JPH10162850A - Fuel cell unconverted gas combustion processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell unconverted gas combustion processing device in which device simplification and low cost are realized. SOLUTION: A burner part 1 is composed of a combustion chamber 3 for combustion, a blower to supply air for combustion to the combustion chamber 3, and a nozzle 6 having plural flame holes 8 at a tip part, a discharge gas supply conduit 5 to guide unconverted gas, and an ignition device 7 provided above the nozzle 6 to ignite unconverted gas jetted from the flame holes 8. At this burner part 1, unconverted hydrogen gas discharged from a fuel cell is pocessed to be diffused and burnt. At this time, the number of the flame holes 8 is set to be 2-4, and each flame hole 8 is formed to have an outer inclination θ of 10-30 deg. to an axial center of the nozzle 6, thereby more favorable diffusion and combustion can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fuel cell,
More specifically, the present invention relates to a fuel cell unreacted gas combustion treatment apparatus for treating unreacted gas discharged from a fuel cell.

[0002]

2. Description of the Related Art A fuel cell has an air electrode, a fuel electrode and an electrolyte interposed between the two electrodes, and a reforming device (steam reforming fuel such as city gas or methanol to produce a hydrogen component gas. A device for generating electric power by electrochemically reacting hydrogen gas supplied from an apparatus for performing the reaction with oxygen in the air via an electrolyte (see Japanese Patent Application Laid-Open No. 6-215789).

Generally, in a fuel cell, about 80% of hydrogen gas supplied to a fuel electrode is consumed in an electrochemical reaction for power generation, and the remaining 20% is unreacted hydrogen gas together with carbon dioxide. Is discharged.

Since unreacted hydrogen gas discharged from a fuel cell is harmful if released directly into the atmosphere, conventionally, this unreacted hydrogen gas is guided to an unreacted gas combustion processing device through an exhaust gas supply line. In this case, the catalyst is combusted by a catalytic combustor. That is, the unreacted hydrogen gas is oxidized by the catalytic reaction and released into the atmosphere as water vapor.

[0005]

However, the exhaust gas treatment by the catalytic combustor described above has a complicated structure, and platinum or palladium is used as a catalyst, which makes the combustion apparatus expensive. This has been a factor in increasing the price of the fuel cell body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and has achieved simplification of the apparatus and cost reduction by treating unreacted hydrogen gas discharged from a battery by diffusion combustion. It is an object of the present invention to provide an unreacted gas combustion treatment device for a fuel cell.

[0007]

That is, according to the present invention, there is provided a burner section for treating unreacted gas discharged from a fuel cell by diffusion combustion, and the burner section performs combustion. A combustion chamber for performing, a blower for supplying air for combustion to the combustion chamber, a nozzle having a plurality of flame holes at a tip portion, an exhaust gas supply pipe for guiding the unreacted gas, An ignition device is provided above the nozzle and ignites unreacted gas ejected from the flame hole.

According to the present invention, the number of the flame holes of the nozzle is two to four.

Further, according to the present invention as set forth in claim 3, the plurality of flame holes are arranged outwardly with respect to the axis of the nozzle.
It is characterized by being formed with an inclination of 30 degrees and being arranged on concentric circles.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIGS. 1 and 2 show a burner unit 1 of an unreacted gas combustion processing apparatus for a fuel cell according to the present invention.
FIG. 1 is different from FIG. 2 only in the shape of a nozzle 6 described later.

As shown in the figure, the burner section 1 has a combustion chamber 3 formed by a combustion cylinder 2 having a bottomed cylindrical shape, and combustion air (primary air) is fed into the combustion chamber 3 at the bottom. Blower 4 is attached.

An exhaust gas supply pipe 5 for introducing unreacted hydrogen gas discharged from a fuel cell body (not shown) at the time of power generation is provided inside the combustion chamber 3. At the downstream end of the exhaust gas supply line 5, a nozzle 6 having a plurality of (four in this embodiment) flame holes 8 formed concentrically at the tip is mounted.
The unreacted hydrogen gas, which is fixed so as to be located near the lower center of the nozzle and has passed through the exhaust gas supply line 5,
It is constituted so that it may be ejected upward from. An ignition device 7 for igniting the ejected unreacted gas is provided above the nozzle 6.

As described above, the unreacted gas combustion processing apparatus of the present invention has a configuration in which the unreacted hydrogen gas introduced and sprayed into the combustion chamber 3 is directly ignited and burned by the ignition device 7. As a result, the structure of the device itself is extremely simplified.

The unreacted gas combustion processing apparatus having the above configuration operates as follows. First, when the fuel cell body starts operating,
Hydrogen gas generated by the reformer is supplied to the hydrogen electrode of the fuel cell through a fuel gas supply pipe, and air (oxygen) is supplied to the air electrode through an air supply path, thereby generating electricity from the fuel cell. Is started.

As a result, unreacted hydrogen gas not deposited in the electrochemical reaction is discharged from the hydrogen electrode out of the hydrogen gas supplied from the reformer. The unreacted hydrogen gas (arrow Y) is sent to the burner unit 1 of the unreacted gas combustion processing device through the exhaust gas supply line 5 and
From the flame hole 8 of the nozzle 6 attached to the tip of the nozzle. The ejected gas is ignited by the discharge spark of the ignition device 7 and forms a flame in the combustion chamber 3 together with the primary air (arrow X) supplied by the blower 4.

As described above, the unreacted hydrogen gas discharged from the fuel cell is processed by diffusion combustion in the unreacted gas combustion processing device, becomes steam, and enters the atmosphere through the exhaust port disposed above the combustion tube 2. Released during.

By the way, as shown in FIGS. 1 and 2,
The nozzle 6 has a plurality of small flame holes 8 formed at the tip thereof. Since the small flame holes 8 cause the nozzle 6 to function as a throttle valve, the unreacted hydrogen gas introduced from the fuel cell is introduced. Can be uniformly ejected and diffused throughout the combustion chamber, so that stable diffusion combustion can be performed.

In particular, when at least 2 to 4 flame holes 8 are formed, unreacted gas ejected from the nozzle 6 during diffusion combustion is sent into the combustion chamber 3 without generating sound. Therefore, the noise of the combustion device can be reduced (when the power generation amount of the fuel cell is large, the amount of unreacted gas discharged from the hydrogen electrode also increases, and a large amount of gas is ejected from the nozzle 6 into the combustion chamber. If the number of the flame holes 8 is one, a gas ejection sound is generated, which may be reflected in the combustion chamber 3 and become noise.

Further, as in the embodiment shown in FIG. 1, the plurality of flame holes 8 are formed in parallel with the axis of the nozzle 6 so that the unreacted gas is jetted in a vertical direction.
When the pitch between the flame holes 8 is short and the plurality of flame holes 8 are too close to each other, the unreacted gas ejected at the time of combustion cannot form an independent flame, and becomes unified. Accordingly, the combustion chamber 3 also becomes vertically elongated and large in shape. However, as in the embodiment shown in FIG.
By forming them with an inclination θ of 0 to 30 degrees and arranging them concentrically, unreacted gas ejected from the flame holes 8 is ejected from the flame holes 8 in different directions. , The combustion flame 9 is formed independently of each other, and the combustion flame 9 can be made shorter. Therefore, the combustion chamber 3 can be made more compact than that shown in FIG.
A compact, low-noise unreacted gas combustion processing device can be realized.

[0020]

As described above, according to the first aspect of the present invention, the burner for processing the unreacted gas discharged from the fuel cell includes a combustion chamber and a combustion chamber provided in the combustion chamber. A configuration including a blower for supplying air, an exhaust gas supply pipe provided with a nozzle having a plurality of flame holes at the tip, and an ignition device for igniting unreacted gas ejected from the flame holes As a result, stable and favorable unreacted gas diffusion combustion processing becomes possible, the structure of the apparatus is simplified as compared with the conventional catalytic combustion processing, and an inexpensive unreacted gas combustion processing apparatus can be realized. .

According to the second aspect of the present invention, when the number of flame holes of the nozzle is plural (2 to 4), the supply amount of the unreacted gas is large. Also, the noise of gas ejection during diffusion combustion is prevented, and a low-noise unreacted gas combustion processing device is obtained.

According to the third aspect of the present invention, the plurality of flame holes are formed with an inclination of 10 to 30 degrees outward with respect to the axis of the nozzle, and they are formed on a concentric circle. With the arrangement, the unreacted gas ejected from the flame holes of the nozzles are ejected in different directions, and the flames are formed independently, so that the combustion flame can be shortened. it can. Thereby, the combustion chamber can be made smaller.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of a burner portion of an unreacted gas combustion processing device for a fuel cell according to an embodiment of the present invention, wherein (a) is a plan view, (b) is a front view, and (c) is a side view. It is.

FIG. 2 is a diagram of the unreacted gas combustion processing device of the fuel cell.
FIG. 3 is a schematic structural view showing another burner part, and FIG.
(b) is a front view, and (c) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner part 2 Combustion cylinder 3 Combustion chamber 4 Blower 5 Exhaust gas supply line 6 Nozzle 7 Ignition device 8 Flame 9 Flame θ Tilt of flame

Claims (3)

[Claims] 1. A burner for treating unreacted gas discharged from a fuel cell by diffusion combustion, wherein the burner includes a combustion chamber for performing combustion and air for combustion in the combustion chamber. A blower for supplying the gas, a nozzle having a plurality of flame holes at a tip end thereof, an exhaust gas supply pipe for guiding the unreacted gas, and an unreacted gas ejected from the flame hole provided above the nozzle And an ignition device for igniting a fuel cell. 2. The unreacted gas combustion processing apparatus for a fuel cell according to claim 1, wherein the number of the flame holes of the nozzle is two to four. 3. The method according to claim 2, wherein the plurality of flame holes are arranged with respect to an axis of the nozzle.
The unreacted gas combustion processing apparatus for a fuel cell according to claim 1 or 2, wherein the apparatus is formed with an inclination of 10 to 30 degrees toward the outside, and they are arranged concentrically.