JP3708482B2 - Fuel cell system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell system for supplying electric power to a motor that is a power source.
[0002]
[Prior art]
For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are respectively provided on both sides of an electrolyte membrane made of a polymer ion exchange membrane (cation exchange membrane) is separated by a separator. It is comprised by pinching.
[0003]
This type of fuel cell is usually used as a fuel cell stack by laminating a predetermined number of electrolytes (electrolyte membranes) / electrode structures and separators. In the fuel cell stack, the fuel gas supplied to the anode side electrode, for example, a hydrogen-containing gas, is hydrogen ionized on the catalyst electrode and moves to the cathode side electrode side through an appropriately humidified electrolyte membrane, Electrons generated during the movement are taken out to an external circuit and used as direct current electric energy. Since the cathode side electrode is supplied with an oxidant gas, for example, an oxygen-containing gas such as air, the hydrogen ions, the electrons and the oxygen gas react to generate water at the cathode side electrode. .
[0004]
By the way, a fuel cell system in which the above fuel cell stack is incorporated, for example, for vehicle use is known. As shown in FIG. 8, the fuel cell system 1 includes a fuel cell stack 2. The fuel cell stack 2 includes a fuel gas supply unit 3 for supplying a fuel gas such as a hydrogen-containing gas, and an oxygen-containing gas. An oxidant gas supply unit 4 for supplying an oxidant gas such as air (for example, air) and a cooling medium supply unit 5 for supplying a cooling medium are provided.
[0005]
The fuel gas supply unit 3 includes a fuel tank 6, and the fuel tank 6 and a fuel gas flow path (not shown) of the fuel cell stack 2 communicate with each other via a fuel gas supply path 7. A fuel gas pump 8 is disposed in the fuel gas supply path 7, and a pump motor 9 is connected to the fuel gas pump 8.
[0006]
The oxidant gas supply unit 4 includes an oxidant gas supply path 10 and an oxidant gas discharge path 11 that communicate with an oxidant gas flow path (not shown) of the fuel cell stack 2. The oxidant gas supply path 10 is provided with an intake filter 12, an oxidant gas pump 14 connected to a pump motor 13, and an intercooler 15, while the oxidant gas discharge path 11 has an exhaust section 16. It is connected to the.
[0007]
The cooling medium supply unit 5 includes a circulation channel 17 that communicates with a cooling medium channel (not shown) of the fuel cell stack 2, and a cooling medium pump to which a pump motor 18 is connected. 19 and a radiator 20 are disposed. The circulation channel 17 is provided with a bypass channel 21 in parallel with the radiator 20, and a valve 22 is disposed in the bypass channel 21. The circulation channel 17 is switched to a channel that passes through the radiator 20 via the valve 22 and a channel that does not pass through the radiator 20.
[0008]
The fuel cell stack 2 configured in this way is mounted, for example, under the floor of a vehicle. Therefore, for example, when the fuel cell system 1 is controlled by a PCU (power control unit) mounted on the front box, the motors 9, 13 and 18 are driven, and the fuel cells are connected via the pumps 8, 14 and 19. The stack 2 is supplied with fuel gas, oxidant gas, and cooling medium.
[0009]
[Problems to be solved by the invention]
However, in the above-described prior art, dedicated motors 9, 13 and 18 are provided for driving the pumps 8, 14 and 19, respectively. For this reason, the fuel cell system 1 as a whole is considerably increased in size, and the structure is complicated and the manufacturing cost is increased.
[0010]
The present invention solves this type of problem, and aims to provide a fuel cell system that can be manufactured economically while miniaturizing and simplifying the structure.
[0011]
[Means for Solving the Problems]
In the present invention, a fuel cell stack that is configured on both sides of an electrolyte and a separator and an electrolyte electrode assembly in which a pair of electrodes are stacked alternately, in parallel to the motor, the fuel gas to the fuel cell stack or a reactant gas supply pump for supplying at least one in which the reaction gas of the oxidizing gas, with a drive shaft of the front SL motor and the driven shaft of the reactant gas supply pump are parallel projecting in the same direction, the A drive shaft and the driven shaft are connected, and a reaction gas driving force transmission mechanism for driving the reaction gas supply pump only by the motor is provided.
[0012]
For this reason, the entire fuel cell system is effectively reduced in size and simplified as compared with a structure in which a dedicated pump motor is provided in a fuel gas supply pump and / or an oxidant gas supply pump, which are reaction gas supply pumps. Thereby, the space efficiency for installing the fuel cell system can be effectively improved, and the fuel cell system can be configured economically.
[0013]
In the fuel cell system, a cooling medium supply pump for supplying a cooling medium to the fuel cell stack, a motor parallel to each other, and the cooling medium supply pump are connected to each other, and the cooling medium supply pump is driven only by the motor. And a refrigerant driving force transmission mechanism for driving the motor . Therefore, it is not necessary to provide a dedicated pump motor for the cooling medium supply pump, and the entire fuel cell system can be simplified.
[0014]
Moreover, a fuel gas supply pump, an oxidant gas supply pump and the cooling medium supply pump, while being driven by a single motor may drive them one body to. As a result, the entire fuel cell system can be configured more simply and economically.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic explanatory diagram of a fuel cell system 30 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective explanatory view of a main part of the fuel cell system 30. The same components as those of the fuel cell system 1 shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0016]
The fuel cell system 30 is for supplying electric power to a main motor 32 as a power source, and is used as, for example, various drive systems for obtaining rotational force in addition to a vehicle drive system.
[0017]
The fuel cell system 30 includes a fuel cell stack 34. The fuel cell stack 34 includes a fuel gas supply unit 36 for supplying a fuel gas such as a hydrogen-containing gas, and an oxygen-containing gas (for example, air). An oxidant gas supply unit 38 for supplying an oxidant gas and a cooling medium supply unit 40 for supplying a cooling medium such as pure water, ethylene glycol, or oil are provided.
[0018]
The fuel gas supply unit 36, the oxidant gas supply unit 38, and the cooling medium supply unit 40 include a fuel gas supply pump 42, an oxidant gas supply supercharger (pump) 44, and a cooling medium supply pump 46. The pump 42, the supercharger 44 and the pump 46 are connected to the main motor 32 via a driving force transmission mechanism 48.
[0019]
The fuel cell stack 34 is configured by stacking a predetermined number of unit fuel cells 50 in the vertical direction (the direction of arrow A). As shown in FIG. 3, the unit fuel cell 50 includes an electrolyte membrane / electrode structure 52 and first and second separators 54, 56 that sandwich the electrolyte membrane / electrode structure 52.
[0020]
In the electrolyte membrane / electrode structure 52, an anode side electrode 60 is provided on one surface of the solid polymer electrolyte membrane 58, and a cathode side electrode 62 is provided on the other surface. The anode-side electrode 60 and the cathode-side electrode 62 are configured by joining a noble metal-based catalyst electrode layer to a gas diffusion layer made of, for example, porous carbon paper that is a porous layer.
[0021]
A fuel gas supply communication hole 64a, a cooling medium supply communication hole 66a, and an oxidant gas discharge communication hole 68b are provided at one end edge of the unit fuel cell 50 in the long side direction (arrow B direction). An oxidant gas supply communication hole 68a, a cooling medium discharge communication hole 66b, and a fuel gas discharge communication hole 64b are provided at the other edge in the long side direction of the unit fuel cell 50.
[0022]
The first and second separators 54 and 56 are made of a metal thin plate or a carbon thin plate. A plurality of oxidant gas flow channel grooves 72 communicating with the oxidant gas supply communication hole 68a and the oxidant gas discharge communication hole 68b are provided on the surface 54a of the first separator 54 facing the cathode side electrode 62. A plurality of fuel gas flow channel grooves 74 communicating with the fuel gas supply communication hole 64a and the fuel gas discharge communication hole 64b are formed on the surface 56a of the second separator 56 facing the anode side electrode 60. A plurality of cooling medium flow channel grooves 76 communicating with the cooling medium supply communication hole 66a and the cooling medium discharge communication hole 66b are formed on the surface 56b of the second separator 56 facing the first separator 54.
[0023]
As shown in FIG. 2, the fuel cell stack 34 is fixed to the upper surface 80 a of the manifold block 80, and a PCU 82 and an air conditioner 84 are stacked on the fuel cell stack 34.
[0024]
As shown in FIGS. 2 and 4 to 6, the main motor 32 is attached to the bottom of the manifold block 80. For example, when the vehicle is idling or the like, the main motor 32 rotates while being disconnected from the drive wheels, and the fuel cell stack 34 is driven by the pumps 42 and 46 and the supercharger 44 to supply auxiliary power. Some power is generated. An air conditioning compressor 90 is arranged in parallel with the main motor 32.
[0025]
The pump 42 and the supercharger 44 are fixed to the side surface 80 b of the manifold block 80, while the pump 46 is assembled to the side surface 80 c of the manifold block 80.
[0026]
The driving force transmission mechanism 48 includes a pulley 94 that is attached to a driving shaft 92 extending from the main motor 32, and three belt grooves 96 a to 96 c are formed in parallel to each other on the outer peripheral surface of the pulley 94. The The first to third drive belts 98a to 98c are engaged with the belt grooves 96a to 96c. A variable speed reduction mechanism may be provided between the drive shaft 92 and the pulley 94 as necessary, and the speed reduction ratio may be variable according to the operating conditions of the fuel cell stack 34.
[0027]
The first drive belt 98a spans the belt groove 96a of the pulley 94 and the pulley 100 provided in the pump 42, and the second drive belt 98b includes the belt groove 96b of the pulley 94 and the air conditioning compressor 90. It is bridged with the pulley 102 provided in the. The third drive belt 98 c is stretched over the belt groove 96 c of the pulley 94 and pulleys 103 and 104 provided in the supercharger 44 and the pump 46.
[0028]
As shown in FIG. 2, the manifold block 80 includes fuel gas passages 106 a and 106 b for communicating the fuel gas supply communication hole 64 a and the fuel gas discharge communication hole 64 b of the fuel cell stack 34 to the pump 42, and an oxidant gas. Oxidant gas passages 108a and 108b for communicating the supply communication hole 68a and the oxidant gas discharge communication hole 68b with the supercharger 44 are provided from the upper surface 80a to the side surface 80b. In the manifold block 80, cooling medium passages 110a and 110b for communicating the cooling medium supply communication hole 66a and the cooling medium discharge communication hole 66b with the pump 46 are provided from the upper surface 80a to the side surface 80c.
[0029]
The operation of the fuel cell system 30 configured as described above will be described below.
[0030]
As will be described later, electric power is supplied to the main motor 32 from the fuel cell stack 34, and a driving shaft 92 is rotated under the driving action of the main motor 32, and a pulley 94 provided on the driving shaft 92. Rotates. First to third drive belts 98a to 98c are engaged with the belt grooves 96a to 96c of the pulley 94, respectively. Accordingly, when the pulley 94 rotates, the first to third drive belts 98a to 98c travel around and the pulleys 100, 102, 103, and 104 are driven to rotate.
[0031]
Since the pump 42 is driven by the rotation of the pulley 100, the fuel gas in the fuel tank 6 is sent to the fuel gas passage 106 a of the manifold block 80 via the pump 42. The pulley 103 is provided in the supercharger 44. When the supercharger 44 is driven, oxygen such as air is supplied as an oxidant gas from the oxidant gas supply unit 38 to the oxidant gas passage 108a of the manifold block 80. A contained gas (hereinafter simply referred to as air) is supplied.
[0032]
Further, when the pump 46 provided with the pulley 104 is driven, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium passage 110 a of the manifold block 80. In addition, when the air conditioning compressor 90 provided with the pulley 102 is driven, the air conditioner 84 is driven and controlled as necessary.
[0033]
A fuel cell stack 34 is mounted on the upper surface 80 a of the manifold block 80. Therefore, the fuel gas, the oxidant gas, and the cooling medium introduced into the fuel gas passage 106a, the oxidant gas passage 108a, and the cooling medium passage 110a of the manifold block 80 are a plurality of sets of unit fuel cells that constitute the fuel cell stack 34. The fuel gas supply communication hole 64a, the oxidant gas supply communication hole 68a, and the cooling medium supply communication hole 66a provided in the cell 50 are sent.
[0034]
As shown in FIG. 3, the fuel gas supplied to the fuel gas supply communication hole 64 a is introduced into the fuel gas passage groove 74 provided in the surface 56 a of the second separator 56. The fuel gas moves along the anode-side electrode 60 constituting the electrolyte membrane / electrode structure 52 and is then discharged into the fuel gas discharge communication hole 64b.
[0035]
On the other hand, the oxidant gas supplied to the oxidant gas supply communication hole 68 a is introduced into the oxidant gas channel groove 72 provided on the surface 54 a of the first separator 54. The oxidant gas moves along the cathode side electrode 62 constituting the electrolyte membrane / electrode structure 52 and is then discharged to the oxidant gas discharge communication hole 68b.
[0036]
Therefore, in the electrolyte membrane / electrode structure 52, the oxidant gas supplied to the cathode side electrode 62 and the fuel gas supplied to the anode side electrode 60 are consumed by an electrochemical reaction in the catalyst electrode to generate power. Done. Electric power is supplied to the main motor 32 by this power generation, and the main motor 32 uses, for example, a vehicle wheel as a power source.
[0037]
In addition, the cooling medium supplied to the cooling medium supply communication hole 66 a moves along the cooling medium flow channel 76 provided on the surface 56 b of the second separator 56. The cooling medium cools the electrolyte membrane / electrode structure 52 and then is discharged into the cooling medium discharge communication hole 66b.
[0038]
In this case, in the present embodiment, for example, the main motor 32 for driving the wheel, the fuel gas supply pump 42, the oxidant gas supply supercharger 44, and the cooling medium supply pump 46 transmit the driving force. They are connected via a mechanism 48. Therefore, when electric power is supplied from the fuel cell stack 34 to the main motor 32 that is a power source, the pump 42 and the supercharger 44 are passed through the first to third drive belts 98a to 98c constituting the drive force transmission mechanism 48. Then, the pump 46 is driven to supply fuel gas, oxidant gas, and cooling medium to the fuel cell stack 34.
[0039]
Thereby, in this embodiment, it is not necessary to provide a dedicated motor for the pump 42, the supercharger 44, and the pump 46, and the entire fuel cell system 30 can be effectively downsized and simplified. Therefore, the installation space efficiency of the fuel cell system 30 is improved and the fuel cell system 30 can be produced economically.
[0040]
In this embodiment, for example, when the fuel cell system 30 is mounted in the front box 122 of the vehicle 120 as shown in FIG. 7, the cooling medium supply pump 46 is moved in the traveling direction of the vehicle 120. (Distance in the direction of arrow C) By disposing the front, the distance between the fuel cell stack 34 and the radiator 20 can be minimized. Similarly, by disposing the fuel gas supply pump 42 close to the fuel tank 6 and behind the vehicle 120 in the traveling direction, the distance between the fuel cell stack 34 and the fuel tank 6 can be minimized. .
[0041]
Further, in this embodiment, the manifold block 80 is provided, and the fuel cell stack 34, the main motor 32, the pumps 42 and 46, the supercharger 44, and the like are assembled to the manifold block 80 to achieve unitization as a whole. For example, the main motor 32 may be installed independently from the manifold block 80. Furthermore, a plate (not shown) may be provided on the outer peripheral side surface of the fuel cell stack 34, and the main motor 32, the pumps 42 and 46, the supercharger 44, and the like may be attached to the plate.
[0042]
【The invention's effect】
In the fuel cell system according to the present invention, a reaction gas supply pump for supplying a reaction gas to a fuel cell stack and a motor for supplying power from a fuel cell system to a motor as a power source and a motor via a driving force transmission mechanism. Are connected. Therefore, the reaction gas supply pump can be driven via a motor, and the entire fuel cell system can be effectively downsized and simplified as compared with a structure in which a dedicated motor is provided in the reaction gas supply pump. it can.
[0043]
Thereby, it is possible to improve the space efficiency for installation of the fuel cell system and to economically configure the fuel cell system.
[Brief description of the drawings]
FIG. 1 is a schematic configuration explanatory diagram of a fuel cell system according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a main part of the fuel cell system.
FIG. 3 is an exploded perspective view of a main part of a fuel cell stack constituting the fuel cell system.
FIG. 4 is a perspective view illustrating a main part of the fuel cell system.
FIG. 5 is a side view of one side of the fuel cell system.
FIG. 6 is another side view of the fuel cell system.
FIG. 7 is a plan view of the fuel cell system mounted on a vehicle.
FIG. 8 is an explanatory diagram of a schematic configuration of a fuel cell system according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 6 ... Fuel tank 20 ... Radiator 30 ... Fuel cell system 32 ... Main motor 34 ... Fuel cell stack 36 ... Fuel gas supply part 38 ... Oxidant gas supply part 40 ... Cooling medium supply part 42, 46 ... Pump 44 ... Supercharger 48 ... Driving force transmission mechanism 50 ... Unit fuel cell 52 ... Electrolyte membrane / electrode structure 54, 56 ... Separator 58 ... Solid polymer electrolyte membrane 60 ... Anode side electrode 62 ... Cathode side electrode 64a ... Fuel gas supply communication hole 64b ... Fuel gas discharge communication hole 66a ... Cooling medium supply communication hole 66b ... Cooling medium discharge communication hole 68a ... Oxidant gas supply communication hole 68b ... Oxidant gas discharge communication hole 72 ... Oxidant gas flow channel 74 ... Fuel gas flow channel 76 ... Cooling medium passage groove 80 ... Manifold block 98a to 98c ... Drive belt 106a, 106b ... Fuel gas passage 08a, 108b ... oxidant gas passages 110a, 110b ... cooling medium passages 120 ... vehicle

Claims (3)

A fuel cell system for supplying electric power to a motor that is a power source for driving a wheel,
A fuel cell stack configured by alternately stacking an electrolyte / electrode structure and a separator provided with a pair of electrodes on both sides of the electrolyte; and
A reaction gas supply pump that is arranged in parallel with the motor and supplies a reaction gas that is at least one of fuel gas and oxidant gas to the fuel cell stack;
With a drive shaft of the front SL motor and the driven shaft of the reactant gas supply pump are parallel projecting in the same direction, and connecting the driven shaft and the drive shaft, the reaction gas supply only by the motor A reaction gas driving force transmission mechanism for driving a pump for use;
A fuel cell system comprising: The fuel cell system according to claim 1, wherein a coolant supply pump for supplying a coolant to the fuel cell stack;
A refrigerant driving force transmission mechanism for connecting the motor and the cooling medium supply pump, which are parallel to each other, and driving the cooling medium supply pump only by the motor;
Equipped with a,
The reaction gas drive force transmission mechanism and the refrigerant driving force transmission mechanism, a fuel cell system characterized Rukoto parallel and provided separately to the drive shaft of the motor. The fuel cell system according to claim 1, wherein the fuel cell stack, the motor, and the reaction gas supply pump are integrally fixed to a manifold block ,
The manifold block is formed with a reaction gas passage communicating with the fuel cell stack and the reaction gas supply pump .

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