CN211011344U - Cylinder type pulverized coal burner - Google Patents

Abstract

The utility model discloses a cylinder pulverized coal burner belongs to the technical field of combustion equipment, including central tuber pipe, once tuber pipe, transition tuber pipe and the secondary tuber pipe that the cover was established in proper order from interior to exterior, be provided with the light oil ignition sleeve pipe in the central tuber pipe, form a wind channel between once tuber pipe and the transition tuber pipe, the wind channel of once in the wind channel is used for carrying the buggy, forms the transition wind channel between transition tuber pipe and the once tuber pipe, forms the secondary wind channel between secondary tuber pipe and the transition tuber pipe, is provided with axial swirler in the secondary wind channel; still include combustor main part and cubic tuber pipe, the combustor main part is including burning a section of thick bamboo and frustum shape barrel in the precombustion, and frustum shape barrel sets up in the precombustion section of thick bamboo, and the path end of frustum shape barrel is connected in the secondary tuber pipe, forms root wind channel between frustum shape barrel and the precombustion section of thick bamboo, and the cubic tuber pipe communicates in the precombustion section of thick bamboo. The combustion of the pulverized coal is always in a weak reducing atmosphere, the generation of fuel type NOx is reduced, and the generation amount of the NOx is reduced.

Description

Cylinder type pulverized coal burner

Technical Field

The utility model relates to a combustion apparatus technical field especially relates to a cylinder pulverized coal burner.

Background

The pulverized coal burner is a core component of a pulverized coal industrial boiler system, and mainly has the function of promoting the combustion of pulverized coal in a hearth through the reasonable proportion of air and pulverized coal, so that the clean and efficient utilization of the pulverized coal is realized. The nitrogen oxides generated in the combustion process of the pulverized coal are divided into a thermal type, a rapid type and a fuel type; the fuel type NOx refers to NOx generated by a series of oxidation-reduction reactions of nitrogen in coal dust in a combustion process, is a main source of NOx in the coal dust combustion process, and accounts for about 80% -90% of the total NOx emission, so that the key for reducing the NOx emission is to reduce the emission of the fuel type NOx.

In the prior art, the German Babcock introduced a low NOx pulverized coal burner with staged air supply-DS burner-in which central air was fed in a swirling manner through a central air pipe located on the central axis of the burner, primary air was introduced in a swirling manner through an annular passage installed between the central air pipe and an inner secondary air pipe, secondary air was divided into two streams of inner secondary air and outer secondary air, and fuel stream was ejected outward through an expansion nozzle, the burner produced a certain oxygen-deficient space and reduced flame temperature by supplying oxygen to a flame with sufficient fuel, achieving the purpose of reducing the amount of NOx generated, Steinm ü and Steinm ü, which are also divided into three streams of primary air, lean air and straight air, respectively, in which VABCO burner was introduced into a primary air pipe with staged air supply, and a Steinm burner was introduced in a swirling manner through a primary air pipe located on the central axis of the burner

Due to the limit of the structure, the various graded air supply pulverized coal burners are used in large pulverized coal boilers, and primary air and secondary air used in the pulverized coal burners are hot air preheated to a certain degree. In other words, if the staged air supply pulverized coal burner is used in a medium-sized and small-sized pulverized coal boiler in which primary air does not have a preheating condition, secondary air has a low preheating temperature, or is not preheated, problems such as difficult ignition, unstable flame, and the like occur, and thus the conventional staged air supply pulverized coal burner is not suitable for the medium-sized and small-sized pulverized coal boiler.

Therefore, there is a need for a tubular pulverized coal burner suitable for small and medium sized boilers to reduce the amount of NOx emissions.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a cylinder pulverized coal burner to realize reducing NOx's emission more effectively.

As the conception, the utility model adopts the technical proposal that:

a cylinder type pulverized coal burner comprises a central air pipe, a primary air pipe, a transition air pipe and a secondary air pipe which are sequentially sleeved from inside to outside, wherein a light oil ignition sleeve is arranged in the central air pipe, a primary air channel is formed between the primary air pipe and the transition air pipe, primary air in the primary air channel is used for carrying pulverized coal, a transition air channel is formed between the transition air pipe and the primary air pipe, a secondary air channel is formed between the secondary air pipe and the transition air pipe, and an axial swirler is arranged in the secondary air channel; still include combustor main part and cubic tuber pipe, the combustor main part is including precombustion section of thick bamboo and frustum shape barrel, frustum shape barrel set up in the precombustion section of thick bamboo, the path end of frustum shape barrel connect in the secondary tuber pipe, frustum shape barrel with form root wind channel between the precombustion section of thick bamboo, the cubic tuber pipe communicate in precombustion section of thick bamboo.

Furthermore, the central air pipe, the primary air pipe, the transition air pipe and the secondary air pipe are coaxial, and the end faces of the central air pipe, the primary air pipe, the transition air pipe and the secondary air pipe, which are communicated with one end of the frustum-shaped cylinder, are flush with each other.

Further, the swirl angle of the secondary air in the secondary air duct is 25-35 degrees.

Further, the frustum-shaped cylinder body is of a frustum-shaped structure, and the cone angle of the frustum-shaped structure is 40-50 degrees.

Further, an included angle between the axial direction of the air outlet of the tertiary air pipe and the axial direction of the pre-combustion cylinder is 15-30 degrees.

Further, in the axial direction of the pre-combustion cylinder, the distance between the outlet of the tertiary air pipe and the secondary air pipe is greater than the distance between the large-diameter end of the frustum-shaped cylinder and the secondary air pipe.

Further, the tertiary air pipe is provided with a plurality of, a plurality of the tuber pipe encircles the circumference interval setting of precombustion section of thick bamboo.

Further, the cylinder pulverized coal burner still includes transition bellows, transition bellows connect in the transition wind channel, be provided with the transition air door on the transition bellows.

Further, the cylinder pulverized coal burner still includes the secondary bellows, the secondary bellows connect in the secondary wind channel, be provided with the secondary air door on the secondary bellows.

Further, the pre-burning barrel comprises an inner barrel and an outer barrel, and the tertiary air pipe is arranged between the inner barrel and the outer barrel.

The utility model has the advantages that:

the utility model provides a cylinder pulverized coal burner carries frustum shape barrel and precombustion section of thick bamboo in through the total amount of wind that needs pulverized coal burning respectively through a wind channel, transition wind channel, secondary wind channel, root wind channel and cubic wind channel, and a wind channel carries the buggy and gets into, can make the burning of buggy be in all the time under weak reducing atmosphere, reduces fuel type NOx's formation to reduce the formation volume of NOx among the pulverized coal combustion process.

Drawings

Fig. 1 is a sectional view of a can-type pulverized coal burner provided by the present invention.

In the figure:

1. a central air duct; 11. a light oil ignition sleeve; 2. a primary air duct; 31. a transition air box; 311. a transition damper; 32. a transition air duct; 41. a secondary air box; 411. a secondary air door; 42. a secondary air duct; 5. a root bellows; 6. a frustum-shaped cylinder; 7. a pre-combustion cylinder; 71. an outer cylinder; 72. an inner barrel; 81. a tertiary air box; 82. a tertiary air pipe; 821. a first air duct; 822. a second air duct;

20. a primary air duct; 30. a transition air duct; 40. a secondary air duct; 401. an axial swirler; 50. root wind channel.

Detailed Description

In order to make the technical problem solved by the present invention, the technical solution adopted by the present invention and the technical effect achieved by the present invention clearer, the technical solution of the present invention will be further explained by combining the drawings and by means of the specific implementation manner. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements related to the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The embodiment provides a cylinder type pulverized coal burner which is mainly suitable for small and medium-sized industrial boilers.

As shown in fig. 1, the cylindrical pulverized coal burner provided in this embodiment includes a central air duct 1, a primary air duct 2, a transition air duct 32, a secondary air duct 42, and a burner main body, which are sequentially sleeved from inside to outside. Wherein, the combustor main part includes frustum shape barrel 6 and precombustion section of thick bamboo 7, and frustum shape barrel 6 is located precombustion section of thick bamboo 7, and the path end of frustum shape barrel 6 is connected in secondary air pipe 42, has the annular clearance between the inner wall of the big footpath end of frustum shape barrel 6 and precombustion section of thick bamboo 7.

The central air pipe 1 is internally provided with a light oil ignition sleeve 11, and the central air pipe 1 is internally communicated with a preset amount of compressed air for providing oxygen at the initial ignition stage of the cylindrical pulverized coal burner. A primary air duct 20 is formed between the primary air pipe 2 and the central air pipe 1 and is used for introducing primary air into the burner main body, in the embodiment, the air volume of the primary air is low, and specifically, the air volume of the primary air is less than or equal to 10% of the total air volume conveyed by the tubular pulverized coal burner. The primary air carries pulverized coal, and the pulverized coal is rapidly ignited and combusted under the action of the high-temperature inner walls of the frustum-shaped cylinder 6 and the pre-combustion cylinder 7 and the high-temperature flue gas (due to the action of the airflow, part of the high-temperature flue gas reflows in the pre-combustion cylinder 7) after entering the combustor main body. In addition, the pulverized coal is conveyed by adopting a concentrated phase, specifically, in the embodiment, the solid-gas ratio is more than 2kgc/kga, so that the pulverized coal can be stably combusted under low load, and the generation amount of NOx is reduced.

A secondary air duct 40 is formed between the secondary air duct 42 and the transition air duct 32, the secondary air duct 40 is used for introducing secondary air into the burner main body, an axial swirler 401 is arranged in the secondary air duct 40, the secondary air generated by the axial swirler 401 is weak swirl air, and the swirl angle is 25-35 degrees. The overfire air enters the burner main body, can entrain the high-temperature flue gas far away from one end of the overfire air pipe 42 of the precombustion cylinder 7, so that a high-temperature flue gas reflux area is formed at the center of the burner main body, and the pulverized coal entering the burner main body can be rapidly ignited and combusted. Preferably, in the present embodiment, the axial swirler 401 is an axial swirler vane.

A transition air duct 30 is formed between the transition air duct 32 and the primary air duct 2, the transition air duct 30 is used for introducing transition air into the burner main body, the transition air is high-speed direct current air or weak rotational flow air, and the weak rotational flow air is realized by arranging rotational flow blades in the transition air duct 30. The ignition point of the pulverized coal can be controlled by controlling the wind speed of the transition wind, and particularly, as described above, a high-temperature flue gas backflow area is arranged in the burner body, so that the pulverized coal can be ignited when being in contact with the high-temperature flue gas. By adjusting the wind speed of the transition wind, for example, when the wind speed of the transition wind is small, the diffusion speed of the pulverized coal carried by the primary wind into the frustum-shaped cylinder 6 is high, the distribution range of the pulverized coal is large, and the ignition point is low; when the wind speed of the transition wind is high, the diffusion speed of the coal dust carried by the primary wind and entering the frustum-shaped cylinder 6 is relatively low under the action of the transition wind, the distribution range of the coal dust is relatively small, and the ignition point is high at the moment. In addition, the fast diffusion of the coal dust is avoided by adjusting the wind speed of the transition wind, the coking of ash and slag formed after the coal dust is combusted on the inner wall of the frustum-shaped cylinder 6 can be avoided, the service life of the frustum-shaped cylinder 6 is prolonged, and the long-time operation of the cylinder type coal dust burner is ensured.

The cylinder pulverized coal burner that this embodiment provided still includes transition bellows 31 and secondary bellows 41, transition bellows 31 is connected in transition wind channel 30, be used for to carry transition wind in the transition wind channel 30, secondary bellows 41 is connected in secondary wind channel 40, be used for to carry the overgrate air in the secondary wind channel 40, be provided with transition air door 311 on the transition bellows 31, be provided with overgrate air door 411 on the secondary bellows 41, can adjust transition wind and overgrate air respectively through the aperture of adjusting transition air door 311 and overgrate air door 411 and account for the proportion of total amount of wind, thereby make the burning of buggy be in reducing atmosphere all the time, reduce the formation of fuel type NOx, thereby reduce the formation volume of NOx. And the wind speed of the transition wind can be adjusted through the transition wind door 311 so as to avoid coking on the inner wall of the frustum-shaped cylinder 6. Further, the transition windbox 31 and the secondary windbox 41 are both common windboxes in the prior art and will not be described in detail herein.

The cylinder pulverized coal burner that this embodiment provided still includes root bellows 5, and root bellows 5 is connected in the root wind channel 50 that forms between frustum shape barrel 6 and the precombustion section of thick bamboo 7, and root bellows 5 is used for letting in root wind to root wind in the root wind channel 50, and root wind spouts through the annular gap between frustum shape barrel 6 and the precombustion section of thick bamboo 7, and in this embodiment, root wind is the direct current wind, and the wind speed of direct current wind is 30-40m/s, mainly plays the effect that the cooling sweeps. Specifically, ash residues in a high-temperature liquid state formed after pulverized coal combustion are diffused towards the inner wall of the pre-combustion cylinder 7 and adhered to the inner wall of the pre-combustion cylinder 7, so that the inner wall of the pre-combustion cylinder 7 is coked, and the high-temperature liquid ash residues generated after pulverized coal combustion can be cooled through root wind, so that coking caused by the adhesion of the high-temperature liquid ash residues to the inner wall of the pre-combustion cylinder 7 is avoided. In addition, the introduction of the root air can convey a certain amount of air into the pre-combustion cylinder 7, which is beneficial to the continuous combustion of the pulverized coal and improves the combustion efficiency of the pulverized coal. Furthermore, the root bellows 5 is a bellows common in the prior art and will not be described in detail herein.

As shown in fig. 1, the pre-combustion cylinder 7 includes an inner cylinder 72 and an outer cylinder 71, the frustum-shaped cylinder 6 is located in the inner cylinder 72, specifically, one end of the inner cylinder 72 is closed, the other end of the inner cylinder 72 has an opening, the closed end of the inner cylinder 72 is provided with a through hole, a small-diameter end of the frustum-shaped cylinder 6 is communicated with the through hole, the pre-combustion cylinder 7 adopts the structure of the inner cylinder 72 and the outer cylinder 71, which can improve the heat preservation effect, avoid excessive loss of temperature in the pre-combustion cylinder 7, and facilitate ignition and sufficient combustion of pulverized coal, the triple air pipes 82 are provided between the outer cylinder 71 and the inner cylinder 72, a triple air duct is formed inside the triple air pipes 82 for conveying tertiary air into the inner cylinder 72 of the pre-combustion cylinder 7, to promote sufficient combustion of pulverized coal, specifically, the triple air pipes 82 are provided with a plurality of triple air pipes 82, the triple air pipes 82 are uniformly arranged along the circumferential direction of the inner cylinder 72, the triple air pipes 82 include a first air pipe 821 and a second air pipe 822 communicated with each other air pipes, the second air pipe 822, the second air pipe is communicated with the second air pipe 7, in the embodiment, in which is communicated with the inner cylinder 7, in the second air pipe 822, in the embodiment, an acute angle β between the axial direction of the air pipe 822, the air pipe 822 which is 15 mm to 30 mm, the axial direction of the axial line of the air pipe 822, the axial line of the air pipe 822 which is not longer than the axial line of the axial line 72, the axial line of the axial line 72, the axial line of the axial line, the axial line of the axial line 72, the axial line of the axial line, the axial line of the axial line 7, the axial line 7, the axial line.

Above-mentioned central tuber pipe 1, the air hose 2 once, transition tuber pipe 32 and the coaxial setting of secondary tuber pipe 42, and central tuber pipe 1, the air hose 2 once, the terminal surface of the one end of transition tuber pipe 32 and secondary tuber pipe 42 intercommunication frustum shape barrel 6 flushes mutually, once wind channel 20, the air outlet in transition wind channel 30 and secondary wind channel 40 all is located the region that the path end of frustum shape barrel 6 encloses, make once wind, can not mutual interference before transition wind and overgrate air enter into frustum shape barrel 6, guarantee once wind, transition wind and overgrate air homoenergetic enough play self effect. In this embodiment, the frustum-shaped cylinder 6 is a frustum-shaped structure, and accordingly the central air pipe 1, the primary air pipe 2, the transition air pipe 32 and the secondary air pipe 42 are circular pipes, and the frustum-shaped structure does not have corners, so that the flow of pulverized coal and wind is facilitated, and coking at the corners can be avoided, thereby avoiding the influence on the service life of the frustum-shaped cylinder 6 due to the overhigh local temperature of the frustum-shaped cylinder 6. In addition, in the embodiment, the cone angle of the frustum-shaped cylinder 6 is 30 to 50 degrees, which is basically consistent with the swirl angle of the secondary air, and the outer reflux area is eliminated. In addition, in the present embodiment, the lengths of the central duct 1, the primary duct 2, the transition duct 32, and the secondary duct 42 are gradually reduced in the axial direction of the central duct 1, and this arrangement can reduce the use of materials and the weight of the can-type pulverized coal burner. Of course, in other embodiments, the lengths of the central air duct 1, the primary air duct 2, the transition air duct 32 and the secondary air duct 42 may be equal.

The frustum-shaped cylinder 6 and the pre-combustion cylinder 7 of the tubular pulverized coal burner provided by the embodiment are both formed by pouring refractory materials, have good heat preservation and heat insulation performance, can maintain the high-temperature state of the local area in the burner main body, promote ignition and combustion of pulverized coal, and ensure stable operation of the tubular pulverized coal burner under low load.

In summary, in the cylindrical pulverized coal burner provided in this embodiment, the total air volume required for pulverized coal combustion is respectively delivered into the frustum-shaped cylinder 6 and the pre-combustion cylinder 7 through the primary air duct 20, the transition air duct 30, the secondary air duct 40, the root air duct 50 and the tertiary air duct, and the primary air enters with pulverized coal, so that the pulverized coal combustion is always in a weak reducing atmosphere, the generation of fuel type NOx is reduced, and the generation amount of NOx in the pulverized coal combustion process is reduced. After secondary air enters the pre-combustion cylinder 7 through the axial rotational flow blades in the secondary air duct 40, high-temperature flue gas at one end of the pre-combustion cylinder 7, which is far away from the secondary air duct 42, can be sucked, so that a high-temperature flue gas reflux area is formed at the center of the pre-combustion cylinder 7, and ignition and combustion of pulverized coal are promoted; the diffusion speed of the pulverized coal can be adjusted by adjusting the wind speed of the transition wind, so that the ignition point of the pulverized coal is adjusted, the pulverized coal can be prevented from being diffused quickly, and coking on the inner wall of the frustum-shaped cylinder 6 is avoided. The ash slag formed by burning the pulverized coal can be cooled through the root wind, so that the ash slag is prevented from being attached to the inner wall of the inner cylinder 72 of the pre-burning cylinder 7 to cause coking.

The above embodiments have been described only the basic principles and features of the present invention, and the present invention is not limited by the above embodiments, and is not departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. The cylindrical pulverized coal burner is characterized by comprising a central air pipe (1), a primary air pipe (2), a transition air pipe (32) and a secondary air pipe (42) which are sequentially sleeved from inside to outside, wherein a light oil ignition sleeve (11) is arranged in the central air pipe (1), a primary air channel (20) is formed between the primary air pipe (2) and the transition air pipe (32), primary air in the primary air channel (20) is used for carrying pulverized coal, a transition air channel (30) is formed between the transition air pipe (32) and the primary air pipe (2), a secondary air channel (40) is formed between the secondary air pipe (42) and the transition air pipe (32), and an axial swirler (401) is arranged in the secondary air channel (40);

still include combustor main part and cubic tuber pipe (82), the combustor main part is including precombustion section of thick bamboo (7) and frustum shape barrel (6), frustum shape barrel (6) set up in precombustion section of thick bamboo (7), the path end of frustum shape barrel (6) connect in secondary tuber pipe (42), frustum shape barrel (6) with form root wind channel (50) between precombustion section of thick bamboo (7), cubic tuber pipe (82) communicate in precombustion section of thick bamboo (7).

2. The cylindrical pulverized coal burner as claimed in claim 1, characterized in that the central air pipe (1), the primary air pipe (2), the transition air pipe (32) and the secondary air pipe (42) are coaxial, and the end surfaces of the central air pipe (1), the primary air pipe (2), the transition air pipe (32) and the secondary air pipe (42) communicated with one end of the frustum-shaped cylinder (6) are flush with each other.

3. The can pulverized coal burner as set forth in claim 1, characterized in that the swirl angle of the secondary air in the secondary air duct (40) is 25 ° to 35 °.

4. The barrel pulverized coal burner as claimed in claim 3, characterized in that the frustum-shaped barrel (6) is of a frustum-conical configuration having a cone angle of 40 ° to 50 °.

5. The barrel pulverized coal burner as claimed in claim 1, characterized in that the angle between the axial direction of the outlet of the tertiary air duct (82) and the axial direction of the pre-combustion barrel (7) is 15 ° to 30 °.

6. The barrel pulverized coal burner as claimed in claim 5, characterized in that the distance between the outlet of the tertiary air duct (82) and the secondary air duct (42) in the axial direction of the pre-combustion barrel (7) is greater than the distance between the large-diameter end of the frustum-shaped cylinder (6) and the secondary air duct (42).

7. The can pulverized coal burner as claimed in claim 1, characterized in that the tertiary air duct (82) is provided in plurality, the tertiary air duct (82) being provided in plurality at intervals around the circumference of the precombustion can (7).

8. The pulverized coal barrel burner as claimed in claim 1, further comprising a transition wind box (31), wherein the transition wind box (31) is connected to the transition wind duct (30), and a transition damper (311) is provided on the transition wind box (31).

9. The can pulverized coal burner of claim 1, further comprising a secondary air box (41), the secondary air box (41) being connected to the secondary air duct (40), the secondary air box (41) being provided with a secondary damper (411).

10. The can pulverized coal burner as claimed in claim 1, characterized in that the precombustion can (7) comprises an inner can (72) and an outer can (71), the tertiary air duct (82) being provided between the inner can (72) and the outer can (71).

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