JP2010125962A - On-vehicle fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical on-vehicle fuel cell system in which the length of hydrogen piping that interconnects a fuel cell and a hydrogen tank is shortened as much as possible, and the number of hydrogen sensors used is reduced. <P>SOLUTION: In the fuel cell system 10, a second section 22c is provided in the rear side of a fuel cell vehicle 12 with respect to the length direction, and a fuel cell stack 14 and a hydrogen gas tank 44 are integrally provided on a sub-frame 90 in the second section 22c. The fuel cell stack 14 has a vertically long shape as seen from the front in the stacking direction, and arranged in the immediate front of the hydrogen gas tank 44 in such a way that the stacking direction is oriented in the vehicle width direction and the upper side of the fuel cell stack 14 is inclined toward the hydrogen gas tank 44. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an in-vehicle fuel cell system that is mounted on a vehicle, in which a plurality of power generation cells are stacked and includes a fuel cell having a vertically long shape when viewed from the front in the stacking direction.

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

  In recent years, this type of fuel cell stack constitutes a fuel cell vehicle by being mounted on a vehicle such as an automobile instead of an internal combustion engine. For example, in a fuel cell vehicle disclosed in Patent Document 1, as shown in FIG. 5, the fuel cell unit 1 is mounted on a bottomed subframe 2, and the subframe 2 includes a cabin 3 of a vehicle body. It is formed in a flat rectangular shape with a size that fits within the range of the projection plane of the vehicle body floor 4 so that it can be disposed below the vehicle.

  Under the vehicle body floor 4, fuel tanks 5, 5 for storing hydrogen to be supplied to the fuel cell unit 1 are mounted and supported by a clamp belt (not shown) or the like at a rear portion of the subframe 2. .

JP 2003-182378 A

  By the way, in the above-mentioned Patent Document 1, the fuel cell unit 1 is mounted on the subframe 2, while the fuel tanks 5, 5 are spaced apart from the fuel cell unit 1 in the rear. For this reason, there is a problem that the hydrogen supply piping connecting the fuel cell unit 1 and the fuel tanks 5 and 5 becomes long, the amount of hydrogen retained increases, and the number of joints increases.

  Moreover, the fuel cell unit 1 and the fuel tanks 5 and 5 are mounted in different sections. Therefore, it is necessary to equip the fuel cell unit 1 and the fuel tanks 5 and 5 with hydrogen sensors individually. However, the hydrogen sensor is considerably expensive and consumes a large amount of electric power, so that there is a problem that it is not economical.

  Furthermore, when the fuel cell unit 1 and the fuel tanks 5 and 5 are arranged in separate sections, two ventilation systems (ventilation fans) are required as a measure against hydrogen leakage. This has the problem that it is not economical.

  The present invention solves this type of problem, shortens the length of the hydrogen pipe connecting the fuel cell and the hydrogen tank as much as possible, reduces the number of hydrogen sensors installed, and is economical. An object is to provide an in-vehicle fuel cell system.

  The present invention relates to an in-vehicle fuel cell system that is mounted on a vehicle, in which a plurality of power generation cells are stacked and a fuel cell having a vertically long shape when viewed from the front in the stacking direction.

  In this in-vehicle fuel cell system, a hydrogen tank is disposed on the rear side in the vehicle length direction of the vehicle, and the fuel cell has a stacking direction in the vehicle width direction and an upper side on the hydrogen tank immediately before the hydrogen tank. It is arranged in a state inclined to the side.

  Further, it is preferable that the fuel cell and the hydrogen tank are integrally mounted on the same frame.

  Further, the fuel cell and the hydrogen tank are preferably accommodated in the same compartment.

  According to the present invention, since the fuel cell is inclined and disposed immediately before the hydrogen tank, the fuel cell and the hydrogen tank can be disposed in close proximity to each other. Therefore, the length of the hydrogen pipe connecting the fuel cell and the hydrogen tank is shortened as much as possible, and the number of relatively expensive hydrogen sensors and exhaust systems can be effectively reduced. Is economical.

  In addition, since the fuel cell is disposed at an inclination, the storage space for the fuel cell can be reduced. Furthermore, it becomes possible to easily improve drainage from the fuel cell.

  FIG. 1 is a schematic side view of a fuel cell vehicle 12 on which an in-vehicle fuel cell system 10 according to an embodiment of the present invention is mounted, and FIG. 2 is the fuel cell vehicle mainly composed of the fuel cell system 10. FIG. 3 is a schematic plan view of the fuel cell system 10.

  In FIG. 3, for the sake of explanation, the arrangement positions of the constituent elements described later are shown at positions different from the actual arrangement positions. The actual arrangement position is shown in FIG. 1 and FIG.

  The fuel cell system 10 supplies a fuel cell stack 14, a cooling medium supply mechanism 16 for supplying a cooling medium to the fuel cell stack 14, and an oxidant gas (for example, air) to the fuel cell stack 14. Oxidant gas supply mechanism 18 and a fuel gas supply mechanism 20 for supplying fuel gas (for example, hydrogen gas) to the fuel cell stack 14.

  In the fuel cell vehicle 12, a cabin 22a, a first section 22b, and a second section 22c are formed via a partition member 22. The first section 22b is formed on the front side in the vehicle length direction, while the second section 22c is formed on the rear side in the vehicle length direction (near the rear wheel).

  The cooling medium supply mechanism 16 includes a radiator 24 disposed on the front side in the traveling direction of the fuel cell vehicle 12 (in the direction of the arrow L1), that is, in the first section 22b. A cooling medium supply pipe 28 and a cooling medium discharge pipe 30 are connected to the radiator 24 via a refrigerant pump 26.

  The oxidant gas supply mechanism 18 includes an air pump 32 disposed close to the refrigerant pump 26. An air supply pipe 34 having one end connected to the air pump 32 is connected to a humidifier (for example, a hollow fiber membrane type) 36, and the other end is connected to the fuel cell stack 14. The

  A used oxidant gas (hereinafter referred to as off-gas) is supplied from the fuel cell stack 14 to the humidifier 36 as a humidified fluid. An off gas supply pipe 40 is connected to the humidifier 36, and a back pressure valve 42 is disposed in the off gas supply pipe 40 (see FIG. 3).

  The fuel gas supply mechanism 20 includes a hydrogen gas tank (hydrogen tank) 44 in which hydrogen gas is stored as fuel gas. One end of a fuel gas supply pipe (hydrogen pipe) 45 is connected to the hydrogen gas tank 44, and the other end of the fuel gas supply pipe 45 is connected to the fuel cell stack 14 via a shutoff valve 46, a regulator 48 and an ejector 50. Connected.

  An exhaust fuel gas pipe 52 through which used fuel gas is discharged is connected to the fuel cell stack 14. The exhaust fuel gas pipe 52 is connected to the ejector 50 via a return pipe 54, and the downstream portion communicates with the purge valve 56.

  As shown in FIG. 2, the fuel cell stack 14 includes a plurality of power generation cells 60 stacked in a horizontal direction (arrow W direction) that is the vehicle width direction. The end plates 62a and 62b are disposed via the insulating plates.

  The fuel cell stack 14 includes a casing (not shown) including end plates 62a and 62b that are formed in a rectangular shape that is long (vertically long) in the vertical direction (arrow C direction). The fuel cell stack 14 has a vertically long shape in a front view from the end plates 62a and 62b that are ends in the stacking direction. By attaching the humidifier 36 to the end plate 62b, the humidifier 36 is integrated with the fuel cell stack 14.

  As shown in FIG. 4, each power generation cell 60 includes an electrolyte membrane / electrode structure 66, and first and second metal separators 68 and 70 having a thin plate shape that sandwich the electrolyte membrane / electrode structure 66. At the same time, it is configured vertically. For example, a carbon separator may be used instead of the first and second metal separators 68 and 70.

  One end edge of the power generation cell 60 in the short side direction (arrow B direction) communicates with each other in the arrow A direction (arrow W direction) to supply an oxidant gas, for example, an oxygen-containing gas. A supply communication hole 72a, a cooling medium supply communication hole 74a for supplying a cooling medium, and a fuel gas discharge communication hole 76b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge of the power generation cell 60 in the short side direction communicates with each other in the direction of the arrow A, the fuel gas supply communication hole 76a for supplying fuel gas, and the cooling medium discharge communication hole for discharging the cooling medium. 74b and an oxidant gas discharge communication hole 72b for discharging the oxidant gas are provided. The cooling medium supply communication hole 74a and the cooling medium discharge communication hole 74b are set in a vertically long shape.

  The electrolyte membrane / electrode structure 66 includes, for example, a solid polymer electrolyte membrane 78 in which a thin film of perfluorosulfonic acid is impregnated with water, and an anode side electrode 80 and a cathode side electrode 82 that sandwich the solid polymer electrolyte membrane 78. With.

  The surface 68a of the first metal separator 68 facing the electrolyte membrane / electrode structure 66 communicates with the fuel gas supply communication hole 76a and the fuel gas discharge communication hole 76b, and extends in the direction of arrow C. Is formed. A cooling medium flow path 86 that connects the cooling medium supply communication hole 74 a and the cooling medium discharge communication hole 74 b is formed on the surface 68 b of the first metal separator 68.

  The surface 70a of the second metal separator 70 facing the electrolyte membrane / electrode structure 66 is provided with, for example, an oxidant gas channel 88 extending in the direction of arrow C, and the oxidant gas channel 88 is oxidized. The oxidant gas supply communication hole 72a and the oxidant gas discharge communication hole 72b communicate with each other. A cooling medium flow path 86 is integrally formed on the surface 70 b of the second metal separator 70 so as to overlap the surface 68 b of the first metal separator 68. Although not shown, a seal member is integrally formed on the first and second metal separators 68 and 70 as necessary.

  As shown in FIGS. 1 and 2, the second section 22 c is provided with a subframe 90, and the fuel cell stack 14, the humidifier 36, and the hydrogen gas tank 44 are integrally mounted on the subframe 90. Placed.

  The fuel cell stack 14 is disposed on the subframe 90 immediately before the hydrogen gas tank 44 with the stacking direction oriented in the vehicle width direction (arrow W direction) and the upper side inclined to the hydrogen gas tank 44 side. The In each power generation cell 60, the oxidant gas discharge communication hole 72b is disposed below, whereby drainage from the oxidant gas discharge communication hole 72b is improved (see FIG. 1).

  The inclination angle of the fuel cell stack 14 is set, for example, corresponding to the angle of the backrest portion of the rear seat 92 in the cabin 22a. In the second section 22c, for example, a hydrogen sensor 94 is disposed at the upper part of the fuel cell stack 14.

  In this embodiment, as shown in FIG. 3, a purge valve (not shown) is provided between the air supply pipe 34 constituting the oxidant gas supply mechanism 18 and the downstream side of the ejector 50 constituting the fuel gas supply mechanism 20. ) May be provided, and the fuel gas remaining in the fuel gas flow path system of the fuel cell stack 14 may be exhausted (purged).

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

  First, as shown in FIG. 3, the air pump 32 that constitutes the oxidant gas supply mechanism 18 is driven, and external air that is an oxidant gas is sucked and introduced into the air supply pipe 34. This air is introduced into the humidifier 36 from the air supply pipe 34 and is humidified by an off-gas which is an oxidant gas used for the reaction, as will be described later. The humidified air is supplied to the oxidant gas supply communication hole 72a in the fuel cell stack 14 through the end plate 62b.

  On the other hand, in the fuel gas supply mechanism 20, the fuel gas (hydrogen gas) in the hydrogen gas tank 44 is depressurized by the regulator 48 under the opening action of the shutoff valve 46, and then passes through the ejector 50 and ends from the fuel gas supply pipe 45. The fuel gas supply communication hole 76a in the fuel cell stack 14 is introduced through the plate 62b.

  Further, in the cooling medium supply mechanism 16, under the action of the refrigerant pump 26, the cooling medium is introduced from the cooling medium supply pipe 28 through the end plate 62 a to the cooling medium supply communication hole 74 a in the fuel cell stack 14.

  As shown in FIG. 4, the air supplied to the power generation cell 60 in the fuel cell stack 14 is introduced into the oxidant gas flow path 88 of the second metal separator 70 from the oxidant gas supply communication hole 72a, and the electrolyte membrane / It moves along the cathode side electrode 82 of the electrode structure 66. On the other hand, the fuel gas is introduced into the fuel gas flow path 84 of the first metal separator 68 from the fuel gas supply communication hole 76 a and moves along the anode side electrode 80 of the electrolyte membrane / electrode structure 66.

  Therefore, in each electrolyte membrane / electrode structure 66, the oxygen in the air supplied to the cathode side electrode 82 and the fuel gas (hydrogen) supplied to the anode side electrode 80 undergo an electrochemical reaction in the electrode catalyst layer. To generate electricity.

  Next, the air consumed by being supplied to the cathode side electrode 82 flows along the oxidant gas discharge communication hole 72b, and then is discharged from the end plate 62b to the humidifier 36 as an off gas (see FIG. 3).

  Similarly, the fuel gas consumed by being supplied to the anode side electrode 80 is discharged and flows into the fuel gas discharge communication hole 76b, and is discharged from the end plate 62b to the discharged fuel gas pipe 52 as discharged fuel gas. Part of the discharged fuel gas discharged to the discharged fuel gas pipe 52 is returned to the fuel gas supply pipe 45 through the return pipe 54 under the suction action of the ejector 50. The discharged fuel gas is mixed with new fuel gas and supplied into the fuel cell stack 14 from the fuel gas introduction pipe 45a. The remaining discharged fuel gas is discharged under the action of opening the purge valve 56.

  Further, as shown in FIG. 4, the cooling medium is introduced into the cooling medium flow path 86 between the first and second metal separators 68 and 70 from the cooling medium supply communication hole 74a, and then flows along the arrow B direction. To do. The cooling medium cools the electrolyte membrane / electrode structure 66, moves through the cooling medium discharge communication hole 74 b, and is discharged from the end plate 62 a to the cooling medium discharge pipe 30. The cooling medium is cooled by the radiator 24 and then supplied to the fuel cell stack 14 from the cooling medium supply pipe 28 under the action of the refrigerant pump 26.

  In this case, in the present embodiment, as shown in FIG. 1, the hydrogen gas tank 44 and the fuel cell stack 14 are arranged close to each other on the same subframe 90. Specifically, the fuel cell stack 14 is integrated with the subframe 90 immediately before the hydrogen gas tank 44 with the stacking direction oriented in the vehicle width direction and the upper side inclined to the hydrogen gas tank 44 side. ing.

  For this reason, the fuel cell stack 14 and the hydrogen gas tank 44 can be arranged in good proximity, and the length of the fuel gas supply pipe 45 that is a hydrogen pipe connecting the fuel cell stack 14 and the hydrogen gas tank 44 is reduced. It becomes possible to shorten the length as much as possible. Accordingly, it is possible to obtain the advantages of reducing the amount of hydrogen held in the fuel gas supply pipe 45, reducing the number of joints, simplifying the configuration, and being economical.

  Moreover, the fuel cell stack 14 and the hydrogen gas tank 44 are arranged in the same second section 22c. Thereby, compared with the structure by which the fuel cell stack 14 and the hydrogen gas tank 44 are arrange | positioned in a separate division, the hydrogen sensor 94 can be reduced to half, ie, can be reduced to one. For this reason, there is an effect that the number of installed relatively expensive hydrogen sensors 94 is reduced and it is economical. At that time, the ventilation system (not shown) such as a ventilation fan is reduced, which is economical.

  Furthermore, the fuel cell stack 14 is disposed to be inclined, for example, corresponding to the inclination of the backrest portion of the rear seat 92 in the cabin 22a. Therefore, the space in the cabin 22a can be effectively retained, while the accommodation space of the second compartment 22c that accommodates the fuel cell stack 14 and the hydrogen gas tank 44 can be easily reduced.

  In addition, the fuel cell stack 14 is disposed so as to incline so that the oxidant gas discharge communication hole 72b faces downward. Thereby, in particular, there is an advantage that it is possible to improve drainage from the oxidant gas discharge communication hole 72b in which a large amount of generated water is generated.

1 is a schematic side view of a fuel cell vehicle on which an in-vehicle fuel cell system according to an embodiment of the present invention is mounted. FIG. 2 is a partial plan view of the fuel cell vehicle mainly including the fuel cell system. It is a schematic structure explanatory view of the fuel cell system. It is a disassembled perspective explanatory drawing of the electric power generation cell which comprises the said fuel cell stack. 2 is an explanatory diagram of a fuel cell vehicle disclosed in Patent Document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 12 ... Fuel cell vehicle 14 ... Fuel cell stack 16 ... Coolant supply mechanism 18 ... Oxidant gas supply mechanism 20 ... Fuel gas supply mechanism 22 ... Partition member 22a ... Cabins 22b, 22c ... Partition 24 ... Radiator 26 ... Refrigerant pump 32 ... Air pump 36 ... Humidifier 44 ... Hydrogen gas tank 45 ... Fuel gas supply piping 60 ... Power generation cells 62a, 62b ... End plates 72a ... Oxidant gas supply communication holes 72b ... Oxidant gas discharge communication holes 74a ... cooling medium supply communication hole 74b ... cooling medium discharge communication hole 76a ... fuel gas supply communication hole 76b ... fuel gas discharge communication hole 90 ... subframe

Claims (3)

A plurality of power generation cells are stacked, and includes a fuel cell having a vertically long shape in a front view from the end in the stacking direction.
A hydrogen tank is disposed on the rear side in the vehicle length direction of the vehicle,
The in-vehicle fuel cell system, wherein the fuel cell is disposed immediately before the hydrogen tank, with the stacking direction oriented in the vehicle width direction and the upper side inclined to the hydrogen tank side.   The in-vehicle fuel cell system according to claim 1, wherein the fuel cell and the hydrogen tank are integrally mounted on the same frame.   The in-vehicle fuel cell system according to claim 1 or 2, wherein the fuel cell and the hydrogen tank are accommodated in the same compartment.

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