Self-temperature-control anti-corrosion waste heat recovery device for boiler preheater

Abstract

The invention relates to the technical field of preheaters, and discloses a self-temperature-control anti-corrosion waste heat recovery device for a boiler preheater, which comprises a mounting frame, a heat exchange pipe is fixedly inserted between the upper wall and the lower wall of the mounting frame, the heat exchange pipe is composed of a plurality of heat exchange sections and heat insulation sections which are arranged in a staggered manner, and the length of the heat exchange sections is greater than that of the heat insulation sections; an air guide pipe and an air supply pipe are fixedly connected to the upper end and the lower end of the mounting frame respectively, a temperature sensor and an air blocking assembly are arranged on the upper side and the lower side of the inner wall of the air guide pipe respectively, and a U-shaped smoke pipe is clamped in the mounting frame in a sliding mode. The adjusting assembly is controlled to drive the two heat insulation flat plates to move face to face or back to back, the heat exchange area of the heat exchange pipes is changed, the air output opening degree of the heat exchange pipes on the right side is adjusted in cooperation with the air blocking assembly, the air output temperature adjusting precision is high, the temperature control effect is good, and the U-shaped smoke pipe is jacked in cooperation with the jacking assembly adaptively; and the scraping ring is driven to scrape smoke dust in a corresponding range on the heat exchange tube on line, so that corrosion and influence on the heat exchange temperature are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of preheaters, and in particular to a self-controlling temperature and corrosion-resistant waste heat recovery device for a boiler preheater. Background Art

[0002] Boiler preheaters are key energy-saving auxiliary equipment in power plant boiler systems. Their core function is to utilize the waste heat from the high-temperature flue gas discharged from the boiler's tail flue to preheat the cold air entering the boiler furnace. This process not only significantly reduces the exhaust gas temperature, minimizing heat loss from the boiler, but also raises the temperature of the air entering the furnace, enhancing the efficiency of fuel combustion within the furnace. This reduces fuel consumption, improves the boiler's overall thermal efficiency, and reduces pollutant emissions from the flue gas. Therefore, they are a crucial component in achieving energy conservation, consumption reduction, and environmentally friendly operation in power plants.

[0003] The invention, with publication number CN118640733B, discloses a temperature-control mechanism with self-detection and regulation, and its application in an air preheater. The temperature-control mechanism includes a first smoke pipe, a second smoke pipe, and an air pipe. The air pipe runs through the first and second smoke pipes, and a heat pipe is provided at the connection point between the first and second smoke pipes and the air pipe. The air pipe is provided with a heating chamber located at the contact portion between the heat pipe and the air pipe. A purification chamber is provided between the first and second smoke pipes, and the ends of the purification chamber are respectively connected to the first and second smoke pipes. The air pipe is provided with an air outlet pipe, and the air pipe has a mixing chamber between the two heating chambers. This invention achieves the function of introducing flue gas from different purification stages to obtain preheated air of different temperature ranges, and then achieves the effect of obtaining air of the required temperature by mixing air of different temperatures. This solves the problem of how to efficiently adjust the temperature of the preheated air while improving the utilization rate of the flue gas waste heat and achieving stable air supply.

[0004] During use, the temperature self-detection and adjustment temperature control mechanism in the above-mentioned patent and its application in the air preheater pass through the first group of heat pipes, are deacidified and cooled in the purification chamber, and then pass through the second group of heat pipes. The fixed flow of air is divided into two streams, which pass through the first group of heat pipes in the high-temperature zone and the second group of heat pipes in the low-temperature zone respectively, and are then mixed and output. The flow rate of the two streams of air is controlled by the flow regulating device to achieve the required temperature adjustment of the mixed air. However, in actual operation, it is necessary to ensure that the flue gas before and after deacidification must have a sufficiently large and stable temperature difference. When the boiler load is low or the fuel type changes, resulting in a decrease in the temperature difference before and after deacidification, the temperature adjustment ability and effect will be greatly weakened, resulting in a smaller air temperature range, and even unable to cover the air temperature required by the process, and the temperature adjustment is limited. After the flue gas flows for a period of time, a certain amount of smoke dust will adhere to the inner wall of the heat pipe. The smoke dust cleaning requires stopping the machine and using soot blowers and other related equipment to clean it, and online cleaning cannot be achieved. The smoke dust will further affect the accuracy of heat exchange. At the same time, since the smoke dust contains impurities such as unburned carbon particles and sulfides, it will cause corrosion problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems of limited air temperature control and inability to clean dust online, which easily lead to corrosion during the use of general boiler preheaters. The present invention provides a self-controlling temperature and anti-corrosion waste heat recovery device for boiler preheaters.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] A self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater comprises a mounting frame, a heat exchange tube is fixedly connected between the upper and lower walls of the mounting frame, the heat exchange tube is composed of a plurality of staggered heat exchange sections and heat insulation sections, the heat exchange section is longer than the heat insulation section, an air guide tube and an air supply tube are fixedly connected to the upper and lower ends of the mounting frame respectively, a temperature sensor and a wind shield assembly are respectively provided on the upper and lower sides of the inner wall of the air guide tube, a U-shaped smoke pipe is slidably clamped in the mounting frame, two heat insulation plates symmetrically sleeved on the heat exchange tube are slidably clamped in the U-shaped smoke pipe, a telescopic heat insulation plate is rotatably connected between the two ends of the heat insulation plate and the inner wall of the U-shaped smoke pipe, and a scraper ring sleeved on the heat exchange tube is fixedly connected to the inner side of the heat insulation plate;

[0008] An adjusting component is provided in the middle of the U-shaped smoke pipe to drive the two insulation plates to move up and down, a lifting component is provided at the bottom of the U-shaped smoke pipe, and a pressure sensor is provided on the rear side of the U-shaped smoke pipe. The pressure sensor electrically controls the lifting component to adjust the top width.

[0009] Furthermore, the windshield assembly includes a windshield insulation plate rotatably connected to the central inner wall of the bottom of the air duct, the top of the windshield insulation plate is movably abutted against the right wall of the inner cavity of the air duct, the front and rear ends of the windshield insulation plate are movably sealed against the inner wall of the air duct, and the bottom end is movably sealed against the upper wall of the mounting frame, the windshield insulation plate separates the heat exchange tube into a heat exchange zone on the left and a heat adjustment zone on the right, the number of heat exchange tubes corresponding to the heat adjustment zone is less than the number of heat exchange tubes corresponding to the heat exchange zone, and the cross-section of the bottom of the air duct is rectangular and is sleeved on the heat exchange tube.

[0010] Furthermore, the windshield assembly also includes a crank fixedly inserted into the shaft of the windshield insulation board, the crank passes through the front wall of the air duct, a telescopic cylinder is rotatably connected between the crank and the air duct, and the temperature sensor electrically feedback controls the telescopic cylinder.

[0011] Furthermore, a fan is rotatably connected to the inner wall of the top of the air duct, and the fan is located below the temperature sensor.

[0012] Furthermore, the middle portion of the U-shaped smoke tube is expanded and has a rectangular cross-section, and the front and rear side walls of the heat-insulating plate and the telescopic heat-insulating plate are movably sealed against the inner wall of the middle portion of the U-shaped smoke tube.

[0013] Furthermore, the adjustment component includes an I-shaped inner pin tube rotatably connected to the middle of the U-shaped smoke pipe, an inner spiral groove is provided on the middle side wall of the inner pin tube, an I-shaped heat-insulating pin tube is rotatably and sealingly connected to the periphery of the inner pin tube, an outer spiral groove is provided on the middle inner wall of the heat-insulating pin tube, the outer spiral groove has the same pitch as the inner spiral groove and is in the opposite direction, a clamping tube is fixedly connected to the rear wall of the U-shaped smoke pipe, a screw slidably engaged with the clamping tube is slidably inserted in the middle of the inner pin tube, a pin protrusion movably engaged with the outer spiral groove and the inner spiral groove is provided on the upper end of the screw, and a worm gear sleeve threadably engaged with the screw is rotatably connected to the front wall of the U-shaped smoke pipe;

[0014] Sliding frames are provided on both the front and rear sides of the inner wall of the heat-insulating flat plate, and the inner pin tube and the heat-insulating pin tube are movably connected with the corresponding sliding frames respectively.

[0015] Furthermore, the front wall of the U-shaped smoke pipe is rotatably connected to a volute sleeve that engages with a worm gear sleeve, and a shaft is rotatably connected between the upper and lower walls of the inner cavity of the installation frame. The volute sleeve is slidably engaged on the shaft, and the shaft is driven by a motor installed on the lower wall of the installation frame, and the temperature sensor electrically feedback controls the motor.

[0016] Furthermore, the jacking assembly includes a gear ring rotatably connected to the lower wall of the inner cavity of the installation frame and having a flange on the bottom periphery. Telescopic protrusions are slidably engaged on the front and rear sides of the flange. The telescopic protrusions are respectively composed of two upper protrusions and lower protrusions in the upper and lower directions of isosceles trapezoids. The upper protrusions are slidably engaged in the lower protrusions and the two are elastically connected. The left and right sides of the lower wall of the U-shaped cigarette pipe are fixedly connected with L-shaped sliding rods movably abutting against the upper wall of the flange. Telescopic cylinder 2 is installed on the front and rear walls of the inner cavity of the installation frame. The telescopic end of the bottom of the telescopic cylinder 2 is fixedly connected with a clamping ring slidably connected to the inner wall of the gear ring, and the clamping ring is movably engaged with the upper protrusion.

[0017] Furthermore, the pressure sensor is installed at the rear end of the clamping tube, a compression spring is fixedly connected between the pressure sensor and the screw, and the pressure sensor electrically feedback controls the second telescopic cylinder.

[0018] Furthermore, the top expansion sleeve of the air supply pipe is connected to the bottom of the heat exchange pipe, the inner wall of the air supply pipe is rotatably sealed and connected to a gear fan, the left wall of the air supply pipe is provided with a suspension platform, and the suspension platform is rotatably connected to a driving gear that meshes with the gear fan, and the driving gear is driven by a second motor installed on the lower wall of the suspension platform, and a reducer is installed on the upper wall of the suspension platform, and the input end of the reducer is fixedly connected to the driving gear, and the output end is fixedly connected to a reduction gear rod that passes through the mounting frame and meshes with the gear ring.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The present invention controls the adjustment component to drive the two insulation plates to move toward or away from each other, thereby changing the heat exchange area of ​​the heat exchange tube, and cooperates with the temperature sensor to monitor the air output temperature, so as to quickly adjust the air output temperature. The air temperature adjustment range is large. When the required temperature is not reached, the wind shield component is cooperated to continue to adjust the air output opening of the right heat exchange tube, so as to fine-tune the air output temperature. The temperature adjustment accuracy is high and the temperature control effect is good.

[0021] 2. The present invention uses a lifting assembly to intermittently lift the U-shaped smoke tube during heat exchange, and the scraping rings on the upper and lower insulation plates scrape the smoke and dust on the heat exchange tube online to avoid corrosion and affect the heat exchange temperature. When the adjustment assembly is used to adjust the heat exchange area of ​​the heat exchange tube, the pressure sensor is acted upon by the adjustment assembly to feedback and adjust the top width of the lifting assembly, thereby achieving smoke and dust scraping on the heat exchange tube in the corresponding range, avoiding ineffective scraping in the remaining range, ensuring rapid recovery of the U-shaped smoke tube, and reducing the duration of heat exchange temperature fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional structural diagram of the present invention;

[0023] Figure 2 The installation frame and the U-shaped smoke pipe of the present invention are partially cut out in three dimensions. Figure 1 ;

[0024] Figure 3 This is a partial three-dimensional cutaway view of the air guide pipe and the U-shaped smoke pipe of the present invention;

[0025] Figure 4 This is a partial three-dimensional cutaway view of the air guide tube of the present invention;

[0026] Figure 5 The installation frame and the U-shaped smoke pipe of the present invention are partially cut out in three dimensions. Figure 2 ;

[0027] Figure 6 This is a partial three-dimensional cross-sectional exploded view of the internal sales pipe and the heat-insulated sales pipe of the present invention;

[0028] Figure 7 This is a three-dimensional structural diagram of the gear ring portion of the present invention;

[0029] Figure 8 It is a partial three-dimensional cutaway view of the gear ring and the telescopic protrusion of the present invention.

[0030] 1. Mounting frame; 2. Heat exchange tube; 3. Air guide tube; 4. Fan; 5. Temperature sensor; 6. Wind shield and heat insulation board; 7. Crank; 8. Telescopic cylinder 1; 9. Air supply tube; 10. Gear fan; 11. Drive gear; 12. Reducer; 13. Reducer gear; 14. Reduction gear rod; 15. U-shaped smoke pipe; 16. Insulation plate; 17. Telescopic insulation board; 18. Slide frame; 19. Scraper ring; 20. Clamping tube; 21. Pressure sensor; 22. Compression spring; 23. L-shaped slide rod; 24. Inner pin tube; 25. Inner spiral groove; 26. Insulation pin tube; 27. Outer spiral groove; 28. Screw; 29. ​​Pin cam; 30. Worm gear sleeve; 31. Worm sleeve; 32. Shaft; 33. Gear ring; 34. Reduction gear rod; 35. U-shaped smoke pipe; 36. Insulation plate; 37. Telescopic insulation board; 38. Slide frame; 39. Scraper ring; 40. Clamping tube; 41. Pressure sensor; 42. Compression spring; 43. L-shaped slide rod; 44. Inner pin tube; 45. Inner spiral groove; 46. Insulation pin tube; 47. Outer spiral groove; 48. Screw; 45. Pin cam; 46. Worm gear sleeve; 47. Worm sleeve; 48. Shaft; 40. Gear ring; 41. Telescopic cam; 42. Clamping ring; 43. Telescopic cylinder 2 DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] Example 1, as Figures 1-8 As shown, a self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater comprises a mounting frame 1, a heat exchange tube 11 is fixedly connected between the upper and lower walls of the mounting frame 1, the heat exchange tube 11 is composed of a plurality of staggered heat exchange sections and heat insulation sections, the length of the heat exchange section is greater than the heat insulation section, the upper and lower ends of the mounting frame 1 are fixedly connected to an air guide 2 and an air supply duct 3, the upper and lower sides of the inner wall of the air guide 2 are respectively provided with a temperature sensor 22 and a wind shield assembly, a U-shaped smoke pipe 4 is slidably connected in the mounting frame 1, the middle part of the U-shaped smoke pipe 4 is expanded and the cross-section is rectangular, two symmetrical heat insulation plates 41 that are movably sleeved on the heat exchange tube 11 are slidably sleeved in the U-shaped smoke pipe 4, telescopic heat insulation plates 42 are rotatably connected between the two ends of the heat insulation plate 41 and the inner wall of the U-shaped smoke pipe 4, the front and rear side walls of the heat insulation plate 41 and the telescopic heat insulation plate 42 are movably sealed against the inner wall of the middle part of the U-shaped smoke pipe 4, and a scraper ring 44 sleeved on the heat exchange tube 11 is fixedly connected to the inner side of the heat insulation plate 41;

[0033] An adjusting assembly is provided in the middle of the U-shaped smoke tube 4 to drive the two insulation plates 41 to move up and down. A lifting assembly is provided at the bottom of the U-shaped smoke tube 4. A pressure sensor 46 is provided on the rear side of the U-shaped smoke tube 4. The pressure sensor 46 electrically controls the lifting assembly to adjust the top width.

[0034] The two ends of the initial U-shaped smoke pipe 4 can be slidably sealed and sleeved or plugged into the corresponding fixed smoke delivery pipe, or connected to the fixed smoke delivery pipe through a telescopic pipe. When in use, the smoke flows from left to right along the U-shaped smoke pipe 4 through the outside of each heat exchange pipe 11. The telescopic insulation plate 42 cooperates with the insulation flat plate 41 to insulate and guide the flow. The air supply pipe 3 transports air upward at a fixed flow rate with the required fixed power. The air passes through the inside of each heat exchange pipe 11 on the left and is output upward by the air guide pipe 2. Since the heat exchange pipe 11 is composed of a number of staggered heat exchange sections and insulation sections, the length of the heat exchange section is greater than the insulation section, and the insulation section does not absorb heat. By controlling and adjusting the assembly with The two heat-insulating plates 41 are moved toward or away from each other, thereby changing the heat-exchanging length of the heat-exchanging tube 11, so as to change the heat-exchanging area of ​​the heat-exchanging tube 11, thereby adjusting the air output temperature. During this period, the temperature sensor 22 continuously monitors the air output temperature. Since it is necessary to make the heat-insulating plate 41 just in the heat-insulating section to reduce heat leakage, the air-conditioning temperature may not reach the required value. When the adjusted air output temperature just reaches the required temperature, the adjustment is completed. When the air output temperature can only be adjusted to slightly lower than the required temperature, the air output temperature is roughly adjusted. The air output opening of the right heat-exchanging tube 11 can be adjusted in conjunction with the windshield component to increase the hot air. Into, similarly use the temperature sensor 22 to monitor the air output temperature, so as to fine-tune the air output temperature, with high temperature regulation accuracy and good temperature control effect. During the heat exchange period, the lifting component intermittently lifts the U-shaped smoke pipe 4, and the scraping rings 44 on the upper and lower insulation plates 41 scrape the smoke on the heat exchange tube 11 online to avoid corrosion and affect the heat exchange temperature. The scraped smoke flows with the smoke to the subsequent process treatment. When the regulating component adjusts the heat exchange range between the two insulation plates 41, the pressure sensor 46 is acted upon by the regulating component to feedback and adjust the top width of the lifting component, thereby achieving the corresponding range of smoke scraping on the heat exchange tube 11, that is, the two The larger the distance between the insulation plates 41 and the more heat exchange tubes 11 participate in the heat exchange, the larger the smoke and dust scraping range will be. Conversely, the smaller the smoke and dust scraping range will be, thereby avoiding ineffective scraping of the remaining ranges, ensuring the rapid recovery of the U-shaped smoke tube 4, and reducing the heat exchange temperature fluctuation time. During this period, when the U-shaped smoke tube 4 drives the insulation plates 41 to move up and down, since the heat exchange section and the heat insulation section in the heat exchange tube 11 are staggered, and in actual use, the lengths of the heat exchange section and the heat insulation section are both small, although the heat exchange area of ​​the heat exchange tube 11 will change slightly, resulting in fluctuations in the air output temperature, the temperature is still within the normal small fluctuation range and does not affect normal operation.

[0035] Embodiment 2, on the basis of the above embodiment, the windshield assembly includes a windshield heat insulation plate 23 rotatably connected to the central inner wall of the bottom of the air duct 2, the top of the windshield heat insulation plate 23 is movably abutted against the right wall of the inner cavity of the air duct 2, the front and rear ends of the windshield heat insulation plate 23 are movably sealed abutted against the inner wall of the air duct 2, and the bottom end is movably sealed abutted against the upper wall of the mounting frame 1, the windshield heat insulation plate 23 separates the heat exchange tube 11 into a heat exchange zone on the left and a heat adjustment zone on the right, the number of heat exchange tubes 11 corresponding to the heat adjustment zone is less than the number of heat exchange tubes 11 corresponding to the heat exchange zone, and the cross-section of the bottom of the air duct 2 is rectangular and is sleeved on the heat exchange tube 11.

[0036] Through this design, the windshield and heat insulation board 23 can insulate and seal the output port of the heat exchange tube 11 in the right heating zone. The air input by the air supply pipe 3 initially passes through the heat exchange zone on the left and is output. When the output air temperature is slightly lower than the required temperature, the opening between the windshield and heat insulation board 23 and the right wall of the inner cavity of the air guide pipe 2 can be adjusted to adjust the temperature to the required temperature. Since the number of heat exchange tubes 11 corresponding to the heating zone is less than the number of heat exchange tubes 11 corresponding to the heat exchange zone, when the windshield and heat insulation board 23 is used to fine-tune the temperature, the interference with the flow in the heat exchange tube 11 in the heat exchange zone can be reduced, thereby avoiding large changes in the mainstream channel temperature.

[0037] The windshield assembly also includes a crank 24 fixedly inserted into the shaft of the windshield insulation board 23. The crank 24 passes through the front wall of the air duct 2. A telescopic cylinder 25 is rotatably connected between the crank 24 and the air duct 2. The temperature sensor 22 electrically feedback controls the telescopic cylinder 25.

[0038] The crank 24 is adjusted by the telescopic cylinder 1 25 to drive the wind shield and heat insulation board 23 to deflect, so that the opening between the wind shield and heat insulation board 23 and the right wall of the inner cavity of the air guide pipe 2 can be stably adjusted.

[0039] Embodiment 3: Based on the above embodiment, a fan 21 is rotatably connected to the inner wall of the top of the air duct 2 , and the fan 21 is located below the temperature sensor 22 .

[0040] Through this design, when the air supply pipe 3 transports air upward, when the heat exchange pipe 11 in the left heat exchange zone and the heat exchange pipe 11 in the right heat adjustment zone both transport heated air upward, the air can be mixed by the fan 21 to ensure that the temperature of each part is consistent, thereby facilitating accurate temperature feedback by the temperature sensor 22.

[0041] Embodiment 4, based on the above embodiment, the adjustment component includes an I-shaped inner pin tube 5 rotatably connected to the middle of the U-shaped smoke tube 4, an inner spiral groove 51 is provided on the middle side wall of the inner pin tube 5, and an I-shaped heat-insulating pin tube 52 is rotatably and sealingly connected to the periphery of the inner pin tube 5, an outer spiral groove 53 is provided on the inner wall of the middle of the heat-insulating pin tube 52, and the outer spiral groove 53 has the same pitch as the inner spiral groove 51 and is in the opposite direction. A clamping tube 45 is fixedly connected to the rear wall of the U-shaped smoke tube 4, and a screw 54 is slidably inserted in the middle of the inner pin tube 5 and is slidably engaged with the clamping tube 45. A pin protrusion 55 is provided on the upper end of the screw 54 for movably engaging with the outer spiral groove 53 and the inner spiral groove 51 respectively. A worm gear sleeve 56 is rotatably connected to the front wall of the U-shaped smoke tube 4;

[0042] Sliding frames 43 are provided on both the front and rear sides of the inner wall of the heat-insulating flat plate 41 , and the inner pin tube 5 and the heat-insulating pin tube 52 are movably connected to the corresponding sliding frames 43 respectively.

[0043] The front wall of the U-shaped smoke pipe 4 is rotatably connected to a volute 57 that meshes with the worm gear sleeve 56. A shaft 58 is rotatably connected between the upper and lower walls of the inner cavity of the mounting frame 1. The volute 57 is slidably engaged on the shaft 58. The shaft 58 is driven by a motor 1 installed on the lower wall of the mounting frame 1, and the temperature sensor 22 electrically feedback controls the motor 1.

[0044] When it is necessary to adjust the heat exchange area involved in the heat exchange tube 11, the motor drives the shaft 58 to drive the volute 57 to rotate, driving the worm gear sleeve 56 to move the screw 54 forward or backward, and the pin protrusion 55 squeezes the corresponding inner spiral groove 51 and the outer spiral groove 53, driving the inner pin tube 5 and the insulation pin tube 52 to deflect in the opposite direction, and the sliding frame 43 is used to adjust the upper and lower insulation plates 41 to move toward or away from each other. The insulation plates 41 are balanced in force and the adjustment is accurate and stable. When the U-shaped smoke pipe 4 moves up and down subsequently, the sliding engagement between the volute 57 and the shaft 58 is utilized to ensure that the volute 57 continues to be connected and locked to the worm gear sleeve 56. Combined with the self-locking properties of the screw 54 and the worm gear sleeve 56, the spacing between the insulation plates 41 is kept stable after adjustment, and the temperature control is reliable.

[0045] Embodiment 5, on the basis of the above embodiment, the jacking assembly includes a gear ring 6 rotatably connected to the lower wall of the inner cavity of the installation frame 1 and having a flange on the bottom periphery, and telescopic protrusions 61 are slidably engaged on the front and rear sides of the flange, and the telescopic protrusions 61 are respectively composed of two upper protrusions and lower protrusions in the up and down directions. The upper protrusions are slidably engaged in the lower protrusions and the two are elastically connected, and the left and right sides of the lower wall of the U-shaped smoke pipe 4 are fixedly connected with L-shaped sliding rods 48 that are movably engaged with the upper wall of the flange, and telescopic cylinders 63 are installed on the front and rear walls of the inner cavity of the installation frame 1. The telescopic end of the bottom of the telescopic cylinder 63 is fixedly connected with a snap ring 62 that is slidably connected to the inner wall of the gear ring 6, and the snap ring 62 is movably engaged with the upper protrusion.

[0046] The pressure sensor 46 is installed at the rear end of the clamping tube 45 . A compression spring 47 is fixedly connected between the pressure sensor 46 and the screw rod 54 . The pressure sensor 46 electrically feedback controls the telescopic cylinder 2 63 .

[0047] During use, the gear ring 6 rotates continuously. When the telescopic projection 61 passes the L-shaped slide bar 48, the U-shaped smoke pipe 4 is automatically lifted up, so that the scraper ring 44 on the heat insulation plate 41 can scrape off the smoke and dust adsorbed on the heat exchange tube 11 to avoid corrosion and affect the heat exchange. When the telescopic projection 61 rotates past the L-shaped slide bar 48, the U-shaped smoke pipe 4 is reset under its own weight.

[0048] When the adjusting screw 54 moves backward, the two heat insulation plates 41 move toward each other, and the heat exchange area involved in the heat exchange tube 11 decreases. The adjusting screw 54 increases the pressure on the pressure sensor 46 through the compression spring 47. The pressure sensor 46 thereby feedback controls the extension of the adjusting telescopic cylinder 2 63, and the retaining ring 62 drives the upper protrusion to be compressed into the lower protrusion. The upper protrusion height of the telescopic protrusion 61 relative to the flange of the gear ring 6 is reduced, and the subsequent height of the U-shaped smoke pipe 4 is thereby reduced. Correspondingly, when the heat exchange length involved in the heat exchange tube 11 increases, the upper protrusion extends from the lower protrusion. When the heat exchange area involved in the heat exchange tube 11 is larger, the upper protrusion will also pull the lower protrusion upward, and the corresponding height of the U-shaped smoke pipe 4 is increased, thereby adaptively scraping the smoke and dust in the corresponding range, avoiding ineffective scraping of the remaining ranges, ensuring the rapid recovery of the U-shaped smoke pipe 4, and reducing the duration of heat exchange temperature fluctuations.

[0049] Example 6. On the basis of the above example, the top of the air supply pipe 3 is expanded and sleeved on the bottom of the heat exchange pipe 11. The inner wall of the air supply pipe 3 is rotatably and sealedly connected to a gear fan 31. A suspension is provided on the left wall of the air supply pipe 3. A driving gear 32 that is rotatably connected to the suspension is engaged with the gear fan 31. The driving gear 32 is driven by a motor 2 installed on the lower wall of the suspension. A reducer 33 is installed on the upper wall of the suspension. The input end of the reducer 33 is fixedly connected to the driving gear 32, and the output end is fixedly connected to a reduction gear rod 34 that passes through the mounting frame 1 and engages with the gear ring 6.

[0050] When in use, motor 2 drives the driving gear 32 so that the gear fan 31 delivers air upward at a fixed flow rate with the required fixed power. The synchronous driving gear 32 inputs power to the reducer 33, and the reducer 33 reduces the output through the reduction gear rod 34. The reduction gear rod 34 slowly drives the gear ring 6 to rotate, thereby realizing the slow cleaning of the heat exchange tube 11 by the scraper ring 44, avoiding large scraping and wear of the heat exchange tube 11, and at the same time increasing the cleaning interval to avoid excessive cleaning.

[0051] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-controlling temperature and corrosion-resistant waste heat recovery device for a boiler preheater, comprising a mounting frame (1), characterized in that: A heat exchange tube (11) is fixedly connected between the upper and lower walls of the installation frame (1), and the heat exchange tube (11) is composed of a plurality of staggered heat exchange sections and heat insulation sections, and the length of the heat exchange section is greater than the heat insulation section. The upper and lower ends of the installation frame (1) are respectively fixedly connected with an air guide tube (2) and an air supply tube (3), and the upper and lower sides of the inner wall of the air guide tube (2) are respectively provided with a temperature sensor (22) and a wind shield assembly. A U-shaped smoke tube (4) is slidably connected in the installation frame (1), and two symmetrical heat insulation plates (41) that are movably sleeved on the heat exchange tube (11) are slidably connected in the U-shaped smoke tube (4). A telescopic heat insulation plate (42) is rotatably connected between the two ends of the heat insulation plate (41) and the inner wall of the U-shaped smoke tube (4), and a scraper ring (44) that is sleeved on the heat exchange tube (11) is fixedly connected on the inner side of the heat insulation plate (41); An adjusting assembly for driving two heat-insulating plates (41) to move up and down is provided in the middle of the U-shaped smoke pipe (4), a lifting assembly is provided at the bottom of the U-shaped smoke pipe (4), and a pressure sensor (46) is provided at the rear side of the U-shaped smoke pipe (4). The pressure sensor (46) electrically controls the lifting assembly to adjust the top width.

2. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 1, characterized in that: The windshield assembly includes a windshield heat insulation plate (23) rotatably connected to the central inner wall of the bottom of the air duct (2); the top of the windshield heat insulation plate (23) is movably abutted against the right wall of the inner cavity of the air duct (2); the front and rear ends of the windshield heat insulation plate (23) are movably sealed against the inner wall of the air duct (2), and the bottom end is movably sealed against the upper wall of the installation frame (1); the windshield heat insulation plate (23) separates the heat exchange tube (11) into a heat exchange zone on the left and a heat adjustment zone on the right; the number of heat exchange tubes (11) corresponding to the heat adjustment zone is less than the number of heat exchange tubes (11) corresponding to the heat exchange zone; the bottom cross-section of the air duct (2) is rectangular and is sleeved on the heat exchange tube (11).

3. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 2, characterized in that: The windshield assembly further comprises a crank (24) fixedly plugged into the shaft of the windshield heat insulation board (23), the crank (24) passing through the front wall of the air duct (2), a telescopic cylinder (25) being rotatably connected between the crank (24) and the air duct (2), and the temperature sensor (22) electrically feedback-controlling the telescopic cylinder (25).

4. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 3, characterized in that: A fan (21) is rotatably connected to the inner wall of the top of the air guide pipe (2), and the fan (21) is located below the temperature sensor (22).

5. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 4, characterized in that: The middle portion of the U-shaped smoke tube (4) is expanded and has a rectangular cross-section. The front and rear side walls of the heat insulating plate (41) and the telescopic heat insulating plate (42) are in movable sealing contact with the inner wall of the middle portion of the U-shaped smoke tube (4).

6. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 5, characterized in that: The regulating assembly comprises an inner pin tube (5) rotatably connected to the middle of the U-shaped smoke pipe (4) in an I-shaped shape, an inner spiral groove (51) being provided on the middle side wall of the inner pin tube (5), an I-shaped heat-insulating pin tube (52) being rotatably sealed on the periphery of the inner pin tube (5), an outer spiral groove (53) being provided on the middle inner wall of the heat-insulating pin tube (52), the outer spiral groove (53) having the same pitch as the inner spiral groove (51) and opposite directions, a clamping tube (45) being fixedly connected to the rear wall of the U-shaped smoke pipe (4), a screw rod (54) being slidably plugged into the middle of the inner pin tube (5) and being slidably engaged with the clamping tube (45), a pin protrusion (55) being movably engaged with the outer spiral groove (53) and the inner spiral groove (51) respectively being provided on the upper end of the screw rod (54), and a worm gear sleeve (56) being threadedly sleeved with the screw rod (54) being rotatably connected to the front wall of the U-shaped smoke pipe (4); Sliding frames (43) are provided on both the front and rear sides of the inner wall of the heat-insulating flat plate (41), and the inner sales tube (5) and the heat-insulating sales tube (52) are respectively movably connected to the corresponding sliding frames (43).

7. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 6, characterized in that: The front wall of the U-shaped smoke pipe (4) is rotatably connected to a worm sleeve (57) meshing with a worm gear sleeve (56); the upper and lower walls of the inner cavity of the installation frame (1) are rotatably connected to a shaft rod (58); the worm sleeve (57) is slidably engaged with the shaft rod (58); the shaft rod (58) is driven by a motor 1 installed on the lower wall of the installation frame (1); and the temperature sensor (22) electrically feedback controls the motor 1.

8. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 7, characterized in that: The lifting assembly includes a gear ring (6) rotatably connected to the lower wall of the inner cavity of the installation frame (1) and having a flange on the bottom periphery. The front and rear sides of the flange are slidably engaged with telescopic protrusions (61). The telescopic protrusions (61) are respectively composed of two upper protrusions and lower protrusions in the form of isosceles trapezoids in the up and down directions. The upper protrusions are slidably engaged in the lower protrusions and the two are elastically connected. The left and right sides of the lower wall of the U-shaped smoke pipe (4) are fixedly connected with L-shaped sliding rods (48) that are movably engaged with the upper wall of the flange. Telescopic cylinder No. 2 (63) is installed on the front and rear walls of the inner cavity of the installation frame (1). The telescopic end of the bottom of the telescopic cylinder No. 2 (63) is fixedly connected with a clamping ring (62) that is slidably connected to the inner wall of the gear ring (6). The clamping ring (62) is movably engaged with the upper protrusion.

9. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 8, characterized in that: The pressure sensor (46) is installed at the rear end of the clamping tube (45), and a compression spring (47) is fixedly connected between the pressure sensor (46) and the screw (54). The pressure sensor (46) electrically feedback controls the telescopic cylinder 2 (63).

10. The self-controlling temperature and anti-corrosion waste heat recovery device for a boiler preheater according to claim 9, characterized in that: The top of the air supply pipe (3) is expanded and sleeved on the bottom of the heat exchange pipe (11); the inner wall of the air supply pipe (3) is rotatably and sealedly connected to a gear fan (31); a suspension platform is provided on the left wall of the air supply pipe (3); a driving gear (32) meshing with the gear fan (31) is rotatably connected in the suspension platform; the driving gear (32) is driven by a second motor installed on the lower wall of the suspension platform; a reducer (33) is installed on the upper wall of the suspension platform; the input end of the reducer (33) is fixedly connected to the driving gear (32), and the output end is fixedly connected to a reduction gear rod (34) that passes through the mounting frame (1) and meshes with the gear ring (6).

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