JP2002134144A - Fuel cell system for traveling body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the pressure of gas supplied to the first side of a hydrogen separation membrane and achieve miniaturization of a compressor. SOLUTION: In this fuel cell system for a traveling body, anode gas from a fuel cell 10 is circulated to the hydrogen separation membrane 8a while reformed gas is supplied to the hydrogen separation membrane 8a and hydrogen passing through the hydrogen separation membrane 8a is supplied to the fuel cell 10. The hydrogen separation membrane 8a is divided into a first side chamber 81, to which the reformed gas is supplied and a second side chamber 82 from which the hydrogen passing through the hydrogen separation membrane 8a is extracted. A steam generating means 14 for cooling the hydrogen and generating steam by waste heat of the hydrogen is disposed downstream of the second side chamber 82. The steam from the steam generating means 14 is supplied to the second side chamber 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reforming type fuel cell system, and more particularly to an improvement in a mobile fuel cell system.

[0002]

2. Description of the Related Art As a reforming type fuel cell system, Japanese Patent Application Laid-Open No. H11-126626 is known, and an anode gas discharged from a fuel cell is supplied to a secondary side of a hydrogen separation membrane of a reformer. (To the purified hydrogen side) to improve the hydrogen permeability.

[0003]

However, in the above conventional example, the ATR (Auto Thermal Rea
ctor), the pressure on the primary side (fuel gas side) of the hydrogen separation membrane that constitutes the reforming section is high, so the compressor for pumping the gas becomes large, and it is mounted on a moving body such as a vehicle. There is a problem that the property is reduced.

Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to reduce the pressure of the gas supplied to the primary side of the hydrogen separation membrane of the reforming section to promote downsizing of the compressor. Aim.

[0005]

According to a first aspect of the present invention, a reformed gas is supplied to a hydrogen separation membrane, hydrogen permeating the hydrogen separation membrane is supplied to a fuel cell, and anode gas from the fuel cell is supplied to the hydrogen separation membrane. In the fuel cell system for a mobile body circulated to the hydrogen separation membrane, the hydrogen separation membrane defines a primary side chamber to which a reformed gas is supplied and a secondary side chamber for extracting hydrogen permeating the hydrogen separation membrane. A steam generator is provided downstream of the secondary chamber to cool the hydrogen and generates steam by waste heat of the hydrogen, and the steam from the steam generator is supplied to the secondary chamber.

A second invention is directed to an evaporator for vaporizing fuel and water using a combustion gas as a heat source, a fuel gas and water vapor from the evaporator, and compressed air from a pressurizing means to form a reformed gas. And a reformer for supplying the reformed gas to the hydrogen separation membrane, supplying hydrogen permeated through the hydrogen separation membrane to the fuel cell, and circulating anode gas from the fuel cell to the hydrogen separation membrane. In the fuel cell system for body, the hydrogen separation membrane defines a primary chamber to which a reformed gas is supplied and a secondary chamber for extracting hydrogen permeating the hydrogen separation membrane, and a downstream side of the secondary chamber. And a steam generating means for generating steam by waste heat of hydrogen. The steam from the steam generating means is supplied to the secondary side chamber, and the steam from the evaporator is also cooled to the secondary side. Concubine Supplies.

[0007]

Accordingly, the first aspect of the present invention is that the hydrogen permeated through the hydrogen separation membrane is extracted from the reformed gas supplied to the primary chamber to the secondary chamber, and the hydrogen is cooled by waste heat when cooling the hydrogen. By supplying the generated water vapor to the secondary chamber in addition to the anode gas, the hydrogen partial pressure in the secondary chamber can be greatly reduced, so that the reformed gas pressure supplied to the primary chamber can also be reduced. This makes it possible to reduce the size of a compressor or the like that supplies the reformed gas under pressure, and to provide a reformed fuel cell system that is excellent in mountability on a moving body such as a vehicle.

In the second invention, hydrogen permeating the hydrogen separation membrane is extracted from the reformed gas supplied to the primary chamber to the secondary chamber, and is generated by waste heat when cooling the hydrogen. By supplying steam to the secondary chamber together with the anode gas and further supplying steam from the evaporator to the secondary chamber, the hydrogen partial pressure in the secondary chamber can be greatly reduced. The pressure of the reformed gas supplied to the fuel cell can also be reduced, and the pressure means such as a compressor that pressurizes and supplies the reformed gas can be significantly reduced in size. A reformed fuel cell system can be provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a reforming type fuel cell system suitable for a moving body such as a vehicle. Water and methanol are supplied from a water tank 2 and a methanol tank 3 to an evaporator 6 via pumps 4 and 5. You.

The ATR reformer 1 that supplies fuel gas (hydrogen) to the fuel cell 10 is supplied with methanol gas and water vapor from the evaporator 6 and pressurized air sent from the compressor 7 (pressurizing means). Then, a reformed gas is generated by the partial oxidation reaction and the steam reforming, and the reformed gas is sent to the primary side chamber 81 of the hydrogen separator 8 to generate hydrogen.

Then, the generated hydrogen gas is sent to the condenser 9 to collect the condensed water, and then supplied to the anode 10 a of the fuel cell 10.

The condenser 9 is formed integrally with the evaporator 14 (steam generating means), and the water recovered by the condenser 9 is circulated to the water tank 2 to recycle the waste heat obtained by cooling the hydrogen gas. The water tank 2 is connected to the evaporator 14 through the pump 13.
Is supplied to produce steam.

On the other hand, air (oxidizing gas) pumped from a compressor or the like (not shown) is supplied to the cathode 10 b of the fuel cell 10, and the exhaust gas from the cathode 10 b is used as a combustion source which is a heat source of the evaporator 6. It is led to the vessel 11.

Exhaust gas (anode gas) from the anode 10a is supplied to the secondary chamber 82 of the hydrogen separator 8 via the circulation pump 12, and water vapor from the evaporator 14 is also supplied to the circulation pump 12. From the downstream, it is supplied to the secondary side chamber 82 of the hydrogen separation membrane.

In the hydrogen separation apparatus 8, primary and secondary chambers 81 and 82 are defined by a hydrogen separation membrane 8a composed of a palladium membrane or a palladium alloy membrane.
1 is supplied with the reformed gas, and the hydrogen that has passed through the hydrogen separation membrane 8a is taken out from the secondary chamber 82, and the hydrogen is sent from the condenser 9 to the anode 10a of the fuel cell 10.

As an example of the hydrogen separation device 8, for example, a hydrogen separation film 8a is formed on the surface of a porous ceramic tube with a palladium film or the like, and a reformed gas is supplied from one peripheral side and the other is supplied to the other peripheral side. This allows hydrogen to permeate the side.

In the hydrogen separator 8, the reformed gas supplied to the primary chamber 81 comes into contact with the hydrogen separation membrane 8a, and only the hydrogen that has passed through the hydrogen separation membrane 8a is converted into the secondary chamber 82.
The hydrogen gas in the secondary side chamber 82 is taken out of the condenser 9
Is supplied to the fuel cell 10 via the.

On the other hand, the reformed gas (methanol, carbon monoxide, nitrogen, etc.) which cannot pass through the hydrogen separation membrane 8a is called a bleed gas, and is supplied from the primary chamber 81 to the combustor 11; The heat source of the evaporator 6.

Air discharged from the cathode 10b of the fuel cell 10 is supplied to the combustor 11 to burn the bleed gas.

Here, the exhaust gas of the anode 10a,
The steam from the evaporator 14 is transferred to the secondary chamber 8 of the hydrogen separation device 8.
2, the anode 1 of the fuel cell 10
The hydrogen gas remaining in the exhaust gas 0a is supplied to the circulation pump 1
The water flows back to the secondary side chamber 82 of the hydrogen separation device 8 via the second, and the steam supplied downstream of the circulation pump 12 also flows into the secondary side chamber 82.

In the above-described conventional example, the partial pressure of hydrogen in the secondary chamber 82 is high, so that pure hydrogen cannot be taken out to the secondary chamber 82 unless the reformed gas pressure in the primary chamber 81 is sufficiently increased.

On the other hand, in the present invention, water is pumped from the water tank 2 via the pump 13, and the water vapor generated by the evaporator 14 utilizing the heat of the condenser 9 is converted to the secondary water of the hydrogen separation device 8. Since it is sent to the side chamber 82 and supplied to the hydrogen separation membrane 8a, the hydrogen partial pressure in the secondary side chamber 82 can be greatly reduced.

Therefore, it is possible to greatly reduce the pressure of the reformed gas supplied to the primary chamber 81 in accordance with the reduction of the hydrogen partial pressure in the secondary chamber 82, and to supply the reformed gas to the ATR reformer 1. The air pressure can be reduced, and as a result, the compressor 7 can be reduced in size, and the reforming type fuel cell system using the ATR reformer 1 can be made compact and easily mounted on a moving body such as a vehicle. It becomes possible.

FIG. 2 shows a second embodiment, in which the steam from the evaporator 6 is also supplied to the hydrogen separator 8 of the first embodiment. Same as the form.

A part of the water vapor generated in the evaporator 6 is branched and supplied to the secondary side chamber 82 of the hydrogen separator 8.

Therefore, the evaporator 1 is provided in the secondary side chamber 82.
Since the steam from the evaporator 6 is added in addition to the steam from the fuel cell 4, the partial pressure of hydrogen in the secondary chamber 82 can be further reduced, and the air pressure supplied to the ATR reformer 1 can be reduced. Thus, the compressor 7 can be further downsized, and the reformed fuel cell system using the ATR reformer 1 can be configured more compactly.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a fuel cell system showing one embodiment of the present invention.

FIG. 2 shows a second embodiment, and is a schematic configuration diagram of a fuel cell system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ATR reformer 2 Water tank 3 Methanol tank 4, 5 Pump 6 Evaporator 7 Compressor 8 Hydrogen separation device 8a Hydrogen separation membrane 9 Condenser 10 Fuel cell 10a Anode 10b Cathode 11 Combustor 12 Circulation pump 13 Pump 14 Evaporation vessel

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C01B 3/56 C01B 3/56 Z H01M 8/00 H01M 8/00 Z 8/06 8/06 G F-term (Reference) 4D006 GA41 HA21 KA71 KB30 MA06 MB04 MC02 PB20 PB66 PC80 4G040 EA02 EA03 EA06 EA07 EB03 EB33 EB35 FA02 FB09 FC01 FE01 4G140 EA02 EA03 EA06 EA07 EB03 EB37 EB39 FA02 BA05 BA01 BA01 BA01 BA01 BA01 BA01 BA02

Claims (2)

[Claims] 1. A mobile fuel for supplying a reformed gas to a hydrogen separation membrane, supplying hydrogen permeated through the hydrogen separation membrane to a fuel cell, and circulating anode gas from the fuel cell to the hydrogen separation membrane. In the battery system, the hydrogen separation membrane includes a primary chamber to which a reformed gas is supplied,
A secondary side chamber for extracting hydrogen permeated through the hydrogen separation membrane; defining a secondary chamber downstream of the secondary side chamber; cooling the hydrogen; and providing steam generating means for generating steam by waste heat of the hydrogen. The steam from the generating means is
A fuel cell system for a moving object, wherein the fuel cell system is supplied to a secondary chamber. 2. An evaporator for vaporizing fuel and water using a combustion gas as a heat source, a reformer for generating a reformed gas from fuel gas and water vapor from the evaporator, and compressed air from a pressurizing means. And supplying the reformed gas to the hydrogen separation membrane and supplying hydrogen permeated through the hydrogen separation membrane to the fuel cell,
In a mobile fuel cell system for circulating anode gas from a fuel cell to the hydrogen separation membrane, the hydrogen separation membrane includes a primary chamber to which a reformed gas is supplied,
A secondary side chamber for extracting hydrogen permeated through the hydrogen separation membrane; defining a secondary chamber downstream of the secondary side chamber; cooling the hydrogen; and providing steam generating means for generating steam by waste heat of the hydrogen. The steam from the generating means is
A fuel cell system for a mobile body, wherein the fuel cell system supplies the steam to the secondary chamber and also supplies the steam from the evaporator to the secondary chamber.