阅读说明：本技术 一种循环流化床锅炉沉降室的排灰装置及排灰方法 (Ash discharge device and ash discharge method for settling chamber of circulating fluidized bed boiler ) 是由 曾永光 常艳 邹超 罗红星 陈志远 宋根炎 鲁俊 董传芝 王万学 李明勇 于 2020-07-24 设计创作，主要内容包括：本发明涉及一种循环流化床锅炉沉降室的排灰装置及排灰方法,所述装置包括锅炉对流受热面及与之相连的烟道竖井,锅炉对流受热面的底部设有前后两排锅炉沉降室,各锅炉沉降室的底部均通过沉降室排灰装置连通至烟道竖井,锅炉沉降室的底部还安装有阻旋式料位开关,沉降室排灰装置包括排灰导管及设于排灰导管上的截断阀、热电阻温度计一及电动球阀一,排灰导管的侧壁还连通有压空吹扫管,烟道竖井的下部通过烟道连接除尘器；烟道竖井沉降室设有用于积灰吹扫的气化风板,气化风板风源来自罗茨风机。本申请提出的循环流化床锅炉沉降室的排灰装置,能够实现对锅炉沉降室内粉尘的密闭自动排放,且使用过程中不产生二次污染,经济性、实用性好。(The invention relates to an ash discharge device and an ash discharge method for a sedimentation chamber of a circulating fluidized bed boiler, wherein the device comprises a convection heating surface of the boiler and a flue vertical shaft connected with the convection heating surface of the boiler, the bottom of the convection heating surface of the boiler is provided with a front row of sedimentation chambers and a rear row of sedimentation chambers of the boiler, the bottom of each sedimentation chamber of the boiler is communicated to the flue vertical shaft through an ash discharge device of the sedimentation chamber, the bottom of each sedimentation chamber of the boiler is also provided with a rotation-resistant material level switch, the ash discharge device of the sedimentation chamber comprises an ash discharge conduit, a cut-off valve arranged on the ash discharge conduit, a first thermal resistance thermometer and a first electric ball valve, the side wall of the ash discharge conduit is also communicated with a pressure-air; the settling chamber of the vertical shaft of the flue is provided with a gasification air plate for blowing accumulated dust, and an air source of the gasification air plate is from a Roots blower. The application provides a circulating fluidized bed boiler settling chamber's ash discharging device can realize the airtight automatic emission of dust in the boiler settling chamber, and does not produce secondary pollution in the use, and economic nature, practicality are good.)

1. The utility model provides an ash discharging device of circulating fluidized bed boiler settling chamber, including boiler convection heating surface (25) and with flue shaft (12) that boiler convection heating surface (25) is connected, the bottom of boiler convection heating surface (25) is equipped with front row boiler settling chamber (4), back row boiler settling chamber (5), its characterized in that, front row boiler settling chamber (4) and back row boiler settling chamber's (5) bottom all communicates flue shaft (12) through settling chamber ash discharging device (23), front row boiler settling chamber (4), back row boiler settling chamber's (5) bottom still installs rotation-resistant formula material level switch (10), settling chamber ash discharging device (23) are including arranging grey pipe (19) and locating cut-off valve (7), thermal resistance thermometer (8) and electronic ball valve (9) on arranging grey pipe (19), rotation-resistant formula material level switch (10) and electronic ball valve (9) interlock, the side wall of the ash discharge conduit (19) is also communicated with a pressure-air purging pipe (20), the pressure-air purging pipe (20) is provided with a second electric ball valve (11), the bottom of the flue vertical shaft (12) is provided with a flue vertical shaft settling chamber (21), and the flue vertical shaft (12) is connected with a dust remover (22) through a flue (24);

the device is characterized in that the flue vertical shaft settling chamber (21) is provided with a gasification air plate (14) for accumulated dust blowing, a second thermal resistance thermometer (18) is arranged on the gasification air plate (14), and the gasification air plate (14) is connected with a Roots blower (15).

2. The ash discharger of the circulating fluidized bed boiler settling chamber as claimed in claim 1, wherein said rotation-resistance type level switch (10), said electric ball valve one (9), said electric ball valve two (11), said thermal resistance thermometer one (8), said thermal resistance thermometer two (18), and said roots blower (15) are connected to a DCS control system.

3. The ash discharging device for the settling chamber of the circulating fluidized bed boiler as claimed in claim 2, wherein the electric ball valve I (9) is interlocked with a primary boiler fan and an induced boiler fan, and the primary boiler fan and the induced boiler fan are also connected to the DCS control system.

4. The ash discharge device of the circulating fluidized bed boiler settling chamber of claim 1, wherein the gasification air plate (14) is welded with an air cap (26).

5. An ash discharge arrangement for a circulating fluidized bed boiler settler according to claim 1, characterized in that the convection heating surface (25) of the boiler comprises a superheater (1), a convection tube (2) and a lower drum (3), and that an air preheater (13) is installed in the shaft (12) of the flue.

6. The ash discharging device of the circulating fluidized bed boiler settling chamber as claimed in claim 1, wherein the inlets of the front row boiler settling chamber (4) and the rear row boiler settling chamber (5) are respectively provided with a grid plate (16).

7. An ash discharge arrangement of a circulating fluidized bed boiler settling chamber according to claim 1, characterized in that the ash discharge duct (19) is provided with a duckbill diffuser nozzle (17) at the end located in the flue shaft (12).

8. A method for discharging ash from an ash discharge device of a settling chamber of a circulating fluidized bed boiler according to any one of claims 1 to 7, comprising the steps of:

s1: when ash discharge operation is required, an electric ball valve I (9) connected with the front-row boiler settling chamber (4) is opened to discharge ash, the ash discharge operation is performed every T1 seconds, the air-pressure purging pipe (20) operates for T2 seconds to purge the ash discharge conduit (19), and in such a circulation manner, the rotation-resistant material level switch (10) at the lower part of the front-row boiler settling chamber (4) monitors that the boiler settling chamber (4) is in a low material level or controls the electric ball valve I (9) of the front-row boiler settling chamber (4) to perform ash discharge operation to be closed when the temperature measured by a thermal resistance thermometer I (8) arranged on the ash discharge conduit (19) is higher than T1 ℃;

s2: opening an electric ball valve I (9) for controlling the ash discharge of the rear-row boiler settling chamber (5), and repeating the S1 operation to control the ash discharge of the rear-row boiler settling chamber (5) until the ash discharge of all the boiler settling chambers (4) is finished;

s3: when the temperature of a second thermal resistance thermometer (18) arranged on the flue shaft (21) is lower than T2 ℃, the Roots blower (15) is started to discharge ash in the flue shaft (21), and the Roots blower (15) is stopped after T3 seconds of starting, so that the ash discharge operation is completed.

9. The ash discharging method of the ash discharging device of the circulating fluidized bed boiler settling chamber as claimed in claim 8, wherein after the roots blower (15) is turned on in step S3, the roots blower (15) supplies air to the gasification air plate (14) for air distribution, and then blows the air into the chimney shaft settling chamber (21) through the hood (26), and lifts the bottom of the chimney shaft settling chamber (21) to be sucked into the dust catcher (22) by the induced draft fan of the boiler.

10. The method for discharging the ash in the ash discharging device of the circulating fluidized bed boiler settling chamber, as claimed in claim 8, wherein the rotation-resistant material level switch (10), the electric ball valve I (9), the electric ball valve II (11), the thermal resistance thermometer I (8), the thermal resistance thermometer II (18), and the Roots blower (15) are connected to a DCS control system, and when ash discharging operation is performed, an automatic ash discharging button on the DCS control system is activated, and the DCS control system controls the operation to be completed from S1 to S3.

Technical Field

The invention relates to the technical field of ash discharge of a settling chamber of a boiler, in particular to an ash discharge device and an ash discharge method for a settling chamber of a circulating fluidized bed boiler.

Background

At the end of the twentieth century, a circulating fluidized bed combustion technology which integrates the advantages of wide fuel adaptability, high combustion efficiency, strong variable working condition capability, low content of smoke-discharging pollutants, good comprehensive utilization of ash and slag and the like is popularized and applied in China.

High-temperature flue gas erodes boilers convection heating surfaces such as a superheater and a convection bank to exchange heat during the operation of the circulating fluidized bed boiler, particles with high mass in the flue gas fall into a settling chamber at the bottom of the convection heating surface under the action of gravity to form furnace dust, and the furnace dust in the settling chamber of the convection heating surface of the boiler needs to be cleaned regularly, otherwise the convection heating surface of the circulating fluidized bed boiler is easily heated unevenly, and the flue gas is easy to drift. The existing boiler convection heating surface settling chamber generally adopts manual ash discharge or an external additionally arranged bin pump and an ash conveying device, so that the environmental pollution is caused or the investment cost is overlarge, and the existing boiler convection heating surface settling chamber is particularly unfavorable for narrow and small boiler room.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides an ash discharge device and an ash discharge method for a settling chamber of a circulating fluidized bed boiler, and solves the technical problems of large environmental pollution and high investment cost in ash discharge of the settling chamber of the existing boiler.

The invention is realized by the following technical scheme:

an ash discharge device of a sedimentation chamber of a circulating fluidized bed boiler comprises a convection heating surface of the boiler and a flue shaft connected with the convection heating surface, the bottom of the convection heating surface of the boiler is provided with a front row of boiler settling chambers and a rear row of boiler settling chambers, the bottoms of the front row of boiler settling chambers and the rear row of boiler settling chambers are communicated to a flue vertical shaft through a settling chamber ash discharging device, the bottom parts of the front row of boiler settling chambers and the rear row of boiler settling chambers are also provided with a rotation-resistant material level switch, the settling chamber ash discharging device comprises an ash discharging guide pipe, a cut-off valve, a first thermal resistance thermometer and a first electric ball valve which are arranged on the ash discharging guide pipe, the rotation-resisting material level switch is interlocked with the electric ball valve, the side wall of the ash discharge conduit is also communicated with an air-compressing blowing pipe, the pressure air purging pipe is provided with a second electric ball valve, the bottom of the flue vertical shaft is provided with a flue vertical shaft settling chamber, and the flue vertical shaft is connected with a dust remover through a flue;

and the settling chamber of the vertical shaft of the flue is provided with a gasification air plate for accumulated dust sweeping, a second thermal resistance thermometer is arranged on the gasification air plate, and the gasification air plate is connected with a Roots blower.

Furthermore, the rotation-resistant material level switch, the electric ball valve I, the electric ball valve II, the thermal resistance thermometer I, the thermal resistance thermometer II and the Roots blower are all connected to a DCS control system.

Furthermore, the first electric ball valve is interlocked with a primary boiler fan and a boiler induced draft fan, and the primary boiler fan and the boiler induced draft fan are also connected to the DCS control system.

Furthermore, a hood is welded on the gasification air plate.

Furthermore, the convection heating surface of the boiler comprises a superheater, a convection pipe and a lower steam pocket, and an air preheater is installed in the vertical shaft of the flue.

Furthermore, the inlets of the settling chambers of the boilers are respectively provided with a grid plate.

Furthermore, one end of the ash discharge conduit in the flue shaft is provided with a duckbill type diffusion nozzle.

An ash discharge method of an ash discharge device of a settling chamber of a circulating fluidized bed boiler specifically comprises the following steps:

s1: when ash discharge operation is required, an electric ball valve connected with a front-row boiler settling chamber is opened to discharge ash, an ash discharge guide pipe is swept by an air-compression sweeping pipe for T2 seconds every T1 seconds during the ash discharge operation, and the operation is circulated in such a way that a rotary resistance type material level switch at the lower part of the front-row boiler settling chamber monitors that the boiler settling chamber is in a low material level or when the temperature measured by a thermal resistance thermometer arranged on the ash discharge guide pipe is higher than T1 ℃, the electric ball valve for controlling the front-row boiler settling chamber to perform ash discharge operation is closed;

s2: opening an electric ball valve for controlling the ash discharge of the settling chambers of the back row boiler, and repeating the operation of S1 to control the ash discharge of the settling chambers of the back row boiler until the ash discharge of all the settling chambers of the back row boiler is finished;

s3: when the temperature of the second thermal resistance thermometer arranged on the flue shaft is lower than T2 ℃, the Roots blower is started to perform ash discharge operation in the flue shaft, and the Roots blower is stopped after T3 seconds of starting, so that the ash discharge operation is completed.

Further, after the roots blower is started in step S3, the air supplied by the roots blower enters the gasification air plate for air distribution, and is blown into the chimney shaft settling chamber through the hood, and the bottom ash of the chimney shaft settling chamber is lifted up and pumped into the dust remover by the boiler induced draft fan.

Furthermore, the rotation-resistant material level switch, the electric ball valve I, the electric ball valve II, the thermal resistance thermometer I, the thermal resistance thermometer II and the Roots blower are connected with the DCS control system, when ash discharge operation is carried out, an automatic ash discharge button on the DCS control system is started, and the DCS control system controls the operation to be completed from S1 to S3.

Compared with the prior art, the invention has the beneficial effects that:

the ash discharge device for the settling chamber of the circulating fluidized bed boiler provided by the invention has the advantages that the collected ash in the settling chamber of the boiler is automatically conveyed to the dust remover for disposal by reasonably arranging the combustion system of the boiler body, so that the automatic discharge and the airtight collection of the ash in the settling chamber of the boiler are realized, conveying equipment such as a bin pump, a material sealing pump and the like is not needed to be additionally arranged, the one-time investment is low, no secondary pollution is generated in the using process, the economy and the practicability are good, and the problems of environmental pollution or overlarge investment cost and the like caused by manual ash discharge of the settling chamber of the boiler or an externally additionally arranged bin pump and an ash conveying device are effectively solved;

the DCS control system is adopted to control ash discharge, so that automatic ash discharge of a settling chamber of the circulating fluidized bed boiler is realized, automatic shutdown of the ash discharge is completed, automation and unmanned operation are realized in the whole operation, and meanwhile, the whole ash discharge process is visually monitored in a DCS system control terminal of a boiler automatic control room.

Drawings

FIG. 1 is a schematic structural view of an ash discharge device of a settling chamber of a circulating fluidized bed boiler according to the present invention;

FIG. 2 is a schematic structural view of the settling chamber ash discharge device of the present invention.

In the figure:

1. a superheater; 2. a convection tube; 3. a lower steam pocket; 4. a front row of boiler settling chambers; 5. a back row boiler settling chamber; 6. an ash discharge pipe; 7. a shut-off valve; 8. a first thermal resistance thermometer; 9. a first electric ball valve; 10. a rotation-resisting material level switch; 11. a second electric ball valve; 12. a flue shaft; 13. an air preheater; 14. a gasification air plate; 15. a Roots blower; 16. a grid plate; 17. a duckbill type diffusion nozzle; 18. a second thermal resistance thermometer; 19. an ash discharge conduit; 20. a pressure-air purging pipe; 21. a flue shaft settling chamber; 22. a dust remover; 23. a settling chamber ash discharge device; 24. a flue; 25. a convection heating surface of the boiler; 26. a blast cap.

Detailed Description

The following examples are presented to illustrate certain embodiments of the invention in particular and should not be construed as limiting the scope of the invention. The present disclosure may be modified from materials, methods, and reaction conditions at the same time, and all such modifications are intended to be within the spirit and scope of the present invention.

As shown in fig. 1-2, an ash discharging device of a circulating fluidized bed boiler settling chamber comprises a boiler convection heating surface 25 and a flue shaft 12 arranged on one side of the boiler convection heating surface 25, wherein the bottom of the boiler convection heating surface 25 is provided with a front row of front boiler settling chambers 4 and a rear row of rear boiler settling chambers 5, the bottoms of the front row of boiler settling chambers 4 and the rear row of rear boiler settling chambers 5 are communicated to the flue shaft 12 through a settling chamber ash discharging device 23, the lower parts of the front row of boiler settling chambers 4 and the rear row of rear boiler settling chambers 5 are further provided with a rotation-resistant material level switch 10, the settling chamber ash discharging device 23 comprises an ash discharging conduit 19, and a blocking valve 7, a thermal resistance thermometer one 8 and an electric ball valve one 9 which are arranged on the ash discharging conduit 19, the rotation-resistant material level switch 10 is interlocked with the electric ball valve one 9, the side wall of the ash discharging conduit 19 is further communicated with an air-pressure purging pipe 20, the pressure-air purging pipe 20 is provided with a second electric ball valve 11, the flue shaft settling chamber 21 is connected with a flue 24, the flue 24 is connected with a dust remover 22, the flue shaft settling chamber 21 is provided with a gasification air plate 14, the gasification air plate 14 is provided with a second thermal resistance thermometer 18, the gasification air plate 14 is provided with an air cap 26 for blowing deposited dust, and the gasification air plate 14 is connected with the Roots blower 15.

The front row boiler settling chamber 4 is connected with one end of an ash discharge conduit 19 through an ash discharge pipe 6, and the other end of the ash discharge conduit 19 extends into the flue vertical shaft 12; similarly, the rear boiler settling chamber 5 is also communicated with the flue shaft 12 through the same structure. The dust deposited at the bottoms of the front row of boiler settling chambers 4 and the rear row of boiler settling chambers 5 is introduced into the flue shaft 12 through the dust discharge pipe 6 and the dust discharge guide pipe 19, the Roots blower 15 uniformly distributes air to the flue shaft settling chamber 21 through the gasification air plate 14, and the furnace dust in the flue shaft settling chamber 21 is lifted up and pumped into the dust remover 22 by the induced draft fan of the boiler for treatment.

The cutoff valve 7 is used for ash discharge partition of the ash discharge guide pipe 19 in an abnormal state, the thermal resistance thermometer I8 is used for judging whether ash discharge is finished or not, the electric ball valve I9 is used for ensuring that ash discharge operation is automatically opened or closed according to control requirements, the air-pressure blowing pipe 20 is used for blowing the ash discharge guide pipe 19 periodically in the ash discharge process to prevent the ash discharge guide pipe 19 from being blocked, and the electric ball valve II 11 is mounted on the air-pressure blowing pipe 20 and used for periodically sending compressed air into the air-pressure blowing pipe 20 in the ash discharge process;

the gasification air plate 14 of the flue shaft settling chamber 21 is used for uniformly distributing air to the bottom of the flue shaft settling chamber 21, and a second thermal resistance thermometer 18 is arranged on the gasification air plate 14 and used for judging the deposition amount of the furnace dust in the flue shaft settling chamber 21.

The rotation-resisting type material level switch 10 is linked with the electric ball valve I9, when the ash in the front row boiler settling chamber 4 or the rear row boiler settling chamber 5 reaches a low level, a low material level alarm signal can be sent out in time, so that the electric ball valve I9 in the ash discharge guide pipe 19 of the linked boiler settling chamber is closed, and the ash discharge operation of the front row boiler settling chamber 4 or the rear row boiler settling chamber 5 is stopped.

In this embodiment, the rotation resistance type material level switch 10, the first electric ball valve 9, the second electric ball valve 11, the first thermal resistance thermometer 8, the second thermal resistance thermometer 18 and the roots blower 15 are all connected to the DCS control system. And automatic ash discharge is realized through the control of a DCS (distributed control system).

In this embodiment, the electric ball valve I9 is interlocked with a boiler primary air fan and a boiler induced draft fan, and the boiler primary air fan and the boiler induced draft fan are also connected to a DCS control system; if any one of the primary air fan and the induced draft fan of the boiler stops running, the electric ball valve I9 cannot be opened, and the automatic ash discharge is closed; only under the condition that a primary air fan of the boiler and a draught fan of the boiler work simultaneously, the electric ball valve I9 can be normally opened, and the automatic ash discharge opening is realized.

In the embodiment, a hood is welded on the gasification air plate 14, and the gasification air plate 14 is connected to the roots blower 15 through the hood; the wind cap accelerates the parallel wind blown by the Roots blower 15 and converts the parallel wind into vertical air flow from bottom to top so as to lift the furnace dust in the flue shaft 21.

In the embodiment, the convection heating surface 25 of the boiler comprises a superheater 1, a convection pipe 2 and a lower steam pocket 3, and an inspection door 12 and an air preheater 13 are arranged above the flue shaft 21.

In this embodiment, the inlets of the front row of boiler settling chambers 4 and the rear row of boiler settling chambers 5 are respectively provided with a grid plate 16 for preventing the larger-sized refractory bricks, refractory castable and impurities from blocking the ash discharge pipes 6 or the ash discharge ducts 19 of the settling chambers.

In this embodiment, the ash discharge duct 19 is provided with a duckbill type diffusion nozzle 17 at one end located in the flue shaft 21 for diffusing the ash discharged from the front row boiler settling chamber 4 and the rear row boiler settling chamber 5 to prevent the ash from accumulating in the flue shaft settling chamber 21.

An automatic ash discharge method of an ash discharge device of a settling chamber of a circulating fluidized bed boiler specifically comprises the following steps:

s1: pressing a 'sedimentation chamber automatic ash discharge opening' function key in a DCS control system, enabling the system to enter automatic ash discharge, opening a first electric ball valve 9 connected with a front row boiler sedimentation chamber 4, discharging ash, wherein every 60 seconds of ash discharge operation, a second electric ball valve 11 arranged on a pressure air purging pipe 20 works for 10 seconds to purge an ash discharge conduit 19, and circulating in such a way, a rotation resistance type material level switch 10 at the bottom of the front row boiler sedimentation chamber 4 monitors that the front row boiler sedimentation chamber 4 is in a low material level or controls the first electric ball valve 9 of the front row boiler sedimentation chamber 4 to be closed when the temperature measured by a first thermal resistance thermometer 8 arranged on the ash discharge conduit 19 is higher than 200 ℃;

s2: when the first electric ball valve 9 connected with the front row of front row boiler settling chamber 4 is closed for 120 seconds, the first electric ball valve 9 arranged on the ash discharge conduit 19 of the rear row of boiler settling chamber 5 is opened for ash discharge operation, every 60 seconds of the ash discharge operation, the second electric ball valve 11 arranged on the air-pressure purging pipe 20 works for 10 seconds to purge the ash discharge conduit 19, and the process is circulated, when the rotary resistance type material level switch 10 at the lower part of the rear row of boiler settling chamber 5 monitors that the rear row of boiler settling chamber 5 is at a low material level or when the temperature measured by the first thermal resistance thermometer 8 arranged on the ash discharge conduit 19 is higher than 200 ℃, the first electric ball valve 9 for controlling the rear row of boiler settling chamber 5 to perform ash discharge operation is closed until the ash discharge of the rear row of boiler settling chamber 5 is completed;

s3: when the first electric ball valve 9 for controlling ash discharge of the rear-row boiler settling chamber 5 is closed for 300 seconds, and when the temperature of the second thermal resistance thermometer 18 arranged on the flue shaft settling chamber 21 is lower than 120 ℃, the Roots blower 15 is automatically and interlockingly started to purge the ash in the flue shaft settling chamber 21, and when the Roots blower 15 is started for 120 seconds, the operation is stopped, and the automatic ash discharge operation is completed;

s4: when the rotation-resistant material level switch 10 sends out a low material level, the system sends out a human voice alarm, the Roots blower 15 starts the system to send out a human voice alarm, and when the temperature measured by the first thermal resistance thermometer 8 arranged on the ash discharge guide pipe 19 of the front-row boiler settling chamber 4 and the rear-row boiler settling chamber 5 is higher than 200 ℃, the system sends out a human voice alarm to prompt an operator.

In this embodiment, after the roots blower 15 is turned on in step S3, the roots blower 15 supplies air to the gasification damper 14 for distribution, and blows the air into the chimney neck settling chamber 21 through the hood 26, so as to lift the bottom ash in the chimney neck settling chamber 21 and draw the ash into the dust collector 22 by the boiler induced draft fan.

A manual ash discharge method of an ash discharge device of a settling chamber of a circulating fluidized bed boiler specifically comprises the following steps:

s1: when ash discharge is needed, manually opening a first electric ball valve 9 connected with a sedimentation chamber 4 of the front-row boiler, discharging ash, wherein every 60 seconds of ash discharge operation, a second electric ball valve 11 arranged on a compressed air purging pipe 20 works for 10 seconds to purge an ash discharge conduit 19, and circulating in this way, monitoring that the sedimentation chamber 4 of the front-row boiler is in a low material level by a rotation-resistant material level switch 10 at the lower part of the sedimentation chamber 4 of the front-row boiler, or controlling the first electric ball valve 9 of the sedimentation chamber 4 of the front-row boiler to perform ash discharge operation to be closed when the temperature measured by a first thermal resistance thermometer 8 arranged on the ash discharge conduit 19 is higher than 200 ℃;

s2: manually opening a first electric ball valve 9 arranged on an ash discharge conduit 19 of a rear-row boiler settling chamber 5, performing ash discharge operation, and operating a second electric ball valve 11 arranged on an air-pressure purging pipe 20 to purge the ash discharge conduit 19 for 10 seconds every 60 seconds of the ash discharge operation, so that when a rotation-resistant material level switch 10 arranged at the lower part of the rear-row boiler settling chamber 5 monitors that the rear-row boiler settling chamber 5 is in a low material level or when the temperature measured by a first thermal resistance thermometer 8 arranged on the ash discharge conduit 19 is higher than 200 ℃, an operator manually closes the first electric ball valve 9 for controlling the rear-row boiler settling chamber 5 to perform ash discharge operation, so that ash discharge of the front-row boiler settling chamber 4 and the rear-row boiler settling chamber 5 is completed;

s3: when the temperature of the second thermal resistance thermometer 18 arranged on the flue shaft settling chamber 21 is lower than 120 ℃, the Roots blower 15 is manually started to perform soot blowing operation in the flue shaft settling chamber 21, and when the Roots blower 15 is started for 120 seconds, the operation is stopped, and the manual soot discharging operation is completed.

The method is characterized in that the furnace dust in the front row of boiler settling chambers 4 and the rear row of boiler settling chambers 5 is discharged into a flue shaft 12 at the bottom of an air preheater 13 through a settling chamber dust discharge guide pipe 19 and enters a boiler dust remover 22 along with the flow of boiler flue gas to be collected and disposed, a rotary resistance material level switch 10 and a thermal resistance thermometer 8 are used as judgment devices for preventing the short circuit of the flue gas generated by the discharged furnace dust, and meanwhile, the Roots blower 15 and an air distribution system of the flue shaft settling chamber 21 are used for realizing the ash discharge for preventing the discharged furnace dust from being accumulated in the flue shaft settling chamber 21 at the bottom of the air preheater 13.

In conclusion, the ash discharging device is arranged in the original boiler body combustion system, is compact in structure, realizes the airtight discharge and automatic/manual discharge of the furnace ash in the settling chamber of the circulating fluidized bed boiler, and solves the problems of environmental pollution or overlarge investment cost and the like caused by manual ash discharging in the settling chamber or an external newly-added bin pump and an ash conveying device.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.