. Therefore, it is only necessary to provide a single ventilation line in the housing 14 that connects the second ventilation port 84b, the through hole 64, and the first ventilation port 84a.

  As a result, it is possible to satisfactorily perform ventilation in the housing 14 with a simple and compact configuration, and it is possible to obtain an economical effect.

  Further, the opening diameter D1 of the first ventilation port 84a is set larger than the opening diameter D2 of the second ventilation port 84b, and the opening diameter D3 of the through hole 64 is larger than the opening diameter D2 of the second ventilation port 84b. Is also set larger.

  Thus, as shown in FIG. 2, the air supplied from the air pump 92 to the second ventilation port 84b is introduced into the second housing portion 70b and ventilated, and then the through hole of the second end plate 24b. 64 can smoothly flow into the first housing portion 70a. This is because pressure loss at the through hole 64 is avoided.

  Furthermore, the air which ventilated the inside of the 1st housing | casing part 70a does not cause a pressure loss, but is discharged | emitted outside from the 1st ventilation port 84a. For this reason, there exists an advantage that the ventilation process in the 1st housing | casing part 70a and the 2nd housing | casing part 70b is performed efficiently and reliably.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 12 ... Fuel cell stack 14 ... Housing 16 ... Fuel cell 24a, 24b ... End plate 32 ... Electrolyte membrane and electrode structure 34, 36 ... Separator 38a ... Oxidant gas inlet communication hole 38b ... Oxidant gas Outlet communication hole 40a ... Fuel gas inlet communication hole 40b ... Fuel gas outlet communication hole 42a ... Cooling medium inlet communication hole 42b ... Cooling medium outlet communication hole 44 ... Oxidant gas channel 46 ... Fuel gas channel 48 ... Cooling medium channel 50, 52, 72a, 72b, 74a, 74b, 78a, 78b, 86a, 86b, 90a, 90b ... seal member 54 ... solid polymer electrolyte membrane 56 ... cathode electrode 58 ... anode electrode 60a ... oxidant gas supply manifold 60b ... Oxidant gas discharge manifold 62a ... Fuel gas supply manifold 62b ... Fuel gas discharge manifold 6 ... through hole 66a ... cooling medium supply manifold 66b ... coolant discharge manifold 68: fuel gas system devices 70a, 70b ... housing 84a, 84b ... ventilation opening

Claims (3)

A fuel cell stack comprising a fuel cell that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas, and a plurality of the fuel cells stacked;
A housing for accommodating the fuel cell stack;
A fuel cell system comprising:
The fuel cell stack has a first end plate disposed at one end in the stacking direction of the fuel cells,
A second end plate is disposed at the other end in the stacking direction of the fuel cell, and a fuel gas system device is disposed on the opposite side of the second end plate from the fuel cell stack,
The housing includes a first housing portion that houses the fuel cell stack and is fixed to one end of the second end plate;
A second housing portion that accommodates the fuel gas system device and is fixed to the other end of the second end plate;
With
The second end plate is formed with a through hole for communicating the first housing part and the second housing part with each other ,
Wherein the first housing portion, while the first ventilation opening is provided, wherein the second housing portion, a fuel cell system second ventilation openings, characterized in Rukoto provided. The fuel cell system according to claim 1, wherein, the opening cross-sectional area of the second ventilation opening or the first ventilation port is input mouth side ventilation arrangements, characterized by being set smaller than the opening cross-sectional area of the through hole A fuel cell system. The fuel cell system according to claim 1 or 2, wherein the second end plate is set to have an outer dimension larger than that of the first end plate,
A first seal member is interposed between one end of the second end plate and the first housing portion, and between the other end of the second end plate and the second housing portion. the second sealing member is via instrumentation,
The fuel cell system, wherein the first seal member and the second seal member are disposed at the same position in the stacking direction with the second end plate interposed therebetween.

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