CN217154169U - Coal dropping cylinder and circulating fluidized bed boiler coal feeding device for preventing coal blockage - Google Patents

Abstract

The utility model belongs to the technical field of boiler coal feeding equipment, in particular to a coal dropping cylinder and a circulating fluidized bed boiler coal feeding device for preventing coal blockage, which comprises a receiving pipe, a fluidized pipe and an outlet pipe, wherein the receiving pipe is communicated with the upper end of the fluidized pipe, and the outlet pipe is communicated with the lower end of the fluidized pipe; the fluidization pipe comprises an inner pipe and an outer pipe, the outer pipe is sleeved outside the inner pipe, and a space is formed between the inner wall of the outer pipe and the outer wall of the inner pipe to form a cavity; the outer pipe is provided with a bottom fluidized air inlet communicated with the cavity; the upper part fluidization air pipe penetrates through the outer pipe and is communicated with the inner pipe; the inner pipe and the adapting pipe are both round pipes, namely, the contact part of the inner pipe and the adapting pipe with the coal particles is a smooth arc, so that the occurrence of coal accumulation at an included angle can be avoided; the fluidized air inlets at the bottom and the upper part of the upper fluidized air pipe are respectively added with fluidized air, so that the fluidized air can effectively prevent the coal particles from being accumulated, and the coal particle drying and dehumidifying device has the pneumatic conveying function and the drying and dehumidifying function.

Description

Coal dropping cylinder and circulating fluidized bed boiler coal feeding device for preventing coal blockage

Technical Field

The utility model belongs to the technical field of the boiler coal feeding equipment, concretely relates to coal breakage section of thick bamboo and prevent circulating fluidized bed boiler coal feeding device of chute blockage.

Background

The existing coal feeding system of the circulating fluidized bed boiler is generally a scraper coal feeder, a square inserting plate door, a square coal dropping cylinder, a feed back valve and a hearth. Wherein, the spile door and the coal dropping cylinder are commonly called as a coal feeding device. During engineering design and installation, a material return valve and a scraper coal feeder with large external dimensions are usually arranged firstly according to a hearth feeding interface, and then a square inserting plate door and a square coal dropping barrel are arranged. Due to slight view of the coal feeding device, most projects have the problems of unreasonable design, irregular installation, variable cross section of the coal dropping cylinder, small inclination angle and the like.

In the operation process of the boiler, when the part of coal as fired with the particle size smaller than 1mm occupies a large area or has a large water content, the coal blockage problem of a coal dropping cylinder can often occur, so that the forced load of the boiler is caused to fall; meanwhile, the person on duty must carry out coal poking and dredging immediately, and hot flue gas returned from the hearth has a large scalding risk to workers, so that the safe, stable and economic operation of the boiler and the safety of the workers are seriously influenced.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problem, an aspect of the present invention is to provide a coal chute, which can reduce blockage; another aspect of the present invention is to provide a coal feeding device for a circulating fluidized bed boiler, which includes the coal chute and prevents coal blockage.

In order to solve the technical problem, the utility model discloses a technical scheme be:

a coal dropping barrel comprises a bearing pipe, a fluidizing pipe and an outlet pipe, wherein the bearing pipe is communicated with the upper end of the fluidizing pipe, and the outlet pipe is communicated with the lower end of the fluidizing pipe;

the fluidization tube comprises an inner tube and an outer tube, the outer tube is sleeved outside the inner tube, a space is formed between the inner wall of the outer tube and the outer wall of the inner tube to form a cavity, the upper end of the cavity is closed, and the lower end of the cavity is provided with an air outlet; the outer pipe is provided with a bottom fluidized air inlet communicated with the cavity; the upper part fluidization air pipe penetrates through the outer pipe and is communicated with the inner pipe; the inner pipe and the adapting pipe are both round pipes.

The coal poking air pipe penetrates through the outer pipe and is communicated with the inner pipe; the coal poking air pipe is positioned below the upper fluidization air pipe.

The coal poking air pipe is a venturi pipe; the coal poking air pipe is arranged upwards in an inclined manner; the included angle between the coal poking air pipe and the inner pipe is 45 degrees.

The upper fluidizing air pipe is arranged upwards and slantways; and an included angle between the upper fluidization air pipe and the inner pipe is 45 degrees.

A ring plate and a rib plate are fixed between the inner wall of the outer pipe and the outer wall of the inner pipe, and a space is formed between the ring plate and the rib plate to form an air outlet; the ring plate is a semi-ring plate.

The bearing pipe is communicated with the inner pipe and forms an included angle;

the included angle between the bearing pipe and the inner pipe is 140-160 degrees.

The outlet pipe and the outer pipe are of an integrated structure.

The utility model provides a circulating fluidized bed boiler coal feeding device of preventing coal blockage, includes picture peg valve and coal breakage section of thick bamboo, the upper end intercommunication of picture peg valve and bolster.

The utility model provides a circulating fluidized bed boiler coal feeding device of preventing coal blockage, the picture peg valve adopts two-way run-on gate valve, and the valve opening of this valve is kidney type hole.

Compared with the prior art, the utility model, the beneficial effect who has is:

the inner pipe is a circular pipe, namely, the contact part of the inner pipe and the coal particles is a smooth circular arc, so that the occurrence of coal accumulation at an included angle can be avoided; the bottom fluidization wind inlet and the upper fluidization wind pipe are arranged, namely, the fluidization wind is additionally arranged at the bottom and the upper part of the coal particles respectively, the fluidization wind energy effectively prevents the coal particles from being accumulated, and the coal particle drying and dehumidifying device has the function of pneumatic conveying and also has the functions of drying and dehumidifying.

The coal poking air pipe is additionally manufactured according to the Venturi contraction pipe principle, and the coal poking air is introduced from 0.6MPa of compressed air. The operator on duty thinks through the running parameter analysis that when the coal blockage condition exists, opens the air feed valve, and compressed air increases through venturi convergent tube velocity of flow increase, kinetic energy increase, acts on the coal blockage position like poking coal drill rod, can effectively play and poke coal mediation effect.

The outlet pipe and the outer pipe are of an integral structure, the inner diameter (outlet) of the outer pipe is larger than that of the inner pipe, namely the section of the outlet section is larger than that of the fluidization section and is in a diffusion type, and the smooth coal flow is further promoted.

The bidirectional split inserting plates enable the coal flow to be in the relative center position of the circulating fluidized bed boiler coal feeding device for preventing coal blockage when the valve is in any opening degree, so that the defects of coal hanging and eccentric wear of the side wall are reduced; the shape of the valve hole is a kidney-shaped hole, so that the possibility of coal accumulation at an included angle is further eliminated.

By the structural arrangement, the problem of coal blockage of the circulating fluidized bed boiler can be effectively prevented and reduced; even if coal blockage occurs, the compressed air coal poking wind can play a role in poking and dredging coal, so that the safe, stable and economic operation of the boiler and the safety of workers are ensured.

Drawings

FIG. 1 is a schematic view of the overall structure of the coal chute of the present invention;

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

FIG. 3 is an enlarged sectional view taken along line B-B of FIG. 1;

FIG. 4 is a schematic structural view of a coal feeder of a circulating fluidized bed boiler for preventing coal blockage according to the present invention;

FIG. 5 is an enlarged cross-sectional view taken along line C-C of FIG. 4;

wherein: the device comprises a bearing pipe 1, a fluidization pipe 2, an inner pipe 20, an outer pipe 21, an outlet pipe 3, a cavity 4, an air outlet 5, a fluidized air inlet at the bottom 6, a fluidized air pipe at the upper part 7, a coal poking air pipe 8, a ring plate 9, a rib plate 10, a plug plate valve 11 and a valve hole 12.

Detailed Description

The technical solutions in the embodiments of the present invention are described below clearly and completely, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

As shown in fig. 1 to 3, a coal chute comprises a receiving pipe 1, a fluidizing pipe 2 and an outlet pipe 3, wherein the receiving pipe 1 is communicated with the upper end of the fluidizing pipe 2, and the outlet pipe 3 is communicated with the lower end of the fluidizing pipe 2;

the fluidization tube 2 comprises an inner tube 20 and an outer tube 21, the outer tube 21 is sleeved outside the inner tube 20, a space is formed between the inner wall of the outer tube 21 and the outer wall of the inner tube 20 to form a cavity 4, the cavity 4 is a wind cavity, the upper end of the cavity is closed, and the lower end of the cavity is provided with an air outlet 5; the outer pipe 21 is provided with a bottom fluidized air inlet 6 communicated with the cavity 4;

specifically, the method comprises the following steps: when the coal particle fluidized air boiler is used, the hot secondary air main pipe of the boiler is communicated with the bottom fluidized air inlet 6, and fluidized air is discharged from the air outlet 5 through the bottom fluidized air inlet 6 and the air cavity, namely, the fluidized air is additionally arranged at the bottom of coal particles.

The device also comprises an upper fluidization air pipe 7, wherein the upper fluidization air pipe 7 is communicated with the inner pipe 20 through an outer pipe 21; the inner pipe 20 and the adapting pipe 1 are both round pipes.

Similarly, the upper fluidizing air pipe 7 is also communicated with a main hot secondary air pipe of the boiler, and the fluidizing air enters the inner pipe 20 through the upper fluidizing air pipe 7, namely, the fluidizing air is additionally arranged on the upper part of the coal particles.

From the overall view, the receiving pipe 1, the fluidizing pipe 2 and the outlet pipe 3 are the receiving section, the fluidizing section and the outlet section of the coal chute.

Further, when the installation inclination angle of the circulating fluidized bed boiler coal feeding device for preventing coal blockage is smaller, coal blockage at the inclined part still possibly occurs when wet coal is extremely seriously adhered, a coal poking air pipe 8 is also arranged, and the coal poking air pipe 8 penetrates through the outer pipe 21 and is communicated with the inner pipe 20; the coal poking air pipe 8 is positioned below the upper fluidizing air pipe 7. When the operator on duty considers that the coal blockage condition exists through the analysis of the operation parameters, the air supply valve can be opened, and the coal poking air pipe 8 (communicated with an air source) enters the inner pipe 20 to play a role in poking and dredging the coal.

Furthermore, the coal poking air pipe 8 is preferably a venturi pipe, namely, the additional coal poking air pipe 8 is manufactured according to the Venturi contraction pipe principle, and the coal poking air is introduced from 0.6MPa of compressed air. The compressed air increases the velocity of flow through the venturi contraction tube, kinetic energy increases, acts on the coal plugging part like poking coal drill rod, and can further play an effective coal poking and dredging role.

Furthermore, the coal poking air pipe 8 is arranged obliquely upwards, so that the acting force can be increased.

Furthermore, the included angle between the coal poking air pipe 8 and the inner pipe 20 is preferably 45 degrees, so that the acting force acting on the coal flow direction and the acting force acting on the coal flow direction perpendicular to the coal flow direction are both relatively large.

Further, the upper fluidizing air pipe 7 is arranged obliquely upwards, so that the acting force can be increased.

Further, similarly, the included angle between the upper fluidization air pipe 7 and the inner pipe 20 is preferably 45 degrees, so that the acting forces of the upper fluidization air on the coal flow direction and the acting force perpendicular to the coal flow direction are both relatively large.

Further, the air outlet 5 may be formed in various structures, for example, corresponding holes may be directly formed; however, in order to improve the supporting effect and the fluidizing effect of the bottom fluidizing air, the following structure is preferably adopted:

an annular plate 9 and a rib plate 10 are fixed between the inner wall of the outer pipe 21 and the outer wall of the inner pipe 20, and a space is formed between the annular plate 9 and the rib plate 10 to form an air outlet 5.

The ring plate 9 is preferably a half ring plate, but may be one-third or three-quarters ring plate, and is adjusted according to actual conditions. Specifically, the method comprises the following steps: the ring plate 9 and the rib plate 10 are fixed by welding.

Further, the adapting pipe 1 is communicated with the inner pipe 20 and forms an included angle. When the whole field arrangement is carried out, the installation inclination angle is 50-70 degrees through the height of the specific receiving section (pipe), namely the included angle between the receiving pipe 1 and the fluidization pipe 2 is preferably 140-160 degrees.

Further, the outlet pipe 3 and the outer pipe 21 are of an integral structure, that is, the lower end of the outer pipe 21 is an outlet section (pipe), the lower end of the inner pipe 20 is positioned in the outer pipe 21, a distance exists between the lower end of the inner pipe 20 and the lower end of the outer pipe 21, and the diameter of the outer pipe 21 is larger than that of the inner pipe 20, so that the section of the outlet section is larger than that of the fluidization section and is in a diffusion type, and the smooth coal flow is further promoted.

Example 2

A135 MW air-cooled steam turbine generator unit of a certain power plant is provided with a 480t/h circulating fluidized bed boiler. The boiler elevation 20 meters department establishes 2 scraper coal feeders, and every scraper coal feeder has 2 coal outlets, and 4 coal outlets are connected with 4 elevation 16 meters return material sloping leg tops through square picture peg door, square coal breakage section of thick bamboo respectively. The square coal dropping cylinder has the original installation defects that the section becomes smaller from top to bottom and the inclination angle of the inclined section is smaller (40 degrees). When inferior coal containing partial coal slime is combusted, the coal blockage problem of a coal dropping cylinder often occurs due to large proportion of part with the particle size smaller than 1mm and large water content, so that the load of a generator set is forced to fall; meanwhile, the person on duty has the safety risk of being scalded by hot smoke returned from the hearth in the coal poking and dredging process.

After the following scheme is adopted, the problems are effectively avoided:

as shown in figures 4 and 5, the coal feeding device of the circulating fluidized bed boiler for preventing coal blockage comprises a flashboard valve 11 and a coal dropping cylinder, wherein the flashboard valve 11 is communicated with the upper end of a bearing pipe 1. When the coal feeder is installed, the flashboard valve 11 is directly communicated with a scraper coal feeder; the lower end of the outlet pipe 3 is communicated with a feed back valve. The coal grain bottom fluidization air inlet port (bottom fluidization air inlet 6) of the upper side part, and the two ports of the middle side part are the coal grain upper fluidization air port (upper fluidization air pipe 7) and the coal poking air port (coal poking air pipe 8) which are respectively connected with the hot secondary air main pipe and the compressed air main pipe.

Specifically, the method comprises the following steps: the diameters of the adapting pipe 1 and the fluidizing pipe 2 are about 800mm, the material is preferably 65Mn hot-rolled manganese-containing carbon steel plate with excellent wear resistance, and the adapting pipe is manufactured by welding after being processed by a plate bending machine.

Furthermore, the flashboard valve 11 preferably adopts a bidirectional split flashboard valve, and the bidirectional split flashboard valve ensures that when the valve is opened at any opening, coal flow is in the central position of the coal feeding device of the circulating fluidized bed boiler for preventing coal blockage, thereby avoiding the defects of coal hanging and eccentric wear on the side wall.

Further, the valve hole 12 of the prior art bi-directional split-spile valve is generally rectangular; the shape of the valve hole 12 of the valve is improved to be a kidney-shaped hole, so that the possibility of coal accumulation at an included angle can be further avoided. Meanwhile, when the kidney-shaped hole is adopted, the gate valve and the bearing pipe are in a long circular (kidney-shaped) butt joint circle shape.

After the technical scheme is adopted, the coal blockage problem of the coal feeding system does not occur, the labor intensity of boiler operators on duty caused by coal poking dredging is reduced, the generated energy of a boiler steam turbine generator unit is increased, double-fine check caused by load reduction of the coal blockage unit is reduced, and the safety risk and the hidden danger caused by manual coal poking and coal cleaning are avoided.

The above description has been made in detail only for the preferred embodiment of the present invention, but the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention within the knowledge scope of those skilled in the art, and all such changes are intended to be encompassed by the present invention.

Claims (10)

1. A coal dropping cylinder is characterized in that: the device comprises a bearing pipe (1), a fluidizing pipe (2) and an outlet pipe (3), wherein the bearing pipe (1) is communicated with the upper end of the fluidizing pipe (2), and the outlet pipe (3) is communicated with the lower end of the fluidizing pipe (2);

the fluidization pipe (2) comprises an inner pipe (20) and an outer pipe (21), the outer pipe (21) is sleeved outside the inner pipe (20), a space is reserved between the inner wall of the outer pipe (21) and the outer wall of the inner pipe (20) to form a cavity (4), the upper end of the cavity (4) is closed, and the lower end of the cavity is provided with an air outlet (5); the outer pipe (21) is provided with a bottom fluidized air inlet (6) communicated with the cavity (4); the fluidized air pipe is characterized by also comprising an upper fluidized air pipe (7), wherein the upper fluidized air pipe (7) penetrates through the outer pipe (21) and is communicated with the inner pipe (20); the inner pipe (20) and the adapting pipe (1) are both round pipes.

2. The coal chute as claimed in claim 1, wherein: the coal poking device also comprises a coal poking air pipe (8), wherein the coal poking air pipe (8) penetrates through the outer pipe (21) and is communicated with the inner pipe (20); the coal poking air pipe (8) is positioned below the upper fluidization air pipe (7).

3. The coal chute as claimed in claim 2, wherein: the coal poking air pipe (8) is a venturi tube; the coal poking air pipe (8) is arranged obliquely upwards; and the included angle between the coal poking air pipe (8) and the inner pipe (20) is 45 degrees.

4. The coal chute as claimed in claim 1, wherein: the upper fluidization air pipe (7) is arranged in an upward inclined manner; and an included angle between the upper fluidization air pipe (7) and the inner pipe (20) is 45 degrees.

5. The coal chute as claimed in claim 1, wherein: a ring plate (9) and a rib plate (10) are fixed between the inner wall of the outer pipe (21) and the outer wall of the inner pipe (20), and a space is reserved between the ring plate (9) and the rib plate (10) to form an air outlet (5); the ring plate (9) is a semi-ring plate.

6. The coal chute as claimed in claim 1, wherein: the bearing pipe (1) is communicated with the inner pipe (20) and forms an included angle.

7. The coal chute as claimed in claim 6, wherein: the included angle between the bearing pipe (1) and the inner pipe (20) is 140-160 degrees.

8. The coal chute as claimed in claim 1, wherein: the outlet pipe (3) and the outer pipe (21) are of an integrated structure.

9. The utility model provides a prevent circulating fluidized bed boiler coal feeding device of chute blockage which characterized in that: comprising a plugboard valve (11) and a coal chute as claimed in any one of claims 1 to 8, the plugboard valve (11) being in communication with the upper end of the adapter (1).

10. The coal feeding apparatus for a circulating fluidized bed boiler for preventing coal clogging according to claim 9, wherein: the flashboard valve (11) adopts a bidirectional split flashboard valve, and a valve hole (12) of the valve is a kidney-shaped hole.

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