CN217004444U

CN217004444U - Self-suction type ash conveying system for secondary air duct of front-and-rear wall opposed combustion boiler

Info

Publication number: CN217004444U
Application number: CN202220225691.5U
Authority: CN
Inventors: 屈维刚; 谢照增; 袁红玉; 白献锁; 李智强; 秦小阳; 邢志刚; 陈乔伟
Original assignee: Datang Sanmenxia Power Generation Co Ltd
Current assignee: Datang Sanmenxia Power Generation Co Ltd
Priority date: 2022-01-27
Filing date: 2022-01-27
Publication date: 2022-07-19
Anticipated expiration: 2032-01-27

Abstract

The utility model provides a front and back wall hedging combustion boiler secondary air duct is from inhaling formula ash conveying system, includes: the secondary air duct, the secondary air duct falls into two sets ofly, arranges respectively on the relative brickwork in two sides, and every group secondary air duct comprises air duct layer and the wind channel wall layer of upper and lower alternate distribution, corresponds the installation one deck combustor on every air duct layer, all is equipped with the ash discharge port on the secondary air duct of every combustor below, and the ash discharge port on the vertical direction passes through the ash discharge pipeline intercommunication, is located ash discharge port below the bottommost and is equipped with the ash collecting bucket, and a plurality of ash collecting buckets are established ties to the water seal baffle department of boiler slag shaft through ash conveying pipeline, through boiler negative pressure suction flying ash. The utility model can fundamentally solve the defects of influence of the accumulated dust on the combustion of the boiler, shutdown for ash removal and the like, reduces the investment of manpower, material resources and financial resources of a company, and ensures the reliability and the economy of the operation of a unit.

Description

Self-suction type ash conveying system for secondary air duct of front-and-back wall opposed combustion boiler

Technical Field

The utility model relates to a pulverized coal boiler with front and rear wall opposed firing, in particular to a secondary air duct self-suction ash conveying system of a front and rear wall opposed firing boiler.

Background

As is known, a pulverized coal boiler with front and rear wall opposed combustion (referred to as a front and rear wall opposed combustion boiler for short) is a combustion device in which a certain number of swirl burners are arranged on two opposite furnace walls to form opposed flames. The main advantages are that the flue gas temperature and speed in the width direction of the upper hearth are uniform, the temperature deviation of the superheated steam is small, and the metal highest temperature point of the whole superheater and reheater can be reduced.

At present, secondary air ducts of a front-wall and rear-wall opposed firing boiler are installed in a rectangular transverse row. The secondary air is led out from the outlet of the tail air preheater, the secondary air is evenly distributed to each layer of combustor for use at 90 degrees in the main box, the pressure head of the secondary air is low, the flow is large, the resistance of fluid passing through a turning flue is increased, pressure drop is generated, hot air carries part of fly ash to impact an air door, an air duct wall, a guide plate and the combustor to be decelerated and deposited when passing through the air preheater, the secondary air is frequently started and stopped along with the participation of a unit in deep peak regulation, and the amount of ash carried by the hot secondary air after the air preheater is blocked is increased. The hot air carrying the fly ash is sent to a hearth combustor through the combustor, a secondary air baffle door and the like, the resistance is large when the equipment parts are arranged, the fly ash is seriously collided and settled, the accumulated ash at the parts is treated, a large amount of manpower, material resources and financial resources are required to be invested, the consumed working hours are long, the safety control risk is large, the environmental pollution is serious, the cross section of an air channel is reduced due to the accumulated ash in the air channel, the oxygen quantity required by peak regulation and stable combustion of a boiler is influenced, the output of an air feeder is increased, and the plant power consumption is increased.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model provides the self-suction ash conveying system for the secondary air duct of the front-and-rear wall opposed combustion boiler, which can effectively avoid the generation of ash deposition in the secondary air duct, does not need to increase an external pneumatic conveying device or stop the boiler, and has low cost, safety and high efficiency.

The technical scheme adopted by the utility model for solving the technical problem is as follows: the method comprises the following steps: the secondary air duct, the secondary air duct falls into two sets ofly, arranges respectively on the relative brickwork in two sides, and every group secondary air duct comprises air duct layer and the wind channel wall layer of upper and lower alternate distribution, corresponds the installation one deck combustor on every air duct layer, all is equipped with the ash discharge port on the secondary air duct of every combustor below, and the ash discharge port on the vertical direction passes through the ash discharge pipeline intercommunication, is located ash discharge port below the bottommost and is equipped with the ash collecting bucket, and a plurality of ash collecting buckets are established ties to the water seal baffle department of boiler slag shaft through ash conveying pipeline, through boiler negative pressure suction flying ash.

Compared with the prior art, the self-suction type ash conveying system for the secondary air duct of the front-wall and rear-wall opposed combustion boiler disclosed by the utility model has the advantages that firstly, aiming at the ash deposition of the secondary air duct of the opposed combustion boiler, the ash conveying system consisting of the ash discharge port, the ash discharge pipeline, the ash collection hopper and the ash conveying pipeline is utilized, the defects that the existing ash deposition influences the combustion of the boiler, stops to clean ash and the like can be fundamentally overcome, the investment of the manpower, material resources and financial resources of a company is reduced, and the reliability and the economy of the operation of a unit are ensured. In addition, the utility model mainly utilizes the negative pressure operation of the boiler, and the ash is circularly conveyed under the action of self-weight flow and furnace bottom air pressure suction, thereby reducing the addition of external pneumatic conveying devices, and reducing the complexity of the system and the cost of newly added equipment.

Drawings

The utility model is further illustrated by the following examples in conjunction with the drawings.

FIG. 1 is a front view of one embodiment of the present invention.

Figure 2 is a side view of one embodiment of the present invention.

In the figure, 1, a boiler, 11, a front furnace wall, 12, a rear furnace wall, 2, an air channel layer, 3, an air channel spacing layer, 4, an ash discharge pipeline, 5, an ash collection hopper, 6, an ash conveying pipeline, 7, a boiler slag well, 71, a left boiler slag well, 72, a right boiler slag well, 8, a scraper slag remover, 9, a slag bin, 10 and a combustor.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, belong to the scope of the present invention.

Fig. 1 and 2 are schematic structural views illustrating a preferred embodiment of the present invention, and a secondary air duct self-priming ash conveying system of a front-and-rear wall opposed-combustion boiler in fig. 2 comprises: the secondary air ducts are divided into two groups and are respectively arranged on furnace walls with two opposite surfaces, the furnace walls with two opposite surfaces generally refer to a front furnace wall 11 and a rear furnace wall 12 of the boiler 1, the burners 10 send air through the secondary air ducts to serve as secondary air, and in the structure shown in the figure, the burners 10 on the front furnace wall 11 and the rear furnace wall 12 are arranged in a direct opposite impact mode and serve as other deformation schemes and can also be arranged in a staggered mode according to a preset rule.

In specific implementation, referring to fig. 1, each set of the secondary air ducts consists of air duct layers 2 and air duct partition layers 3 which are alternately distributed up and down, the air duct partition layers 3 are designed to be used as channels of central air, each air duct layer 2 is correspondingly provided with a layer of burners 10, specifically, 3 layers of 6 sets of 30 burners A, B, C, D, E, F are provided, wherein A, B, C burners are arranged in the air ducts of the front furnace wall 11, and D, E, F burners are arranged in the air ducts of the rear furnace wall 12 (see fig. 2). 10 burners are arranged in each layer of 2 groups of air channels, A, D2 groups are used as a first layer, B, E2 groups are used as a second layer, C, F is used as a third layer, and 2 air channel spacing layers 3 are arranged between the first layer and the second layer and between the second layer and the third layer respectively. All be equipped with the ash discharge port on the secondary air duct of every combustor 10 below, have air duct interlayer 3 because of secondary air duct stereoscopic arrangement, in order to prevent that upper wind ash from strikeing into air duct interlayer 3, the last ash discharge port of vertical direction passes through ash discharge pipeline 4 intercommunication, ash discharge pipeline 4 is formed in air duct interlayer 3, and is specific, respectively with thick wall pipeline UNICOM between A, B, C, D, E, the F combustor air duct, 20 altogether. An ash collecting hopper 5 is arranged below the ash discharging port at the lowest part, a plurality of ash collecting hoppers 5 are connected in series to a water seal baffle of a boiler slag well 7 through an ash conveying pipeline 6, and fly ash is sucked under negative pressure through the boiler 1.

In this embodiment, the dust outlet is specifically set to be a hole with a diameter of Φ 100, but is not limited thereto, the shape of the dust outlet may also be any shape such as a rectangle, a triangle, an ellipse, etc., which is adapted to the shape of the cross section of the dust exhaust pipe 4, and the setting may be performed by referring to other influence factors, and the size of the dust outlet is determined by comprehensively considering, for example, the pipe wall thickness, the length, the dust absorption power, the dust deposition, etc.

In consideration of wear allowance and prolonged service life, the ash discharge pipe 4 and the ash conveying pipe 6 are preferably thick-walled pipes, such as pipes with the thickness of 8mm or 10 mm.

Meanwhile, the oxygen required by combustion of the boiler 1 is mainly exerted in a main burner area and a burnout air area, and the pipe diameter of a pipeline needing to be conveyed for ash deposition in a secondary air channel is not too large, so that the requirement can be met by selecting a pipeline with the diameter of phi 108 according to an ash conveying specification.

According to the hole with the ash discharge opening phi of 100, the ash collecting hopper 5 can be a 60-degree conical ash collecting hopper with the diameter of 1000mm multiplied by 600mm, so that the deposited and accumulated fly ash can fall into the hopper efficiently. The lower part of the ash collecting hopper 5 can be further provided with an isolation inserting plate door or an electromagnetic valve which is arranged on a platform with the height of 17 meters of the boiler 1, and the ash conveying pipeline 6 is arranged between the height of 6 meters and the height of 17 meters of the boiler 1, so that the ash collecting hopper is safe and convenient for later maintenance operation.

All pipelines and joints must be fully welded to prevent air leakage, and metal expansion joints are arranged at the joints of the ash conveying pipeline 6 and the water seal baffle plate and the joints of the ash discharge pipeline 4 and the secondary air duct, and comprise an ash collecting hopper 5 connected with the metal expansion joints to prevent the pipelines from being broken by cold and hot expansion.

Referring to fig. 1, in the embodiment, the boiler slag well 7 is divided into a left part and a right part, each group of secondary air ducts is divided into a left part and a right part, and the ash collection hoppers 5 of the two parts are collected and then communicated to the left boiler slag well 71 and the right boiler slag well 72 respectively. Further, the outlet of the boiler slag well 7 is also sequentially connected with a scraper slag salvaging machine 8 and a slag bin 9. Specifically, five ash collecting hoppers 5 are arranged in an air duct at the lowest layer of the front furnace wall 11, six ash collecting hoppers are led out by phi 108 multiplied by 10mm, two water seal baffles of the front wall of the slag shaft of 6 meters, phi 108 multiplied by 10mm and communicated to the scraper slag remover 8, are converged into a tee joint, and the rear furnace wall 12 is symmetrically arranged with the front furnace wall and has the same structure. The accumulated ash is conveyed to flow by negative pressure suction of the boiler 1 and falls into a slag dragging machine to be scraped to a slag bin 9.

As the ash conveying pipeline 6 is arranged in the boiler 1, the pipeline is prevented from extruding the outer edge of the water-sealed tank at the bottom of the lower furnace in the cold and hot expansion process of the boiler 1, and the cold and hot displacement of the water seal is also considered for the selection of the ash conveying pipeline 6.

On one hand, the embodiment of the utility model mainly utilizes the negative pressure operation of the boiler 1, and the ash is circularly conveyed under the action of self-weight flow and furnace bottom air pressure suction, thereby reducing the increase of external pneumatic conveying devices, and reducing the complexity of the system and the application cost of newly added equipment. On the other hand, the dust is efficiently collected and transported in the operation, the dust deposition at the burner 10 and the secondary air baffle door is greatly reduced, the supply of secondary air is sufficient, the sufficient and stable combustion is promoted, and the reliability and the economical efficiency of the unit operation are ensured.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiment according to the technical spirit of the present invention are included in the protection scope of the present invention.

Claims

1. The utility model provides a front and back wall hedging combustion boiler secondary air duct is from inhaling formula ash conveying system, characterized by includes: secondary air duct, secondary air duct falls into two sets ofly, arranges respectively on the relative brickwork in two sides, every group secondary air duct comprises air duct layer (2) and air duct wall (3) that distribute from top to bottom in turn, correspond installation one deck combustor (10) on every air duct layer (2), all be equipped with the ash discharge mouth on the secondary air duct of every combustor (10) below, the last ash discharge mouth of vertical direction passes through ash discharge pipeline (4) intercommunication, it is equipped with ash collecting hopper (5) to be located ash discharge mouth below the bottom, a plurality of ash collecting hopper (5) are established ties to the water seal baffle department of boiler slag shaft (7) through ash conveying pipeline (6), through boiler negative pressure suction flying ash.

2. The self-suction ash conveying system for the secondary air duct of the front-and-rear wall opposed combustion boiler as claimed in claim 1, which is characterized in that: the ash discharge port is a phi 100 hole.

3. The self-priming ash conveying system for the secondary air duct of the front-wall and rear-wall opposed combustion boiler as claimed in claim 2, which is characterized in that: and the ash discharge pipeline (4) and the ash conveying pipeline (6) are pipelines with phi 108 multiplied by 8 mm.

4. The self-priming ash conveying system for the secondary air duct of the front-and-back wall opposed firing boiler as claimed in claim 3, which is characterized in that: the ash collecting hopper (5) is a 60-degree conical ash collecting hopper with the size of 1000mm multiplied by 600 mm.

5. The self-priming ash conveying system for the secondary air duct of the front-and-back wall opposed-firing boiler as claimed in claim 1, 2, 3 or 4, wherein: the ash conveying pipeline (6) is arranged at the height of 6-17 meters of the boiler (1).

6. The self-priming ash conveying system for the secondary air duct of the front-and-back wall opposed-firing boiler as claimed in claim 1, 2, 3 or 4, wherein: and metal expansion joints are arranged at the joint of the ash conveying pipeline (6) and the water seal baffle and the joint of the ash discharge pipeline (4) and the secondary air channel.

7. The self-priming ash conveying system for the secondary air duct of the front-wall and rear-wall opposed combustion boiler as claimed in claim 1, which is characterized in that: the boiler slag well (7) is divided into a left side and a right side, each group of secondary air channels is divided into a left part and a right part, and the ash collecting hoppers (5) of the two parts are collected respectively and then communicated to the left boiler slag well (71) and the right boiler slag well (72).

8. The self-suction ash conveying system for the secondary air duct of the front-and-rear wall opposed-firing boiler as claimed in claim 1 or 7, characterized in that: the outlet of the boiler slag well (7) is also sequentially connected with a scraper slag salvaging machine (8) and a slag bin (9).

9. The self-priming ash conveying system for the secondary air duct of the front-wall and rear-wall opposed combustion boiler as claimed in claim 8, wherein: the burners (10) located on the two opposite furnace walls are arranged in a direct-facing opposed manner.