CN210153781U - Flame stable combustion ring and cyclone burner - Google Patents

Abstract

The utility model relates to the field of burners, in particular to a flame stable combustion ring and a cyclone burner, wherein the flame stable combustion ring comprises a flaring structure with a gradually-expanding central hole, and the distance from the outer wall of the flaring structure to the central axis of the gradually-expanding central hole along the airflow direction is gradually increased; the flaring structure comprises a plurality of flaring segments which are distributed circumferentially and form the gradually-expanding central hole, and the axial extension directions of the outer walls of at least two flaring segments are different from the included angle between the central axes of the gradually-expanding central hole. The utility model discloses can improve combustion efficiency and different coal types when the adaptability of high-quality coal and inferior coal, the low-load of reinforcing boiler surely fires the ability in the contact boundary that increases high temperature flue gas and wind powder air current. The utility model also provides a cyclone burner, including foretell flame surely fires the ring, can improve combustion efficiency, reduce nitrogen oxide's content.

Description

Flame stable combustion ring and cyclone burner

Technical Field

The utility model relates to a combustor field especially relates to a flame surely fires ring and cyclone burner.

Background

At present, the cyclone burner is widely applied to a large coal-fired power station boiler unit. The nozzles of the cyclone burner are usually arranged on the front wall and the rear wall of the boiler, the working environment is very severe, and the cyclone burner is always subjected to the heat radiation of high-temperature flue gas and the long-term scouring of high-speed pulverized coal airflow during the operation. And because the influence of factors such as large coal quality fluctuation, large circumferential deviation of primary air wind speed and pulverized coal concentration and the like, the circumferential heating unevenness of the nozzle of the burner is ubiquitous in the operation process of the cyclone burner, so that the thermal stress is easily released everywhere, and the cyclone burner is further caused to break down, such as the problems of burning loss deformation of the nozzle of the cyclone burner, cracking of welding seams, non-splitting of bolts and the like. Further, when the cyclone burner fails, the aerodynamic field at the burner outlet is deteriorated, the combustion structure is deteriorated, and problems such as high NOx emission and low boiler combustion efficiency are caused.

The main part of the primary air nozzle of the cyclone burner is a flame stable combustion ring, which is a benign blunt body, and the generated reverse flow forms a stable backflow area of the cyclone burner, so that the combustion efficiency and the low-load stable combustion capability are improved, and the formation of initial pollutants is reduced. The flame stable burning ring is generally integrally cast by heat-resistant steel or rolled by sheet metal parts and is formed by one-step processing. Because the velocity field and the concentration field of pulverized coal airflow at the outlet of the cyclone burner have large nonuniformity, and the temperature field inside the primary air flame stable combustion ring along the circumferential direction has large temperature gradient, the thermal stress on each part of the flame stable combustion ring along the circumferential direction is nonuniform, the thermal expansion amount of each part is different, and the problems of deformation and falling of the stable combustion ring, nozzle burning loss and the like are often caused. Burning loss and coking of a nozzle of the combustor further cause the deterioration of the aerodynamic field characteristic near the outlet of the combustor, and the problems of the combustor such as flash, combustion efficiency reduction, high-temperature corrosion and the like occur.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a flame surely fires ring and cyclone burner can make the thermal stress of combustor spout obtain the release, reduces cyclone burner's fault rate.

To achieve the purpose, the utility model adopts the following technical proposal:

a flame stable combustion ring comprises a flaring structure provided with a gradually-expanding central hole, wherein the distance from the outer wall of the flaring structure to the central axis of the gradually-expanding central hole is gradually increased along the airflow direction;

the flaring structure comprises a plurality of flaring segments which are distributed circumferentially and form the gradually-expanding central hole, and the axial extension directions of the outer walls of at least two flaring segments are different from the included angle between the central axes of the gradually-expanding central hole.

As a preferable technical scheme of the flame stable combustion ring, the included angles between the axial extension directions of the outer walls of the two adjacent flaring sections and the central axis of the gradually-flaring central hole are different.

As a preferable technical scheme of the flame stable combustion ring, each flaring section is arc-shaped, and the central axis of each flaring section is coincided with the central axis of the gradually-enlarged central hole.

As a preferred technical scheme of the flame stable combustion ring, the radial lengths of the small-diameter ends of the flaring sections are different.

As a preferred technical scheme of the flame stable combustion ring, a first interval is arranged between every two adjacent flaring sections.

As a preferred technical scheme of the flame stable combustion ring, the flame stable combustion ring further comprises a stable combustion ring body provided with a central through hole, wherein the central through hole and the gradually-expanded central hole are coaxially distributed;

the combustion stabilizing ring body is divided into a plurality of body sections which correspond to the flaring sections one to one, and a second interval is arranged between every two adjacent body sections.

As a preferable technical solution of the flame stabilizing ring, each body section is connected with the corresponding flared section through a connecting rib.

As an optimal technical scheme of the flame stable combustion ring, the flame stable combustion ring further comprises a plurality of stable combustion teeth, and the stable combustion teeth are circumferentially arranged on the inner wall of the central through hole at intervals.

As a preferable technical scheme of the flame stable combustion ring, the flame stable combustion ring further comprises a stable combustion straight section, and the outer diameter of the stable combustion straight section is smaller than the minimum outer diameter of the flaring structure.

The utility model also provides a cyclone burner, including foretell flame surely fires the ring.

The utility model has the advantages that: the utility model provides a flaring structure of ring is surely fired to flame includes that a plurality of circumference distribute and form the flaring section of gradually expanding the centre bore, and the axial extending direction of two at least flaring section outer walls is different with the contained angle between the central axis of gradually expanding the centre bore. Through the arrangement, the contact boundary of high-temperature flue gas and air-powder airflow is increased, the combustion efficiency is improved, the adaptability of different coal types such as high-quality coal and low-quality coal is improved, and the low-load stable combustion capacity of the boiler is enhanced.

The utility model also provides a cyclone burner, including foretell flame surely fires the ring, can improve combustion efficiency, reduce nitrogen oxide's content.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

Fig. 1 is a schematic structural view of a flame stabilizing ring provided in an embodiment of the present invention;

FIG. 2 is a sectional view taken along line A-A of FIG. 1;

fig. 3 is a sectional view taken along line B-B in fig. 1.

In the figure:

1. a flaring structure; 11. a first flared section; 12. a second flared section; 13. gradually expanding the central hole; 14. a first interval;

2. a body section; 21. a second interval; 3. a combustion stabilizing tooth; 4. and (5) stably burning the straight section.

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.

Fig. 1 is a schematic structural view of a flame stabilizing ring provided in the present embodiment, and fig. 2 is a sectional view taken along a line a-a in fig. 1; fig. 3 is a sectional view taken along line B-B in fig. 1. As shown in fig. 1 to 3, the flame stabilizing ring provided in this embodiment is disposed between the primary air duct and the secondary air duct and disposed at the primary air nozzle. Specifically, the flame stable combustion ring comprises a flaring structure 1, a gradually-expanding central hole 13 is formed in the flaring structure 1, and the distance from the outer wall of the flaring structure 1 to the central axis of the gradually-expanding central hole 13 along the airflow direction is gradually increased. By adopting the flaring structure 1, the mixing time of secondary air and primary air can be delayed, so that an anoxic atmosphere is formed in the primary air at the initial stage of ignition, the nitrogen oxides at the initial stage are fully reduced, and the flame stability near a flame stabilizing ring is promoted. The hole wall of the gradually expanding center hole 13 is gradually increased in distance from the central axis thereof in the air flow direction.

And because foretell flaring structure 1 locates between primary air pipe and the secondary air pipe, can make and form the negative pressure in the space between primary air pipe and the secondary air pipe to make the high temperature flue gas of primary air spout entrainment, form annular high temperature flue gas backward flow district. The flame stable combustion ring in the embodiment is mainly applied to the cyclone burner, the cyclone burner is internally provided with the cyclone blades, and concentrated pulverized coal airflow at the periphery of the primary air nozzle enters the high-temperature flue gas backflow area under the turbulent flow effect of the cyclone blades, so that the pulverized coal airflow is instantly heated by huge heat and is ignited for combustion.

And the arrangement of the gradually-expanded central hole 13 can ensure that the light pulverized coal airflow in the central area of the primary air nozzle is not influenced by the turbulent flow effect and is directly injected into the boiler, thereby ensuring the drainage strength of the primary air, and the primary air and the rotational flow secondary air are strongly mixed, thereby realizing the sufficient combustion of the pulverized coal.

The flaring structure 1 provided by the present embodiment includes a plurality of flaring segments that are circumferentially distributed and form the diverging center hole 13, and the included angles between the axial extending directions of the outer walls of at least two flaring segments and the central axis of the diverging center hole 13 are different. Due to the fact that coal types are different, classification of high-quality coal, low-quality coal and other coal types exists, the contact boundary of high-temperature flue gas and air-powder airflow can be increased through the arrangement, the combustion efficiency is improved, the adaptability of different coal types such as the high-quality coal and the low-quality coal is improved, and meanwhile the low-load stable combustion capacity of the boiler is enhanced.

Further, the included angle between the axial extending direction of the outer walls of two adjacent flaring segments and the central axis of the gradually-expanding central hole 13 is different. The flaring segments in this embodiment are divided into two types, namely a first flaring segment 11 and a second flaring segment 12, and the first flaring segment 11 and the second flaring segment 12 are alternately arranged at equal intervals in the circumferential direction. In the circumferential direction, the flaring structure 1 is divided into five to ten body segments 2. In the present embodiment, the flare structure 1 is divided into eight flare sections, four first flare sections 11 and four second flare sections 12.

The included angle between the axial extension direction of the outer wall of the first flaring section 11 and the central axis of the gradually-expanding central hole 13 is α and ranges from 5 degrees to 30 degrees, and the included angle between the axial extension direction of the outer wall of the second flaring section 12 and the central axis of the gradually-expanding central hole 13 is β and ranges from 15 degrees to 40 degrees according to different coal types.

Further, the radial length of the small diameter ends of two adjacent flaring segments is different, specifically, the radial length of the small diameter end of the first flaring segment 11 is smaller than that of the small diameter end of the second flaring segment 12, and the flaring segments are arranged in a staggered manner along the circumferential direction. The difference between the large diameter end and the small diameter end of the first flaring segment 11 and the second flaring segment 12 is different according to the type of the boiler and the type of coal. Through the arrangement, the combustion can be further enhanced, the high-temperature smoke backflow amount is improved, the oxygen concentration in flame is reduced, an annular backflow area is formed, the wind-powder airflow is further enhanced to catch fire rapidly, the temperature rise time of the wind-powder airflow is shortened, and the coal type adaptability and the low-load stable combustion capacity of the combustor are enhanced.

Further, the flame stable combustion ring also comprises a stable combustion ring body provided with a central through hole, and the central through hole and the gradually-expanded central hole 13 are coaxially distributed; the combustion stabilizing ring body is divided into a plurality of body segments 2. This body section 2 sets up with flaring section one-to-one, and this body section 2 is located the minor diameter end that corresponds the flaring section and is connected through splice bar welded connection, reduces the use of welding seam, reduces the possibility of welding seam fracture. The connection mode has the advantages of convenient assembly and disassembly, and greatly reduces the workload of maintenance; and the processing technology of the flame stable combustion ring is simplified, the consumption of raw materials is reduced by a sectional processing mode, and the manufacturing cost is reduced.

Further, above-mentioned flame surely fires ring still includes a plurality of surely fires tooth 3, and a plurality of surely fire 3 circumference intervals of tooth locate central through-hole inner wall. The arrangement of the combustion stabilizing teeth 3 can increase the turbulence at the airflow outlet of the pulverized coal, and improve the ignition speed and combustion stabilizing property of primary air. The number of the combustion stabilizing teeth 3 can be 8-24, and the specific value is determined according to the size of the primary air nozzle. In this embodiment, the number of the combustion stabilizing teeth 3 is eight, and the windward side of the combustion stabilizing teeth 32 is provided with a surfacing wear-resistant layer so as to reduce the direct abrasion between the windward side and the pulverized coal airflow and prolong the service life.

This embodiment is through surely firing tooth 3 and the cooperation of above-mentioned flaring structure 1, realizes that the vortex is stable, can not lead to the wearing and tearing of buggy air current because of the flow resistance is too big.

Further, the flame stable combustion ring also comprises a stable combustion straight section 4, and the outer diameter of the stable combustion straight section 4 is smaller than the minimum outer diameter of the flaring structure 1. Specifically, the combustion stabilizing straight section 4 and the combustion stabilizing ring body are welded by support columns or are connected by bolts.

Further, the flame stabilizing ring provided by the embodiment is made of 0Cr23Ni13, and the 0Cr23Ni13 has good high temperature resistance, so that the flame stabilizing ring has good burning loss prevention performance.

The flame stable combustion ring is arranged on the primary air nozzle, the temperature of the primary air nozzle is high, and severe thermal stress exists in the working process of the flame stable combustion ring; and because the buggy dead weight's reason, lead to the buggy concentration of primary air spout downside to a bit high relatively, the temperature of corresponding primary air spout downside is than with the upside temperature of primary air spout high, consequently, the ring is surely burnt to flame has the inhomogeneous problem of circumference thermal stress, leads to the expansion volume diverse at each position of the ring is surely burnt to flame, often causes the ring of surely burning to flame to warp the problem that drops, spout burning loss etc..

Therefore, a first interval 14 exists between two adjacent flaring sections in the embodiment, and thermal stress can be released, so that the problems of weld joint cracking, nozzle burning loss and the like caused by uneven heating of the flame combustion stabilizing ring of the swirl burner along the circumferential direction are thoroughly solved. A second interval 21 is arranged between two adjacent body sections 2, the width of the second interval 21 between two adjacent body sections 2 is equal to the width of the first interval 14 between two corresponding flaring sections, and the width value range of the first interval 14 is 2mm-20 mm.

The embodiment also provides a cyclone burner, including foretell flame surely fires the ring, can improve combustion efficiency, reduce nitrogen oxide's content, extension cyclone burner's life and maintenance cycle.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims (10)

1. The flame stable combustion ring is characterized by comprising a flaring structure (1) provided with a gradually-expanding central hole (13), wherein the distance from the outer wall of the flaring structure (1) to the central axis of the gradually-expanding central hole (13) along the airflow direction is gradually increased;

the flaring structure (1) comprises a plurality of flaring sections which are circumferentially distributed and form the gradually-flaring center hole (13), and the axial extension directions of the outer walls of the flaring sections are different from the included angle between the central axes of the gradually-flaring center hole (13).

2. The flame stabilizing ring according to claim 1, wherein the included angle between the axial extension direction of the outer walls of two adjacent flaring segments and the central axis of the gradually-expanding central hole (13) is different.

3. The flame stabilizing ring according to claim 1, wherein each of said flared sections is arcuate, and a central axis of each of said flared sections coincides with a central axis of said diverging central bore (13).

4. The flame stabilizing ring of claim 3, wherein the radial length of the small diameter ends of adjacent flared sections is different.

5. The flame stabilizing ring according to claim 1, wherein a first space (14) is provided between two adjacent flared sections.

6. The flame stable combustion ring according to claim 5, further comprising a stable combustion ring body provided with a central through hole, wherein the central through hole is coaxially distributed with the gradually-expanded central hole (13);

the combustion stabilizing ring body is divided into a plurality of body sections (2) corresponding to the flaring sections one by one, and a second interval (21) is arranged between every two adjacent body sections (2).

7. A flame stabilizing ring according to claim 6, wherein each body segment (2) is connected with the corresponding flared segment by a connecting rib.

8. The flame combustion stabilizing ring according to claim 6, further comprising a plurality of combustion stabilizing teeth (3), wherein the plurality of combustion stabilizing teeth (3) are circumferentially spaced on the inner wall of the central through hole.

9. The flame stabilizing ring according to claim 1, further comprising a stabilizing straight section (4), wherein the outer diameter of the stabilizing straight section (4) is smaller than the smallest outer diameter of the flare structure (1).

10. A swirl burner comprising a flame stabilizing ring according to any one of claims 1 to 9.

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