JPH1151309A - Combustion equipment for gas fired boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation and adhesion of carbon by supplying steam within a specific range per specific heating quality fuel supplied from a tertiary burner for an additional combustion from the tertiary burner. SOLUTION: A flame is held by a primary burner to ensure a stable combustion and a main combustion is obtained, by a secondary burner. Further, a tertiary burner 3 having an inside pipe 31 for supplying fuel for additional combustion, an outside pipe 32 for supplying steam and a mixing part 33 at an end part achieves a complete combustion. In this combustion, steam of 0.1 to 0.5 kg per 10,000 kcal of heating quality held in the fuel for additional combustion supplied from the inside pipe 31 is supplied to the tertiary burner 3 from the outside pipe 32. In the mixing part 33, the fuel for additional combustion is mixed with steam in the mixing part 33 and the mixture is jetted to a furnace. Thus, the generation and adhesion of carbon can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a combustion device in a gas-fired boiler.

[0002]

2. Description of the Related Art A conventional apparatus will be described with reference to FIG. FIG. 3 is a sectional view of a combustion device in a conventional gas-fired boiler.

A conventional combustion device in a gas-fired boiler mainly includes a primary burner 1 for performing stable combustion, a secondary burner 2 for performing main combustion, a tertiary burner 3A for performing additional combustion, and a burner tile 4. It is configured as an element.

That is, in the primary burner 1, the primary air 1
The primary fuel 12 is mixed into the stream 1 and the mixed stream is swirled by the swirler 13 and introduced into the furnace from the outlet provided with the flame stabilizing plate 14, and is stabilized in combination with the function of the flame stabilizing plate 14 and the like. It is configured to maintain combustion.

In the secondary burner 2, a swirling flow of secondary air 21 is passed through a swirler 23, and a secondary fuel 22
Into the furnace from around the combustion area of the primary burner 1 to perform main combustion.

Further, the tertiary burner 3A is supplied with a tertiary fuel alone or a mixture of the tertiary fuel and tertiary air,
This is charged into the furnace from outside the combustion zone formed by the secondary burner 2 to perform additional combustion.

The primary, secondary, and tertiary burners 1,
The combustion device combining 2, 3A supplies fuel with an appropriate distribution ratio to each burner, and supplies an air ratio of 1 to the primary burner 1.
As described above, the air having an air ratio of 1.2 to 1.5 is supplied to the secondary burner 2, and the tertiary burner 3 </ b> A is made of a single fuel to secure the residual oxygen concentration of the combustion gas by the fuel for the secondary burner 2. often turning, even when turning on the air, the air ratio is 0.1 to 0.5, and is configured to achieve very low NO _X combustion.

[0008]

In the above-mentioned prior art, there is a local shortage of air near the injection nozzle of the tertiary burner 3A, and carbon adheres to the furnace wall 5 with which the flame of the tertiary burner 3A comes into contact. Failure occurs.

In addition, in the case of supplying a single fuel to the tertiary burner 3A, the tendency becomes more remarkable.

An object of the present invention is to provide a device which solves such a problem and suppresses generation and adhesion of carbon.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a gas having a primary burner for stable combustion, a secondary burner for main combustion, and a tertiary burner for additional combustion. In the combustion device of the boiler, the calorific value of the fuel supplied from the tertiary burner is 10,000 Kcal.
An object of the present invention is to provide a combustion apparatus for a gas-fired boiler configured to feed 0.1 to 0.5 kg of steam from the tertiary burner.

That is, the hydrocarbons in the gaseous fuel are thermally decomposed to generate carbon particles, which react with water vapor supplied thereto to become carbon dioxide or carbon monoxide. Adhesion will be suppressed.

The amount of water vapor that reacts with the carbon particles generated by the thermal decomposition of hydrocarbons in the gaseous fuel is preferably not less than not less than an appropriate amount. It has been found that 0.1 to 0.5 Kg is optimal for the calorific value of the gas fuel supplied from the tertiary burner of 10,000 Kcal.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of a combustion device in a gas-fired boiler according to the present embodiment, and FIG.
3 shows the details of part A of FIG.

FIG. 1 is a schematic display to show the general outline of the apparatus. As far as it is concerned, there is no particular division from FIG. 3 showing the above-mentioned conventional apparatus, but as shown in FIG. Both are completely different in the main part, and needless to say, they are different devices.

However, in the present embodiment, the same parts as those in the conventional art are denoted by the same reference numerals in FIG. 1 as those in FIG. Was omitted and the explanation was simplified.

The tertiary burner 3 according to the present embodiment has a double pipe structure at its main part, and has an inner pipe 31 for supplying fuel for additional combustion and an outer pipe 32 for supplying steam. In addition, the distal end portion has a mixing section 33 that communicates with the inner pipe 31 and the outer pipe 32 to receive and mix the fuel and the steam.

In the present embodiment, under such a configuration, the primary burner 1 performs the main combustion with the secondary burner 2 while ensuring the flame by the primary burner 1 to ensure stable combustion, and further the combustion with the tertiary burner 3. To be complete.

At the time of this combustion, in the tertiary burner 3, 0.1 to 0.5 kg per 10000 kcal of the amount of heat held by the additional combustion fuel supplied from the inner pipe 31.
Is supplied from the outer pipe 32, and the additional fuel and the steam are mixed in the mixing section 33 and then ejected into the furnace.

That is, by mixing the additional fuel and steam in the mixing section 33 provided at the tip of the tertiary burner 3 and then charging the mixed fuel into the furnace, carbon generated by the thermal decomposition of hydrocarbons in the additional fuel is generated. The particles react with water vapor (H ₂ O) to produce carbon dioxide (CO ₂ ) or carbon monoxide (CO).
The following chemical reaction occurs.

Due to this chemical reaction, the generation and adhesion of carbon are suppressed even under the condition of local air shortage such as the installation position of the tertiary burner 3. According to the verification by the experiments conducted by the inventors, the amount is 0.1 to 0.000 per 10,000 Kcal of the amount of heat held by the additional combustion fuel as described above.
5 kg, particularly preferably 0.2 to 0.3 kg per 10,000 Kcal of the amount of heat held by the fuel for additional combustion
Met.

The steam is injected from the tertiary burner 3 and, in addition to the chemical reaction, the steam is cooled by the injected steam to lower the temperature in the furnace, thereby suppressing the generation of thermal NO _X accompanying the combustion. is intended to be obtained together effect say capable of performing NO _X reduction combustion.

Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to such an embodiment.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0025]

According to the present invention, a gas-fired boiler having a primary burner for stable combustion, a secondary burner for main combustion, and a tertiary burner for additional combustion is supplied from the tertiary burner. Fuel of 10,000Kc
With the configuration in which 0.1 to 0.5 kg of water vapor per al is injected from the tertiary burner, carbon particles generated by thermal decomposition of hydrocarbons in gaseous fuel react with water vapor to produce carbon dioxide, or the carbon monoxide, the generation of so-called carbon here, to suppress the adhesion, also those which were able to achieve a reduction of the generated NO _X in cooling by water vapor.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of a combustion device for a gas-fired boiler according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a main part A of FIG. 1;

FIG. 3 is an explanatory diagram showing an outline of a conventional gas-fired boiler combustion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary burner 2 Secondary burner 3, 3A Tertiary burner 4 Burner tile 5 Furnace wall 11 Primary air 12 Primary fuel 13 Swirler 14 Flame holding plate 21 Secondary air 22 Secondary fuel 23 Swirler 31 Inner tube 32 Outer tube 33 Mixing part 34 Tertiary fuel 35 Steam

Claims (1)

[Claims] In a combustion apparatus for a gas-fired boiler having a primary burner for stable combustion, a secondary burner for main combustion, and a tertiary burner for additional combustion, 0 to 100 Kcal of calorific value of fuel supplied from the tertiary burner. .1 to
A combustion apparatus for a gas-fired boiler, wherein 0.5 kg of steam is supplied from the tertiary burner.