Low-temperature economizer flue cyclone flow guide anti-deposition system and control method thereof

Abstract

This invention provides a low-temperature economizer flue gas swirl flow guiding and ash accumulation prevention system and its control method, belonging to the technical field of thermal power plant equipment. It can at least partially solve the problems of existing methods that mostly use high-pressure steam or compressed air to periodically purge the flue gas, which easily generates a strong scouring effect on the surface of the flue gas and heat exchange components, and the existing ash removal system is difficult to accurately control the ash removal according to the actual degree of ash accumulation. This invention includes a flue gas body, on which a spiral flow guiding component, an ash accumulation monitoring module, a bubbling ash removal module, and a DCS control module are installed. The spiral flow guiding component of this invention uses a small-sized spiral plate with a central cylinder to accurately guide the rotation of the central flue gas. The nested secondary spiral plate further enhances the swirl. Compared with the traditional large-sized flow guiding structure, it reduces airflow resistance and improves the flue gas mixing uniformity by more than 40%, effectively eliminating ash accumulation in local stagnation areas.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal power plant equipment, specifically relating to a low-temperature economizer flue swirl flow guiding and ash accumulation prevention system and its control method. Background Technology

[0002] Low-temperature economizers, as crucial equipment for waste heat recovery from flue gas at the tail end of thermal power plant boilers, typically employ square cross-section structures in their flues to accommodate space constraints and equipment connection requirements. However, during actual operation, due to uneven flow field distribution within the flue, fly ash particles carried in the flue gas tend to deposit in localized areas, particularly at the right angles of square flues, often forming significant low-velocity or stagnant zones, thus exacerbating ash accumulation. To improve flue gas flow, existing technologies typically incorporate flat guide vanes or large-scale spiral guide structures to guide the flow direction. However, these guide structures have limited ability to guide the central flue gas under complex operating conditions, failing to achieve sufficient rotation and uniform mixing, and may still create low-velocity areas within the flue, resulting in ineffective mitigation of fly ash deposition problems. Long-term accumulation of ash in the flue not only reduces the effective flow area and forces the flue gas velocity to increase locally, thus affecting the heat exchange efficiency of the low-temperature economizer, but also causes continuous erosion and wear on the heat exchange tube bundle and the inner wall of the flue, reducing the safety and service life of the equipment.

[0003] To address the issue of ash accumulation, existing cleaning methods often employ high-pressure steam or compressed air to periodically purge the flue. However, while removing ash, these methods can cause significant scouring of the flue and heat exchange components, posing a risk of wear. Furthermore, existing cleaning systems rely heavily on manual experience or scheduled operations, lacking real-time monitoring and quantitative assessment of flue ash accumulation. This makes precise control of cleaning based on the actual degree of ash buildup difficult, leading to either untimely or excessive cleaning, impacting the economic efficiency and reliability of the equipment. Therefore, we propose a low-temperature economizer flue swirl-flow guiding system for preventing ash accumulation and its control method. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a low-temperature economizer flue swirl flow guiding and ash accumulation prevention system and its control method.

[0005] This invention provides a low-temperature economizer flue swirl guiding and ash-prevention system, comprising a flue body, wherein the flue body is provided with: A spiral flow guiding assembly is disposed inside the flue body, and the spiral flow guiding assembly includes multiple sets of spiral flow guiding units spaced apart along the flow direction of the flue gas; The ash accumulation monitoring module includes multiple weight sensing units installed inside the flue body to collect ash weight data in real time during operation. The bubbling cleaning module includes a bubbling assembly disposed on the inner wall of one side of the flue body, an air supply pipe connected to the bubbling assembly, and a blower unit disposed at one end of the air supply pipe, for cleaning the accumulated ash inside the flue body; and The DCS control module is connected to the dust accumulation monitoring module and the bubbling cleaning module to calculate the dust accumulation height based on the signal from the dust accumulation monitoring module, and to control the cleaning action of the bubbling cleaning module based on the dust accumulation height.

[0006] Furthermore, the spiral guide assembly includes a central cylinder and a first-stage spiral guide plate disposed on the outer peripheral surface of the central cylinder. The outer diameter of the first-stage spiral guide plate is 1 / 5 to 1 / 3 of the cross-sectional dimension of the flue body, and the lead of the first-stage spiral guide plate is 1.5 to 3 times its own diameter.

[0007] Specifically, the flue body is a square cross-section flue, and the right angle of the inner wall of the flue body is provided with a rounded chamfer.

[0008] Preferably, the radius of the rounded chamfer is in the range of 50mm to 200mm, and the inner wall of the rounded chamfer is provided with a wear-resistant ceramic lining.

[0009] Specifically, the number of weight sensing units is no less than 6. The weight sensing units are respectively arranged at the four corners of one side of the flue body, and the weight sensing units are respectively arranged at both ends of each spiral flow guiding unit. The weight sensing units are provided with stainless steel anti-wear protective covers.

[0010] Furthermore, the bubbling assembly includes multiple bubbling tubes, and multiple nozzles are spaced apart on the bubbling tubes. The openings of the nozzles face the ash accumulation area inside the flue body, and the flue gas injection velocity at the nozzle outlet is 4 to 8 m / s.

[0011] Furthermore, the air inlet of the blower unit is connected to an exhaust pipe, one end of which is connected to the inlet flue of the dust collector downstream of the flue gas.

[0012] Specifically, the exhaust pipe is equipped with a dust filter and a check valve on the section between the blower unit and the dust collector, and the air supply pipe is equipped with a flow regulating valve, which is electrically connected to the DCS control module.

[0013] Furthermore, the spiral guide assembly also includes a secondary spiral guide plate, which is disposed on the inner circumferential surface of the central cylinder. The outer diameter of the secondary spiral guide plate is 80% to 90% of the diameter of the central cylinder, and the lead of the secondary spiral guide plate is 1.5 to 2.5 times its own diameter.

[0014] Another aspect of the present invention provides a low-temperature economizer flue swirl guiding and ash-prevention system. The method is implemented using the aforementioned low-temperature economizer flue swirl guiding and ash-prevention system and includes the following steps: S1: The accumulated ash is guided to converge towards the central airflow zone by the spiral flow guide assembly of the flue body; S2: The weight sensing unit of the dust accumulation monitoring module collects the dust accumulation weight signal at the dust accumulation point in real time and transmits the dust accumulation weight signal to the DCS control module; S3: The DCS control module calculates the actual dust accumulation height, and starts the bubbling dust removal module when the actual dust accumulation height reaches the dust removal threshold. S4: The blower unit draws clean flue gas from downstream through the exhaust pipe and sprays it out through the air supply pipe and the nozzle of the bubbling assembly to form a boiling airflow that loosens the accumulated ash. S5: The loosened ash is carried by the mainstream flue gas into the dust collector downstream of the flue gas for processing. During the ash removal process, the DCS control module monitors the weight of the ash in real time and calculates the ash height. When the ash height is lower than the warning threshold, the ash removal is stopped.

[0015] The beneficial effects of this invention are as follows: Equipped with a spiral guide assembly, this system uses small-sized spiral plates paired with a central cylinder to precisely guide the rotation of central flue gas. Nested secondary spiral plates further enhance the swirling flow. Compared to traditional large-sized guide structures, this reduces airflow resistance while improving flue gas mixing uniformity by over 40%, effectively eliminating ash accumulation in localized stagnation zones. The rounded chamfers eliminate right-angle stagnation zones, and the inclined bottom guides ash accumulation to converge. The spiral guide plate assembly achieves flow field homogenization. The synergistic effect of these three components reduces the long-term retention of fly ash in localized areas from the source, extending the ash accumulation cycle from the traditional 7 days to over 30 days. Attached Figure Description

[0016] Figure 1 This is an overall layout diagram of a low-temperature economizer flue swirl guiding and ash-prevention system according to a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the spiral guide component structure of a low-temperature economizer flue swirl guide anti-ash accumulation system according to a specific embodiment of the present invention. Figure 3This is a schematic diagram of the installation of the bubbling cleaning module of the flue swirl guiding and anti-ash accumulation system for a low-temperature economizer according to a specific embodiment of the present invention. Figure 4 This is a control logic block diagram of a low-temperature economizer flue swirl guiding and ash-prevention system according to a specific embodiment of the present invention. Figure 5 The flowchart illustrates the steps of a low-temperature economizer flue swirl flow guiding and ash accumulation prevention control method according to a specific embodiment of the present invention.

[0017] Among them, 1 is the flue body, 101 is the rounded chamfer, 102 is the bottom inclined section, and 103 is the guide groove; 2. Spiral guide assembly, 201. Central cylinder, 202. Primary spiral guide plate, 203. Secondary spiral guide plate; 3. Dust accumulation monitoring module, 301 weight sensing unit, 302 anti-wear protective cover; 4 Bubble cleaning module, 401 Blower unit, 402 Air extraction pipeline, 403 Dust filter, 404 Check valve, 405 Air supply pipeline, 406 Flow regulating valve, 407 Bubble assembly, 4071 Bubble tube, 4072 Nozzle. 5 DCS control modules, 6 dust collectors. Detailed Implementation

[0018] 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 and specific embodiments.

[0019] like Figure 1 , Figure 2As shown in the figure, a low-temperature economizer flue swirl flow guiding and ash-prevention system provided by a specific embodiment of the present invention includes a flue body 1, on which are provided: a spiral flow guiding assembly 2, disposed inside the flue body 1, the spiral flow guiding assembly 2 including multiple sets of spiral flow guiding units spaced apart along the flow direction of the flue gas; an ash accumulation monitoring module 3, including multiple weight sensing units 301 disposed inside the flue body 1 for real-time collection of ash weight data during operation; and a bubbling ash removal module 4, including a bubbling assembly 407 disposed on one inner wall of the flue body 1, an air supply pipe 405 connected to the bubbling assembly 407, and a blower unit 401 disposed at one end of the air supply pipe 405 for cleaning the ash accumulation inside the flue body 1. The system includes a DCS control module 5, which is connected to the ash accumulation monitoring module 3 and the bubbling cleaning module 4 to calculate the ash accumulation height based on the signal from the ash accumulation monitoring module 3 and control the cleaning action of the bubbling cleaning module 4 based on the ash accumulation height. The bottom of the flue body 1 is inclined downward at 3° to 8° along the flue gas flow direction, using gravity to guide the deposited fly ash to converge towards the central airflow stable area of ​​the flue body 1, avoiding long-term stagnation at the corners. A guide groove 103 is provided at the lowest point of the inclined section 102 at the bottom of the flue body 1. The guide groove 103 extends along the flue gas flow direction, with a width of 50mm to 100mm and a depth of 20mm to 30mm, corresponding to the nozzle position of the bubbling assembly 407, further guiding the ash accumulation towards the mainstream flue gas.

[0020] Specifically, the spiral guide component 2 is installed inside the flue body 1, and multiple sets of spiral guide units are arranged at intervals along the flue gas flow direction. Its function is to guide the flue gas in the central area of ​​the flue to form a stable vortex, improve the lateral and radial mixing capacity of the flue gas; eliminate the low-speed zone and stagnation zone in the square flue, reduce the fly ash deposition tendency in the right-angle part and corner area of ​​the flue; improve the overall flow field uniformity in the flue, make the flue gas velocity distribution more reasonable, and suppress the formation of ash accumulation from the source.

[0021] Furthermore, during the flow of flue gas along the flue body 1, when the flue gas flows through the spiral guide unit, the first-stage spiral guide plate 202 applies a tangential velocity component to the flue gas, causing the central flue gas to rotate. Multiple spiral guide units act sequentially along the flow direction, causing the swirling effect to be superimposed step by step, thereby forming a stable and continuous rotating flow field in the flue. When a second-stage spiral guide plate 203 is provided, the flue gas inside the central cylinder 201 is further guided, enhancing the rotation intensity and axial stability of the flue gas, and enabling the flue gas to achieve more thorough mixing in the radial and axial directions. The first-stage spiral guide plate 202 is made of wear-resistant alloy steel. The spiral angle range is 15° to 30°. It is welded and fixed to the outside of the central cylinder 201 by continuous winding. The weld is ground smooth and sprayed with an anti-wear coating. The two ends of the central cylinder 201 are fixed to the inner wall of the flue body 1 by cross brackets. The cross brackets adopt a hollow design to reduce airflow resistance.

[0022] Furthermore, the ash accumulation monitoring module 3, through weight sensing units 301 installed at multiple locations inside the flue body 1, realizes real-time monitoring of the ash accumulation status in areas prone to ash accumulation in the flue. Its main functions include: acquiring information on the actual weight change of ash accumulation; providing basic data for calculating ash accumulation height; and providing objective basis for judging the timing of ash removal. The weight sensing unit adopts a high-temperature resistant weighing module.

[0023] Based on the above basic implementation method, the spiral guide assembly 2 includes a central cylinder 201 and a first-stage spiral guide plate 202 disposed on the outer circumferential surface of the central cylinder 201. The outer diameter of the first-stage spiral guide plate 202 is 1 / 5 to 1 / 3 of the cross-sectional size of the flue body 1, and the lead of the first-stage spiral guide plate 202 is 1.5 to 3 times its own diameter.

[0024] Specifically, this outer diameter range allows the primary spiral guide plate 202 to primarily act on the central airflow region of the flue, without occupying most of the flue's flow area. This avoids excessive blockage of the flue's flow cross-section and prevents a significant increase in system resistance. It focuses on controlling the central flue gas flow state, driving the surrounding flue gas to move in tandem through the central swirling flow. While ensuring the swirling effect, it also considers the safety and economy of flue operation. This guide range can achieve a balance between swirling intensity and axial flow, preventing excessive pressure loss due to excessively strong swirling. It also avoids the difficulty in eliminating stagnation zones due to insufficiently weak swirling. This allows the flue gas to maintain stable forward movement while achieving effective rotation and mixing when passing through the spiral guide unit.

[0025] In one specific embodiment, the flue body 1 is a square cross-section flue, and the inner wall of the flue body 1 has a rounded chamfer 101 at the right angle; the radius of the rounded chamfer 101 is in the range of 50mm to 200mm, and the inner wall of the rounded chamfer 101 is provided with a wear-resistant ceramic lining; the number of weight sensing units 301 is not less than 6, wherein a weight sensing unit 301 is provided at each of the four corners on one side of the flue body 1, and a weight sensing unit 301 is provided at each of the two end faces of each spiral guide unit; the weight sensing unit 301 is provided with a stainless steel anti-wear protective cover 302; the measurement range of the weight sensing unit 301 is 0 to 50kg, the accuracy is ±0.1kg, and the working temperature range is -40℃ to 400℃, which is suitable for the working environment of the low-temperature economizer flue.

[0026] In this embodiment, a rounded chamfer is provided at the right angle of the inner wall of the square flue, which can eliminate the airflow separation phenomenon in the right angle area and reduce the formation of low-speed stagnation zone; guide the flue gas to transition smoothly along the arc, reduce the probability of fly ash deposition in the corner area; and, in conjunction with the spiral flow guide component 2, further improve the overall flow field distribution of the flue.

[0027] Furthermore, a wear-resistant ceramic lining is installed on the inner wall of the chamfered corner 101 to improve the wear resistance of the flue inner wall, reduce the wear of fly ash on the metal wall surface, extend the service life of the flue and related components, and ensure the stability and reliability of the flue structure under long-term operating conditions. The weight sensing unit 301 is set at the four corners of the flue body 1 and the end face of each spiral guide unit, which can cover typical areas in the flue that are prone to ash accumulation. This improves the representativeness and accuracy of the ash accumulation monitoring results. The stainless steel wear-resistant protective cover prevents high-temperature flue gas and fly ash from directly eroding the sensor, thus improving measurement stability.

[0028] In another specific embodiment, the bubbling assembly 407 includes multiple bubbling tubes 4071, and multiple nozzles 4072 are spaced apart on the bubbling tubes 4071. The openings of the nozzles 4072 face the ash accumulation area inside the flue body 1. The flue gas jet velocity at the outlet of the nozzles 4072 is 4-8 m / s, which can both make the ash boil and flow and avoid scouring damage to the inner wall of the flue. The air inlet of the blower unit 401 is connected to the exhaust pipe 402. One end of the exhaust pipe 402 is connected to the inlet flue of the dust collector 6 downstream of the flue gas. A dust filter 403 and a check valve 404 are installed on the section of the exhaust pipe 402 between the blower unit 401 and the dust collector 6. A flow regulating valve 406 is installed on the air supply pipe 405. The flow regulating valve 406 is electrically connected to the DCS control module 5. The blower unit 401 is a variable frequency fan.

[0029] Specifically, the bubbling tube 4071 extends along the width of the flue body 1, and the nozzle 4072 opens upwards or at an angle of 30° to 45° to the horizontal. The orifice diameter of the nozzle 4072 is 3mm to 8mm, and the spacing between adjacent nozzles 4072 is 50mm to 100mm. The bubbling tube 4071 is made of 304 stainless steel and is detachably connected to the bottom of the flue body 1 via pipe clamps. The DCS control module 5 has a built-in ash accumulation height conversion model. It calculates the actual ash accumulation height by using the ash weight collected by the weight sensor 301, the sensor installation area, and the preset fly ash bulk density (preset to 0.8-1.2g / cm³ based on the characteristics of coal combustion in power plants). It also presets a first-level warning threshold (50mm-80mm). The DCS control module 5 is connected to the blower unit 401 and the flow regulating valve 406 on the air supply pipeline 405. It can control the start and stop of the dust removal action and the airflow intensity according to the degree of dust accumulation. The DCS control module 5 also has a multi-point signal comprehensive analysis function. When the dust accumulation height detected by any two adjacent sensors reaches the secondary dust removal threshold, or the dust accumulation height of a single sensor exceeds 150mm, the emergency dust removal program is immediately triggered and an audible and visual alarm is issued to remind the operators. The dust filter 403 on the exhaust pipeline 402 is equipped with a differential pressure monitoring module. When the differential pressure exceeds 3kPa, the DCS control module 5 issues a filter element replacement reminder to ensure the flue gas filtration effect.

[0030] Furthermore, the spiral guide assembly 2 also includes a secondary spiral guide plate 203, which is disposed on the inner circumferential surface of the central cylinder 201. The outer diameter of the secondary spiral guide plate 203 is 80% to 90% of the diameter of the central cylinder 201, and the lead of the secondary spiral guide plate 203 is 1.5 to 2.5 times its own diameter. The spiral direction of the secondary spiral guide plate 203 is consistent with that of the primary spiral guide plate 202. The edges of both the primary and secondary spiral guide plates 203 are provided with a smooth transition chamfer of 2 to 5 mm to avoid local vortices generated by airflow impact and further optimize the flow field characteristics.

[0031] In one specific implementation, the parameters of the primary and secondary spiral guide plates 203 are set as follows: The helix angle ranges from 15° to 45°. The design logic is as follows: if the helix angle is less than 15°, the rotation effect is weak and the centrifugal force is insufficient; if the helix angle is greater than 45°, the resistance increases dramatically, and the loss outweighs the gain. The pitch can be uniform or variable. The design logic is: small pitch in the inlet section (to enhance rotation) and large pitch in the outlet section (to stabilize the flow field); the higher the flow velocity, the smaller the pitch should be.

[0032] In this embodiment, the parameters also include the cross-sectional profile of the ventilation duct, which is a gradually expanding type. The design logic is: outlet cross-sectional area = (1.5~3.0) × outlet cross-sectional area of ​​the tapered tube, to ensure a reasonable diffusion ratio and realize the conversion of kinetic energy into static pressure.

[0033] Furthermore, the parameters also include: The number of guide vanes should be between 3 and 8 (odd numbers are preferred). The design logic is to reduce airflow interference and avoid resonance. The thickness of the guide vanes should be ≤ 1 / 10 of the channel width to reduce blockage losses. The inlet transition section has a radius of 5mm (R≥5mm). The design logic is to avoid airflow separation at the connection between the converging tube outlet and the spiral plate, thereby reducing local energy loss.

[0034] In another specific embodiment, such as Figure 5 As shown, this invention provides a low-temperature economizer flue swirl flow guiding and ash-prevention system. The method is implemented using the aforementioned low-temperature economizer flue swirl flow guiding and ash-prevention system, and includes the following steps: S1: The spiral guide component 2 of the flue body 1 guides the accumulated ash to converge towards the central airflow area. The first-stage spiral guide plate 202 of the spiral guide component 2 drives the central flue gas to rotate. The second-stage spiral guide plate 203 of the spiral guide component 2 enhances the swirling effect, making the flue gas mix evenly and eliminating local stagnation areas. S2: The weight sensing unit of the dust accumulation monitoring module collects the dust accumulation weight signal at the dust accumulation point in real time and transmits the dust accumulation weight signal to the DCS control module. S3: DCS control module 5 calculates the actual dust accumulation height. When the actual dust accumulation height reaches the first-level warning threshold, it issues a warning. When the actual dust accumulation height reaches the second-level cleaning threshold, it starts the bubbling cleaning module 4. S4: The blower unit 401 draws clean flue gas from downstream through the exhaust pipe 402, and sprays it out through the air supply pipe 405 and the bubble assembly 407 to form a boiling airflow that loosens the accumulated ash. S5: The loosened ash is carried by the mainstream flue gas into the dust collector 6 downstream of the flue gas for processing. During the ash removal process, the DCS control module 5 monitors the weight of the ash in real time and calculates the ash height. When the ash height is lower than the first-level warning threshold, the ash removal stops.

[0035] Specifically, the rounded chamfer of the flue body 1 eliminates the right-angle stagnation zone, and the 3° to 8° inclined structure at the bottom uses gravity to guide the accumulated ash to converge towards the central airflow stabilization zone; the first-stage spiral guide plate 202 of the spiral guide plate assembly 2 drives the flue gas in the central area to rotate, and the nested second-stage spiral guide plate 203 enhances the swirling effect, making the flue gas velocity evenly distributed and avoiding ash deposition caused by excessively low local flow velocity; the weight sensing unit 301 collects the ash weight signal at the easily accumulating area in real time and transmits it to the DCS control module 5 through a high-temperature resistant cable; the DCS control module 5 converts the weight signal into the actual ash height through the ash height conversion model. When the ash height is at the first-stage warning threshold (50mm-80mm), the DCS screen displays a warning message to remind the operators to pay attention; when the ash height reaches the second-stage cleaning threshold (80mm-120mm), the cleaning program is automatically triggered.

[0036] Furthermore, the DCS control module 5 controls the start of the blower unit 401, which draws clean flue gas from the inlet of the downstream dust collector 6 through the extraction pipe 402. After being filtered by the dust filter 403, the flue gas is delivered to the bubbling assembly 407 through the air supply pipe 405. The variable frequency blower adjusts its output power according to the degree of ash accumulation, the flow regulating valve 406 controls the airflow intensity, and the nozzle 4072 sprays flue gas at a speed of 4-8 m / s, forming a boiling airflow that loosens and suspends the ash at the bottom. The loosened ash, carried by the mainstream flue gas, flows through the flue body 1. The dust is removed by the downstream dust collector 6. During the dust removal process, the DCS control module 5 monitors the weight sensor signals in real time. When the dust height detected by all sensors is lower than the first-level warning threshold, the blower is stopped and the flow regulating valve is closed, and the dust removal program ends. When the dust height of a single sensor exceeds 150mm or two adjacent sensors reach the second-level threshold, the DCS control module 5 starts the emergency dust removal program. The blower runs at maximum output power and an audible and visual alarm is issued. The operator can perform auxiliary operations according to the prompts.

[0037] To aid in a better understanding of the present invention, a more comprehensive and specific embodiment is described. In this embodiment, the present invention provides a low-temperature economizer flue swirl-flow guiding and ash-prevention system, comprising a flue body 1, on which are disposed: a spiral guiding assembly 2, disposed inside the flue body 1, the spiral guiding assembly 2 including multiple sets of spiral guiding units spaced apart along the flow direction of the flue gas; an ash accumulation monitoring module 3, including multiple weight sensing units 301 disposed inside the flue body 1 for real-time acquisition of ash weight data during operation; a bubbling ash removal module 4, including a bubbling assembly 407 disposed on one inner wall of the flue body 1, an air supply pipe 405 connected to the bubbling assembly 407, and a blower unit 401 disposed at one end of the air supply pipe 405 for cleaning the ash accumulation inside the flue body 1; and a DCS control module 5, signal-connected to the ash accumulation monitoring module 3 and the bubbling ash removal module 4, for calculating the ash accumulation height based on the signal from the ash accumulation monitoring module 3 and controlling the ash removal action of the bubbling ash removal module 4 based on the ash accumulation height.

[0038] In this embodiment, the spiral guide assembly 2 includes a central cylinder 201 and a primary spiral guide plate 202 disposed on the outer circumferential surface of the central cylinder 201. The outer diameter of the primary spiral guide plate 202 is 1 / 5 to 1 / 3 of the cross-sectional dimension of the flue body 1, and the lead of the primary spiral guide plate 202 is 1.5 to 3 times its own diameter. The flue body 1 is a square cross-section flue, and a rounded chamfer 101 is provided at the right angle of the inner wall of the flue body 1. The rounded chamfer 101... The radius ranges from 50mm to 200mm, and the inner wall of the rounded chamfer 101 is lined with a wear-resistant ceramic lining; the number of weight sensing units 301 is not less than 6; among them, weight sensing units 301 are respectively arranged at the four corners of one side of the flue body 1, and weight sensing units 301 are respectively arranged at both ends of each spiral guide unit. The weight sensing unit 301 is provided with a stainless steel anti-wear protective cover 302; the bubbling assembly 407 includes multiple bubbling tubes 4071, the bubbling tubes Multiple nozzles 4072 are spaced apart on the 4071, with the openings of the nozzles 4072 facing the ash accumulation area inside the flue body 1. The flue gas jet velocity at the nozzle 4072 outlet is 4-8 m / s. The air inlet of the blower unit 401 is connected to an exhaust pipe 402, one end of which is connected to the inlet flue of the dust collector 6 downstream of the flue gas. A dust filter 403 and a check valve are installed on the section of the exhaust pipe 402 between the blower unit 401 and the dust collector 6. 404. A flow regulating valve 406 is installed on the air supply pipeline 405. The flow regulating valve 406 is electrically connected to the DCS control module 5. The spiral guide assembly 2 also includes a secondary spiral guide plate 203. The secondary spiral guide plate 203 is set on the inner circumferential surface of the central cylinder 201. The outer diameter of the secondary spiral guide plate 203 is 80% to 90% of the diameter of the central cylinder 201. The lead of the secondary spiral guide plate 203 is 1.5 to 2.5 times its own diameter.

[0039] Specifically, another aspect of the present invention provides a low-temperature economizer flue swirl guiding and ash-prevention system. This method, implemented using the aforementioned low-temperature economizer flue swirl guiding and ash-prevention system, includes the following steps: S1: The spiral guide component 2 of the flue body 1 guides the accumulated ash to converge towards the central airflow area. The first-stage spiral guide plate 202 of the spiral guide component 2 drives the central flue gas to rotate. The second-stage spiral guide plate 203 of the spiral guide component 2 enhances the swirling effect, making the flue gas mix evenly and eliminating local stagnation areas. S2: The weight sensing unit of the dust accumulation monitoring module collects the dust accumulation weight signal at the dust accumulation point in real time and transmits the dust accumulation weight signal to the DCS control module. S3: DCS control module 5 calculates the actual dust accumulation height. When the actual dust accumulation height reaches the first-level warning threshold, it issues a warning. When the actual dust accumulation height reaches the second-level cleaning threshold, it starts the bubbling cleaning module 4. S4: The blower unit 401 draws clean flue gas from downstream through the exhaust pipe 402, and sprays it out through the air supply pipe 405 and the bubble assembly 407 to form a boiling airflow that loosens the accumulated ash. S5: The loosened ash is carried by the mainstream flue gas into the dust collector 6 downstream of the flue gas for processing. During the ash removal process, the DCS control module 5 monitors the weight of the ash in real time and calculates the ash height. When the ash height is lower than the first-level warning threshold, the ash removal stops.

[0040] In summary, the embodiments disclosed herein have at least the following technical effects: By setting spiral guide components 2 arranged at intervals along the flue gas flow direction inside the flue body 1, the flue gas in the central area of ​​the flue forms a stable swirling flow and mixes synergistically with the circumferential flue gas, effectively reducing the low-speed stagnation zone in the right-angle area and corner position of the square flue, and reducing the possibility of fly ash deposition from the source. By limiting the outer diameter and lead of the first-stage spiral guide plate 202 within a reasonable range, the flow state of the central flue gas can be effectively controlled without significantly increasing the flue resistance, so that the swirling intensity and axial flow are kept in balance, taking into account both the safety and stability of the flue operation. A secondary spiral guide plate 203 is installed inside the central cylinder, which works in conjunction with the primary spiral guide plate 202 to further enhance the rotation effect of the central flue gas, improve the mixing uniformity of the flue gas in the radial and axial directions, and reduce the local ash accumulation phenomenon caused by the unstable flow field. By setting a rounded chamfer 101 at the right angle of the inner wall of the square flue, the flue gas is guided to transition smoothly, reducing the phenomenon of airflow separation. At the same time, a wear-resistant ceramic lining is set on the inner wall of the rounded chamfer 101 to improve the wear resistance of the inner wall of the flue, which is conducive to extending the service life of the flue and related components. By setting weight sensing units 301 at multiple locations in the flue where ash easily accumulates, the information on changes in ash weight can be obtained in real time, and the ash height can be calculated by the DCS control module 5, providing an objective basis for judging the timing of ash removal and reducing the uncertainty brought about by human experience judgment. The bubbling cleaning method is adopted, which loosens the accumulated ash by low-speed flue gas injection and achieves cleaning under the carry-on effect of mainstream flue gas. This avoids the strong scouring of the flue and heat exchange components caused by high-pressure purging, which helps to reduce the risk of equipment wear. By installing a dust filter 403 and a check valve 404 on the exhaust pipe, and a flow regulating valve 406 connected to the DCS control module 5 on the supply pipe 405, it is possible to prevent dust from entering the blower unit 401, avoid backflow of flue gas, and adjust the cleaning intensity according to the degree of dust accumulation, thereby improving the safety and stability of the system operation. By combining swirl flow guidance, anti-ash accumulation structure with ash accumulation monitoring and ash removal control, a collaborative operation mode of "flow guidance to suppress ash accumulation - monitoring and judging status - ash removal as needed" is formed, which is conducive to improving the overall operating efficiency and long-term stability of the low-temperature economizer flue.

[0041] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A low-temperature economizer flue swirl flow guiding and ash accumulation prevention system, characterized in that, Includes a flue body, on which are provided: A spiral flow guiding assembly is disposed inside the flue body, and the spiral flow guiding assembly includes multiple sets of spiral flow guiding units spaced apart along the flow direction of the flue gas; The ash accumulation monitoring module includes multiple weight sensing units installed inside the flue body to collect ash weight data in real time during operation. The bubbling cleaning module includes a bubbling component disposed on the inner wall of one side of the flue body, an air supply pipe connected to the bubbling component, and a blower unit disposed at one end of the air supply pipe, for cleaning the accumulated ash inside the flue body. as well as The DCS control module is connected to the dust accumulation monitoring module and the bubbling cleaning module to calculate the dust accumulation height based on the signal from the dust accumulation monitoring module, and to control the cleaning action of the bubbling cleaning module based on the dust accumulation height.

2. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 1, characterized in that, The spiral guide assembly includes a central cylinder and a first-stage spiral guide plate disposed on the outer peripheral surface of the central cylinder. The outer diameter of the first-stage spiral guide plate is 1 / 5 to 1 / 3 of the cross-sectional dimension of the flue body, and the lead of the first-stage spiral guide plate is 1.5 to 3 times its own diameter.

3. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 1, characterized in that, The flue body is a square cross-section flue, and the right angle of the inner wall of the flue body is provided with a rounded chamfer.

4. The low-temperature economizer flue swirl flow guiding and ash-prevention system according to claim 3, characterized in that, The radius of the rounded chamfer ranges from 50mm to 200mm, and the inner wall of the rounded chamfer is provided with a wear-resistant ceramic lining.

5. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 1, characterized in that, The number of weight sensing units is no less than 6. The weight sensing units are respectively arranged at the four corners of one side of the flue body, and the weight sensing units are respectively arranged at both ends of each spiral flow guiding unit. The weight sensing units are provided with stainless steel anti-wear protective covers.

6. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 1, characterized in that, The bubbling assembly includes multiple bubbling tubes, and multiple nozzles are spaced apart on the bubbling tubes. The openings of the nozzles face the ash accumulation area inside the flue body, and the flue gas injection velocity at the nozzle outlet is 4 to 8 m / s.

7. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 1, characterized in that, The air inlet of the blower unit is connected to an exhaust pipe, one end of which is connected to the inlet flue of the dust collector downstream of the flue gas.

8. The low-temperature economizer flue swirl flow guiding and ash accumulation prevention system according to claim 7, characterized in that, The exhaust pipe is equipped with a dust filter and a check valve on the section between the blower unit and the dust collector. The air supply pipe is equipped with a flow regulating valve, which is electrically connected to the DCS control module.

9. The low-temperature economizer flue swirl guiding and ash-prevention system according to any one of claims 1 to 8, characterized in that, The spiral guide assembly further includes a secondary spiral guide plate, which is disposed on the inner circumferential surface of the central cylinder. The outer diameter of the secondary spiral guide plate is 80% to 90% of the diameter of the central cylinder, and the lead of the secondary spiral guide plate is 1.5 to 2.5 times its own diameter.

10. A method for controlling swirl flow and preventing ash accumulation in the flue gas duct of a low-temperature economizer, characterized in that, The method is implemented using the low-temperature economizer flue swirl guiding and ash-prevention system according to any one of claims 1 to 9, and includes the following steps: S1: The accumulated ash is guided to converge towards the central airflow zone by the spiral flow guide assembly of the flue body; S2: The weight sensing unit of the dust accumulation monitoring module collects the dust accumulation weight signal at the dust accumulation point in real time and transmits the dust accumulation weight signal to the DCS control module; S3: The DCS control module calculates the actual dust accumulation height, and starts the bubbling dust removal module when the actual dust accumulation height reaches the dust removal threshold. S4: The blower unit draws clean flue gas from downstream through the exhaust pipe and sprays it out through the air supply pipe and the nozzle of the bubbling assembly to form a boiling airflow that loosens the accumulated ash. S5: The loosened ash is carried by the mainstream flue gas into the dust collector downstream of the flue gas for processing. During the ash removal process, the DCS control module monitors the weight of the ash in real time and calculates the ash height. When the ash height is lower than the warning threshold, the ash removal is stopped.

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