JP2002053302A - Burner for fuel reformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and high reliability burner for fuel reformer which is capable of stably combusting a fuel gas with simple structure by preventing the problems such as the instability of flame due to condensed water, the generation of noise or accidental fire. SOLUTION: The burner is used for heating a fuel reformer to reform a hydrocarbon-based fuel into a hydrogen enriched reformed gas. The fuel gas supply pipe for supplying the fuel gas to a burner combustion part is formed into a double tube structure, the inside tube of the double tube is used as a fuel gas supply pipe line for supplying the fuel gas to a burner combustion part and the outside tube of the double tube is used as a condensed water discharge pipe line for discharging the condensed water in the burner combustion part to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a burner for a fuel reformer, and more particularly to a burner for a fuel reformer for reforming a hydrocarbon-based fuel into a hydrogen-rich reformed gas.

[0002]

2. Description of the Related Art A hydrocarbon-based fuel, for example, a mixed gas of methane and steam [for example, steam / carbon (molar ratio) = 2.
5) is supplied to a fuel reformer to reform it into a hydrogen-rich reformed gas for use in fuel cells and the like, because the chemical reaction in the fuel reformer is an endothermic reaction. The chemical reaction is performed while constantly heating with a burner.

FIG. 4 is a sectional view of a conventional fuel reformer, and FIG. 5 is a sectional view of a burner of the conventional fuel reformer shown in FIG. In FIG. 4, a fuel reformer 1 includes a reforming tube outer tube 2, a reforming tube inner tube 3, a reforming tube inner tube upper plate 4, a reforming tube outer tube upper plate 5, and a reforming tube outer tube upper plate 5. A reforming pipe 9 provided with a reforming raw fuel inlet 6, a reformed gas outlet 7 and the like, and a heating unit 8 for introducing a combustion gas for heating into a hollow portion provided at the center thereof; , A catalyst tube 10 mounted inside the reforming tube 9, and a reformer filled between the reforming tube inner tube 3 and the catalyst tube 10 and also disposed on the reforming tube inner tube upper plate 4. Catalyst 11 (for example, N supported on alumina
i, a ruthenium catalyst, etc.) and the flue gas coming into contact with the outside of the reforming pipe 9 and leading it, and then the flue gas pipe 13 discharged outside from the flue gas outlet 12 and the combustion gas into the heating unit 8. Gas tube 14 extending and inserted for
And a burner 15 provided at a lower portion of the combustion gas pipe 14 for burning fuel gas.

In FIG. 4, a fuel gas and air are introduced into a burner 15 to burn the fuel gas, and the combustion gas is led to a heating unit 8 through a combustion gas pipe 14 as shown by a dashed arrow, thereby forming a reforming catalyst 11. After heating the flue gas, the combustion exhaust gas
The exhaust gas is discharged from the combustion exhaust gas outlet 12 through the space between the exhaust gas and the combustion exhaust gas pipe 13. On the other hand, a hydrocarbon-based fuel, for example, methane is introduced into the fuel reformer 1 together with water vapor from the raw fuel inlet 6 as shown by an arrow, and is brought into contact with the heated reforming catalyst 11 for reforming. The operation temperature of the fuel reformer 1 is controlled to be approximately 700 ° C. (the outlet temperature of the reforming catalyst 11). Generated reformed gas (steam / carbon (molar ratio)
Reforming a raw material of about 2.5 = about 75% of hydrogen, about 10% of carbon monoxide, about 10% of carbon dioxide, and the remaining methane gas and reformed gas containing water are obtained. As shown, the gas is discharged from the reformed gas outlet 7 through the space between the outer tube 2 of the reforming tube and the catalyst tube 10.

[0005] As shown in FIG. 5, the burner 15 has a gas diffusion plate 16 at its tip and a fuel gas supply pipe 18 provided with a large number of gas ejection holes 17 below the gas diffusion plate 16. An air injection unit 21 fixed to the pipe 18 and the burner case 19 and provided with a large number of flame holes 20, and an air supply pipe 22 for introducing combustion air into the burner case 19 are provided.

In the burner 15 having the above-described structure, the fuel gas supplied through the fuel gas supply pipe 18 is injected from the gas injection hole 17 at the tip, and as shown by the solid arrow, the gas diffusion plate 16 and the air injection section 21 are provided. And is ejected to the burner combustion part 23 through the space between the bottom part 21-1. On the other hand, as shown by the solid line arrows, the combustion air supplied through the air supply pipe 22 passes through the combustion air chamber 24, is injected from the flame hole 20 of the air injection unit 21 to the burner combustion unit 23, and mixes with the fuel gas. Combustion of the fuel gas is performed.

There is no particular problem when using a hydrocarbon-based fuel such as methane gas or propane gas as the fuel gas. However, when the fuel cell or the fuel reformer is started or when it is operated stably, the fuel gas is not used. Off-gas which is unreacted hydrogen gas after using the reformed gas itself or after using the reformed gas in a fuel cell (for example, about 3% hydrogen)
However, it is necessary to use an off-gas containing 0% and the balance carbon dioxide, methane gas and moisture, or use a mixture of a hydrocarbon-based fuel such as methane gas and propane gas and an off-gas of a fuel cell. Since the quality gas and the off-gas of the fuel cell contain moisture, the following troubles occur.

That is, as shown in FIG. 5, a fuel gas such as a reformed gas containing water or an off-gas of a fuel cell is injected from a gas injection hole 17 at a tip through a fuel gas supply pipe 18, and is indicated by a solid arrow. As described above, the burner combustion part 23 passes between the gas diffusion plate 16 and the bottom 21-1 of the air injection part 21.
While the fuel gas is ejected, the water contained in the fuel gas condenses into liquid water and accumulates on the bottom 21-1. When the amount of accumulated water increases, the gas ejection holes 17 are clogged with water, When the ejection holes 17 are clogged with water, the ejection speed of the fuel gas partially increases, the flame becomes unstable, noise is generated, and in the worst case, there is a problem of misfiring.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems and to stably combust a fuel gas even when a reformed gas containing water or an off-gas of a fuel cell is used as the fuel gas. It is an object of the present invention to provide a highly reliable burner for a fuel reformer with a simple configuration, low cost, low cost, and high reliability.

[0010]

According to a first aspect of the present invention, there is provided a fuel reformer burner for heating a fuel reformer for reforming a hydrocarbon-based fuel into a hydrogen-rich reformed gas. A burner to be used, wherein a fuel gas supply pipe for supplying fuel gas to the burner combustion section has a double pipe structure, and an inner pipe of the double pipe is used as a fuel gas supply pipe for supplying fuel gas to the burner combustion section. The outer pipe of the double pipe is used as a condensed water discharge pipe for discharging the condensed water in the burner combustion section to the outside.

According to a second aspect of the present invention, there is provided a burner for a fuel reformer according to the first aspect, wherein the fuel gas is a mixture of a hydrocarbon fuel and an off-gas of a fuel cell or an off-gas or reforming of a fuel cell. It is a gas.

According to a third aspect of the present invention, there is provided a burner for a fuel reformer according to the first or second aspect, wherein a drain discharge pipe is connected to the outer pipe.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory sectional view of an embodiment of a burner for a fuel reformer of the present invention, and FIG. 2 is an explanatory sectional view of a burner for another fuel reformer of the present invention;
FIG. 3 is an explanatory plan view of the burner for a fuel reformer shown in FIG. 1 to 3, the same components as those of the related art are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, a burner 15A according to the present invention comprises:
The fuel gas supply pipe 18 has a double pipe structure, and the inner pipe 18-1 of the double pipe is used as a fuel gas supply pipe for supplying fuel gas to the burner combustion section 23. The outer pipe 18-2 is used as a condensed water discharge conduit for discharging the condensed water condensed in the burner combustion section 23, and is provided at a lower portion of the outer pipe 18-2 for discharging the condensed water to the outside. It is the same as the burner 15 shown in FIG. 5, except that the drain discharge pipe 25 is connected and installed.

As shown in FIG. 1, the upper portion of the outer tube 18-2 is opened so as to communicate with the burner combustion portion 23, and the air ejection portion 2 is opened.
1 is fixedly installed on the bottom 21-1. Therefore, a fuel gas such as a reformed gas containing water or an off-gas of a fuel cell is injected from the gas injection hole 17 at the tip through the fuel gas supply pipe 18, and the gas diffusion plate 16 shown in FIG. The water contained in the fuel gas is condensed to become liquid water while being ejected to the burner combustion section 23 through the space between the bottom 21-1 and the bottom section 21-1 of the air injection section 21.
Even when moving upward, the condensed water passes through the opening of the outer pipe 18-2 of the double pipe as shown by the dashed arrow, and
It flows downward through the gap d between the inner pipe 2 and the inner pipe 18-1, and is discharged to the outside via the drain discharge pipe 25. As described above, since the condensed water does not accumulate on the bottom 21-1 and the gas ejection holes 17 are not clogged with water, the fuel gas can be stably burned.

The gap d between the outer tube 18-2 and the inner tube 18-1
If the width is too narrow, condensed water cannot be discharged, so it is preferable to widen it for discharging condensed water.However, if it is too wide, air flow and flame will be adversely affected. Is desirable.

Although the material of the burner 15A of the present invention is not particularly limited, it is preferable to use stainless steel in consideration of durability, corrosion resistance, strength and the like.

The burner 15B for a fuel reformer according to the present invention shown in FIG. 2 has a funnel-shaped air ejection part 21-2 whose inner diameter increases as the air ejection part goes upward, and the air ejection part 21-
The burner 15A is the same as the burner 15A shown in FIG. 1 except that the lower part of the burner 15 is directly fixed to the upper end of the outer pipe 18-2 of the double pipe.

Since the burner 15B for the fuel reformer of the present invention uses the funnel-shaped air ejection portion 21-2, condensation generated when a fuel gas such as a reformed gas containing water or an off-gas of a fuel cell is used. Water is easy to flow and condensed water is transferred to the outer pipe 1
The liquid flows downward through the gap d between the outer pipe 18-2 and the inner pipe 18-1 through the opening 8-2, and can be easily discharged to the outside through the drain discharge pipe 25.

The description of the above embodiments is for describing the present invention, and does not limit the scope of the invention described in the claims or reduce the scope thereof. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

[0021]

According to a first aspect of the present invention, there is provided a burner for a fuel reformer, wherein a fuel gas supply pipe for supplying fuel gas to a burner combustion section has a double pipe structure, and an inner pipe of the double pipe is connected to the burner combustion section. Since the outer pipe of the double pipe is used as a condensed water discharge pipe for discharging the condensed water of the burner combustion part to the outside, the flame caused by the condensed water is used. In addition to being able to prevent problems such as instability, noise generation, and misfire, it can stably burn fuel gas, and has a remarkable effect of simple configuration, low cost, low cost, and high reliability. To play.

In the burner for a fuel reformer according to a second aspect of the present invention, the fuel gas is a fuel gas containing water such as a mixture of a hydrocarbon-based fuel and an off-gas of a fuel cell or an off-gas or a reformed gas of a fuel cell. However, it is possible to prevent problems such as flame instability, noise generation, and misfire caused by condensed water, and to achieve a remarkable effect that fuel gas can be stably burned.

In the fuel reformer burner according to the third aspect of the present invention, since the drain discharge pipe is connected to the outer pipe, the condensed water flowing through the outer pipe can be easily discharged to the outside through the drain discharge pipe. It has a remarkable effect that it can be discharged.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of one embodiment of a burner for a fuel reformer of the present invention.

FIG. 2 is an explanatory sectional view of another burner for a fuel reformer of the present invention.

FIG. 3 is an explanatory plan view of the burner for a fuel reformer shown in FIG. 2;

FIG. 4 is an explanatory sectional view of a conventional fuel reformer.

5 is an explanatory sectional view of the conventional burner for a fuel reformer shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel reformer 15, 15A, 15B Burner for fuel reformers 16 Gas diffusion plate 17 Gas ejection hole 18 Fuel gas supply pipe 18-1 Inner tube 18-2 Outer tube 20 Flame hole 21 Air ejection portion 21-1 Bottom 22 Air supply pipe 23 Burner combustion part 24 Air chamber 25 Drain discharge pipe

Continued on the front page (72) Inventor Keigo Miyai 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. (reference) 3K019 AA02 AA08 BA04 BB02 BD09 4G040 EA03 EA06 EB14 5H027 BA01 BA09

Claims (3)

[Claims] 1. A burner used for heating a fuel reformer for reforming a hydrocarbon-based fuel into a hydrogen-rich reformed gas, comprising a fuel gas supply pipe for supplying a fuel gas to a burner combustion section. The inner pipe of this double pipe is used as a fuel gas supply pipe for supplying fuel gas to the burner combustion section.
The burner for a fuel reformer, wherein the outer pipe of the double pipe is used as a condensed water discharge pipe for discharging condensed water in a burner combustion section to the outside. 2. The burner for a fuel reformer according to claim 1, wherein the fuel gas is a mixture of a hydrocarbon-based fuel and a fuel cell off-gas, or a fuel cell off-gas or reformed gas. 3. The burner for a fuel reformer according to claim 1, wherein a drain discharge pipe is connected to the outer pipe.