CN1525100A - Composite multifunctional DC burner - Google Patents

Abstract

The invention discloses a composite multi-functional direct-flow burner, which has a performance-adjusting air nozzle III, a secondary air nozzle, a pulverized coal level concentration primary air nozzle on the upper and lower sides and an unfired side, and a performance-adjusting air II nozzle in sequence. , the other upper and lower sides and the back side of the coal powder level concentration of the primary air nozzle tapered, another secondary air nozzle, the upper and lower sides and the side of the back fire side of the tapered coal level concentration of the primary air nozzle is equipped with a performance Adjusting wind I nozzle, primary air nozzle axis and performance adjusting air III nozzle axis deviate from the secondary air nozzle axis to the fire side, and performance regulating air II nozzle is bent to the water cooling wall side by a part of the flow channel of the secondary air nozzle. The invention has wide application range of coal quality, waterproof cold wall slagging (coke), high temperature corrosion resistance, low load stable combustion, low nitrogen oxide emission, low fly ash slag combustible content, small furnace outlet smoke temperature deviation, Self-adjusting performance, resistance to four-corner wind powder deviation and other advantages.

Description

Composite multifunctional DC burner

Technical field

The invention relates to a composite multifunctional direct-flow burner.

Background technique

Furnace slagging accidents often occur in pulverized coal combustion boilers due to reasons such as coal type, furnace structure and combustion system, which affect the safe and economical operation of the boiler. Especially for boilers burning coal with low ash melting point and strong slagging tendency, slagging accidents are especially prone to occur. At present, in order to prevent slagging, some boilers adopt a low heat load of the furnace, but this leads to an increase in the cost of the boiler and a reduction in combustion efficiency; The large rotational momentum of the wind and the turbulent dispersion of pulverized coal particles lead to the slagging of the concentric reverse tangential system when burning coal with a very low ash melting point and a strong slagging tendency, and it is easy to affect the combustion stability.

Contents of Invention

The purpose of the present invention is to provide a composite multi-functional once-through burner.

It sequentially has the performance adjustment air nozzle III, the secondary air nozzle, the upper and lower sides and the back fire side tapering coal powder level concentration primary air nozzle, the performance adjustment wind II nozzle, the upper and lower side and the back fire side tapering coal powder level concentration The primary air nozzle, the other secondary air nozzle, and the other upper and lower sides and the side of the back fire side gradually shrinking pulverized coal. , The performance adjustment wind II nozzle adopts a folding nozzle, and a part of the flow channel of the secondary air nozzle is bent to the side of the water wall.

The invention has wide application range of coal quality, waterproof cold wall slagging (coke), high temperature corrosion resistance, low load stable combustion, low nitrogen oxide emission, low fly ash slag combustible content, small furnace outlet smoke temperature deviation, Self-adjusting performance, resistance to four-corner wind powder deviation and other advantages.

The tapered primary air nozzle improves the rigidity of the primary air jet, and at the same time reduces the rotational strength in the furnace to reduce the centrifugal separation and wall-attachment tendency of coal powder particles. The oxygen content in the area near the water wall on the back fire side of the primary air jet is increased, and the temperature in the local area of the water wall is reduced, so as to prevent the slagging of the water wall. The composite application of deflected primary air, performance-adjusted air I and performance-adjusted air II is beneficial to slow down the mixing of primary air jet and secondary air, increase the concentration of coal powder, and is beneficial to ignition and stable combustion. At the same time, due to the graded air supply in the horizontal section and in the height direction, it has a certain effect on reducing the release of nitrogen oxides from boiler combustion.

Description of drawings

Fig. 1 is a structural schematic diagram of a composite multi-functional once-through burner;

Fig. 2 is a cross-sectional layout diagram of a composite multi-functional once-through burner furnace;

Fig. 3 is a schematic diagram of the structure of the primary air nozzle of the composite multi-functional direct current burner.

Detailed ways

The composite multi-functional direct-flow burner has performance regulating air III nozzle 5, secondary air nozzle 4, primary air nozzle 1 with coal powder level concentration on the upper and lower sides and back fire side tapered, performance regulating air II nozzle 3, upper and lower sides and back fire side Primary air nozzle 1, primary air nozzle 1, secondary air nozzle 4, primary air nozzle 1, pulverized coal level concentration, which gradually shrinks on the back fire side, performance adjustment air nozzle 2, primary air nozzle 1 The axis of the air nozzle 1 deviates from the axis of the secondary air nozzle 4, the performance adjustment air II nozzle 3 adopts a folding nozzle, and a part of the flow channel of the secondary air nozzle 4 is bent to the side of the water wall.

The taper angle of the primary air nozzle 1 is 2-15 degrees, and the included angle ψ of the axis of the primary air nozzle 1 and the axis of the secondary air nozzle 4 is 3-10 degrees. The performance adjustment wind I nozzle 2 is arranged on the back fire side of the primary air nozzle 1, and the included angle θ between the performance adjustment air I nozzle 2 axis and the water cooling wall is 5-40 degrees. The included angle ω between the 3 axes of the performance adjustment wind II nozzle and the water cooling wall is 5-40 degrees. The included angle ψ between the axis 5 of the performance adjustment wind III nozzle and the axis 4 deviated from the secondary air nozzle is 3-10 degrees.

The primary air nozzle adopted by the composite multi-functional direct-flow burner has a coal powder horizontal density structure with tapering on the upper and lower sides and tapering on the back fire side. While the outlet pulverized coal air jet is rigid, due to the function of the tapered nozzle, the pulverized coal is relatively concentrated in the center of the jet, which reduces the tendency of the pulverized coal particles to move to the water wall caused by jet diffusion and turbulent dispersion. Adopting the form that the back fire side of the primary air nozzle is tapered and not tapered toward the fire side, which is conducive to the movement of coal powder to the fire side, which is not only conducive to the ignition and combustion of coal powder, but also conducive to preventing the water cooling of coal powder particles to the back fire side Adhesion to the wall.

The axis of the primary air nozzle deviates from the axis of the secondary air nozzle to the fire side at a certain angle, and the primary air jet flows against the upstream flow of the top, which is conducive to the ignition of the primary wind and prevents the primary air jet from being scoured by the upstream flow and sticking to the wall. The upstream flow of the wind against the top is beneficial to reduce the rotation intensity in the furnace, and can weaken the tendency of pulverized coal particles to stick to the water wall due to centrifugal separation. The choice of the deflection angle of the primary air jet is to ensure that the rotation direction of the air flow in the furnace remains unchanged. Generally, due to the large momentum of the secondary air, a smaller primary air deflection angle will not affect the direction of the air flow in the furnace.

The performance adjustment wind I is arranged on the backfire side of the primary air nozzle, and the axis of the performance adjustment wind I nozzle is located between the axis of the secondary air nozzle and the water cooling wall, and has a certain angle between the water cooling wall and the axis of the secondary air nozzle, that is, neither Parallel to the water-cooled wall and not parallel to the axis of the secondary air nozzle, this arrangement can form a layer of wind film between the main combustion area of the furnace and the water-cooled wall, reduce the temperature of the water-cooled wall in the burner area, and increase the oxygen content near the water-cooled wall , reduce the reducing atmosphere near the water wall to achieve the purpose of slag prevention; at the same time, realize the cross-section graded air supply to reduce the formation of nitrogen oxides.

The present invention arranges the performance-adjusting air II between the two layers of primary air. The performance-adjusting air II can adopt a direct-flow nozzle, and can also use part of the secondary air channel to bend to form a secondary air, and the remaining secondary air is still sprayed according to the original axis. Entering the furnace, this part is bent to the angle between the secondary air and the water-cooled wall to form a certain angle, and is located between the original secondary air axis and the water-cooled wall, so as to form a layer of wind film between the main combustion area of the furnace and the water-cooled wall . In addition to turning to the secondary air, the other secondary air is still injected into the furnace according to the original axis, which can provide oxygen for the primary air in time after the fire, so that the pulverized coal can be completely burned.

The performance regulating air III is arranged on the top of the burner group, and the performance regulating air III also deviates from the secondary air at a certain angle and is injected toward the fire side. The performance adjustment air III is arranged above the secondary air in the uppermost layer of the burner group, which can ensure the combustion of pulverized coal and weaken the rotation intensity of the air flow in the furnace. The input of performance regulating air III can form air classification in the direction of height in the furnace, so as to achieve the effect of reducing nitrogen oxide emissions and reducing the deviation of flue gas temperature at the furnace outlet.

Due to the deflection arrangement of the primary air, the primary air adopts the form of pulverized coal horizontal concentration nozzles that taper from the upper and lower sides and the back fire side, and the performance adjustment wind I on the back fire side of the primary air and the performance adjustment wind II located between the primary air nozzles on the second floor This kind of combustion system has a wide range of coal quality, waterproof and cold wall slagging (coke), high temperature corrosion resistance, low load stable combustion, low nitrogen oxide emissions, low fly ash slag combustible content, Small furnace outlet flue temperature deviation, self-regulation performance, resistance to four-corner wind powder deviation and other advantages.

As shown in Figure 2, (6) is the primary air spout and performance adjustment wind III spout axis; (7) is the secondary air spout central axis; (8) is the performance adjustment wind I spout central axis; (9) is the performance regulation Wind II turns to the central axis of the secondary air nozzle.

As shown in Figure 3, (10) and (11) in the figure are the tapering structures on the upper and lower sides of the primary air spout respectively, while (12) is the tapering structure on the back fire side, and the spout to the fire side (13) adopts a flat plate structure, No taper.

Claims (5)

1. A composite multi-functional straight-through burner, characterized in that it has a performance-adjusting wind III spout (5), a secondary air spout (4), the coal powder level concentration and light primary air that gradually shrinks on the upper and lower sides and the back fire side Nozzle (1), performance adjustment air II nozzle (3), pulverized coal level concentration on the upper and lower sides and the back fire side tapered primary air nozzle (1) secondary air nozzle (4), the upper and lower sides and the back fire side tapered The primary air nozzle (1) with the level of pulverized coal concentration is equipped with a performance adjustment air nozzle (2) on the back fire side, the axis of the primary air nozzle (1) deviates from the axis of the secondary air nozzle (4), and the performance adjustment air nozzle (3) adopts Folding toward the spout, a part of the flow path of the secondary air spout (4) is folded toward the water wall side. 2. A compound multi-functional once-through burner according to claim 1, characterized in that the taper angle of said primary air nozzle (1) is 2 to 15 degrees, and the primary air nozzle (1) axis and two The included angle ψ of the axes of the secondary air spout (4) is 3-10 degrees. 3. a kind of composite multi-functional straight-through burner according to claim 1, is characterized in that said performance adjustment wind I spout (2) is arranged on the back fire side of primary air spout (1), and performance adjustment wind I spout (2) The angle θ between the axis and the water wall is 5 to 40 degrees. 4. A composite multifunctional once-through burner according to claim 1, characterized in that the angle ω between the axis of the performance-adjusting wind II nozzle (3) and the water-cooled wall is 5-40 degrees. 5. A kind of composite multi-functional once-through burner according to claim 1, characterized in that said performance adjustment wind III nozzle (5) axis and the angle ψ that deviates from the axis of the secondary air nozzle (4) is 3～ 10 degrees.

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