System and method for solving ash blockage of tail flue of boiler

Abstract

The invention discloses a system and method for solving ash blocking of a boiler tail flue, and particularly relates to the technical field of cogeneration engineering, the system comprises a boiler tail outlet flue, a dust remover and an induced draft fan, and a port of the boiler tail outlet flue faces downwards in the vertical direction; the output end of the dust remover is connected with the input end of the induced draft fan, and the input end of the dust remover is fixedly communicated with a first flange connector fixedly installed on the side wall of the boiler tail outlet flue. A first pipeline communicated with the input end of the induced draft fan is communicated with an ash hopper port of the boiler tail outlet flue. A part of flue gas is guided by an outlet of the induced draft fan, the flue flow speed is increased and the sticky ash is disturbed through the injection device, the ash pipe is arranged at the position where the ash is prone to being accumulated, the ash is fed into the inlet flue of the dust remover through pressure difference, and the problem of ash accumulation in the tail flue is solved in the most economical mode by combining air cannon vibration bridging ash and wall sticky ash intermittently released on the ash hopper.

Description

Technical Field

[0001] The present invention relates to the technical field of cogeneration engineering, and in particular to a system and method for solving ash blockage in a boiler tail flue. Background Art

[0002] The problem of ash accumulation in the tail flue of the boiler is a common problem in the operation of general industrial solid waste cogeneration projects, affecting the long-term stable operation of the unit and even the safety of the flue support structure. There are two main reasons for the ash accumulation in the tail flue: on the one hand, the ash after the general industrial solid waste or biomass is burned in the boiler has a certain degree of adhesion, which easily forms bridges or sticks to the wall in the ash hopper, causing the ash in the hopper to flow poorly and form ash accumulation; on the other hand, the cross-section of the tail flue is designed according to the rated load condition of the boiler, and the flow rate is generally around 12m / s. However, the operating conditions of the boiler in the cogeneration project are often affected by the external heating load, and low-load operation conditions are very common. Due to the low flow rate in the tail flue under low-load conditions, the ash in the flue cannot be blown away, which will lead to a vicious cycle and more and more ash will accumulate.

[0003] There are two main ways to solve the dust accumulation in the tail flue: One is to use manual methods, where a dedicated person enters the flue to clean the ash every time the furnace is shut down. This method is labor-intensive and time-consuming, and cannot meet the requirements for cleaning during operation. The second is to use pneumatic conveying equipment to transport the ash at the bottom of the flue through the ash pipe and transport it to the ash storage by compressed air positive pressure; In summary, although the above solutions to dust accumulation can achieve continuous dust discharge, they require the installation of facilities such as silo pumps, have certain requirements on the height of the flue bottom, and have high investment and operating costs. They cannot solve the problems of bridging or wall sticking. Summary of the Invention

[0004] The purpose of the present invention is to provide a system and method for solving the ash blockage of the boiler tail flue, so as to solve the above-mentioned problem.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a system for solving the problem of ash blockage in the tail flue of a boiler, comprising a boiler tail outlet flue, a dust collector and an induced draft fan, wherein the port of the boiler tail outlet flue is vertically downward; The output end of the dust collector is connected to the input end of the induced draft fan, and its input end is fixedly connected to the first flange interface fixedly installed on the side wall of the boiler tail outlet flue; The ash hopper port of the flue gas outlet at the tail end of the boiler is connected to a first pipe which is also connected to the input end of the induced draft fan; The output end of the induced draft fan is connected to an induced draft fan outlet flue; An injection device is fixedly installed on the input end of the dust collector, and the output end of the injection device is in the same direction as the flue gas flow; The exhaust duct at the induced draft fan outlet is connected in parallel with a second pipe, and the second pipe is connected in parallel with the input end of the injection device.

[0006] Preferably, a second gate valve is connected in series to the first pipeline, and a first gate valve is connected in series to the second pipeline.

[0007] Preferably, the output end of the dust collector is connected in parallel with a third pipe, the third pipe end is connected in parallel with the first pipe, and is located at the output end of the gate valve 2.

[0008] Preferably, the ash hopper of the flue at the tail end of the boiler is fixedly mounted with a plurality of air cannon tubes distributed in a circular array, and the axes of the air cannon tubes are arranged horizontally.

[0009] Preferably, the injection device is composed of a plurality of injection ports distributed in a circular array, and the angle between the injection ports and the inner wall of the dust collector input end is 45°.

[0010] Preferably, a guide ring distributed adjacent to the ash hopper is welded to the inner wall of the flue at the tail end of the boiler, and a groove is formed between the guide ring and the inner wall of the flue at the tail end of the boiler, and the end of the groove faces the ash hopper; It also includes a lining metal plate, one end of which is bent to form a connecting portion, the connecting portion is located in the groove and welded to the inner wall of the boiler tail outlet flue; A through hole is provided on the inner lining metal plate, and a first corrugated compensating tube is fixedly connected between the through hole and the end of the air gun barrel. The first corrugated compensating tube is provided with air holes distributed in a circumferential manner, and the air holes are connected to the cavity between the boiler tail outlet flue and the inner lining metal plate.

[0011] Preferably, the lining metal plate is provided with at least three gap holes distributed in a circular array, and wedge blocks with inclined surfaces fitting together to close the gap holes are fixedly installed at both ends of the lining metal plate at the gap holes.

[0012] Preferably, a U-shaped portion is bent on the inner lining metal plate and is located between two adjacent gap holes. In a default state, the ends of the U-shaped portion are in abutting connection.

[0013] Preferably, an elastic memory sheet metal part fixedly mounted on one of the wedge-shaped blocks adjacent to the gap slit passes through the puncture groove provided on the lining metal plate into the cavity and is fixedly connected to the side wall of the lining metal plate, and the U-shaped portion is located within the length coverage range of the elastic memory sheet metal part.

[0014] A method for solving ash blockage in a boiler tail flue, comprising the system for solving ash blockage in a boiler tail flue as described in the solution, the method comprising the following steps: S01. The negative pressure difference generated by the operation of the induced draft fan continuously draws the dust accumulated in the two ash hoppers into the flue before dust removal. After being captured by the dust collector, it is transported to the ash storage, forming a closed-loop ash transportation path. During the operation of step S02 and step S01, air cannons are arranged circumferentially around the ash hopper at the bottom of the flue at the tail of the boiler to release high-pressure gas shock waves at regular intervals to destroy the compacted structure of the ash in the ash hopper; During the operation of step S03 and step S01, an adjustable injection device is set between the exhaust fan outlet flue and the flue before dust removal, and the start and stop are controlled by the gate valve 1, and the device is set to the following two working positions: High load condition: Close the gate valve 1 and rely on the natural flow rate of the flue to prevent dust accumulation; Low load condition: Open the gate valve 1 to inject part of the purified flue gas into the flue before dust removal from the circumferential injection port at a 45° downstream angle, forming a swirl disturbance to inhibit the sedimentation of ash particles.

[0015] In the above technical solution, the present invention provides a system and method for solving the ash blockage of the boiler tail flue, which has the following beneficial effects: 1. A portion of the positive-pressure flue gas from the induced draft fan outlet is injected into the ash-prone area in the negative-pressure zone through the ejector device, thereby increasing the flue gas flow velocity in the flue in that area and disturbing the ash sticking, effectively solving the serious ash accumulation problem in that area when the boiler is running at low load without adding additional equipment or investment. 2. The negative pressure difference between the two places in the flue before dust removal is used as the power to achieve continuous ash discharge, replacing the conventional pneumatic conveying system under the ash hopper. This not only reduces equipment investment and operating costs, but also solves the problem that the ash hopper outlet is too low to install a silo pump. 3. Install an air cannon outside the ash hopper and use the impact force generated by the air cannon to impact the ash hopper, which can effectively solve the problem of ash sticking to the wall due to high humidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 A schematic diagram of the organizational structure provided by an embodiment of the present invention; Figure 2 A schematic cross-sectional view of a flue gas outlet at the tail end of a boiler according to an embodiment of the present invention; Figure 3A schematic diagram of a partially enlarged structure of the inner lining metal plate and the boiler tail outlet flue provided in an embodiment of the present invention; Figure 4 The embodiment of the present invention provides Figure 3 Schematic diagram of the operating principle structure.

[0018] Description of reference numerals: 1. Boiler tail outlet flue; 11. First flange interface; 2. Dust collector front flue; 3. Dust collector; 4. Induced draft fan; 5. Induced draft fan outlet flue; 6. Gate valve 1; 7. Injection device; 8. Air cannon tube; 9. Gate valve 2; 10. Gate valve 3; 100. Guide ring; 200. Groove; 300. Lining metal plate; 301. Connecting part; 302. Through hole; 303. First corrugated compensation pipe; 304. Wedge block; 305. U-shaped part; 306. Elastic memory sheet metal; 400. Cavity; 500. Gap slit hole; 600. Second corrugated compensation pipe; 700. Corrugated compensation ring; 800. Concave guide groove. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0020] A system for solving ash blockage in a boiler tail flue comprises a boiler tail outlet flue 1, a dust collector 3, an induced draft fan 4, a gate valve 1 6 and a gate valve 2 9. The system comprises: Example 1:

[0021] Combine Figure 1 As shown, the port of the boiler tail outlet flue 1 is vertically downward, and the output end of the dust collector 3 is connected to the input end of the induced draft fan 4, and its input end is fixedly connected to the first flange interface 11 fixedly installed on the side wall of the boiler tail outlet flue 1.

[0022] Furthermore, the ash hopper port of the boiler tail outlet flue 1 is connected to a first pipeline which is also connected to the input end of the induced draft fan 4 , and the first pipeline is connected in series with a gate valve 2 9 .

[0023] Furthermore, the output end of the induced draft fan 4 is connected to the induced draft fan outlet flue 5, and the induced draft fan outlet flue 5 is connected in parallel to a second pipe, which is connected in parallel to the input end of the injection device 7. The second pipe is also connected in series to a gate valve 1 6. The output end of the dust collector 3 is connected in parallel to a third pipe, and the end of the third pipe is connected in parallel to the first pipe and is located at the output end of the gate valve 2 9. In this embodiment, when the induced draft fan 4 is in operation, the negative pressure difference between two locations is used as a driving force to merge the ash from the ash hopper at the bottom of the boiler tail outlet flue 1 and the ash hopper at the vertical bend of the pre-dust removal flue 2 (that is, the input end of the dust collector 3) through the ash pipe into the pre-dust removal flue 2. The ash is then sucked into the dust collector 3 by the suction force of the induced draft fan 4 for dust removal, and finally sent to the ash bin. This replaces the conventional pneumatic conveying system below the ash hopper, simplifies the system, and achieves continuous ash discharge. This not only reduces equipment investment and operating costs, but also solves the problem of the ash hopper outlet being too low to install a silo pump.

[0024] Furthermore, an injection device 7 is fixedly mounted on the input end of the dust collector 3. The output end of the injection device 7 is aligned with the direction of flue gas flow. The injection device 7 is composed of multiple injection ports distributed in a circular array, and the angle between the injection ports and the inner wall of the input end of the dust collector 3 is 45 degrees. The outlet of the injection device 7 is arranged in a circle of injection ports along the circumference of the pre-dust removal flue 2. The injection ports are connected to the flue at a 45-degree angle to the centerline of the flue in the direction of flue gas flow. By returning a portion of the high-pressure flue gas from the exhaust fan outlet, the flow velocity in the flue is increased and the accumulated dust in the flue is disturbed. This solves the problem of low-load flow velocity being too low to blow away the dust in the flue, effectively solving the serious problem of low-load dust accumulation. During operation, a gate valve 6 is provided on the flue gas duct between the injection device 7 and the exhaust fan outlet flue 5 to control the switch state of the returned flue gas. When the boiler is running at a higher load, the flow rate of the flue 2 before dust removal is higher, and generally there is no dust accumulation. At this time, the gate valve 6 is in the closed state; when the boiler is running at a lower load, the flow rate of the flue 2 before dust removal is low, and dust accumulation is likely to occur. At this time, the gate valve 6 is in the open state.

[0025] Furthermore, the ash hopper of the boiler tail flue 1 is fixedly mounted with a plurality of air cannon tubes 8 distributed in a circular array, with the axes of the air cannon tubes 8 arranged horizontally. The air cannon tubes 8 are supplied with air by an air pump. During operation, the air pump inflates the air. When the pressure reaches a predetermined level, the air cannon tubes 8 release the air pressure. The impact force generated by the air cannon tubes impacts the ash hopper, effectively solving the problem of ash sticking to the wall due to high humidity, such as ash sticking to the wall, and allowing the ash in the ash hopper to resume gravity flow and flow smoothly into the ash collection pipe, that is, the ash hopper of the boiler tail flue 1.

[0026] It should be noted that the ash dropping pipes of the ash hopper at the bottom of the boiler tail outlet flue 1 and the ash hopper at the bottom of the vertical bend of the flue 2 before dust removal are respectively provided with gate valve 2 9 and gate valve 3 10, both of which are in normally open state and serve as a shut-off during maintenance.

[0027] In summary, Example 1 achieves continuous ash discharge during operation, reducing labor intensity and improving unit operational safety and stability. Furthermore, it simplifies the continuous ash discharge system and fully utilizes existing equipment, significantly reducing equipment investment and operating costs while effectively resolving the issue of the ash hopper outlet being too low to accommodate a silo pump. Furthermore, it effectively addresses the issue of ash sticking to the flue wall due to high humidity, effectively solving the problem of ash accumulation in the tail flue in the most economical and effective way.

[0028] Example 2:

[0029] Combine Figure 2-4 As shown, in this embodiment, a guide ring 100 distributed adjacent to the ash hopper is welded on the inner wall of the flue duct 1 at the tail end of the boiler. A groove 200 is formed between the guide ring 100 and the inner wall of the flue duct 1 at the tail end of the boiler, and the end of the groove 200 faces the ash hopper. It also includes a lining metal plate 300, one end of which is bent to form a connecting portion 301, the connecting portion 301 is located in the groove 200 and welded to the inner wall of the boiler tail outlet flue 1; A through hole 302 is provided on the inner lining metal plate 300, and a first corrugated compensation tube 303 is fixedly connected between the through hole 302 and the end of the air gun tube 8. The first corrugated compensation tube 303 is provided with air holes distributed in a circular pattern, and the air holes are connected to the cavity 400 between the boiler tail outlet flue 1 and the inner lining metal plate 300.

[0030] Specifically, in this embodiment, a flange is welded to the port of the ash hopper at the boiler tail flue outlet 1, and the end of the inner lining metal plate 300 contacts the flange. A corrugated compensation ring 700 is fixedly welded between the inner wall of the ash hopper. Similarly, a second corrugated compensation pipe 600 is fixedly installed between the through hole 302 in the inner lining metal plate 300 and the first flange interface 11.

[0031] That is, when the air cannon tube 8 is running, part of the air flow enters the cavity 400 through the air holes. Because the cavity 400 is in a sealed state, when the air pressure inside the cavity 400 increases, the lining metal plate 300 bulges toward the inside of the ash hopper under the action of the air pressure, and then returns to the inside of the air cannon tube 8 with the gas, and recovers instantly, thereby forming an effect similar to knocking on the inner wall of the lining metal plate 300 to prevent dust accumulation on the inner wall of the ash hopper.

[0032] As an embodiment further provided by the present invention, the lining metal plate 300 is provided with no less than three gap holes 500 distributed in a circular array, and the two ends of the lining metal plate 300 located at the gap holes 500 are fixedly installed with wedge blocks 304 with inclined surfaces that fit together to close the gap holes 500.

[0033] Specifically, in the embodiment, one of the two wedge blocks 304 located in a gap hole 500 is fixed, defined as a, and the other side is not fixed, defined as b. Figure 4 It can also be seen that the two inclined surfaces are in contact, thereby eliminating the gap slit 500. Therefore, when the air cannon tube 8 is running, part of the air flow enters the cavity 400 through the air hole. After the instantaneous strong air flow enters, b will be lifted up, and b lifted up by the air pressure will be inclined toward the inside of the lining metal plate 300, so multiple streams of air entering the inside of the lining metal plate 300 will form a vortex, and the air flow will spirally rise, thereby increasing the time that dust stays in the air. Because the air cannon tube 8 here releases the air cannon tube according to a predetermined periodic rule, the periodic spiral rising air flow can utilize the vortex to accumulate dust and avoid the contact between dust and the ash hopper, that is, the lining metal plate 300; at the same time, the periodic release can also accelerate the vortex, that is, the vortex of a cycle is strengthened again during the weakening process, thereby increasing the dust gathering effect.

[0034] As a further embodiment provided by the present invention, a U-shaped portion 305 is bent on the lining metal plate 300 and located between two adjacent gap holes 500 . In a default state, the ends of the U-shaped portion 305 are in abutment connection.

[0035] Furthermore, an elastic memory sheet metal part 306 fixedly mounted on a wedge block 304 of an adjacent gap slit hole 500 passes through a puncture groove provided on the lining metal plate 300 and enters the cavity 400 and is fixedly connected to the side wall of the lining metal plate 300, and the U-shaped portion 305 is located within the length coverage range of the elastic memory sheet metal part 306.

[0036] Specific, combined Figure 2 and Figure 3 It can be seen that the elastic memory sheet metal 306 in the embodiment is installed on b, and the elastic memory sheet metal 306 is attached to the inner wall of the lining metal plate 300 and then passes through the puncture groove into the cavity 400, and is bent and attached to the inner wall of the concave guide channel 800 welded on the inner wall of the boiler tail outlet flue 1, and finally lies on the lining metal plate 300, that is, the wedge block 304 of another gap hole 500, that is, a.

[0037] In the embodiment, when a strong airflow enters instantly, it will push up b, and b, which is pushed up by the air pressure, tilts toward the inside of the lining metal plate 300. At this time, the elastic memory sheet metal 306 moves toward the inside of the cavity 400 along with the tilted b, thereby forming a push to open the U-shaped portion 305 port and increase it, that is, b extends laterally and is parallel to a, so that the portion between two adjacent gap slits 500 of the lining metal plate 300 has a certain degree of ductility, that is, displacement. Here, the gap slit 500 is formed after b and a are staggered. The airflow passes through the gap slit 500 to ensure the formation of a spiral upward airflow.

[0038] It should be noted that during the upward process, the spiral upward airflow is blocked and guided by the side of the guide ring 100 facing the groove 200, causing the airflow to be inclined downward, that is, toward the mid-vertical line of the boiler tail outlet flue 1, thereby forming a localized circulation. The air flow speed here is relatively fast, which will quickly attract the dust falling into the ash hopper and enter the ash hopper. Then, the spiral upward airflow is periodically formed to accumulate dust.

[0039] Example 3:

[0040] Based on the first embodiment, a method for solving the problem of ash blockage in the tail flue of a boiler includes the following steps: The negative pressure difference generated by the operation of S01 and induced draft fan 4 continuously draws the dust accumulated in the two ash hoppers into the pre-dust removal flue 2, which is captured by the dust collector 3 and then transported to the ash storage, forming a closed-loop ash transportation path; During the operation of step S02 and step S01, air cannon tubes 8 are arranged circumferentially at the bottom of the ash hopper at the tail outlet flue 1 of the boiler to release high-pressure gas shock waves at regular intervals to destroy the compacted structure of the ash in the ash hopper; During the operation of step S03 and step S01, an adjustable injection device 7 is installed between the exhaust fan outlet flue 5 and the pre-dust removal flue 2, and the start and stop of the device is controlled by a gate valve 6, and the device is arranged in the following two working positions: High load condition: Close the gate valve 6 and rely on the natural flow velocity of the flue (15m / s) to prevent dust accumulation; Low load condition: open the gate valve 6, and inject part of the purified flue gas into the pre-dust removal flue 2 from the circumferential injection port at a 45° downstream angle to form a swirl disturbance (the flow rate is increased to more than 12m / s) to inhibit the sedimentation of ash particles.

[0041] The implementation process of the above dust removal method includes: 1. After the boiler is started, the air cannon tube 8 is automatically cleaned according to the preset cycle (10-30 minutes / time); 2. Real-time monitoring of boiler load (any commonly known detection element such as a pressure sensor or an air pressure sensor can be used). When the load rate is lower than 50%, the DCS system automatically opens the gate valve 6 and activates the injection disturbance; 3. Under the action of negative pressure, the accumulated ash in the ash hopper is divided into two paths through the gate valve 2 9 and the gate valve 3 10 and then flows into the flue 2 before dust removal; 4. After the ash-containing air flow is purified by the dust collector 3, the clean flue gas is discharged with pressure through the induced draft fan 4, and the captured ash is transported to the ash storage.

[0042] The above-mentioned multi-mechanical synergy of negative pressure suction + mechanical cleaning + pneumatic disturbance breaks through the technical limitations of traditional single cleaning methods. The injection angle is dynamically matched with the flue gas flow field, reducing energy consumption while improving anti-clogging efficiency. The injection angle is dynamically matched with the flue gas flow field, reducing energy consumption while improving anti-clogging efficiency.

[0043] It should be noted that the above-mentioned control program and electronic components are common technical knowledge to those skilled in the art, and therefore will not be described in detail.

[0044] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A system for solving the problem of ash blockage in the tail flue of a boiler, comprising a boiler tail outlet flue (1), a dust collector (3) and an induced draft fan (4), characterized in that: The port of the boiler tail outlet flue (1) is vertically downward; The output end of the dust collector (3) is connected to the input end of the induced draft fan (4), and the input end thereof is fixedly connected to a first flange interface (11) fixedly installed on the side wall of the boiler tail outlet flue (1); The ash hopper port of the boiler tail outlet flue (1) is provided with a first pipe connected to the input end of the induced draft fan (4); The output end of the induced draft fan (4) is connected to an induced draft fan outlet flue (5); An injection device (7) is fixedly mounted on the input end of the dust collector (3), and the output end of the injection device (7) is oriented in the same direction as the flow direction of the flue gas; The exhaust fan outlet flue (5) is connected in parallel with a second pipe, and the second pipe is connected in parallel with the input end of the injection device (7).

2. A system for solving ash blockage in the tail flue of a boiler according to claim 1, characterized in that: The first pipeline is connected in series with a second gate valve (9), and the second pipeline is connected in series with a first gate valve (6).

3. The system for solving ash blockage in the tail flue of a boiler according to claim 1 is characterized in that: The output end of the dust collector (3) is connected in parallel with a third pipeline, and the end of the third pipeline is connected in parallel with the first pipeline and is located at the output end of the second gate valve (9).

4. The system for solving ash blockage in the tail flue of a boiler according to claim 1 is characterized in that: The ash hopper of the flue gas outlet (1) at the rear of the boiler is fixedly provided with a plurality of air cannon tubes (8) distributed in a circumferential array, and the axes of the air cannon tubes (8) are arranged horizontally.

5. The system for solving ash blockage in the tail flue of a boiler according to claim 1 is characterized in that: The injection device (7) is composed of a plurality of injection ports distributed in a circumferential array, and the angle between the injection ports and the inner wall of the flue at the input end of the dust collector (3) is 45°.

6. The system for solving ash blockage in the tail flue of a boiler according to claim 4 is characterized in that: A guide ring (100) distributed adjacent to the ash hopper is welded to the inner wall of the boiler tail outlet flue (1), a groove (200) is formed between the guide ring (100) and the inner wall of the boiler tail outlet flue (1), and an end of the groove (200) faces the ash hopper; It also includes a lining metal plate (300), one end of which is bent to form a connecting portion (301), the connecting portion (301) being located in the groove (200) and welded to the inner wall of the boiler tail outlet flue (1); A through hole (302) is provided on the inner lining metal plate (300), and a first corrugated compensating tube (303) is fixedly connected between the through hole (302) and the end of the air cannon tube (8). The first corrugated compensating tube (303) is provided with circumferentially distributed air holes, and the air holes are connected to the cavity (400) between the boiler tail outlet flue (1) and the inner lining metal plate (300).

7. The system for solving ash blockage in the tail flue of a boiler according to claim 6, characterized in that: The inner lining metal plate (300) is provided with no less than three gap holes (500) distributed in a circumferential array, and wedge-shaped blocks (304) with inclined surfaces affixed to each other for closing the gap holes (500) are fixedly mounted at both ends of the inner lining metal plate (300) at the gap holes (500).

8. The system for solving ash blockage in the tail flue of a boiler according to claim 7, characterized in that: A U-shaped portion (305) is bent on the inner lining metal plate (300) and is located between two adjacent gap holes (500). In a default state, the ends of the U-shaped portion (305) are in abutting connection.

9. The system for solving ash blockage in the tail flue of a boiler according to claim 7, characterized in that: An elastic memory sheet metal part (306) fixedly mounted on one of the wedge-shaped blocks (304) adjacent to the gap slit hole (500) passes through a puncture groove provided on the lining metal plate (300) and enters the cavity (400) and is fixedly connected to the side wall of the lining metal plate (300), and the U-shaped portion (305) is located within the length coverage range of the elastic memory sheet metal part (306).

10. A method for solving ash blockage in a boiler tail flue, comprising the system for solving ash blockage in a boiler tail flue according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: The negative pressure difference generated by the operation of S01 and the induced draft fan (4) continuously draws the dust accumulated in the two ash hoppers into the pre-dust removal flue (2), which is then captured by the dust collector (3) and transported to the ash storage, forming a closed-loop ash transport path; During the operation of step S02 and step S01, air cannon tubes (8) are arranged circumferentially at the bottom ash hopper of the flue gas outlet (1) at the rear of the boiler to release high-pressure gas shock waves at regular intervals to destroy the compacted structure of the ash in the ash hopper; During the operation of step S03 and step S01, an adjustable injection device (7) is provided between the exhaust fan outlet flue (5) and the pre-dust removal flue (2), and the start and stop of the device is controlled by a gate valve (6), and the device is arranged to be movable in the following two positions: High load condition: Close the gate valve 1 (6) and rely on the natural flow rate of the flue to prevent dust accumulation; Low load condition: open the gate valve 1 (6) and inject part of the purified flue gas into the pre-dust removal flue (2) from the circumferential injection port at a 45° downstream angle, forming a swirl disturbance to inhibit the sedimentation of ash particles.

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