JP2961036B2 - 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 a combustion apparatus applied to a boiler furnace.

[0002]

2. Description of the Related Art First, three typical conventional combustion systems will be described. 1) Corner firing method Fig. 3 shows the corner firing method. A main burner (2) that blows out in the tangential direction of a virtual cylinder at the center of the furnace is set at each corner of the furnace (1), and the flame burns while forming a vortex. 2) Front firing method Fig. 4 shows the front firing method. Furnace (1)
The main burner (2) is installed on the front wall of the, and burns while creating a jet toward the rear wall. 3) Opposing firing method Fig. 5 shows an opposing firing method. Main burners (2) are installed on both the front wall and the rear wall of the furnace (1) and burn while creating a colliding jet at the center of the furnace.

[0003]

In the conventional boiler combustion apparatus, the corner firing method is suitable for long flame combustion, and the front firing method and the opposed firing method are suitable for short flame combustion. However, when the properties of the fuel used change, for example, when the brand of coal changes, the length of the flame changes and the heat load distribution of the furnace and the properties of the exhaust gas change. It is necessary to adjust the wind box damper of the burner. This damper adjustment requires several days of operation by a manufacturer's operation instructor with many years of experience, and is troublesome.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention relates to a furnace having a vertical rectangular cylindrical shape, and a furnace provided at or near a corner of the furnace and directed toward a central axis of the furnace. A main burner for ejecting fuel and air, a flame control nozzle provided at a position lower than the main burner for ejecting nonflammable gas, means for adjusting the direction of the flame control nozzle up, down, left and right; A means for adjusting a gas flow rate is proposed.

[0005]

When the jet jetting out from the flame control nozzle installed at a position lower than the main burner forms a vortex, the flame of the main burner is dragged by the vortex below without rotating momentum and rotates. In the present invention, the state of the vortex of the upper main burner is controlled by adjusting the strength of the vortex formed by the jet of the flame control nozzle by the ejection direction and the flow rate, and the flame length by changing the coal type or the like. Can be responded to.

[0006]

An embodiment of the present invention will be described with reference to FIGS. (1) is a boiler furnace of a thermal power plant, which is a vertical cylinder having a rectangular cross section. Main burner (2)
Are installed at or near corners of the furnace (1) so as to eject fuel and air toward the central axis (6) of the furnace (1). The main burners (2) may be provided in multiple stages (four stages in the illustrated example), and the ejection direction may be fixed to the left and right, and may be swung up and down. This is the same as the conventional corner-firing type burner shown in FIG. 3 in which the jetting direction is directed toward the central axis (6) of the furnace (1).

Next, a furnace (1) is provided below the main burner (2).
At each corner or near the corner of
A flame control nozzle (4) which can be swung up and down and is oriented in a tangential direction of a virtual cylinder centered on a central axis (6) of the furnace (1) is installed. The flame control nozzle (4) is configured to circulate and emit heated air or boiler exhaust gas. The flow rate of these ejected gases can be adjusted by a damper (not shown).

[0008] The flame control nozzle (4) may be installed at or near the center of each furnace wall at a position lower than the main burner (2). Also in this case, the jet direction is furnace (1)
To the left and right and up and down so as to face the tangential direction of the virtual cylinder about the central axis (6).

[0009] In the combustion device configured as described above, the main burner (2) installed at the corner of the furnace (1).
From there, fuel and air are injected toward the central axis (6) to form a flame (3). A jet (5) of a non-combustible gas such as air or exhaust gas is formed from a flame control nozzle (4) installed at a position lower than the main burner (2).

Here, when the jet direction of the flame control nozzle (4) is directed to the central axis (6) of the furnace (1), as shown in FIG. 1, a jet (5) of air or exhaust gas is formed. It collides with the opposing jet (5) and does not turn. In this case, the flame (3) of the main burner (2) also collides with the opposed flame (3), the whole does not turn, and is similar to the conventional opposed firing method shown in FIG. It becomes a combustion state. Therefore, it can be said that this combustion method is suitable when the flame (3) is short, that is, when the fuel is flammable, or when the ejection speed is low.

On the other hand, if the flame (3) is long, the opposing flames (3) collide with each other and cause inconvenience. Therefore, as shown in FIG. The ejection direction is not directed to the central axis (6) of the furnace (1), but to the tangential direction of the virtual cylinder about the central axis (6). As a result, the jet (5) of the ejected nonflammable gas is swirled, and the jet (5) forms a vortex. Then, the main burner (2) above it
The flame (3) is dragged by the vortex of the jet (5), so that the entire flame forms a vortex. Since these flames (3) form a vortex without colliding with the opposed flames (3), the combustion is similar to the conventional corner firing combustion system shown in FIG.

[0012]

According to the present invention, the flame of the main burner can be controlled from the opposed firing method to the corner firing by adjusting the ejection direction and the flow rate of the flame control nozzle. Therefore, even if the properties of the fuel change and the flame length changes, the opposing firing can be selected in the case of a short flame and the corner firing can be selected in the case of a long flame. Can be performed.

[Brief description of the drawings]

FIG. 1 is a side view and a plan view of a boiler combustion device according to an embodiment of the present invention, showing a state in which the flame is not swirling.

FIG. 2 is a plan view and a plan view of the boiler combustion device, showing a state in which a flame is swirling.

FIG. 3 is a side view and a plan view of a conventional corner firing type boiler combustion device.

FIG. 4 is a side view and a plan view of a conventional front firing type boiler combustion device.

FIG. 5 is a side view and a plan view of a conventional opposed firing boiler combustion device.

[Explanation of symbols]

 (1) Furnace (2) Main burner (3) Flame (4) Flame control nozzle (5) Jet (6) Central axis of furnace

Claims (1)

(57) [Claims] 1. A furnace having a vertical rectangular cylindrical shape, a main burner provided at or near a corner portion of the furnace for injecting fuel and air toward a central axis of the furnace, and a lower position than the main burner. Boiler combustion, comprising: a flame control nozzle for ejecting a nonflammable gas, a means for adjusting the direction of the flame control nozzle vertically and horizontally, and a means for adjusting the flow rate of the nonflammable gas. apparatus.