A super large furnace integrated steam boiler

Abstract

The present application relates to the technical field of boiler equipment, and discloses a super-large hearth integrated steam boiler, which comprises a boiler body, a hearth and an economizer arranged in the boiler cylinder. The economizer comprises a first flue group, a second flue group, a first smoke box, a second smoke box, a reversing assembly and a plurality of ash removal devices. The reversing assembly switches the communication state of the hearth, the smoke outlet and the end of the two flue groups, so that the flue gas flow direction of the same flue group is opposite in the adjacent two smoke passing states. The ash removal devices move along the flue under the action of flue gas and scrape off the ash on the inner wall of the flue. After reversing, the ash removal devices return under the action of reverse flue gas, so that the ash on the inner wall of the flue is removed reciprocally. The end of part of the flue is provided with a smoke passing hole and an extension pipe. The extension pipe avoids the smoke passing hole in the open position and blocks the smoke passing hole in the closed position, so that the flue gas can reliably move the ash removal devices in the reverse direction, and the heat exchange attenuation and the exhaust resistance increase caused by the ash accumulation in the economizer are reduced.

Description

Technical Field

[0001] This invention relates to the field of boiler equipment technology, specifically to an ultra-large furnace integrated steam boiler. Background Technology

[0002] A fully assembled steam boiler is a boiler unit that has undergone major assembly at the manufacturing plant, including the boiler body, combustion chamber, flue gas heat exchange channels, heating surfaces, and safety accessories, before being transported to the user site. It features minimal on-site installation work, a short installation period, and high equipment integrity. With increasing industrial steam loads and stricter requirements for low-NOx combustion, boiler furnace volume, flue gas residence time, and tail-end heat exchange capacity all need to be correspondingly increased. While maintaining the advantages of fully assembled transportation and rapid on-site installation, ultra-large furnace fully assembled steam boilers require the arrangement of the furnace, flue tube heating surfaces, and smoke box within the limited boiler shell space to ensure that the high-temperature flue gas after combustion can be fully heat-exchanged before being discharged.

[0003] Chinese patent document CN220892206U discloses an integrated corner tube steam boiler and its heating system. This boiler adjusts the arrangement of the heating surfaces in the integrated boiler body, furnace, flue gas duct, and external boiler drum to increase the integrated transport capacity. Chinese patent document CN2250474Y discloses an external ash removal and flue gas tube flameout device for boilers. It sets up flameout tubes and disturbance fins in the flue gas tubes and guides the flameout tubes outside the furnace to achieve ash removal, thus maintaining the heat exchange efficiency of the flue gas tubes. The above-mentioned prior art has improved the integrated boiler capacity and flue gas tube ash removal from the perspectives of integrated boiler capacity and integrated boiler ash removal, respectively. However, it does not include a linkage design for the online self-ash removal action of the flue gas tube assembly with built-in economizer in ultra-large furnace integrated boilers after long-term ash accumulation due to flue gas scouring.

[0004] In the actual operation of ultra-large furnace integrated steam boilers, after the flue gas generated by combustion in the furnace enters the heat exchange area of ​​the flue tubes inside the boiler shell, dust, incompletely burned particles, and condensed deposits in the flue gas easily accumulate on the inner wall of the flue tubes. With prolonged operation, the ash layer on the inner wall of the flue tubes gradually thickens, the flue gas flow cross-section decreases, the heat exchange resistance between the inner wall of the flue tubes and the flue gas increases, the heat exchange efficiency of the economizer decreases, the exhaust gas temperature rises, and the overall thermal efficiency of the boiler decreases. Conventional soot blowing structures require separate soot blowing media, injection pipelines, or manual maintenance channels, which are difficult to arrange within the compact boiler shell. Furthermore, soot blowing is usually concentrated in a localized area, making continuous scraping along the length of each flue tube difficult. If fixed cleaning components are placed directly inside the flue tubes, their position at the end or middle of the tubes will affect the flue gas flow area and increase boiler operating resistance. Therefore, existing integrated steam boilers still require a structure that can utilize flue gas flow direction switching to drive the reciprocating movement of the cleaning components and continuously scrape away the ash accumulation on the inner wall of the flue tubes during operation. Summary of the Invention

[0005] This invention provides an ultra-large furnace integrated steam boiler, which aims to solve the problems in related technologies such as the easy accumulation of ash in the smoke tubes of the economizer inside the boiler shell after long-term scouring by flue gas, the complex layout of manual or external soot blowing structures, and the difficulty in continuous online cleaning of the inner wall of the smoke tubes.

[0006] An ultra-large furnace integrated steam boiler includes a boiler body and a furnace disposed within the boiler body. The boiler body includes a boiler shell, a front tube sheet, and a rear tube sheet. An economizer is installed inside the boiler shell. The economizer includes a first smoke tube group, a second smoke tube group, a first smoke box, a second smoke box, a reversing assembly, and multiple ash removal components. Both the first and second smoke tube groups include multiple smoke tubes, which are connected between the front and rear tube sheets. The first smoke box is located at the front end of the boiler body and connects to the furnace and the exhaust port. The second smoke box is located at the rear end of the boiler body. The two ends of the first and second smoke tube groups are connected. Each is connected to the first smoke box and the second smoke box respectively; the reversing component is set in the first smoke box and is used to switch the connection state between the furnace, the flue gas outlet and the first smoke pipe group and the second smoke pipe group near the first smoke box, so that the flue gas flow direction of the first smoke pipe group and the second smoke pipe group is opposite in two adjacent flue gas states; multiple ash removal components are respectively set in the corresponding smoke pipes. The ash removal components can move along the smoke pipe under the push of the flue gas and scrape off the soot attached to the inner wall of the smoke pipe during the movement; after the flue gas flow direction is switched, the ash removal components move in the opposite direction along the corresponding smoke pipe under the push of the flue gas after the reversal, so as to reciprocate to clean the inner wall of the smoke pipe.

[0007] Its effect is as follows: the first and second smoke tube groups together form a zigzag energy-saving heat exchange channel set inside the boiler shell. The first smoke box simultaneously undertakes the functions of distributing incoming smoke from the furnace and collecting exhaust smoke, while the second smoke box serves as the transfer point between the two sets of smoke tubes. After the reversing component changes the connection between the furnace, the exhaust port, and the end of the two sets of smoke tubes near the first smoke box, the flue gas flow direction of the same smoke tube group is opposite in two adjacent flue gas flow states. The cleaning components inside the smoke tubes move back and forth along the smoke tubes under the action of flue gas pressure. The movement power of the cleaning components comes from the flue gas flow and flue gas reversal that exist during boiler operation. It is not necessary to install motors, cylinders, or cables in each smoke tube separately, and it can complete the scraping of the inner wall of the smoke tubes during normal flue gas heat exchange in the boiler. When the cleaning components move, they scrape off the soot adhering to the inner wall of the smoke tubes, allowing the soot to be carried into the smoke box with the flue gas or fall to the bottom of the smoke box, reducing the heat exchange thermal resistance and flue gas resistance caused by ash accumulation on the inner wall of the smoke tubes. Since the first and second smoke tube groups are subjected to flue gas scouring in opposite directions before and after switching, the reciprocating stroke of the cleaning components can cover the length of the smoke tubes, which is suitable for the online self-cleaning requirements of ultra-large furnace integrated steam boilers during long-term operation.

[0008] Furthermore, the reversing assembly includes a partition and a drive unit. The partition is disposed within the first smoke box and divides the first smoke box into a flow chamber one and a flow chamber two, which are respectively connected to the first smoke pipe group and the second smoke pipe group. The drive unit is drivenly connected to the partition and is used to drive the partition to switch positions, so that the first flow chamber and the second flow chamber are respectively connected to the furnace or the exhaust port. The partition changes the correspondence between the two flow chambers and the furnace or the exhaust port within the first smoke box, causing the two sets of smoke pipes to switch between the smoke inlet channel and the smoke return channel, thereby providing the flue gas pressure required for the reverse movement of the cleaning component.

[0009] Furthermore, the baffle has a first switching position and a second switching position. When the baffle is in the first switching position, the furnace is connected to the first circulation chamber, and the flue gas outlet is connected to the second circulation chamber. The flue gas passes through the first circulation chamber, the first flue pipe group, the second smoke box, the second flue pipe group, and the second circulation chamber in sequence before entering the flue gas outlet. When the baffle is in the second switching position, the furnace is connected to the second circulation chamber, and the flue gas outlet is connected to the first circulation chamber. The flue gas passes through the second circulation chamber, the second flue pipe group, the second smoke box, the first flue pipe group, and the first circulation chamber in sequence before entering the flue gas outlet. Through the above two switching positions, the first flue pipe group and the second flue pipe group respectively serve as the inlet flue gas heat exchange channel and the return flue gas heat exchange channel in different working cycles, so that the cleaning components in the same flue pipe group obtain opposite driving forces in the two cycles.

[0010] Furthermore, a smoke passage hole is provided at the end of the flue pipe, penetrating the pipe wall and used to connect the inner cavity of the flue pipe with the corresponding first or second smoke box. The smoke passage hole provides a lateral smoke inlet or outlet path at the end of the flue pipe, ensuring that the inner cavity of the flue pipe can still connect with the corresponding smoke box through the smoke passage hole when the cleaning component approaches the end, thereby reducing the blockage of flue gas flow caused by the cleaning component reaching the end.

[0011] Furthermore, extension tubes are slidably fitted at both ends of the flue pipe, extending into the corresponding first or second smoke box. Multiple guide sleeves, coaxially arranged with the extension tubes, are fixedly installed inside the first or second smoke box. An annular flow channel allows flue gas to pass through between the guide sleeves and the extension tubes. The extension tubes can move axially between an open and closed position. When in the open position, the extension tube avoids the smoke passage, allowing the inner cavity of the flue pipe to communicate with the corresponding first or second smoke box via the smoke passage. When in the closed position, the extension tube blocks the smoke passage, allowing flue gas to enter the inner cavity of the flue pipe through the axial channel of the extension tube. By opening and closing the smoke passage, the extension tube ensures that the end of the flue pipe is in a smoke-avoiding state when the cleaning component reaches the end, and in an axial pushing state when the flue gas enters in the opposite direction, guaranteeing that the cleaning component completes the end reversal.

[0012] Furthermore, the length of the cleaning component along the axial direction of the flue is greater than the axial travel of the extension tube between the open and closed positions. When the cleaning component pushes the extension tube to the open position, one end of the cleaning component is located inside the extension tube, and the other end is located inside the flue. This structure ensures that the cleaning component maintains a guiding fit with the flue while pushing the extension tube to open the flue hole, preventing the cleaning component from becoming misaligned or stuck after completely disengaging from the inner cavity of the flue.

[0013] Furthermore, the extension pipe is equipped with a pushing edge. After the reversing assembly switches the flue gas flow direction, the pushing edge on the extension pipe located on the smoke inlet side is pushed by the flue gas, causing the extension pipe to move to a closed position and block the smoke passage. This allows the reversed flue gas to act on the cleaning component through the axial channel of the extension pipe, pushing the cleaning component to move towards the other end of the flue pipe. The annular flow channel between the guide sleeve and the extension pipe guides the flue gas entering the smoke box to the position of the pushing edge, so that the flue gas pressure first pushes the extension pipe to close the smoke passage, and then concentrates to push the cleaning component to move in the opposite direction through the axial channel of the extension pipe, avoiding the smoke passage from remaining open on the smoke inlet side and causing a flue gas short circuit.

[0014] Furthermore, a guide end is provided at the end of the flue pipe, and the extension pipe is slidably sleeved on the guide end. A limiting element is provided on the guide end, and an elongated groove extending along the length of the extension pipe is provided. The limiting element is located in the elongated groove and restricts the movement of the extension pipe between the open and closed positions through the two ends of the elongated groove. The guide end provides axial sliding support for the extension pipe, and the limiting element cooperates with the elongated groove to limit the stroke of the extension pipe, so as to stabilize the avoidance and blocking position of the flue hole.

[0015] Furthermore, the cleaning component consists of at least two arc-shaped components that can be closed to form a circular structure. A spreading component is provided between adjacent arc-shaped components. The spreading component is used to drive the arc-shaped components to move radially outward along the cleaning component, so that the outer surface of the arc-shaped components abuts against the inner wall of the flue. Under the action of the spreading component, the arc-shaped components are pressed against the inner wall of the flue, so that the cleaning component can adapt to the inner diameter error of the flue and maintain the ash scraping contact force during the movement.

[0016] Furthermore, the spreading assembly includes a compression spring connected between adjacent arc-shaped members, with a mounting groove for mounting the compression spring at one end of each arc-shaped member. The compression spring is installed in the mounting groove and applies a spreading force to the adjacent arc-shaped members, so that the arc-shaped members remain closed to form a stable annular structure when they expand and contract radially.

[0017] By adopting the above technical solution, the beneficial effects of the present invention are as follows: 1. The present invention provides a first flue pipe group, a second flue pipe group, and a reversing component inside the boiler shell. By using the partition inside the first flue box to switch the connection between the furnace, the flue outlet, and the end of the two flue pipe groups near the first flue box, the flue gas changes direction in two adjacent flue gas states. The cleaning components inside the flue pipes reciprocate with the change of flue gas direction, realizing online cleaning of the inner wall of the energy-saving flue pipes, reducing the increase in flue gas resistance and the decrease in heat exchange efficiency caused by ash accumulation.

[0018] 2. This invention, through the cooperation of the flue hole, extension pipe, diversion sleeve, annular flow channel, pushing edge and cleaning component, enables the cleaning component to push the extension pipe to avoid the flue hole when it reaches the end of the flue pipe, thereby ensuring that the flue gas is smoothly discharged at the end; after the flue gas changes direction, the pushing edge is first subjected to force and drives the extension pipe to block the flue hole, so that the flue gas is concentrated through the axial channel of the extension pipe to push the cleaning component back, avoiding short-circuit leakage of flue gas and improving the reliability of the reciprocating cleaning action.

[0019] 3. The present invention forms a cleaning component that can be radially expanded by using an arc-shaped component, a compression spring, and a mounting groove. This allows the cleaning component to remain attached to the inner wall of the flue even when there are manufacturing errors, thermal deformation, or local ash accumulation resistance in the flue. It also maintains a stable scraping state under the push of flue gas, reducing the risk of the cleaning component getting stuck and insufficient cleaning contact force. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0022] Figure 3 This is a cross-sectional view of the first tobacco box in this invention.

[0023] Figure 4 This is a schematic diagram of the extension tube in this invention.

[0024] Figure 5 This is a partial cross-sectional view of the end of the flue pipe in this invention.

[0025] Figure 6 This is a schematic diagram of the structure of the dust removal component in this invention.

[0026] Figure label: 1. Boiler body; 11. Boiler shell; 12. Front tube sheet; 13. Rear tube sheet; 14. Furnace; 15. Exhaust port; 2. Eco-friendly device; 21. First smoke tube assembly; 22. Second smoke tube assembly; 23. Smoke tube; 231. Smoke vent; 24. First smoke box; 241. Flow chamber one; 242. Flow chamber two; 25. Second smoke box; 3. Reversing assembly; 31. Baffle plate; 32. Drive component; 4. Ash removal component; 41. Arc-shaped component; 42. Spreading assembly; 421. Compression spring; 422. Mounting groove; 5. Extension tube; 51. Pushing edge; 52. Long groove; 53. Axial channel; 6. Drainage sleeve; 61. Annular flow channel; 7. Guide end; 71. Limiting component. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] like Figures 1-6 As shown, an ultra-large furnace integrated steam boiler includes a boiler body 1 and a furnace 14 disposed within the boiler body 1. The boiler body 1 includes a boiler shell 11, a front tube sheet 12, and a rear tube sheet 13. The front tube sheet 12 and the rear tube sheet 13 are respectively disposed at the front and rear ends of the boiler shell 11. The furnace 14 is located within the boiler shell 11 and forms a combustion space. An economizer 2 is disposed within the boiler shell 11. The economizer 2 is positioned on the flue gas flow path of the furnace 14 and is used to receive the flue gas formed after combustion in the furnace 14. The economizer 2 includes a first flue tube group 21, a second flue tube group 22, a first smoke box 24, a second smoke box 25, a reversing assembly 3, and multiple ash removal components 4. Both the first flue tube group 21 and the second flue tube group 22 include multiple flue tubes 23. Each flue tube 23 is connected between the front tube sheet 12 and the rear tube sheet 13, and the inner cavity of the flue tube 23 forms a heat exchange channel for the flue gas to pass through.

[0029] The first smoke box 24 is located at the front end of the boiler body 1, and the second smoke box 25 is located at the rear end of the boiler body 1. The first smoke box 24 connects both the furnace 14 and the exhaust port 15. The flue gas generated in the furnace 14 enters the first smoke box 24 and is distributed to the corresponding flue tube group by the reversing assembly 3. After undergoing heat exchange, the flue gas returns to the first smoke box 24 and is discharged from the exhaust port 15. The second smoke box 25 is located at the end of the first flue tube group 21 and the second flue tube group 22 away from the first smoke box 24. The second smoke box 25 serves as a transfer smoke box between the two sets of flue tubes 23, allowing the flue gas passing through one set of flue tubes to enter the other set. The first smoke box 24, the first flue tube group 21, the second smoke box 25, and the second flue tube group 22 together form a reversible flue gas flow path, extending the heat exchange path of the flue gas within the boiler shell 11.

[0030] A reversing assembly 3 is disposed within the first smoke box 24. The reversing assembly 3 includes a partition 31 and a driving component 32. The partition 31 is disposed within the first smoke box 24 and divides the first smoke box 24 into a first flow chamber 241 and a second flow chamber 242. The first flow chamber 241 is connected to the end of the first smoke pipe assembly 21 near the first smoke box 24, and the second flow chamber 242 is connected to the end of the second smoke pipe assembly 22 near the first smoke box 24. The driving component 32 is drively connected to the partition 31 and drives the partition 31 to switch positions within the first smoke box 24, so that the first flow chamber 241 and the second flow chamber 242 are respectively connected to the furnace 14 or the exhaust port 15. The driving component 32 can perform the switching action of the partition 31 by using a rotary actuator, an electric push rod, or a pneumatic actuator. After the partition 31 switches, it changes the correspondence between the smoke entering the furnace 14 and the exhaust port 15 between the two flow chambers.

[0031] The baffle 31 has a first switching position and a second switching position. When the baffle 31 is in the first switching position, the furnace 14 is connected to the first flow chamber 241, and the flue gas outlet 15 is connected to the second flow chamber 242. At this time, the flue gas generated in the furnace 14 enters the first flow chamber 241, then enters the first flue gas tube group 21 and flows along the first flue gas tube group 21 from the front tube plate 12 side to the rear tube plate 13 side. The flue gas then enters the second smoke box 25 and then enters the second flue gas tube group 22, flowing along the second flue gas tube group 22 from the rear tube plate 13 side to the front tube plate 12 side, and finally enters the second flow chamber 242 and is discharged from the flue gas outlet 15. In this state, the first flue gas tube group 21 serves as the inlet flue gas heat exchange channel, and the second flue gas tube group 22 serves as the return flue gas heat exchange channel.

[0032] When the baffle 31 is in the second switching position, the furnace 14 is connected to the second flow chamber 242, and the exhaust port 15 is connected to the first flow chamber 241. At this time, the flue gas generated in the furnace 14 enters the second flow chamber 242, then enters the second flue pipe group 22 and flows along the second flue pipe group 22 from the side of the front tube plate 12 to the side of the rear tube plate 13. The flue gas enters the second smoke box 25 and then enters the first flue pipe group 21, and flows along the first flue pipe group 21 from the side of the rear tube plate 13 to the side of the front tube plate 12. Finally, it enters the first flow chamber 241 and is discharged from the exhaust port 15. Compared with the first switching position, the flue gas flow direction in the first flue pipe group 21 and the second flue pipe group 22 both change in the opposite direction, so that the cleaning components 4 in each flue pipe 23 obtain reverse flue gas driving force.

[0033] Multiple cleaning components 4 are respectively installed inside corresponding flue pipes 23. The cleaning components 4 can move along the flue pipe 23 under the propulsion of flue gas, scraping away the soot adhering to the inner wall of the flue pipe 23 during the movement. The outer periphery of the cleaning component 4 maintains scraping contact or elastic abutment contact with the inner wall of the flue pipe 23. When the flue gas flows along the flue pipe 23, the flue gas pressure acts on the smoke-facing side of the cleaning component 4, causing the cleaning component 4 to move axially along the flue pipe 23. During the movement of the cleaning component 4, its outer periphery scrapes the inner wall of the flue pipe 23, peeling off the soot adhering to the inner wall of the flue pipe 23. The peeled soot enters the flue box with the flue gas or falls into the collection area at the bottom of the flue box.

[0034] After the flue gas flow direction is switched, the cleaning component 4 moves in the opposite direction along the corresponding flue pipe 23 under the push of the diverted flue gas. In the first flue gas flow state, the cleaning component 4 moves from one end of the flue pipe 23 to the other, and in the second flue gas flow state, it returns from that end, causing the cleaning component 4 to form a reciprocating cleaning motion within the flue pipe 23. This reciprocating motion corresponds to the switching action of the diversion component 3, eliminating the need for an additional independent cleaning drive mechanism; the change in flue gas flow direction itself provides the power for the diversion movement of the cleaning component 4.

[0035] A smoke passage hole 231 is provided at the end of the smoke pipe 23. The smoke passage hole 231 penetrates the wall of the smoke pipe 23 and is used to connect the inner cavity of the smoke pipe 23 with the corresponding first smoke box 24 or second smoke box 25. The smoke passage hole 231 is located in the end area of ​​the smoke pipe 23 near the smoke box, and multiple smoke passage holes 231 are arranged circumferentially along the smoke pipe 23. The arrangement of the smoke passage hole 231 provides a lateral communication path at the end of the smoke pipe 23 in addition to the axial port. When the cleaning component 4 moves to the end of the smoke pipe 23 and approaches the smoke box, the flue gas can still flow between the inner cavity of the smoke pipe 23 and the smoke box through the smoke passage hole 231, avoiding local pressure buildup caused by the cleaning component 4 occupying the end of the smoke pipe 23.

[0036] Both ends of the flue pipe 23 are slidably fitted with extension pipes 5, which extend into the corresponding first smoke box 24 or second smoke box 25. The extension pipes 5 are coaxially arranged with the flue pipe 23 and can move between an open position and a closed position along the axial direction of the flue pipe 23. The extension pipe 5 has an axial channel 53, which is connected to the inner cavity of the flue pipe 23. When the extension pipe 5 is in the open position, it avoids the smoke passage 231, and the inner cavity of the flue pipe 23 is connected to the corresponding smoke box through the smoke passage 231. When the extension pipe 5 is in the closed position, it covers and blocks the smoke passage 231, preventing the flue gas from bypassing the smoke passage 231 and instead allowing it to enter the inner cavity of the flue pipe 23 through the axial channel 53 of the extension pipe 5.

[0037] The open position of the extension pipe 5 corresponds to the smoke discharge avoidance state after the cleaning component 4 reaches the end of the flue pipe 23. When the cleaning component 4 moves to the end of the flue pipe 23, it pushes the extension pipe 5 to move axially along the flue pipe 23, causing the extension pipe 5 to move from the closed position to the open position. At this time, the smoke passage 231 is exposed, and the inner cavity of the flue pipe 23 is connected to the smoke box through the smoke passage 231. Smoke can be discharged or enter through the smoke passage 231, preventing the cleaning component 4 from blocking the outlet of the flue pipe 23 after reaching the end. The closed position of the extension pipe 5 corresponds to the initial state where the smoke enters the flue pipe 23 in the opposite direction and pushes the cleaning component 4 away from the end. After the extension pipe 5 is in the closed position, the smoke passage 231 is blocked, and the reversed smoke enters the flue pipe 23 through the axial channel 53 of the extension pipe 5. The smoke pressure is concentrated on the smoke-facing side of the cleaning component 4, giving the cleaning component 4 the thrust to move away from the end and towards the other end of the flue pipe 23.

[0038] Multiple guide sleeves 6, coaxially arranged with extension pipes 5, are fixedly installed inside the first smoke box 24 or the second smoke box 25. Each guide sleeve 6 corresponds to one extension pipe 5, and the guide sleeve 6 is sleeved on the outside of the extension pipe 5. There is an annular flow channel 61 between the guide sleeve 6 and the extension pipe 5 to allow flue gas to pass through. The annular flow channel 61 forms an annular smoke inlet channel along the outer circumference of the extension pipe 5. After entering the smoke box, the flue gas enters the annular flow channel 61 and flows along the outside of the extension pipe 5. The outlet of the guide sleeve 6 faces the pushing edge 51 on the extension pipe 5, so that the flue gas flows out of the annular flow channel 61 and acts on the pushing edge 51.

[0039] One end of the extension pipe 5 that extends into the smoke box is provided with a pushing edge 51, which protrudes radially outward along the extension pipe 5. After the reversing assembly 3 switches the direction of flue gas flow, the end of the smoke pipe 23, which was originally on the exhaust side, becomes the inlet side. The flue gas pressure in the smoke box increases, and the flue gas enters the annular flow channel 61 between the guide sleeve 6 and the extension pipe 5, and flows along the annular flow channel 61 towards the pushing edge 51. When the flue gas impacts the pushing edge 51, it applies a thrust along the axial direction of the smoke pipe 23 to the pushing edge 51. The pushing edge 51 drives the extension pipe 5 to move towards the closed position, causing the extension pipe 5 to block the smoke passage 231.

[0040] Through the cooperation of the guide sleeve 6, the annular flow channel 61, and the pushing edge 51, the flue gas first forms an axial drive on the extension pipe 5 before entering the flue pipe 23. After the extension pipe 5 moves to the closed position, the flue gas passage 231 is blocked, and the flue gas after reversal enters the inner cavity of the flue pipe 23 through the axial channel 53 of the extension pipe 5 and acts on the cleaning component 4. If the flue gas passage 231 is still open after reversal, some flue gas will bypass through the flue gas passage 231, resulting in insufficient axial thrust on the cleaning component 4. By concentrating and guiding the flue gas to impact the pushing edge 51 through the annular flow channel 61, the extension pipe 5 first completes the closing action, and then the flue gas is concentrated to push the cleaning component 4, ensuring reliable reverse start-up of the cleaning component 4.

[0041] The length of the cleaning component 4 along the axial direction of the flue pipe 23 is greater than the axial travel of the extension pipe 5 between the open and closed positions. When the cleaning component 4 pushes the extension pipe 5 to the open position, one end of the cleaning component 4 is located inside the extension pipe 5, while the other end remains inside the flue pipe 23. This structure ensures that the cleaning component 4 does not completely detach from the flue pipe 23 during the reversal process at the end of the flue pipe 23, and the cleaning component 4 is always guided and constrained by the inner wall of the flue pipe 23 or the inner wall of the extension pipe 5. After one end of the cleaning component 4 enters the extension pipe 5, it can push the extension pipe 5 to the open position, while the other end of the cleaning component 4 remains inside the flue pipe 23. This allows the cleaning component 4 to re-enter the cleaning stroke along the axis of the flue pipe 23 when pushed back by the flue gas, avoiding end deflection.

[0042] A guide end 7 is provided at the end of the flue pipe 23, and the extension pipe 5 is slidably sleeved on the guide end 7. The guide end 7 is fixed to the outside of the end of the flue pipe 23 and is coaxially arranged with the flue pipe 23. The guide end 7 is used to support the extension pipe 5 to slide along the axial direction of the flue pipe 23. A limiting member 71 is provided on the guide end 7, and an elongated groove 52 extending along its length is provided on the extension pipe 5. The limiting member 71 is located in the elongated groove 52. When the extension pipe 5 slides relative to the guide end 7, the elongated groove 52 moves along the limiting member 71. When the limiting member 71 abuts against one end of the elongated groove 52, it limits the opening position of the extension pipe 5. When the limiting member 71 abuts against the other end of the elongated groove 52, it limits the closing position of the extension pipe 5.

[0043] The guide end 7, the limiting member 71, and the elongated groove 52 together restrict the sliding trajectory and sliding stroke of the extension tube 5. When the extension tube 5 moves to the open position under the pushing action of the cleaning member 4, one end of the elongated groove 52 abuts against the limiting member 71 to prevent the extension tube 5 from moving outward. When the extension tube 5 moves to the closed position after the pushing edge 51 is acted upon by the flue gas, the other end of the elongated groove 52 abuts against the limiting member 71 to prevent the extension tube 5 from moving inward excessively. Through this limiting structure, the extension tube 5 maintains a stable position during repeated opening and closing, and the avoidance and blocking state of the smoke vent 231 is accurate.

[0044] The cleaning component 4 consists of at least two arc-shaped components 41 that can be closed to form a circular structure. Multiple arc-shaped components 41 are arranged circumferentially along the flue pipe 23, with a spreading assembly 42 between adjacent arc-shaped components 41. The spreading assembly 42 drives the arc-shaped components 41 to move radially outward along the cleaning component 4, causing the outer surface of the arc-shaped components 41 to abut against the inner wall of the flue pipe 23. The outer surface of the arc-shaped components 41 forms a scraping surface, which contacts the inner wall of the flue pipe 23 during the movement of the cleaning component 4, scraping off the soot adhering to the inner wall of the flue pipe 23. Radial adjustment space is maintained between the arc-shaped components 41, allowing the cleaning component 4 to adapt to deviations in the inner diameter of the flue pipe 23 and minor deformations under hot operation.

[0045] The spreading assembly 42 includes a compression spring 421 connected between adjacent arc-shaped members 41. One end of each arc-shaped member 41 has a mounting groove 422 for mounting the compression spring 421, and the other end has two limiting blocks that can be inserted into the mounting groove 422 of the adjacent arc-shaped members 41. The two limiting blocks contact the front and rear side walls of the mounting groove 422 respectively, thereby restricting the relative movement of the adjacent arc-shaped members 41 along the axial direction of the cleaning member 4. The compression spring 421 is disposed in the mounting groove 422 and applies an elastic force that moves away from each other to the adjacent arc-shaped members 41, causing the multiple arc-shaped members 41 to spread outward as a whole. When the cleaning member 4 is resisted by a local protrusion or ash accumulation on the inner wall of the flue pipe 23, the arc-shaped members 41 slightly retract inward, and after passing the resistance position, they return to the inner wall of the flue pipe 23 under the action of the compression spring 421.

[0046] A scraping section is provided at the outer edges of both the front and rear sides of the arc-shaped component 41. An arc-shaped scraping ridge is formed on the side of the scraping section away from the center of the arc-shaped component 41, extending circumferentially along the arc-shaped component 41. The cross-section of the scraping section along the axial direction of the cleaning component 4 gradually narrows from the inner side of the arc-shaped component 41 towards the arc-shaped scraping ridge, allowing the arc-shaped scraping ridge to create a wall-scraping effect as the cleaning component 4 moves along the flue pipe 23. When the cleaning component 4 moves along the flue pipe 23 driven by the flue gas, the arc-shaped scraping ridge located at the front of the moving direction first scrapes away the soot adhering to the inner wall of the flue pipe 23, while the arc-shaped scraping ridge located at the rear of the moving direction continues to scrape away the remaining soot, thereby improving the cleaning effect on the inner wall of the flue pipe 23.

[0047] The working process of this invention is as follows: When the boiler is initially running, high-temperature flue gas is generated by combustion in the furnace 14, and the reversing assembly 3 puts the baffle 31 in the first switching position. The flue gas enters the first flow chamber 241 from the furnace 14, flows to the second smoke box 25 through the first smoke pipe group 21, and then returns to the second flow chamber 242 through the second smoke pipe group 22 and is discharged from the exhaust port 15. During this process, the cleaning element 4 in the first smoke pipe group 21 moves along the direction from the front tube plate 12 to the rear tube plate 13, and the cleaning element 4 in the second smoke pipe group 22 moves along the direction from the rear tube plate 13 to the front tube plate 12. During the movement, each cleaning element 4 scrapes off the soot attached to the inner wall of the corresponding smoke pipe 23.

[0048] When the cleaning component 4 moves to the end of the flue 23, it pushes against the extension pipe 5 at that end, causing the extension pipe 5 to move to the open position and avoid the flue hole 231. After the flue hole 231 is opened, a lateral communication path is formed between the inner cavity of the flue 23 and the corresponding flue box, allowing flue gas to flow into or out of the flue box through the flue hole 231. The cleaning component 4 does not completely block the flue gas flow path when it stops at the end of the flue 23. Since the axial length of the cleaning component 4 is greater than the axial stroke of the extension pipe 5, one end of the cleaning component 4 enters the extension pipe 5, while the other end remains inside the flue 23, keeping the cleaning component 4 in a guided state.

[0049] When reverse cleaning is required, the drive unit 32 drives the partition 31 to switch from the first switching position to the second switching position. The furnace 14 is connected to the second flow chamber 242, and the flue gas outlet 15 is connected to the first flow chamber 241. The flue gas flow direction in the first flue pipe group 21 and the second flue pipe group 22 is reversed. After the reversal, the flue gas in the smoke box located on the smoke inlet side enters the annular flow channel 61 between the guide sleeve 6 and the extension pipe 5. The annular flow channel 61 guides the flue gas to the pushing edge 51. The flue gas impacts the pushing edge 51 and applies axial thrust to the pushing edge 51. The pushing edge 51 drives the extension pipe 5 to move to the closed position, so that the extension pipe 5 blocks the smoke passage 231. After the smoke passage 231 is blocked, the flue gas enters the inner cavity of the smoke pipe 23 through the axial channel 53 of the extension pipe 5 and concentrates on the end of the cleaning component 4, pushing the cleaning component 4 to move along the smoke pipe 23 to the other end.

[0050] During the reverse movement of the cleaning component 4, the arc-shaped component 41, under the action of the compression spring 421, continues to press against the inner wall of the flue pipe 23, scraping off the soot that was not completely peeled off or redeposited in the previous flue cycle. After the cleaning component 4 reaches the other end of the flue pipe 23, it continues to push the extension pipe 5 at the other end to move to the open position, so that the flue hole 231 at the other end opens and forms a flue gas discharge avoidance state. Subsequently, when the reversing assembly 3 switches again, the extension pipe 5 at this end moves to the closed position under the action of the flue gas in the corresponding flue box, the guide sleeve 6, the annular flow channel 61 and the pushing edge 51, and the cleaning component 4 enters the next reverse stroke.

[0051] Through the aforementioned continuous actions, the flue pipes 23 in the first flue pipe group 21 and the second flue pipe group 22 repeatedly undergo flue gas direction switching during boiler operation. The cleaning component 4 moves back and forth within the flue pipe 23 as the flue gas direction changes, while the extension pipe 5 switches between open and closed positions based on the pushing and pushing edge 51 of the cleaning component 4 under the action of the flue gas. An end-reversing cooperation relationship is formed between the flue gas passage 231, the extension pipe 5, the guide sleeve 6, the annular flow channel 61, and the pushing edge 51, ensuring that the cleaning component 4 does not block the flue gas when it reaches the end of the flue pipe 23, and obtains stable axial thrust when the flue gas enters in the reverse direction. Thus, while maintaining the compactness of the overall structure, the boiler achieves automatic reciprocating cleaning of the inner wall of the flue pipe 23, improves the heat exchange stability of the economizer 2, and reduces the workload of boiler shutdown maintenance.

[0052] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A super-large furnace-integrated steam boiler, comprising a boiler body and a furnace disposed within the boiler body, characterized in that: The boiler body includes a boiler shell, a front tube sheet, and a rear tube sheet, and an economizer is installed inside the boiler shell. The energy-saving device includes a first smoke pipe assembly, a second smoke pipe assembly, a first smoke box, a second smoke box, a reversing assembly, and multiple dust removal components; The first and second smoke tube groups each include multiple smoke tubes, which are connected between the front tube sheet and the rear tube sheet. The first smoke box is located at the front end of the boiler body and is connected to the furnace and the exhaust port. The second smoke box is located at the rear end of the boiler body. Both ends of the first and second smoke tube groups are connected to the first and second smoke boxes, respectively. The reversing component is located inside the first smoke box and is used to switch the connection state between the furnace, the exhaust port and the first smoke pipe group and the second smoke pipe group near the first smoke box, so that the flue gas flow direction of the first smoke pipe group and the second smoke pipe group is opposite in two adjacent smoke passage states. Multiple cleaning components are installed in the corresponding flue pipes. The cleaning components can move along the flue pipes under the push of the flue gas and scrape off the soot adhering to the inner wall of the flue pipes during the movement. After the flue gas flow direction is switched, the cleaning component moves in the opposite direction along the corresponding flue pipe under the push of the flue gas after the reversal, so as to reciprocate to clean the inner wall of the flue pipe. The end of the flue pipe has a smoke passage hole that penetrates the pipe wall and connects the inner cavity of the flue pipe to the corresponding first or second smoke box. Extension pipes are slidably fitted onto both ends of the flue pipe, extending into the corresponding first or second smoke box. Multiple guide sleeves coaxially arranged with the extension pipes are fixedly installed inside the first or second smoke box. An annular flow channel for flue gas passage exists between the guide sleeves and the extension pipes. The extension pipes can move axially between an open and closed position. When the extension pipe is in the open position, it avoids the smoke passage hole, allowing the inner cavity of the flue pipe to connect with the corresponding first or second smoke box via the smoke passage hole. When in the closed position, the smoke passage is blocked, allowing the flue gas to enter the inner cavity of the flue pipe through the axial channel of the extension pipe. The length of the cleaning component along the axial direction of the flue pipe is greater than the axial travel of the extension pipe between the open and closed positions. When the cleaning component pushes the extension pipe to the open position, one end of the cleaning component is located inside the extension pipe, and the other end is located inside the flue pipe. The extension pipe is provided with a pushing edge. After the reversing component switches the flue gas flow direction, the pushing edge on the extension pipe located on the smoke inlet side is pushed by the flue gas, causing the extension pipe to move to the closed position and block the smoke passage. The flue gas after reversal acts on the cleaning component through the axial channel of the extension pipe and pushes the cleaning component to move to the other end of the flue pipe.

2. The ultra-large furnace integrated steam boiler according to claim 1, characterized in that, The reversing assembly includes a partition and a drive unit. The partition is disposed in the first smoke box and divides the first smoke box into a flow chamber one and a flow chamber two, which are respectively connected to the first smoke pipe group and the second smoke pipe group. The drive unit is drivenly connected to the partition and is used to drive the partition to switch positions so that the flow chamber one and the flow chamber two are respectively connected to the furnace or the exhaust port.

3. The ultra-large furnace integrated steam boiler according to claim 2, characterized in that, The partition has a first switching position and a second switching position; When the partition is in the first switching position, the furnace is connected to the first flow chamber and the flue gas outlet is connected to the second flow chamber. The flue gas passes through the first flow chamber, the first flue pipe group, the second smoke box, the second flue pipe group and the second flow chamber in sequence before entering the flue gas outlet. When the partition is in the second switching position, the furnace is connected to the second flow chamber, and the flue gas is connected to the first flow chamber. The flue gas passes through the second flow chamber, the second flue pipe group, the second flue box, the first flue pipe group and the first flow chamber in sequence before entering the flue gas outlet.

4. The ultra-large furnace integrated steam boiler according to claim 1, characterized in that, The end of the flue pipe is provided with a guide end, the extension pipe is slidably sleeved on the guide end, the guide end is provided with a limiting element, the extension pipe is provided with a long groove extending along its length direction, the limiting element is located in the long groove, and the extension pipe is restricted from moving between the open position and the closed position through the two ends of the long groove.

5. The ultra-large furnace integrated steam boiler according to claim 1, characterized in that, The cleaning component consists of at least two arc-shaped components that can be enclosed to form a circular structure. A spreading component is provided between adjacent arc-shaped components. The spreading component is used to drive the arc-shaped components to move radially outward along the cleaning component, so that the outer side of the arc-shaped components abuts against the inner wall of the flue.

6. The ultra-large furnace integrated steam boiler according to claim 5, characterized in that, The spreading assembly includes a compression spring connected between adjacent arc-shaped members, with a mounting groove for mounting the compression spring at one end of each arc-shaped member.

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