Fuel cell system with unreacted anode gas treatment and discharge facilities

Abstract

A fuel cell system with unreacted anode gas treatment and discharge facilities includes a fuel cell stack and an unreacted anode gas discharge pipeline connected at an end to a hydrogen outlet port of the fuel cell stack. Unreacted anode gas discharged via the hydrogen outlet port is led by the unreacted anode gas discharge pipeline to a catalytic converter or to a cathode catalytic bed of the fuel cell stack via an oxygen inlet port thereof, so that the unreacted anode gas reacts with oxygen at the catalytic converter or the cathode catalytic bed to produce reaction product, which is then discharged.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein:

FIG. 1 is a block diagram of a conventional fuel cell system;

FIG. 2 is a block diagram of a fuel cell system according to a first embodiment of the present invention;

FIG. 3 is a schematic view of a gas mixing chamber included in the fuel cell system according to the first embodiment of the present invention;

FIG. 4 is a block diagram of a fuel cell system according to a second embodiment of the present invention; and

FIG. 5 is a schematic view showing the unreacted anode gas reacts with oxygen at a cathode catalytic bed in the fuel cell stack according to the second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIG. 2 that is a block diagram of a fuel cell system 200 according to a first embodiment of the present invention. As shown, the fuel cell system 200 includes a fuel cell stack 1, a hydrogen pipeline 2a, an oxygen pipeline 3a, a gas mixing chamber 4, and a catalytic converter 5.

The fuel cell system 200 is different from the conventional fuel cell system 100 in that, in addition to a hydrogen source 21, a pressurizing unit 22, and a hydrogen recycling pipeline 23, the hydrogen pipeline 2a further includes an unreacted anode gas discharge pipeline 24 and a valve unit 25.

Hydrogen supplied from the hydrogen source 21 is guided into the fuel cell stack 1 via a hydrogen inlet port 11; and hydrogen or anode gas that is not used in the reaction is discharged from the fuel cell stack 1 via a hydrogen outlet port 12. The discharged unreacted anode gas is pressurized by the pressurizing unit 22. A part of the pressurized unreacted anode gas is led by the hydrogen recycling pipeline 23 to the hydrogen inlet port 11 again, while the other part of the pressurized unreacted anode gas is led through the unreacted anode gas discharge pipeline 24 under control of the valve unit 25 into the gas mixing chamber 4.

The fuel cell system 200 according to the first embodiment of the present invention is different from the conventional fuel cell system 100 also in that the oxygen pipeline 3a further includes a valve unit 32 and an oxygen branch line 33. A part of oxygen supplied from the oxygen source 31 is guided into the fuel cell stack 1 via an oxygen inlet port 13; and oxygen that is not used in the reaction is discharged via an oxygen outlet port 14 into ambient air. The other part of the oxygen supplied from the oxygen source 31 is led through the oxygen branch line 33 under control of the valve unit 32 into the gas mixing chamber 4.

In the gas mixing chamber 4, hydrogen and oxygen are fully mixed, and the gas mixture is further led to the catalytic converter 5, at where a chemical reaction occurs to produce reaction product B, which is then discharged from the catalytic converter 5 to external environment.

The gas mixing chamber 4 adopted in the fuel cell system 200 according to the first embodiment of the present invention is provided with proper connecting ports, to which the unreacted anode gas discharge pipeline 24 and the oxygen branch line 33 are connected so as to lead unreacted anode gas and oxygen into the gas mixing chamber 4. Alternatively, the gas mixing chamber 4 may be configured as shown in FIG. 3.

Please refer to FIG. 3 which is a schematic view of a gas mixing chamber included in the fuel cell system according to the first embodiment. The gas mixing chamber 4 includes a nozzle 41 and a mixing room 42. The nozzle 41 communicates with the mixing room 42 and the unreacted anode gas discharge pipeline 24, so that the unreacted anode gas H is guided via the unreacted anode gas discharge pipeline 24 into the gas mixing chamber 4. Meanwhile, oxygen A is guided via a flared opening 411 of the nozzle 41 into the gas mixing chamber 4.

Please refer to FIG. 4 that is a block diagram of a fuel cell system 300 according to a second embodiment of the present invention. As shown, the fuel cell system 300 includes a fuel cell stack 1, a hydrogen pipeline 2b, and an oxygen pipeline 3b. Please refer to FIG. 5. FIG. 5 is a schematic view showing the unreacted anode gas reacts with oxygen at a cathode catalytic bed in the fuel cell stack according to the second embodiment. The fuel cell stack 1 in the fuel cell system 300 of the second embodiment includes a cathode catalytic bed 15, an anode catalytic bed 16, and a proton exchange membrane 17.

The fuel cell system 300 is different from the conventional fuel cell system 100 in that, in addition to the hydrogen source 21, the pressurizing unit 22, and the hydrogen recycling pipeline 23, the hydrogen pipeline 2b further includes a valve unit 25 and an unreacted anode gas discharge pipeline 26.

The fuel cell system 300 functions differently from the conventional fuel cell system 100 in that unreacted anode gas H discharged via the hydrogen outlet port 12 is pressurized by the pressurizing unit 22. A part of the pressurized unreacted anode gas H is led through the unreacted anode gas discharge pipeline 26 under control of the valve unit 25 to the oxygen inlet port 13 of the fuel cell stack 1, and then to the cathode catalytic bed 15 of the fuel cell stack 1. The unreacted anode gas H led to the fuel cell stack 1 and oxygen A supplied from the oxygen source 31 to the fuel cell stack 1 via the oxygen inlet port 13 conduct a combustion reaction at the cathode catalytic bed 15 to produce reaction product B, which is then discharged via the oxygen outlet port 14.

In the illustrated embodiments of the present invention, the oxygen source and the hydrogen source are provided mainly to supply oxygen and hydrogen needed by the fuel cell stack. Any other known types of oxygen and hydrogen sources providing equivalent function and effect may also be employed in the present invention. For example, the oxygen source may be ambient air and a cooperative blower, or a high-pressure oxygen cylinder or tank; and the hydrogen source may be a high-pressure hydrogen cylinder or tank, or a hydrogen storage alloy.

Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Claims

1. A fuel cell system, comprising: a fuel cell stack, which including: a hydrogen inlet port for guiding a hydrogen supplied from a hydrogen source into the fuel cell stack;a hydrogen outlet port for discharging an unreacted hydrogen;an oxygen inlet port for guiding an oxygen supplied from an oxygen source into the fuel cell stack; andan oxygen outlet port for discharging an unreacted oxygen;a catalytic converter;an oxygen branch line extended between and connected to the oxygen source and the catalytic converter, so as to lead the oxygen to the catalytic converter; andan unreacted anode gas discharge pipeline extended between and connected to the hydrogen outlet port of the fuel cell stack and the catalytic converter for leading the unreacted hydrogen to the catalytic converter;wherein the unreacted hydrogen and the oxygen led to the catalytic converter react with each other to produce a reaction product, which is then discharged from the catalytic converter.

2. The fuel cell system as claimed in claim 1, further comprising a hydrogen recycling pipeline extended between and connected to the unreacted hydrogen discharge pipeline and the hydrogen inlet port of the fuel cell stack for leading the unreacted hydrogen discharged from the hydrogen outlet port of the fuel cell stack to the hydrogen inlet port.

3. The fuel cell system as claimed in claim 1, wherein the hydrogen source is selected from the group consisting of hydrogen storage alloys and a hydrogen cylinder/tank.

4. The fuel cell system as claimed in claim 1, wherein the oxygen source is selected from the group consisting of an oxygen cylinder/tank and an air blower.

5. The fuel cell system as claimed in claim 1, further comprising a gas mixing chamber communicably connected to the catalytic converter, the unreacted hydrogen discharge pipeline, and the oxygen branch line.

6. The fuel cell system as claimed in claim 5, wherein the gas mixing chamber further comprises a nozzle for connecting the gas mixing chamber to the unreacted hydrogen discharge pipeline and the oxygen branch line.

7. The fuel cell system as claimed in claim 1, further comprising a valve unit connected to the unreacted hydrogen discharge pipeline.

8. The fuel cell system as claimed in claim 1, further comprising a valve unit connected to the oxygen branch line.

9. The fuel cell system as claimed in claim 1, further comprising a pressurizing unit connected to the unreacted hydrogen discharge pipeline.

10. The fuel cell system as claimed in claim 1, wherein the unreacted oxygen is directly discharged into ambient air.

11. A fuel cell system, comprising: a fuel cell stack, which including: a cathode catalytic bed;a hydrogen inlet port for guiding a hydrogen supplied from a hydrogen source into the fuel cell stack;a hydrogen outlet port for discharging an unreacted hydrogen;an oxygen inlet port for guiding an oxygen supplied from an oxygen source into the cathode catalytic bed; andan oxygen outlet port for discharging an unreacted oxygen; andan unreacted hydrogen discharge pipeline extended between and connected to the hydrogen outlet port and the oxygen inlet port of the fuel cell stack for leading the unreacted hydrogen to the cathode catalytic bed of the fuel cell stack;wherein the unreacted hydrogen and the oxygen led to the cathode catalytic bed react with each other to produce a reaction product, which is then discharged from the oxygen outlet port.

12. The fuel cell system as claimed in claim 11, further comprising a hydrogen recycling pipeline extended between and connected to the unreacted hydrogen discharge pipeline and the hydrogen inlet port of the fuel cell stack for leading the unreacted hydrogen discharged from the hydrogen outlet port of the fuel cell stack to the hydrogen inlet port.

13. The fuel cell system as claimed in claim 11, wherein the hydrogen source is selected from the group consisting of hydrogen storage alloys and a hydrogen cylinder/tank.

14. The fuel cell system as claimed in claim 11, wherein the oxygen source is selected from the group consisting of an oxygen cylinder/tank and an air blower.

15. The fuel cell system as claimed in claim 11, further comprising a valve unit connected to the unreacted hydrogen discharge pipeline.

16. The fuel cell system as claimed in claim 11, further comprising a pressurizing unit connected to the unreacted hydrogen discharge pipeline.

17. The fuel cell system as claimed in claim 11, wherein the unreacted oxygen is directly discharged into ambient air.