CN114151787B

CN114151787B - Anti-blocking slag discharging structure of circulating fluidized bed boiler

Info

Publication number: CN114151787B
Application number: CN202111549366.0A
Authority: CN
Inventors: 卢照丹
Original assignee: Wuxi Huaguang Environment and Energy Group Co Ltd
Current assignee: Wuxi Huaguang Environment and Energy Group Co Ltd
Filing date: 2021-12-17
Publication date: 2024-05-31
Anticipated expiration: 2041-12-17

Abstract

The invention relates to the technical field of circulating fluidized bed boilers, in particular to an anti-blocking slag discharging structure of a circulating fluidized bed boiler, which can enable slag discharging of the boiler to be smoother, prevent the boiler from operating and coking and reduce the operating loss of bed materials.

Description

Anti-blocking slag discharging structure of circulating fluidized bed boiler

Technical Field

The invention relates to the technical field of circulating fluidized bed boilers, in particular to an anti-blocking slag discharging structure of a circulating fluidized bed boiler.

Background

Under the large background of realizing carbon reaching peak and carbon neutralization, the traditional coal-fired boiler is greatly polluted by carbon emission enlargement, and is gradually eliminated and replaced, and renewable energy and clean energy become the main stream of current development. The new boilers for burning solid wastes or biomasses are more concerned by various manufacturers, the reutilization of the solid wastes and biomasses is realized through different technical routes, and at present, the new boilers are still in a development stage, and part of problems are in need of being solved.

The solid waste is more complicated compared with biomass fuel and traditional fire coal, and the condition that biomass is taken as an example, compared with the north of a south power plant, a large amount of straw is not used for burning is not possessed, so that part of building templates are often blended, a large amount of iron nails and iron wires exist in the building templates, although the iron nails are treated through the iron remover during fuel feeding, a large amount of iron nails are still remained on the templates, the iron wires and the fuel are entangled together and cannot be thoroughly removed through the iron remover, long-time accumulation enables the iron nails to be accumulated on a bed to block a slag dropping pipe, slag of a boiler is not smooth, coking is further generated, and normal and safe operation of the boiler is seriously affected.

Part of manufacturers adopt a scheme of amplifying the slag dropping pipe, so that large-mass and large-volume slag which is difficult to fluidize is discharged. However, the simple amplifying slag dropping pipe is easy to form a fluidization dead zone around the slag dropping pipe, which is not completely beneficial to fluidization and smooth discharge of slag, and meanwhile, the loss of fine ash and combustible materials is increased when the slag dropping pipe is too large, which is not beneficial to long-term economic and stable operation of the boiler.

Disclosure of Invention

In order to solve the problems that the existing circulating fluidized bed boiler is unsmooth in deslagging, the normal operation of the boiler is easy to be influenced by coking, and the running loss of bed materials is large due to the fact that a deslagging pipe is simply enlarged, the invention provides an anti-blocking deslagging structure of the circulating fluidized bed boiler, which can enable the deslagging of the boiler to be more unsmooth, prevent the running coking of the boiler and reduce the running loss of the bed materials.

The technical scheme is as follows: the utility model provides a circulating fluidized bed boiler prevents stifled sediment structure, its includes the air distribution plate, install the takeover of taking the hood on the air distribution plate, air distribution plate central point puts and is provided with the slag notch, slag notch connection slag fall pipe, its characterized in that, slag fall pipe is square slag fall pipe, connect two symmetrical arrangement's loose wind branch pipes on the lateral wall of slag fall pipe, the air outlet slope of loose wind branch pipe upwards arranges.

The device is further characterized in that the connecting section of the loose wind branch pipe and the slag falling pipe is obliquely upwards arranged, and the inclination angle is 20-60 degrees;

the two loose wind branch pipes are connected with one end of the same loose wind master pipe, the other end of the loose wind master pipe is connected with a high-pressure fan or a compressed air source, and the loose wind master pipe is provided with a regulating valve and a pressure sensor;

The front side and the rear side of the air distribution plate are arranged in a step-like manner by taking the central position as a symmetrical center, and the front end and the rear end are higher than the central position;

The outer peripheral surface of the connecting pipe is provided with a boss, the hood is supported on the boss, a circle of clamping ring is arranged at the edge of the boss, a gap of 1mm is reserved between the outer surface of the hood in a cold state and the inner side surface of the clamping ring, and the hood props against the clamping ring to realize locking when being heated and expanded.

After the invention is adopted, the slag dropping pipe adopts a square structure, the occupation ratio of the slag dropping pipe to the depth of the bed surface is larger than that of the traditional circular slag dropping pipe when the cross section of the slag dropping pipe is the same, slag is discharged conveniently, and the square has smaller influence on the arrangement of the hood and the connecting pipe than that of the circular slag dropping pipe when the cross section of the slag dropping pipe is enlarged, so that fluidization is facilitated; two symmetrically arranged loose wind branch pipes blow loose wind obliquely upwards into the hearth to realize opposite impact lifting and better blow slag, so that a fluidization dead zone is avoided, fine ash and combustible materials in the hearth can be blown back into the hearth, and the loss of bed materials and overhigh slag discharge carbon content are avoided; by the technical means, the boiler slag discharge is smoother, the boiler operation coking is prevented, and the bed material operation loss is reduced; further, loose wind can be adjusted by the governing valve and the pressure sensor, thereby realizing that slag discharge of different bed materials is adjustable, being more favorable to fluidization, taking over the arrangement of snap ring, the hood is heated and expanded when in thermal state operation, realizing thermal state self-locking, preventing invasion objects such as iron nails, iron wires and the like from entering the contact surface of taking over the snap ring and the hood, being favorable to maintaining normal fluidization, promoting slag discharge, leading two sides of the air distribution plate to be arranged in a step shape toward the center, being more favorable to leading slag blocks to be close to slag dropping pipes, and being more favorable to slag discharge.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic view of an arrangement of air distribution plates;

FIG. 3 is a schematic view of a slag dropping pipe;

FIG. 4 is a top view of FIG. 3;

FIG. 5 is a schematic view of the loose wind feed state of FIG. 3;

FIG. 6 is a schematic view of a hood and adapter (cold state).

Detailed Description

See fig. 1 to 6, a circulating fluidized bed boiler prevents stifled sediment structure, it includes furnace 1, the position of furnace front wall 2 and furnace back wall 3 has been marked in fig. 1, furnace 1 bottom is provided with air distributor plate 4, install take over 6 of taking hood 5 on the air distributor plate 4, air distributor plate 4 central point puts and is provided with the slag notch, slag notch connection slag pipe 7, slag pipe 7 is square adiabatic slag pipe, for the convenience of description, regard the limit that slag pipe 7 is parallel with furnace front side and rear side as the width of slag pipe, regard the limit that slag pipe 7 is parallel with furnace left side and right side as the length of slag pipe, length: the width is typically 400:200 or 400:300, etc., and the ratio thereof can be adjusted according to the actual condition of the fuel, but the length must be larger than the width. When the cross section area of the slag falling pipe 7 is the same, compared with a round slag falling pipe, the square slag falling pipe has a larger ratio of the depth of the bed surface, so slag is discharged, 3.14 x 1 can be achieved by the square slag falling pipe when the cross section area is 3.14, the radius of the round slag falling pipe is 1, the diameter is 2, and the square length is longer, so slag can enter the slag falling pipe more conveniently; when the cross section of the slag falling pipe 7 is enlarged, the square slag falling pipe has smaller influence on the arrangement of the bed hood compared with the circular slag falling pipe, so that the hood arrangement is simpler and more reasonable, fluidization is facilitated, because the circular slag falling pipe is enlarged in 360-degree direction simultaneously, the hood of one circle is required to be arranged again, and when the square slag falling pipe is enlarged, only the length or width of the hood of a small part can be changed, and only the hood of a small part needs to be adjusted.

Two loose air branch pipes 8 which are symmetrically arranged are connected to the side wall of the slag falling pipe 7, and air outlets of the loose air branch pipes 8 are obliquely upwards arranged, and the structure is generally as follows: the connecting section of the loosening air branch pipe 8 and the slag falling pipe 7 is obliquely upwards arranged, and the inclination angle can be 20-60 degrees, and is usually 45 degrees.

The two loose wind branch pipes 8 are connected with one end of the same loose wind pipe 9, the other end of the loose wind pipe 9 is connected with a high-pressure fan or a compressed air source, and the loose wind pipe 9 is provided with an adjusting valve 10 and a pressure sensor 11; when the device is operated, the regulating valve is opened, loose wind is introduced into the slag falling pipe 7 through the two loose wind branch pipes 8, is lifted after being hedging in the slag falling pipe 7, blows slag at the bottom, plays a role in fluidization, avoids generating a fluidization dead zone, and simultaneously can blow fine ash and combustible matters on the air distribution plate 4 back into the hearth 1, so that the loss of bed materials and overhigh carbon content in slag discharging are avoided. The deslagging and fluidization states can be judged by observing the change of the pressure value of the pressure sensor 11 corresponding to fuels in different states, and the deslagging of different bed materials can be truly adjusted by correspondingly adjusting the opening degree of the regulating valve 10 to control the amount of the introduced loosening air. The introduced loosening wind can simultaneously play a role in cooling the slag falling pipe 7, thereby being beneficial to preventing the slag falling pipe 7 from deforming and increasing the operation reliability.

The air distribution plates 4 are arranged in a step shape by taking the central position as the front side and the rear side of the symmetrical center, and the front end and the rear end are higher than the central position, so that slag blocks can approach the slag dropping pipe by self gravity, and slag discharging is facilitated. The step-shaped inclination angle is set to be 5-20 degrees according to different fuel properties.

The outer peripheral surface of the connecting pipe 6 is provided with a boss 12, the hood 5 is supported on the boss 12, and the edge of the boss 12 is provided with a circle of clamping rings 13. In order to maintain operation safety, fluidization and slag discharge are ensured, primary air is slightly used to be larger, a hood is easily blown up, iron wires and iron nails are easily invaded into gaps generated by the hood and a connecting pipe pedestal, and fluidization, slag discharge and subsequent maintenance are affected.

In the application, a gap of 1mm is reserved between the outer surface of the hood 5 in a cold state and the inner side surface of the clamping ring 13, the hood 5 is heated and expanded in a hot state operation, the inner surface of the clamping ring 13 is tightly attached to the outer surface of the hood 5, so that the hot state self-locking is realized, and invasion objects such as iron nails, iron wires and the like are prevented from entering the contact surface between the connecting pipe pedestal and the hood, thereby being beneficial to maintaining normal fluidization and promoting slag discharge.

By using the optimization scheme of the invention, the slag discharge of the boiler can be more smooth, the operation coking of the boiler is prevented, and the operation loss of the bed material is reduced; the scheme also has the capability of maintaining normal deslagging by adjusting deslagging loosening air when the deslagging grain diameter changes sharply.

Claims

1. The anti-blocking slag discharging structure of the circulating fluidized bed boiler comprises a wind distribution plate, wherein a connecting pipe with a wind cap is arranged on the wind distribution plate, a slag hole is formed in the center of the wind distribution plate, and the slag hole is connected with a slag discharging pipe; the connecting section of the loose wind branch pipe and the slag falling pipe is obliquely upwards arranged, and the inclination angle is 20-60 degrees; the two loose wind branch pipes are connected with one end of the same loose wind parent pipe, the other end of the loose wind parent pipe is connected with a high-pressure fan or a compressed air source, a regulating valve and a pressure sensor are installed on the loose wind parent pipe, a boss is arranged on the outer peripheral surface of the connecting pipe, a hood is supported on the boss, a circle of clamping ring is arranged on the edge of the boss, a gap of 1mm is reserved between the outer surface of the hood in a cold state and the inner side surface of the clamping ring, and the hood props against the clamping ring to realize locking when being heated and expanded.

2. The anti-blocking slag discharging structure of a circulating fluidized bed boiler according to claim 1, wherein the air distribution plates are arranged in a step shape with the center position as the front and rear sides of the symmetry center, and the front and rear ends are higher than the center position.