JP3207664B2 - Boiler combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an apparatus for burning pulverized coal fuel in a vertical, rectangular tubular furnace such as a coal-fired boiler.

[0002]

2. Description of the Related Art FIG. 2 is a horizontal sectional view showing an example of a conventional pulverized coal-fired boiler furnace. (5) in the figure is a boiler furnace,
(6) shows a burner, (7) shows a flame, and (8) shows a flame collision part (slag attachment part). In this example,
In order to enhance the reduction and denitration effect, burners (6) are provided at the center of each side of the horizontal cross section of the furnace wall with high radiation intensity, and the direction of injection of the pulverized coal mixture of the burners (6) is adjusted on the furnace horizontal cross section. A combustion method is adopted in which the fuel and air are injected while swirling in the same direction (rightward, clockwise in the illustrated example) with respect to the perpendicular to the wall to improve the combustibility of coal. . However, in this combustion method, the flame (7) hits the (8) portion of the furnace wall, and the molten coal ash (slag) adheres, which may cause a trouble.

[0003]

In the conventional boiler combustion apparatus, the flame (7) extending from the burner outlet hits the furnace wall as shown in FIG. 2, and the molten slag adheres to the part (8). There was a problem. An object of the present invention is to prevent the slag from adhering by controlling the direction of the flame extending from the burner outlet so that the flame does not hit the furnace wall.

[0004]

Means for Solving the Problems In order to achieve the above object, the present inventor has set forth a boiler combustion apparatus for burning pulverized fuel in a rectangular cylindrical furnace whose axis is substantially vertical. A burner that is provided at the center of each side and inclines in the same direction with respect to the perpendicular of the furnace wall on the furnace horizontal cross section and injects the pulverized fuel / fuel mixture, and is provided in proximity to the inclination direction of the burner , Of the primary air injected from the burner
The present invention proposes a boiler combustion device including a jet air port that injects air at a speed of 60 to 80 m / s, which is equivalent to a momentum .

[0005]

According to the present invention, the burner flame can be controlled by the air jetted from the jet airport so that the flame of the burner does not hit the furnace wall, so that the molten coal ash adheres to the furnace wall. Is prevented. Also, the air injected from this jet airport
Of the primary air so that its kinetic energy does not decay
It is maintained at the same level as the momentum, and the flow velocity is 60-8.
It is set to 0m / s, and there is concern about flow velocity less than 60m / s.
`` If the slag adheres to the flame
And the flow velocity exceeds 80m / s.
May result in impaired stable ignition of coal, etc.
Without further increase in air and fuel swirl, favorable combustion is promoted.

[0006]

FIG. 1 is a horizontal sectional view showing an embodiment of the present invention. In the figure, (1) is a boiler furnace having a rectangular tube shape whose axis is almost vertical, and (2) is provided at the center of each side in the horizontal section of the furnace wall. A burner that inclines in the direction (rightward, clockwise in the illustrated example) and injects the pulverized fuel-fuel mixture, and (3) is provided near the inclining direction (rightward) of the burner (2) to remove air The jet air port for jetting, (4) is a flame.

That is, in this embodiment, the jet air port (3) is located adjacent to the downstream side of the burner (2) in the flame swirling direction.
Attach and blow air at a flow rate of 60-80m / s.
Control so that the flame (4) does not hit the furnace wall. In this case, if the flow velocity is less than 60 m / s, the flame may hit the furnace wall and the molten slag may adhere.
If it exceeds 0 m / s, stable ignition of coal may be impaired.

[0008] The air distribution of the jet port is determined by the momentum ρ · v ² · FA (ρ: air density, v: jet velocity, FA:
It has been found that the effect of the jet air port can be obtained by setting the cross-sectional area of the air outlet at the same level as the primary air. That is, if the suffix 1 is used for the primary air and the suffix j is used for the jet air ejected air, ρ ₁ v ₁ ² FA ₁ = ρ _j v _j ² FA _j . Since the primary air is 20 m / s at 80 ° C. and the jet air port is 60 m / s to 80 m / s at 300 ° C., FA _j is as follows.

[0009]

(Equation 1)

That is, the sectional area of the outlet of the jet air port may be about 10 to 18% of the sectional area of the outlet of the primary air. The higher the jet air flow velocity, the smaller the cross-sectional area of the jet air outlet can be, but the upper limit must be 80 m / s due to conditions such as stable ignition of coal.

[0011]

According to the conventional furnace, the slag adheres because the flame hits the furnace wall. In the present invention, this is prevented by controlling the flow of the flame with the air jetted from the jet air port. can do. Further, the air injected from the jet air port enhances the turning of the fuel and air in the furnace, so that the combustibility of the pulverized fuel is improved.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing one embodiment of the present invention.

FIG. 2 is a horizontal sectional view showing an example of a conventional pulverized coal-fired boiler furnace.

[Explanation of symbols]

 (1) Boiler furnace (2) Burner (3) Jet airport (4) Flame (5) Boiler furnace (6) Burner (7) Flame (8) Flame collision part (Slag attachment part)

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Toshishi Maruta 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (56) References JP-A-63-282402 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) F23C 5/32

Claims (1)

(57) [Claims] 1. A boiler combustion apparatus for burning pulverized fuel in a furnace having a substantially cylindrical shape whose axis is substantially vertical, provided at a central portion of each side in a horizontal section of a furnace wall, wherein the furnace wall is disposed on a horizontal section of the furnace. A burner for injecting the pulverized fuel mixture in the same direction with respect to the vertical, and a burner provided in close proximity to the inclining direction of the burner for transporting primary air injected from the burner;
A boiler combustion device comprising: a jet air port that injects air at a speed of 60 to 80 m / s, which is equivalent to a momentum .