JP3244912B2 - Fuel cell system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system .

[0002]

2. Description of the Related Art A fuel cell using a solid polymer as an electrolyte, unlike other fuel cells, does not contain water and does not exhibit ion conductivity unless a humidifying operation is performed.
For this reason, a “humidification system” that has not been considered in conventional “phosphoric acid type fuel cells” or the like must be configured.

The structure of a conventional "humidification system" is shown in FIGS.
This will be described with reference to FIG. FIG. 4 is a schematic diagram of a “humidification system” in which humidification units are arranged in series. In the figure, reference numeral 01 denotes an anode humidifying section, 02 denotes a cathode humidifying section, 03 denotes a fuel cell, 04 denotes a humidifying water heat receiving section, 05 denotes a pump, 06 denotes a radiator, 07 denotes an exhaust section, 09 denotes steam, and 010 denotes humidification. The circulation pipes of the water are shown respectively. In the above configuration, the humidification water circulating in the circulation pipe 010 is given heat generated by the reaction of the fuel cell 03 in the humidification water heat receiving section 04, and then is guided to the anode humidification section 01 and the cathode humidification section 02. The humidifying steam amount in the humidifying units 01 and 02 is increased. As a result, sufficient steam 09 is given to the introduced hydrogen (H ₂ ) in the anode humidifying section 01 and to the air (Air) in the one cathode humidifying section 02.

[0005] As shown in FIG.
There is also a "humidification system" in which two are arranged in parallel.

[0005]

As a humidification method, there are a method of supplying fuel gas and oxidizing gas with vapor moisture to the cell and a method of directly injecting water into the cell. Is a method of simply humidifying the anode and the cathode.

Here, it is possible to maintain the temperature of the humidifying water by heating it using the reaction heat generated by the power generator of the fuel cell. In this heating, the anode humidifying part 01 and the cathode are heated. Anode humidification water and cathode humidification water are drawn out from the humidification unit 02 by one circulation pipe 010 and heated by the humidification water heat receiving unit 04 of the fuel cell 03, and thereafter, the anode humidification unit 01 and the cathode humidification unit 02
The fuel gas and the oxidizing gas contained in the humidifying water, for example, in a dissolved state, in a bubble state, etc.
It is conceivable that they are mixed in the middle and part A and have a risk of flammable explosion.

[0007] The present invention has been made in view of the above problems, when the humidification of the solid polymer electrolyte fuel cell, and an object thereof is to provide a highly high reliability safety fuel cell system.

[0008]

A fuel cell system according to the present invention that achieves the above object provides a solid polymer electrolyte fuel cell power generator and steam for supplying fuel gas to the power generator.
Oxidant gas supplied to the anode humidifying unit and said power generating body obtain
In a fuel cell system having a cathode humidifying unit for providing steam to the anode and a system for cooling reaction heat generated by the power generator, the anode humidifying unit and the cathode humidifying unit
The supplied humidifying circulating water is heated by the reaction heat of the fuel cell power generator, and the humidifying circulating water introduced into the anode humidifying section and the humidifying humidifying section introduced into the cathode humidifying section .
Circulating water is circulated in separate systems without mixing.

[0009]

A system for receiving reaction heat generated by the power generator without mixing anode humidification water and cathode humidification water is provided and controlled.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below.

(Embodiment 1) A first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a case where humidification is performed by a so-called “bubbling method” using a humidification pot (bubble).

FIG. 1 is a system diagram of a fuel cell system according to this embodiment. In the figure, reference numeral 11 denotes an anode humidifier, 1
2 is a cathode humidifier, 13 is a fuel cell, 14A, 14B
Is a humidified water heat receiving section, 15A and 15B are pumps, 16A and 1
6B shows a radiator, and 17A and 17B show exhaust parts.

As shown in FIG. 1, in this embodiment, a water supply pipe 21 for supplying humidifying water (H ₂ O) for supplying water consumed in the humidifying section includes an anode humidifying section 11 and a cathode humidifying section. Before the introduction of the section 12, it is branched on the way, and the anode humidifying section 1
1 and the cathode humidifier 12. The introduced water is separately supplied from the humidifying units 11 and 12 to the fuel cell 13.
After being guided into the fuel cell 13 from the anode circulation pipe 22 and the cathode circulation pipe 23 connected to the fuel cell 13 and heated here, the humidification unit 11 is independently passed through the respective circulation pipes 22 and 23. , 12 and separately provide steam 19 to hydrogen (H ₂ ) as fuel gas and air (Air).

In this embodiment, a "bubbling method" is used as a method for humidifying a gas or the like. In this bubbling method, as shown in FIG. 2, a liquid (water) 32 is filled in a cylindrical body 31, and the liquid 32 is passed through a gas introduction pipe 34 provided with, for example, a porous body 33 at the tip end. A gas (H _{2 or} Air) 35 is introduced, and the gas 35 is
It humidifies by diffusing inside. Conventionally, in the case of humidification using the "bubbling method", gas mixing was prevented by liquid level management. However, the system lacked reliability. By providing an independent circulation system, there was no danger of mixing and the safety of the system was enhanced.

Next, the operation of the present system will be described.

The fuel gas (hydrogen or the like) flowing to the anode of the fuel cell is supplied from, for example, a reformer, a cylinder, a hydrogen storage alloy or the like, enters the anode humidifying section (humidifying pot) 11 and is humidified, and then enters the fuel cell 13. Consumed. Here, the anode humidification water for fuel gas humidification is heated by the fuel cell 13,
Anode humidification unit 11 through anode circulation pipe 22
Enter. Part of the moisture is entrained in the fuel gas as vapor to humidify the fuel cell anode. The remaining water is pump 15A
And enters the fuel cell 13 again. This anode humidification water circulation system and the fuel cell 1 together with the cathode humidification water circulation system
3 and plays a role of a cooling system, and excess heat is radiated by the radiator 16A during humidification.

On the other hand, an oxidizing gas (air or the like) flowing to the fuel cell cathode is supplied from, for example, a blower, a cylinder, a compressor, a turbine, etc., enters a cathode humidifying section (humidifying pot) 12 and is humidified. to go into.
The cathode humidification water humidifies the cathode and cools the fuel cell in the same system as the anode humidification water. During this time, there is no danger of mixing of fuel gas and oxidizing gas, ignition and explosion without mixing the cathode humidification water and the anode humidification water.

(Embodiment 2) FIG. 3 is a schematic system diagram of a so-called "direct humidification system" in which humidification is performed by directly injecting water. In the figure, reference numeral 11 denotes an anode humidifier, 12
Is a cathode humidifying unit, 13 is a fuel cell, 14A and 14B are humidified water heat receiving units, 15A and 15B are pumps, 16A and 16
B is a radiator, 17A and 17B are exhaust parts, 18A and 18B
Represents a humidified water-liquid separation pot.

In the above configuration, the anode humidification water and the cathode humidification water are supplied to the humidification water heat receiving portions 14A, 14A in the fuel cell 13.
After receiving the heat at B, it is supplied to the anode and cathode, directly humidifies the anode and cathode, and discharged together with the fuel gas and the oxidizing gas, respectively. The discharged humidified water and gas are separated by the gas-liquid separation pots 18A and 18B. Then, the humidified water is separately pumped by the anode circulation pipe 22 and the anode circulation pipe 23.
B, through the radiators 16A and 16B, is supplied to the fuel cell 13 again. During this time, there is no possibility that the anode humidification water and the cathode humidification water are mixed because they are completely different systems.

As described above, in the conventional humidifying method, gas-liquid mixing is prevented by simply performing liquid level control using a bubbler, and the reliability is lacking. Reliability is improved. On the other hand, in a humidifier using a membrane, the pressure of the gas was made lower than the osmotic pressure of the water membrane to prevent the gas from entering the liquid, and the reliability was lacking. , Improve reliability

[0021]

As described above, according to the present invention, since the anode humidification water and the cathode humidification water are completely different systems, there is no possibility of mixing and a safe humidification system can be constructed.

Further, it is possible to easily control the humidifying temperature and the amount of humidified water for the anode and the cathode.

[Brief description of the drawings]

FIG. 1 is a system diagram of a humidification system according to a first embodiment.

FIG. 2 is a schematic view of a bubbler.

FIG. 3 is a system diagram of a humidification system according to a second embodiment.

FIG. 4 is a system diagram of a conventional humidification system.

FIG. 5 is a system diagram of a conventional humidification system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Anode humidification part 12 Cathode humidification part 13 Fuel cell 14 Humidification water heat receiving part 15A, 15B Pump 16A, 16B Radiator 17A, 17B Exhaust part 18A, 18B Humidification water vapor-liquid separation pot 19 Steam 21 Water supply pipe 22 Anode circulation pipe 23 Cathode circulation pipe

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Ryuji Horioka 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (56) References JP-A-3-102774 (JP, A) JP-A-3 −20971 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/04 H01M 8/10

Claims (1)

(57) [Claims] 1. A solid polymer electrolyte fuel and the battery power generating body, the upper
An anode humidifier for supplying steam to the fuel gas supplied to the power generator, and a steam for supplying the oxidant gas to the power generator.
In a fuel cell system having a cathode humidifier and a system for cooling reaction heat generated by the power generator, the fuel is supplied to the anode humidifier and the cathode humidifier.
Humidifying circulating water heated by the reaction heat of the fuel cell power generator, and humidifying circulating water introduced into the anode humidifying section;
A fuel cell system , wherein circulation of humidifying circulating water introduced into a cathode humidifying section is controlled in separate systems without mixing .