CN215637117U

CN215637117U - Coal-fired four-corner boiler

Info

Publication number: CN215637117U
Application number: CN202122201228.5U
Authority: CN
Inventors: 于宝成; 李顺波; 刘革伟
Original assignee: WUHAN TIANHE TECHNOLOGY CO LTD
Current assignee: WUHAN TIANHE TECHNOLOGY CO LTD
Priority date: 2021-09-13
Filing date: 2021-09-13
Publication date: 2022-01-25
Anticipated expiration: 2031-09-13

Abstract

The utility model provides a coal-fired four-corner boiler which comprises a primary air burner and a secondary air burner, wherein the primary air burner and the secondary air burner are respectively provided with a plurality of layers, an air box bin-dividing partition plate is arranged in the secondary air burner, the secondary air burner is divided into an upper layer and a lower layer, a paranoia nozzle is arranged at the upper layer, a direct-blowing combustion-supporting air nozzle is arranged at the lower layer, nozzle swing angle linkage crank arms are arranged at the upper layer and the lower layer, and the nozzle swing angle linkage crank arms are connected with the nozzle baffle through pull rods and are used for controlling the flow of the nozzles. This scheme is effectual solved bellows pressure differential lower, furnace export both sides gas temperature deviation is great, slag combustible content is on the high side, nitrogen oxide scheduling problem, carries out the branch storehouse with coal fired power plant four corners boiler's overgrate air combustor and reforms transform, can effectively improve the flexibility regulating power of overgrate air, and when the low-load, the air current channel through closing part overgrate air spout improves the bellows pressure of overgrate air.

Description

Coal-fired four-corner boiler

Technical Field

The utility model relates to the technical field of coal-fired boilers, in particular to a coal-fired four-corner boiler.

Background

When low-nitrogen is transformed, the operation load of a boiler of a thermal power plant is higher, the operation condition under high load is mainly considered during the transformation design, and the phenomenon that the pressure of a secondary air box is lower exists during low-load operation. The investigation of the low-nitrogen transformation project discovers that the coal quality change of the operation of the power plant is large after the low-nitrogen transformation, and the peak-adjusting low-load operation of the thermal power plant becomes a normal state because the power generation ratio of new energy is gradually increased. The load of the grid is adjusted to change rapidly in order to respond rapidly during peak adjustment, and when the load is low or the coal quality is poor, one mill group needs to be put into operation more at the same load of the boiler, so that the primary air rate is increased, and the secondary air rate is reduced. Meanwhile, with the increase of the number of layers of primary air delivery, the delivery quantity of matched secondary air nozzles needs to be increased, so that the through-flow section of secondary air is increased, and the phenomenon of low differential pressure of a secondary air box is highlighted in more low-nitrogen modified power plants.

The pressure of the secondary air box is low, direct reaction is carried out when the secondary wind speed is low, the overall rigidity of bottom supporting wind, deflection secondary wind and the like is weakened, the rotation quantity of the secondary wind is reduced, and therefore the flame tangential circle in the furnace is enlarged. The phenomena of water wall coking, high-temperature corrosion, high slag combustible content, weak low-load combustion anti-interference capability and the like are easily caused. The low pressure difference of the secondary air box can also cause the integral weakening of SOFA wind rigidity, the anti-despinning capability of the SOFA wind is reduced, and the smoke temperature deviation at two sides of the outlet of the hearth is increased. The low pressure difference of the secondary air box causes the little SOFA wind volume distribution and the poor staged combustion effect, and causes the increase of the generation of nitrogen oxides.

Patent publication No. CN103216821B discloses a boiler primary and secondary air multi-stage layered combustion system and method, but the combustion system has higher slag combustible content and higher nitrogen oxide content in the use process; patent number CN206386921U discloses a coal fired boiler burner of four corners tangential circle suitable for burning high proportion brown coal, but the device is not convenient for adjust the amount of wind of spout, and the nitrogen oxide is high, influences the result of use.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art and provide the coal-fired four-corner boiler which is convenient for solving the problems of low pressure difference of an air box, large smoke temperature deviation at two sides of a hearth outlet, high content of slag combustible and high content of nitrogen oxide.

The technical scheme of the utility model is as follows: the utility model provides a coal-fired four corners boiler, includes once wind combustor and overgrate air combustor, once wind combustor and overgrate air combustor all set up a plurality of layers, be equipped with bellows branch storehouse baffle in the overgrate air combustor, two-layer about falling into the overgrate air combustor, the upper strata is equipped with the spout of holding partially, and the lower floor is equipped with the combustion-supporting wind spout of blowing directly, and upper and lower two-layer all is equipped with spout pivot angle linkage turning arm, and spout pivot angle linkage turning arm passes through the pull rod and is connected with the spout baffle for the flow of control spout.

Further, the upper layer and the lower layer are both provided with air doors, each air door comprises air door blades and an air door switch linkage crank arm, and the air door switch linkage crank arms are used for controlling the opening and closing of the air door blades or adjusting the opening of the air doors.

Further, the primary air burner is provided with six layers of A, B, C, D, E and F; eight layers of secondary air burners are arranged, namely AA, AB, BC, CD, DE, EF, FF and OFA.

Further, overfire air burners AA, FF and OFA do not all set up bellows and divide the storehouse baffle, and overfire air burners AB, BC, CD, DE, EF and FF all set up bellows and divide the storehouse baffle, and overfire air burner AA is for holding in the palm end overfire air, and overfire air burners FF and OFA locate the top of coal-fired four-corner boiler.

Further, the overgrate air burner AA is provided with a horizontal manual oscillating piece.

Furthermore, the ratio of the flow area of the paranoid air nozzle to the flow area of the direct-blowing combustion-supporting air nozzle is 3-5: 4-7.

Further, the primary air burner is provided with a nozzle, a bluff body is arranged in the middle of the nozzle, the bluff body is installed on the inner wall of the peripheral air, a peripheral air outer wall is further arranged on the outer side of the inner wall of the peripheral air, and a peripheral air ventilation cavity is formed between the inner wall of the peripheral air and the outer wall of the peripheral air.

The utility model has the following characteristics: this scheme is effectual has solved bellows pressure differential lower, furnace export both sides gas temperature deviation is great, slag combustible substance content is on the high side, the high scheduling problem of nitrogen oxide, divide the storehouse with coal fired power plant four corners boiler's overgrate air combustor to reform transform, can effectively improve the flexibility regulating power of overgrate air, when the low-load, airflow channel through closing partial overgrate air spout improves the bellows pressure of overgrate air, spout pivot angle linkage turning arm can pass through controller intelligent control, the realization is to the automatic control of spout flow, effectual control effect and the operation safety of having improved.

The detailed structure of the present invention will be further described with reference to the accompanying drawings and the detailed description.

Drawings

FIG. 1 is a schematic view of the nozzle and damper before and after the improvement of the overfire air burner of the present invention;

FIG. 2 is a schematic diagram of the overfire air burner configuration of the present invention;

FIG. 3 is a schematic view of a primary air jet of the present invention;

the air-conditioning system comprises 1-eccentric wind nozzles, 2-direct-blowing natural wind nozzles, 3-air box bin dividing partition plates, 4-nozzle swing angle linkage connecting levers, 5-air door switch linkage connecting levers, 6-air door blades, 7-pull rods, 8-peripheral wind ventilation cavities, 9-bluff bodies, 10-peripheral wind inner walls and 11-peripheral wind outer walls.

Detailed Description

As shown in the attached drawings: a coal-fired four-corner boiler comprises a primary air burner and a secondary air burner, wherein the primary air burner and the secondary air burner are both provided with a plurality of layers, air box bin-dividing partition plates 3 are arranged in the secondary air burner, the secondary air burner is divided into an upper layer and a lower layer, a deflected air nozzle 1 is arranged on the upper layer, a direct-blowing natural air nozzle 2 is arranged on the lower layer, nozzle swinging angle linkage connecting arms 4 are arranged on the upper layer and the lower layer, the nozzle swinging angle linkage connecting arms 4 are connected with nozzle baffles through pull rods 7 and are used for controlling the flow of nozzles, and the ratio of the flow area of the deflected air nozzle 1 to the flow area of the direct-blowing natural air nozzle 2 is 3-5: 4-7; preferably, the ratio of the flow area of the paranoid wind nozzle 1 to the flow area of the direct-blowing natural wind nozzle 2 is 3-4: 5-7; preferably, the ratio of the flow area of the paranoid wind nozzle 1 to the flow area of the direct-blowing natural wind nozzle 2 is 4:6, so that the adjustment of the component is convenient, the flexibility adjustment capability of the secondary wind is effectively improved, and the air box pressure of the secondary wind is improved by closing the airflow channel of part of the secondary wind nozzles at low load.

Preferably, the deviated air nozzle 1 and the direct-blowing natural air nozzle 2 are respectively provided with a set of pull rod 7 and a nozzle swing angle linkage connecting lever 4, the outer part of the connecting lever is connected with an angle vertical swing connecting rod, the length of the pull rod 7 and the nozzle swing angle linkage connecting lever 4 are arranged in a matched mode, and when the sub-bin nozzles swing, the vertical swing angle is required to be consistent with the vertical swing angle of the main burner.

In the embodiment, the upper layer and the lower layer are both provided with air doors, each air door comprises an air door blade 6 and an air door switch linkage crank arm 5, and the air door switch linkage crank arms 5 are used for controlling the opening and closing of the air door blades 6 or adjusting the opening of the air doors.

In another embodiment, the primary air burners are provided with six layers A, B, C, D, E and F; eight layers of secondary air burners are arranged, namely AA, AB, BC, CD, DE, EF, FF and OFA. Preferably, the overgrate air burners AA, FF and OFA are not provided with air box partition plates 3, the overgrate air burners AB, BC, CD, DE, EF and FF are provided with air box partition plates 3, the overgrate air burners AA are used for supporting bottom overgrate air, the overgrate air burners FF and OFA are arranged at the tops of the four-corner coal-fired boiler, and the overgrate air burners AA are provided with horizontal manual swinging pieces, so that the control of the air doors and the nozzle flow of the overgrate air burners AA is facilitated to be improved.

In the embodiment, the primary air burner is provided with a nozzle, a bluff body 9 is arranged in the middle of the nozzle, the bluff body 9 is arranged on a peripheral air inner wall 10, a peripheral air outer wall 11 is further arranged on the outer side of the peripheral air inner wall 10, and a peripheral air ventilation cavity 8 is formed between the peripheral air inner wall 10 and the peripheral air outer wall 11; specifically, the main body of the primary air burner is kept unchanged (the elevation, the trend and the structural form of a pulverized coal pipeline and a pulverized coal elbow are not changed, equipment is used for convenience), the cross section of the peripheral air of the non-internal combustion primary air nozzle is reduced and modified, and the through-flow cross section is reduced by 20-50%; a primary air burner nozzle (containing peripheral air), wherein a blunt body 9 is arranged in the middle of the nozzle and is a conventional primary air nozzle, peripheral air reduction transformation is carried out, and a reduced part is a peripheral air ventilation cavity 8; when the wind is reduced, the structures of the bluff body 9 and the inner wall 10 of the perimeter wind are maintained unchanged, and the outer wall 11 of the perimeter wind is reduced.

This scheme is effectual to have solved bellows pressure differential lower, furnace export both sides gas temperature deviation is great, slag combustible substance content is on the high side, the high scheduling problem of nitrogen oxide, divide the storehouse with coal fired power plant's overgrate air combustor to reform transform, can effectively improve the flexibility regulating power of overgrate air, when the low-load, airflow channel through closing partial overgrate air spout improves the bellows pressure of overgrate air, spout pivot angle linkage turning arm 4 can be through controller intelligent control, the realization is to the automatic control of spout flow, effectual control effect and the operation safety of having improved.

The above description is of the preferred embodiment of the present invention and the technical principles applied thereto, and it will be apparent to those skilled in the art that any changes and modifications based on the equivalent changes and simple substitutions of the technical solutions of the present invention are within the protection scope of the present invention without departing from the spirit and scope of the present invention.

Claims

1. The utility model provides a coal-fired four corners boiler, includes once wind combustor and overgrate air combustor, once wind combustor and overgrate air combustor all set up a plurality of layers, its characterized in that: the secondary air burner is internally provided with an air box bin separation baffle, the secondary air burner is divided into an upper layer and a lower layer, the upper layer is provided with a paranoil nozzle, the lower layer is provided with a direct-blowing combustion-supporting air nozzle, the upper layer and the lower layer are both provided with nozzle swing angle linkage connecting levers, and the nozzle swing angle linkage connecting levers are connected with nozzle baffles through pull rods and are used for controlling the flow of the nozzles.

2. The coal fired tetragonal boiler of claim 1, wherein: the upper layer and the lower layer are both provided with air doors, each air door comprises air door blades and an air door switch linkage crank arm, and the air door switch linkage crank arms are used for controlling the opening and closing of the air door blades or adjusting the opening of the air doors.

3. The coal fired tetragonal boiler of claim 1, wherein: the primary air burner is provided with six layers of A, B, C, D, E and F; eight layers of secondary air burners are arranged, namely AA, AB, BC, CD, DE, EF, FF and OFA.

4. The coal fired tetragonal boiler of claim 3, wherein: the overfire air burners AA, FF and OFA are not provided with air box partition plates, the overfire air burners AB, BC, CD, DE, EF and FF are provided with air box partition plates, the overfire air burners AA are bottom supporting overfire air, and the overfire air burners FF and OFA are arranged at the top of the coal-fired four-corner boiler.

5. The coal fired tetragonal boiler of claim 4, wherein: the overgrate air combustor AA is provided with a horizontal manual swinging piece.

6. The coal fired tetragonal boiler of claim 1, wherein: the ratio of the flow area of the paranoid air nozzle to the flow area of the direct-blowing combustion-supporting air nozzle is 3-5: 4-7.

7. The coal-fired tetragonal boiler according to any one of claims 1 to 6, wherein: the primary air burner is provided with a nozzle, a bluff body is arranged in the middle of the nozzle and mounted on a peripheral air inner wall, a peripheral air outer wall is further arranged on the outer side of the peripheral air inner wall, and a peripheral air ventilation cavity is formed between the peripheral air inner wall and the peripheral air outer wall.