CN111536506A - Boiler over-fire air device - Google Patents

Abstract

The invention discloses a boiler over-fire air device, comprising: the air conditioner comprises an over-fire air nozzle and an air regulator connected with a burner nozzle; the air regulator comprises a supporting plate and an over-fire air sleeve, the over-fire air sleeve is connected with the supporting plate to form an air regulating channel, and a burner nozzle is communicated with the air regulating channel; the over-fire air sleeve comprises an over-fire air cylinder arranged on the supporting plate and a sleeve baffle plate sleeved on the over-fire air cylinder, an air inlet of the air adjusting channel is formed between the sleeve baffle plate and the supporting plate, and the sleeve baffle plate can slide relative to the over-fire air cylinder to adjust the opening of the air inlet of the air adjusting channel; the burnout air duct is a flow equalizing barrel body with central symmetry. The over-fire air device can ensure good penetration and covering of over-fire air under the condition of less over-fire air consumption, ensure full and timely burning of unburned carbon granules and CO at the upper part of the hearth, reduce inclined partial burning of the boiler, and avoid the occurrence of thermal corrosion and the like due to local overheating in the boiler.

Description

A boiler exhaust air device

technical field

The invention relates to the technical field of pulverized coal boiler combustion, in particular to an exhaust air device.

Background technique

In the context of increasingly strict national environmental protection policies, environmental protection emission standards have been gradually raised. In order to reduce the emission of nitrogen oxides in NOx coal-fired power plants, the combustion boiler generally adopts the staged combustion method. Axial Air Staged Combustion (OFA) technology is the most effective staged combustion technology, and the overburning air device is one of the most important equipment of this technology.

At present, most of the current burnout air devices adopt the structure of coupling the internal central direct current air and the external swirl wind. A single direct current central air cannot cover the width direction of the boiler, and the coupled flow of the external swirling air and the central direct current air allows the penetration of the burnout air. Not enough power. It is common to have a large amount of burnout air, insufficient penetration in the depth direction of the boiler furnace and insufficient coverage in the width of the furnace hearth, which is easy to cause delayed combustion of unburned carbon particles and CO, resulting in fly ash in the boiler flue gas, high CO, and boiler efficiency. decline, etc. The existing over-burning air device mostly adopts a hinge transmission mechanism, and the over-burning air device is easy to get stuck and difficult to adjust.

There are also related technologies that use double-layer burn-out air nozzles on the burn-out air device to meet the needs of penetration, coverage and air grading combustion, but the existence of the double-layer burn-out air reduces the opening area of the burn-up air, resulting in boiler combustion. Further oxygen-deficient combustion in the boiler area will cause problems such as high temperature corrosion of the boiler, which will bring great economic problems and safety hazards to the operation of the boiler.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides an over-burning air device with an oval nozzle, which can ensure good penetration and coverage of the over-burning air under the condition of less amount of over-burning air, and ensure the upper part of the furnace. The unburned carbon particles and CO are fully and timely burned out.

According to one aspect of the present invention, there is provided an over-burn air device for a boiler, comprising: an over-burn air nozzle and an air regulator connected with the burner nozzle; the air regulator includes a support plate and an over-burn air sleeve, the over-burn air is The sleeve is connected with the support plate to form an air-adjusting channel, and the burner nozzle is communicated with the air-adjusting channel; the burn-out air sleeve includes a burn-out air duct set on the support plate and a sleeve baffle set on the burn-out air duct , the air inlet of the air regulation channel is formed between the sleeve baffle and the support plate, and the sleeve baffle can slide relative to the burnout air duct in the axial direction to adjust the opening of the air inlet of the air regulation channel; The cylinder is a center-symmetrical flow equalizing cylinder, and the upper ring of the cylinder body of the burn-out air cylinder is provided with an equalizing hole.

Optionally, the opening rate of the burn-out air duct is 40-60%, and the diameter of the equalizing hole is 10-20 mm.

Optionally, the air regulator further includes a roller skating guide rail arranged along the axial direction of the sleeve baffle plate, the roller skating guide rail is equipped with a roller skating structure, and the sleeve baffle plate and the roller skating structure are connected by sliding in the roller skating guide rail through the roller skating structure to adjust the intake. The opening of the vent.

Optionally, a flow guide structure is provided in the air regulating channel, the flow guide structure is arranged on the support plate and extends toward the burnout air nozzle, and the diameter of the flow guide structure is tapered along the extending direction.

Optionally, the flow guide structure includes a support cone arranged on the support plate and a conical flow guide part arranged on the support cone; the conical flow guide part and the support cone form a predetermined angle.

Optionally, the nozzle of the burnout air nozzle is an elliptical nozzle, and the long axis of the elliptical nozzle is 1.5 to 3 times the short axis.

Optionally, it further includes a swinging device, the swinging device includes a rectangular frame body, a transmission assembly connected with the rectangular frame body, and a swing pull rod connected with the transmission assembly; the rectangular frame body is arranged in the burnout nozzle, and the swing pull rod can drive the rectangular frame. The body swings in the exhaust air nozzle to adjust the outlet angle of the exhaust air ejected from the rectangular frame.

Optionally, the rectangular frame body is provided with a cross support plate, and the center intersection of the cross support plate is located at the center of the rectangular frame body.

Optionally, the center intersection of the cross support plate is arranged at the intersection of the long axis and the short axis of the elliptical nozzle of the burn-out air nozzle, and the rectangular frame body is supported by the transverse support plate of the cross support plate when the swing pull rod drives the rectangular frame body to swing. For the shaft to swing back and forth within a predetermined angular displacement range.

Optionally, the initial position of the rectangular frame body is perpendicular to the axial direction of the exhaust air device, and the predetermined angular displacement of the reciprocating swing of the rectangular frame body is 10-20°.

The burn-out air device of the invention can ensure the good penetration and coverage of the burn-out air under the condition of less burn-out air consumption, ensure that the unburned carbon particles and CO in the upper part of the furnace are fully and timely burned out, and reduce the occurrence of boilers. Slanted and slanted burning to avoid local overheating and thermal corrosion in the boiler.

The nozzle of the burn-out air nozzle of the burn-out air device of the present invention is a flat ellipse, and the burn-out air diffuses and covers the furnace chamber along both sides of the long axis of the ellipse when the burn-out air is sprayed; The burn-out wind is gathered into the center to accelerate the airflow near the diversion structure, and the burn-up wind can penetrate the depth of the furnace longitudinally when sprayed into the furnace, taking into account the incident depth of the burn-up wind and the lateral diffusion effect.

The over-burning air device of the present invention can be equipped with an over-burning air swing device that can be adjusted up and down in the elliptical nozzle, and the axial staging combustion distance between the over-burning air and the burner can be adjusted by swinging up and down, so as to meet the requirements of low NOx and staged combustion. The system needs flexible adjustment to the overburning air.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 is the structural representation of the boiler burnout air device of the present application;

Fig. 2 is the installation structure schematic diagram of the boiler burnout air device of the present application and the boiler hearth;

3 is a schematic structural diagram of a flow guide structure in a specific embodiment;

FIG. 4 is a schematic structural diagram of the exhaust air nozzle and the swing device in the specific embodiment.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. It should be noted that the embodiments in this application and the feature vectors in the embodiments may be arbitrarily combined with each other unless there is a conflict.

At present, most of the current burnout air devices adopt the structure of coupling the internal central direct current air and the external swirl wind. A single direct current central air cannot cover the width direction of the boiler, and the coupled flow of the external swirling air and the central direct current air allows the penetration of the burnout air. Not enough power. It is common to have a large amount of burnout air, insufficient penetration in the depth direction of the boiler furnace and insufficient coverage in the width of the furnace hearth, which is easy to cause delayed combustion of unburned carbon particles and CO, resulting in fly ash in the boiler flue gas, high CO, and boiler efficiency. decline, etc. The existing over-burning air device mostly adopts a hinge transmission mechanism, and the over-burning air device is easy to get stuck and difficult to adjust.

There are also related technologies that use double-layer burn-out air nozzles on the burn-out air device to meet the needs of penetration, coverage and air grading combustion, but the existence of the double-layer burn-out air reduces the opening area of the burn-up air, resulting in boiler combustion. Further oxygen-deficient combustion in the boiler area will cause problems such as high temperature corrosion of the boiler, which will bring great economic problems and safety hazards to the operation of the boiler.

To this end, the present application provides a boiler burnout air device, a boiler burnout air device, comprising an air regulator 30, a support plate 31 and a burnout air sleeve, and the burnout air sleeve is connected with the support plate 31 to form a The air regulating channel 001, the burner nozzle 10 is communicated with the air regulating channel 001; the burnout air sleeve includes the burnout air duct 32 arranged on the support plate 31 and the sleeve baffle 33 sleeved on the burnout air duct 32 , the air inlet of the air regulating channel 001 is formed between the sleeve baffle 33 and the support plate 31, and the sleeve baffle 33 can slide relative to the burnout air duct 32 in the axial direction to adjust the air inlet of the air regulating channel 001 The opening degree; the burn-out air duct 32 is a center-symmetrical flow equalizing cylinder, and the upper ring of the burn-out air duct 32 is provided with an equalizing hole. The burn-out air device of the present application is arranged in the burn-out bellows of the boiler, and the gas in the burn-out bellows passes through the air inlet and then flows into the air-adjusting channel 001 through the burn-out air duct 32 to prevent the burn-out wind from being sprayed into The uneven air distribution in the furnace will cause the boiler to be skewed and burnt, and avoid local overheating and thermal corrosion in the boiler.

As shown in FIG. 1 , the boiler burnout air device of the present application includes an air regulator 30, a support plate 31 and a burnout air sleeve. The burnout air sleeve is connected with the support plate 31 to form an air adjustment channel 001, and the burner nozzle 10 communicates with the air regulating channel 001; the burn-out air sleeve includes the burn-out air duct 32 set on the support plate 31 and the sleeve baffle 33 set on the burn-out air duct 32, and the sleeve baffle 33 is connected to the support plate 31. The air inlet of the air regulating channel 001 is formed between the plates 31, and the sleeve baffle 33 can slide relative to the burn-out air duct 32 in the axial direction to adjust the opening of the air inlet of the air-conditioning channel 001; the burn-out air duct 32 It is a center-symmetrical flow equalizing cylinder, and the upper ring of the cylinder body of the burn-out air cylinder 32 is provided with an equalizing hole.

As an example, the opening ratio of the burn-out air duct 32 is 40-60%, and the diameter of the equalizing hole is 10-20 mm. For example, the opening ratio of the burnout air duct 32 may be 45%, 50%, 55% or 58%, and the diameter of the equalizing holes may be 12mm, 14mm, 16mm, 17mm or 19mm.

As an example, the air regulator 30 of the present application further includes a roller skating guide 34 arranged along the axial direction of the sleeve baffle 33 , the roller skating guide 34 is equipped with a roller skating structure 35 , and the sleeve baffle 33 is connected with the roller skating structure 35 . The opening of the air inlet of the air regulating passage 001 is adjusted by sliding the roller sliding structure 35 in the roller sliding guide rail 34 . The boiler burnout air device of the present application is provided with a roller skating guide 34 and a roller skating structure 35, and the sleeve baffle 33 can slide in the roller skating guide 34, and can flexibly adjust the amount of burnt air entering the air regulating passage 001. The sleeve baffle 33 It slides flexibly in the roller guide rail 34, and will not jam even if it is in the high ash environment in the boiler for a long time.

Based on the above example, in a feasible implementation manner, as shown in FIG. 2 , the over-burning air device of the boiler of the present application further includes a bracket 60 , and the support plate 31 and the burner nozzle 10 of the over-burning air device of the present application are fixedly arranged on bracket 60 .

Based on the above example, in a feasible implementation, as shown in FIGS. 1 and 2 , the sleeve baffle 33 is connected to the sleeve pull rod 36 , and the sleeve pull rod 36 can push the sleeve baffle 33 to slide on the wheel guide rail 34 to Adjust the opening of the air inlet of the air conditioning channel 001 and then adjust the burnout air volume entering the air conditioning channel 001 . The burnout air device of the present application is placed in the burnout air box of the boiler, and the sleeve pull rod 36 can be extended out of the boiler through the connection of the sleeve pull rod 36 with the sleeve baffle plate 33, which is convenient for operation. As shown in FIG. 2 , as an embodiment of the present application, an operation panel 70 is provided outside the boiler for the overburning air device of the boiler of the present application. The sleeve tie rod 36 extends out of the boiler and extends out of the operation panel 70 to form an operation handle. During the application process of the burn-up air device of the application, the burn-up air volume entering the air regulating channel 001 can be adjusted through the sleeve pull rod 36 .

As an example, as shown in FIG. 1 , the air regulating channel 001 is provided with a diversion structure 40 , the diversion structure 40 is disposed on the support plate 31 and extends toward the burnout air nozzle 10 , and the diameter of the diversion structure 40 is along the The extension direction tapers. When the exhaust air entering the air regulating passage 001 in the annular direction flows in a predetermined direction, it is guided by the diversion structure 40 and turns to flow in the direction of the exhaust air nozzle 10 . squirting. In the boiler over-burning air device of the present application, the guide structure 40 is arranged in the air regulating channel 001 to guide the over-burning air to be ejected to the over-burning air nozzle 10 and accelerate the over-burning air, so as to improve the over-burning air ejected by the over-burning air device. The penetration force of the wind in the depth direction of the boiler furnace ensures that the unburned carbon particles and CO in the upper part of the furnace are fully and timely burned out. Specifically, a plurality of flow guide devices 40 may be arranged on the support plate 31 , for example, 2-4 flow guide structures 40 may be evenly arranged on the support plate 31 .

Based on the above-mentioned exemplary embodiment, in a feasible implementation manner, the flow guide structure 40 may be a center-symmetric tapered flow guide structure. For example, the flow guiding structure 40 may be a tapered conical flow guiding structure or a tapered conical flow guiding structure.

Based on the above-mentioned exemplary embodiment, in another feasible implementation manner, in another exemplary embodiment of the present disclosure, the flow guiding structure 40 may be a step-tapered flow guiding structure. As an embodiment of the present application, as shown in FIG. 3 , the flow guide structure 40 includes a support cone 41 arranged on the support plate 31 and a conical flow guide portion 42 arranged on the support cone 41 ; the tapered flow guide portion 42 It forms a predetermined angle with the supporting circular platform 41 . The burnt-out wind entering into the air-adjusting channel 001 in the circumferential direction flows to the side wall of the round table supporting the round table 41 in a predetermined direction. The included angle between the flow portion 42 and the support truncated truncated 41 is folded twice along the flow direction of the tapered flow guide portion 42 , and the exhausted air after the secondary turn flows forward along the tapered flow guide portion 42 in the conical shape. The extended ends of the guide portion 42 are collected to form a central accelerated air flow, and the central accelerated air flow is ejected from the exhaust air nozzle 10 .

Based on the above exemplary embodiment, in a feasible implementation manner, the air guide structure 40 further includes a central through hole arranged along the extending direction, and the air guide structure 40 is disposed on the support plate 31 and between the support plate 31 to form an air inlet gap , part of the exhausted air entering the air regulating channel 001 flows into the central through hole of the diversion structure 40 through the air inlet gap, and the rest of the exhausted air is collected at the extension end of the diversion structure 40, which can further accelerate the exhausted air and improve the The penetrating power of the burn-up air ejected by the burn-up air device in the depth direction of the boiler furnace.

As an example, as shown in FIG. 4 , the burnout air nozzles of the burnout air nozzle 10 are flat elliptical nozzles, and the long axis of the burnout air nozzles is 1.5 to 3 times the short axis. When the center accelerated air flow is ejected from the burnout air nozzle 10 , it spreads to both sides along the long axis direction of the ellipse. While the burn-out air flow penetrates at high speed in the center, it can spread along the width direction of the boiler to improve the coverage of the burn-up air in the width direction of the furnace.

The specific shape of the nozzle of the burn-up air nozzle 10 can be set according to the boiler's demand for the burn-off air.

As an example, as shown in FIGS. 1 and 4 , the overburning air device of the present application further includes a swing device 20 , and the swing device 20 includes a rectangular frame body 21 , a transmission assembly 25 connected to the rectangular frame body 21 , and a transmission assembly 25 . The connected swing pull rod 26, the rectangular frame body 21 is arranged in the burnout air nozzle 10, and the swing pull rod 26 can drive the rectangular frame body 21 to swing in the burnout air nozzle 10 to adjust the amount of the burnout air ejected from the rectangular frame body 21. The air outlet angle then adjusts the axial staging combustion distance between the burnout air of the boiler and the burner, so as to meet the flexible adjustment needs of the low NOx and staged combustion system for the burnout air.

Based on the above example, in a feasible implementation manner, as shown in FIG. 4 , the length of the rectangular frame body 21 is one-half to two-thirds of the long axis of the elliptical nozzle of the burner nozzle 10 , and the rectangular frame body The width of 21 is one-half to two-thirds of the short axis of the elliptical nozzle of the burner nozzle 10 .

Based on the above-mentioned exemplary embodiment, in a feasible implementation, as shown in FIG. 1 and FIG. 3 , the rectangular frame body 21 is provided with a cross support plate 22 , and the center intersection of the cross support plate 22 is located at the center of the rectangular frame body 21 . Right in the center.

Based on the above-mentioned exemplary embodiment, in a feasible implementation, as shown in FIG. 4 , the rectangular frame body 21 is arranged in the burn-out air nozzle 10 , and the central intersection of the cross support plate 22 is arranged at the end of the burn-out air nozzle 10 . At the intersection of the long axis and the short axis, when the swing rod 26 drives the rectangular frame body 21 to swing in the exhaust air nozzle 10, the rectangular frame body 21 reciprocates within a predetermined angular displacement range with the lateral support plate 221 of the cross support plate 22 as the axis swing.

As an embodiment of the present application, the initial position of the rectangular frame body 21 is perpendicular to the axial direction of the overburning air device, and the predetermined angular displacement of the reciprocating swing of the rectangular frame body 21 is 10-20°. When the rectangular frame body 21 rotates forward relative to the nozzle of the burner nozzle 10, the over-burning air ejected from the rectangular frame body 21 is injected downward at a predetermined angle, reducing the axial staged combustion between the over-burning air and the burner. distance; when the rectangular frame body 21 rotates backward relative to the nozzle of the burner nozzle 10, the over-burning air ejected from the rectangular frame body 21 is sprayed upward at a predetermined angle, increasing the axial grading between the exhaust air and the burner Combustion distance; flexibly meet the adjustment needs of low NOx and staged combustion systems for overburning air.

Based on the above-mentioned exemplary embodiment, in a feasible implementation manner, as shown in FIGS. 1 and 2 , the transmission assembly 25 includes a first transmission rod 251 connected with the swing pull rod 26 and a first transmission rod 251 connected with the first transmission rod 251 through a rotating shaft 255 . The second transmission rod 252 is connected to the lateral support plate 221 of the rectangular frame 21, and the swinging rod 26 can drive the first transmission rod 251 to reciprocate with the rotation shaft 255 as the axis, thereby driving the second transmission rod 252 to The rotating shaft 255 is a shaft for reciprocating motion, and the reciprocating motion of the second transmission rod 252 drives the rectangular frame body 21 to swing back and forth in the exhaust air nozzle 10 .

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements, but also no Other elements expressly listed, or those inherent to the article or equipment are also included. Without further limitation, an element defined by the phrase "comprising" does not preclude the presence of additional identical elements in the article or device comprising said element.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them, and the present invention is only described in detail with reference to the preferred embodiments. It should be understood by those of ordinary skill in the art that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims (10)

1. A boiler burn-out air device, characterized in that it comprises: a burn-out air nozzle (10) and an air regulator (30) connected with the burner nozzle (10); The air regulator (30) includes a support plate (31) and an over-burning air sleeve, the over-burning air sleeve is connected with the support plate (31) to form an air-adjusting channel (001), and the burner nozzle is (10) communicated with the air regulating channel (001); the burnout air sleeve includes a burnout air duct (32) arranged on the support plate (31) and a burnout air duct (32) sleeved on the burnout air duct (32) the sleeve baffle (33), the air inlet of the air regulating channel (001) is formed between the sleeve baffle (33) and the support plate (31), the sleeve baffle The plate (33) is slidable relative to the burnout air duct (32) in the axial direction to adjust the opening of the air inlet of the air regulating passage (001); the burnout air duct (32) is the center A symmetrical flow-equalizing cylinder is provided with flow-equalizing holes in the upper ring of the cylinder body of the burn-out air cylinder (32). 2 . The boiler burnout air device according to claim 1 , characterized in that the opening ratio of the burnout air duct ( 32 ) is 40-60%, and the diameter of the flow equalizing hole is 10-20 mm. 3 . 3. The boiler overburning air device according to claim 2, characterized in that, the register (30) further comprises a wheel guide rail (34) arranged along the axial direction of the sleeve baffle plate (33) , the roller skating guide rail (34) is equipped with a roller skating structure (35), and the sleeve baffle plate (33) is connected with the roller skating structure (35) through the roller skating structure (35) on the roller skating guide rail (34). ) to adjust the opening of the air inlet. 4. The boiler overburning air device according to claim 1, characterized in that, a flow guiding structure (40) is provided in the air regulating channel (001), and the flow guiding structure (40) is arranged on the support The plate (31) extends in the direction of the exhaust air nozzle (10), and the diameter of the flow guiding structure (40) is tapered along the extending direction. 5. The boiler overburning air device according to claim 4, characterized in that, the flow guiding structure (40) comprises a support circular platform (41) arranged on the support plate (31) and a support disc (41) arranged on the support plate (31) A conical guide portion (42) on the circular truncated truncated (41); the conical guide portion (42) and the support truncated truncated (41) form a predetermined angle. 6. The boiler burnout air device according to claim 1, characterized in that the nozzle of the burnout air nozzle (10) is an elliptical nozzle, and the long axis of the elliptical nozzle is 1.5-3 mm of the short axis. times. 7. The boiler overburning air device according to claim 6, characterized in that it further comprises a swinging device (20), and the swinging device (20) comprises a rectangular frame body (21), and the rectangular frame body (21) ) connected to the transmission assembly (25) and the swing rod (26) connected to the transmission assembly (25); the rectangular frame (21) is arranged in the burn-out air nozzle (10), the swing rod (26) (26) The rectangular frame body (21) can be driven to swing in the burnout air nozzle (10) to adjust the outlet angle of the burnout air jetted from the rectangular frame body (21). 8 . The boiler overburning air device according to claim 7 , wherein a cross support plate ( 22 ) is arranged in the rectangular frame body ( 21 ), and the center intersection of the cross support plate ( 22 ) is located at the center of the cross support plate ( 22 ). 9 . The center of the rectangular frame (21). 9. The boiler burnout air device according to claim 8, characterized in that, the central intersection of the cross support plate (22) is arranged at the length of the elliptical nozzle of the burnout air nozzle (10). The intersection point of the axis and the short axis, when the swing rod (26) drives the rectangular frame body (21) to swing, the rectangular frame body (21) is supported by the transverse support plate (221) of the cross support plate (22). For the shaft to swing back and forth within a predetermined angular displacement range. 10. The boiler overburning air device according to claim 9, wherein the initial position of the rectangular frame body (21) is perpendicular to the axial direction of the overburning air device, and the rectangular frame body (21) is perpendicular to the axial direction of the overburning air device. The predetermined angular displacement of the reciprocating swing in 21) is 10 to 20°.

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