A shell-and-tube heat exchanger with cleaning structure

Abstract

The application discloses a column tube type heat exchanger with a cleaning structure and belongs to the technical field of heat exchangers. The heat exchanger comprises an outer shell, a heat exchange tube bundle and a cleaning mechanism. The scraping piece of the inner tube bundle wall cleaning piece is arranged as a composite structure of a rigid scraping block and an air bag, and a closed communication air path is formed by using a communication pipe, so that the scraping piece can self-adaptively adjust the scraping force according to the change of the water body pressure in the tube during the movement of the scraping piece on the inner wall of the heat exchange tube, the effective scraping of hard thick dirt and the flexible peeling of fine impurities are organically combined, the technical contradiction that the traditional rigid scraping structure is easy to scratch the tube wall and the flexible cleaning structure cannot remove hard dirt is overcome, and the thoroughness of the inner wall cleaning and the tube wall protection are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more specifically, to a shell-and-tube heat exchanger with a cleaning structure. Background Technology

[0002] Shell-and-tube heat exchangers are core heat exchange equipment in industrial fields such as chemical engineering, energy, HVAC, and wastewater treatment. They primarily rely on the heat exchange between the media inside and outside the tube bundle to achieve heat transfer. With their robust structure, high heat exchange efficiency, and strong adaptability, they are widely used in various industrial production processes. During long-term operation, scale, impurities, dust, flocculent matter, and other substances in the medium easily adhere to the inner and outer walls of the heat exchange tube bundle, forming a stubborn fouling layer. Since the thermal conductivity of this fouling layer is much lower than that of the metal tube walls, it significantly reduces the overall heat exchange efficiency of the heat exchanger, increases energy consumption, and in severe cases, can cause tube blockage, impede media flow, lead to equipment failure, and shorten the lifespan of the heat exchanger. Therefore, regular cleaning of the heat exchange tube bundle is crucial to ensuring stable equipment operation.

[0003] Currently, existing shell-and-tube heat exchanger cleaning structures cannot achieve synchronous, adaptive, and integrated cleaning of the inner and outer walls of the heat exchange tube bundle. Specifically, most existing conventional cleaning equipment only performs unidirectional cleaning operations on the inner or outer walls of the heat exchange tube bundle, and cannot rely on the equipment's own medium power to achieve synchronous and coordinated cleaning of the inner and outer walls. The cleaning process is cumbersome and the work efficiency is low. For cleaning the inner wall of tube bundles, traditional rigid scraping structures can only perform simple scraping operations and cannot adaptively adjust according to the thickness of the dirt on the tube wall and the state of the medium water flow. During the scraping process, problems such as cleaning deviation and tube wall scratches are prone to occur. Moreover, the fine impurities after scraping are very easy to re-adhere to the tube wall and cannot be completely removed. Over time, they will still form a new dirt layer. On the other hand, some flexible cleaning structures cannot effectively remove the hard and thick scale attached to the tube wall, and their cleaning adaptability is extremely poor. Meanwhile, for cleaning the outer wall of tube bundles, existing cleaning structures mostly use fixed brushes or single scraping rings, which can only achieve local cleaning with a fixed stroke. They cannot adapt to the complex structure of multiple tube bundles for all-round reciprocating scraping and cleaning. It is difficult to clean the dead corners and impurities in the gaps between tube bundles and the connection positions of baffles.

[0004] In summary, the existing cleaning structures of shell-and-tube heat exchangers have asynchronous cleaning of the inner and outer walls, which cannot meet the cleaning requirements of industrial equipment under long-term continuous operation, thus restricting the heat exchange stability and long-term operating performance of shell-and-tube heat exchangers. Therefore, a shell-and-tube heat exchanger with a cleaning structure is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a shell-and-tube heat exchanger with a cleaning structure to solve the problems mentioned in the background art.

[0006] The present invention provides the following technical solution: a shell-and-tube heat exchanger with a cleaning structure, comprising: an outer shell, a heat exchange tube bundle, and a cleaning mechanism; The outer shell consists of a heat exchange cylinder and cold liquid inlet and cold liquid outlet detachably connected to both ends of the heat exchange cylinder. The heat exchange cylinder, cold liquid inlet, and cold liquid outlet form a closed heat exchange cavity. Both the cold liquid inlet and cold liquid outlet are provided with a medium flow interface for the heat exchange medium to flow in and out. The heat exchange tube bundle is adapted to be installed inside the sealed heat exchange cavity of the outer shell. It consists of multiple heat exchange tubes, multiple baffles sleeved on the outside of the multiple heat exchange tubes, and two floating head end plates fixedly connected to both ends of the multiple heat exchange tubes. The baffles are arranged at equal intervals perpendicular to the axis of the heat exchange tubes to disturb the flow direction of the shell-side medium. The cleaning mechanism is an integrated structure adapted for simultaneous cleaning of the inner and outer walls of the heat exchange tube bundle, including a guide frame, a flow drive component, an inner tube bundle wall cleaning component, and an outer tube bundle wall cleaning component. The guide frame is fixedly connected to the inside of the cold liquid inlet end and is set with a hollow frame structure. It is used to connect and support the flow supply drive component, and at the same time constrain the linear displacement path of the inner tube bundle wall cleaning component. The flow supply drive component is fixedly connected to the middle of the guide frame and is sealed and fixedly connected to the internal medium channel of the cold liquid inlet end. It uses the fluid power of the cooling medium as the drive source to synchronously drive the inner tube bundle wall cleaning component and the outer tube bundle wall cleaning component to operate in conjunction. The inner tube bundle wall cleaning component includes two symmetrically arranged transmission disc frames, with multiple traction rods fixedly connected between the two transmission disc frames. The multiple traction rods are arranged in a circular array at equal intervals, and multiple scraping components for cleaning the inner wall of the heat exchange tube bundle are connected to the outside of the traction rods. The scraping component includes a rigid scraper, which is a semi-circular cylindrical structure that fits the inner wall of the heat exchange tube bundle. The rigid scraper has two symmetrically shaped inclined grooves on its outer side, and an airbag that can open and close in a fan-shaped structure is fixedly connected in the inclined groove. A connecting pipe is fixedly connected between the two airbags, and the connecting pipe is set through the interior of the rigid scraper to form a closed air passage. The gas inside the airbag is transferred to each other by the squeezing of water in the pipe, which drives the airbag to adaptively expand and contract its volume and open and close in a fan shape. This works in conjunction with the rigid scraper to scrape off the dirt on the tube wall, and at the same time, the deformation and shaking remove residual impurities.

[0007] According to the above technical solution, the two floating head end plates are arranged symmetrically. The surface of the floating head end plate is provided with fixed through holes corresponding to each heat exchange pipe opening. The outer side of the plate facing the inner tube bundle wall cleaning component is set with an inward structure, which can adapt to the reciprocating stroke of the inner tube bundle wall cleaning component, reduce the dead angle of medium flow, and at the same time play a limiting and protective role.

[0008] According to the above technical solution, one of the transmission disc frames is connected to the flow supply drive component and slides against the inner wall of the guide frame to achieve directional reciprocating movement; the other transmission disc frame is sleeved on the outside of the flow supply drive component and forms an elastic constraint with the corresponding side floating head end plate through the circumferentially arranged elastic element to achieve the reset buffer of the cleaning mechanism.

[0009] According to the above technical solution, the flow drive component includes a reciprocating screw sleeve that is adapted to drive one of the transmission disc frames, and a drive shaft is coaxially sleeved inside the reciprocating screw sleeve. The drive shaft is rotatably connected at both ends between the cold liquid inlet end and the cold liquid outlet end, and the drive shaft rod moves through the entire structure of the heat exchange tube bundle. The drive shaft and the two floating head end plates are rotatably sealed by wear-resistant sealing pairs at their penetration positions.

[0010] According to the above technical solution, a turbine structure is fixedly connected to the outside of the drive shaft. The inlet end of the turbine structure is sealed and fixed to the inner wall of the cold liquid inlet end through a variable diameter pipe. The medium flow rate is increased by the variable diameter pressurization, which provides power for the operation of the turbine structure.

[0011] According to the above technical solution, the outlet end of the turbine structure is fixedly connected to a spray ring, which is sleeved on the outside of the drive shaft and the guide frame. The spray ring has high-pressure spray holes evenly opened on its surface, which can flush impurities in the gaps of the outer wall of the tube bundle under high pressure. The power output end of the drive shaft is connected to the outer tube bundle wall cleaning component for transmission, providing rotational driving force for the outer wall cleaning operation.

[0012] According to the above technical solution, the outer tube bundle wall cleaning component is composed of an extrusion bushing and multiple cleaning units sleeved outside the extrusion bushing; The extrusion sleeve is fitted onto the outside of the drive shaft and rotates synchronously with it, used to connect constraints and link the synchronous operation of each group of cleaning units; each group of cleaning units consists of a rigid scraping ring frame, a rigid extrusion ring, and a sliding column fixedly connected to the inner wall of the rigid extrusion ring; The rigid scraper ring is sleeved on the outside of the heat exchange tube bundle to form a sliding fit structure, and the inner ring of the rigid scraper ring is fixedly connected to the outer ring of the rigid extrusion ring as a whole; the rigid extrusion ring is sleeved on the outside of the extrusion bushing to form a sliding extrusion fit structure, and the sliding column and the cam groove opened on the outside of the extrusion bushing form a sliding extrusion fit structure.

[0013] According to the above technical solution, the outer wall of the extrusion sleeve is provided with a cam groove, and the end of the sliding column is slidably embedded in the cam groove. When the drive shaft drives the extrusion sleeve to rotate, the rigid extrusion ring and the rigid scraping ring frame are driven to reciprocate linearly along the heat exchange tube axis through the dynamic extrusion cooperation between the cam groove and the sliding column, so as to realize continuous reciprocating scraping and cleaning of the outer wall of the heat exchange tube bundle.

[0014] According to the above technical solution, both the rigid scraping ring and the rigid extrusion ring have inclined grooves at their edges for scraping off hard impurities; wherein, a high-density soft brush ring is fixedly connected to the inclined groove of the rigid extrusion ring, and the soft brush ring flexibly fits against the outer wall of the heat exchange tube, which can clean up fine flocculent and dust impurities, and achieve a layered cleaning effect that combines hard scraping and soft cleaning.

[0015] According to the above technical solution, a miniature one-way pressure regulating valve is installed on the middle part of the connecting pipe. The one-way pressure regulating valve is used to maintain the balanced and stable air pressure inside the airbags on both sides, avoid excessive deformation of one side of the airbag, ensure the smoothness of the scraping component moving and cleaning on the inner wall of the heat exchange tube bundle, and at the same time prevent the medium inside the pipe from flowing back into the airbag cavity.

[0016] Compared with the prior art, the beneficial effects of the present invention, using the above technical solution, are as follows: 1. This invention sets the scraper of the inner tube wall cleaning component as a composite structure of a rigid scraper and an airbag, and uses a connecting pipe to form a closed air passage. This allows the scraper to adaptively adjust the scraping force according to the change in water pressure inside the heat exchange tube during its movement. This achieves an organic combination of effective scraping of hard, thick scale and flexible removal of fine impurities, overcoming the technical contradictions of traditional rigid scraping structures that easily scratch the tube wall and flexible cleaning structures that cannot remove hard scale. It significantly improves the thoroughness of inner wall cleaning and the protection of the tube wall. Specifically, when the traction rod drives the scraper to move back and forth inside the heat exchange tube, the flowing medium inside the tube continuously applies fluid pressure to the outside of the airbag. The front airbag in the direction of travel is squeezed and contracted by the water flow, and the internal gas is quickly transferred to the rear airbag through the connecting pipe. The rear airbag inflates and expands, fanning out to form a flexible extrusion surface that fits tightly against the tube wall. When the cleaning component returns in the opposite direction, the pressure direction reverses, and the front and rear airbags exchange gases, achieving bidirectional adaptive deformation. The mechanical scraping action of the rigid scraper and the fluid-driven deformation of the airbag are completely synchronized. The rigid scraper first peels off large pieces of hard dirt, and the expanding airbag continuously exerts elastic pressure on the pipe wall. The airbag moves with the airflow and continuously vibrates in a small fan shape. The high-frequency micro-vibration generated by the vibration can completely remove the fine flocculent matter, dust and soft mud remaining on the pipe wall after scraping, preventing impurities from re-adhering to the pipe wall after standing.

[0017] 2. This invention, through the linkage design of the turbine structure, reciprocating screw sleeve, and drive shaft in the flow drive component, uses the fluid power of the cooling medium itself as the single drive source to synchronously drive the linear reciprocating motion of the inner tube bundle wall cleaning component and the rotational-reciprocating conversion motion of the outer tube bundle wall cleaning component. This achieves synchronous automated cleaning of the inner and outer walls of the heat exchange tube bundle without the need for external power input, reducing equipment energy consumption and operating costs. Furthermore, the sliding fit structure of the cam groove and slide column of the extrusion sleeve in the outer tube bundle wall cleaning component transforms the rotational motion of the drive shaft into the continuous reciprocating linear motion of the cleaning unit along the axis of the heat exchange tube. Combined with the hard scraping of the rigid wall scraping ring and the flexible cleaning layered cleaning design of the rigid extrusion ring, it achieves all-round, dead-angle-free cleaning of the outer wall of the heat exchange tube bundle, effectively solving the problem of difficult cleaning of impurities in the tube bundle gaps and baffle connection positions in the prior art. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a cross-sectional schematic diagram of the outer shell structure of the present invention; Figure 4 This is a schematic diagram showing the disassembled structure of the heat exchanger tube bundle of the present invention; Figure 5 This is a schematic diagram of the cleaning mechanism structure of the present invention; Figure 6 This is a schematic diagram of the flow supply drive structure of the present invention; Figure 7 This is a schematic diagram of the inner tube bundle wall cleaning component of the present invention; Figure 8 This is a schematic diagram of the scraping component structure of the present invention; Figure 9 This is a schematic diagram of the outer tube bundle wall cleaning component of the present invention; Figure 10 This is a schematic diagram of the cleaning unit structure of the present invention.

[0019] The following are the labeling instructions in the diagram: 10. Outer shell; 11. Heat exchanger cylinder; 12. Cold liquid inlet end; 13. Cold liquid outlet end; 20. Heat exchanger tube bundle; 21. Heat exchange tube; 22. Baffle plate; 23. Floating head end plate; 30. Cleaning mechanism; 31. Guide frame; 32. Flow supply drive component; 33. Inner tube bundle wall cleaning component; 34. Outer tube bundle wall cleaning component; 321. Reciprocating screw sleeve; 322. Drive shaft; 323. Turbine structure; 324. Reducer; 325. Spray ring; 331. Transmission disc frame; 332. Traction rod; 333. Scraper component; 334. Rigid scraper block; 335. Airbag; 336. Connecting pipe; 341. Extrusion bushing; 342. Cleaning unit; 343. Rigid scraper ring frame; 344. Rigid extrusion ring; 345. Sliding column. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Reference Figure 1 , Figure 2 and Figure 3 A shell-and-tube heat exchanger with a cleaning structure includes an outer shell 10, a heat exchange tube bundle 20, and a cleaning mechanism 30. The outer shell 10 consists of a heat exchange cylinder 11 and cold liquid inlet end 12 and cold liquid outlet end 13 detachably connected to both ends of the heat exchange cylinder 11. The heat exchange cylinder 11, cold liquid inlet end 12, and cold liquid outlet end 13 enclose a closed heat exchange cavity. Both the cold liquid inlet end 12 and the cold liquid outlet end 13 are provided with medium flow interfaces for the flow of heat exchange medium. The cold liquid inlet end 12 and the cold liquid outlet end 13 can be connected to the heat exchange cylinder 11 by flange or threaded connection for easy disassembly and maintenance. The heat exchange tube bundle 20 is adapted to be installed inside the sealed heat exchange cavity of the outer shell 10. It consists of multiple heat exchange tubes 21, multiple baffles 22 sleeved on the outside of the multiple heat exchange tubes 21, and two floating end plates 23 fixedly connected to both ends of the multiple heat exchange tubes 21. The baffles 22 are arranged at equal intervals perpendicular to the axis of the heat exchange tubes 21 to disturb the flow direction of the shell-side medium, enhance the heat exchange contact effect, and improve the overall heat exchange efficiency. The number and arrangement of the heat exchange tubes 21 can be adjusted according to the actual heat exchange requirements, and the spacing of the baffles 22 can also be optimized according to the shell-side medium flow rate and heat exchange requirements. The cleaning mechanism 30 is an integrated structure adapted for the synchronous cleaning of the inner and outer walls of the heat exchanger tube bundle 20. It includes a guide frame 31, a flow drive component 32, an inner tube bundle wall cleaning component 33, and an outer tube bundle wall cleaning component 34. The guide frame 31 is fixedly connected to the inside of the cold liquid inlet end 12 and adopts a hollow frame structure. It is mainly used to connect and support the flow drive component 32, while precisely constraining the linear displacement path of the inner tube bundle wall cleaning component 33 to prevent deviation or jamming during the cleaning operation. The hollow structure of the guide frame 31 ensures that the cooling medium can pass smoothly without affecting the normal operation of the heat exchanger. The flow drive component 32 is fixedly connected to the middle of the guide frame 31 and is sealed and fixedly connected to the internal medium channel of the cold liquid inlet end 12. Using the fluid power of the cooling medium as the driving source, it can synchronously drive the inner tube bundle wall cleaning component 33 and the outer tube bundle wall cleaning component 34 to operate in conjunction, realizing the synchronous automated cleaning operation of the inner and outer walls of the heat exchanger tube bundle 20.

[0022] This shell-and-tube heat exchanger with a cleaning structure achieves synchronous and automated cleaning of the inner and outer walls of the heat exchange tube bundle 20 by setting the cleaning mechanism 30 as an integrated structure adapted to the synchronous cleaning of the inner and outer walls of the heat exchange tube bundle 20 and using the fluid power of the cooling medium as the driving source. This effectively solves the problems of asynchronous cleaning of the inner and outer walls and cumbersome cleaning procedures.

[0023] Reference Figure 4 and Figure 7 The two floating head end plates 23 are arranged symmetrically. The surface of the floating head end plate 23 is provided with fixed through holes corresponding to the openings of each heat exchange tube 21. The outer side of the floating head end plate 23 facing the inner tube bundle wall cleaning component 33 is set with an inward structure, which can adapt to the reciprocating stroke of the inner tube bundle wall cleaning component 33, reduce the dead angle of medium flow, and at the same time play a limiting and protective role. The inner tube bundle wall cleaning component 33 includes two symmetrically arranged transmission disc frames 331, and multiple traction rods 332 are fixedly connected between the two transmission disc frames 331. The multiple traction rods 332 are arranged in a ring array at equal intervals. Multiple scraping components 333 for cleaning the inner wall of the heat exchange tube bundle 20 are connected to the outside of the traction rods 332 in a staggered and equally spaced structure. One of the transmission disc frames 331 is connected to the flow drive component 32 and slides against the inner wall of the guide frame 31 to achieve directional reciprocating movement; the other transmission disc frame 331 is sleeved on the outside of the flow drive component 32 and forms an elastic constraint with the corresponding side floating head end plate 23 through the circumferentially arranged elastic element to achieve the reset buffer of the cleaning mechanism; the elastic element can be a compression spring or a disc spring. When the flow drive component 32 stops working, the elastic element can push the inner tube bundle wall cleaning component 33 back to the initial position to avoid the scraping component 333 staying at a certain position on the inner wall of the heat exchange tube 21 for a long time and causing local excessive wear.

[0024] This shell-and-tube heat exchanger with a cleaning structure effectively reduces dead angles in medium flow by setting the outer side of the floating head end plate 23 to a concave structure, while providing limit protection for the reciprocating motion of the inner tube bundle wall cleaning component 33; through the cooperation of the transmission disc frame 331, the traction rod 332 and the scraping component 333 in the inner tube bundle wall cleaning component 33, a comprehensive cleaning of the inner wall of the heat exchange tube bundle 20 is achieved.

[0025] Reference Figure 7 and Figure 8 The scraping component 333 includes a rigid scraper 334, with two adjacent rigid scrapers 334 arranged in a staggered and symmetrical manner, and the rigid scraper 334 is a semi-circular cylindrical structure that fits the inner wall of the heat exchange tube bundle 20. The rigid scraper block 334 of the semi-circular cylinder has two symmetrically shaped grooves on its outside, and an airbag 335 that can open and close in a fan-shaped structure is fixedly connected in the grooves; a connecting pipe 336 is fixedly connected between the two airbags 335, and the connecting pipe 336 is set through the interior of the rigid scraper block 334 to form a closed connecting air passage. The gas inside the airbag 335 is transferred to each other by squeezing the water inside the tube, which drives the airbag 335 to adapt to volume expansion and contraction and fan-shaped opening and closing. In conjunction with the rigid scraper 334, the dirt on the tube wall is scraped off. At the same time, the residual impurities are removed by deformation and shaking, ensuring that no impurities are re-attached after the inner wall of the heat exchange tube bundle 20 is cleaned. Specifically, when the scraper 333 moves on the inner wall of the heat exchange tube 21, the water flow in the tube will exert a squeezing effect on the airbag 335, causing one side of the airbag 335 to compress and the other side of the airbag 335 to expand. The two airbags 335 exchange gases through the connecting tube 336, thereby realizing the adaptive volume change and fan-shaped opening and closing action of the airbag 335. During this process, the deformation of the airbag 335 will produce slight vibrations, which helps to peel the fine impurities scraped off by the rigid scraper 334 from the tube wall and prevent the impurities from adhering again.

[0026] This shell-and-tube heat exchanger with a cleaning structure combines hard scraping with flexible shaking through the cooperation between the rigid scraper 334 and the airbag 335 in the scraper 333. This effectively removes the hard, thick scale adhering to the tube wall and removes residual impurities through the deformation and shaking of the airbag 335, significantly improving the cleaning effect and thoroughness of the inner wall. Specifically, the cleaning mechanism of the scraper 333 is as follows: the semi-circular cylindrical structure of the rigid scraper 334 forms line contact with the inner wall of the heat exchange tube 21 for scraping, and the front edge of its inclined groove wedges and peels off the hard scale and crystalline impurities adhering to the tube wall; at the same time, under the periodic pulsating pressure of the water flow in the tube, the airbag 335 transfers gas back and forth through the connecting pipe 336, driving the airbag 335 to exhibit periodic volume expansion and contraction and fan-shaped opening and closing motion. Furthermore, the cleaning mechanism of the scraper 333 in this embodiment differs from the simple combination of traditional rigid scraping and flexible cleaning, specifically manifested as the organic unity of the following three synergistic effects: The first effect is the wedging and peeling of hard, thick scale: the semi-circular cylindrical structure of the rigid scraper 334 forms line contact with the inner wall of the heat exchange tube 21 through its front edge. Under the axial thrust of the traction rod 332, this edge weds and peels off the hard scale and crystalline impurities adhering to the tube wall. Unlike existing technologies that rely solely on mechanical scraping with a scraper, in this application, the scraping action of the rigid scraper 334 is linked to the deformation state of the airbag 335. When the airbag 335 at the front end of the travel direction is compressed and contracted by the water flow, the contact pressure between the scraping edge of the rigid scraper 334 and the tube wall is finely adjusted, preventing the rigid scraper 334 from scratching the tube wall due to excessive contact force when encountering large pieces of hard scale. The second effect is the dynamic removal of residual impurities: Under the periodic pulsating pressure of the water flow in the pipe, the airbag 335 transfers gas back and forth through the connecting pipe 336, driving the airbag 335 to exhibit periodic volume expansion and contraction and fan-shaped opening and closing motion. This periodic motion produces the following cleaning effect: The fan-shaped opening and closing motion of the airbag 335 generates radial disturbance to the tube wall, which peels away the fine impurity particles that are still adsorbed on the tube wall after being scraped off by the rigid scraper 334 from the tube wall interface. The periodic volume change of the airbag 335 generates local pressure fluctuations in the gap between the scraper 333 and the pipe wall, forming a micro-jet scouring effect, which dislodges the impurity particles from the pipe wall surface. The deformation of the airbag 335 is dynamic and alternating. The periodic disturbance and micro-jet effect it generates can actively "drive" impurities away from the pipe wall rather than passively "adhere". The third effect is the secondary flexible polishing of the pipe wall surface: during the deformation of the airbag 335, its outer surface and the pipe wall generate flexible contact friction, which performs secondary polishing on the pipe wall surface after the rigid scraper 334 has scraped off, removing the residual trace impurity film layer; this flexible polishing effect utilizes the elastic properties of the surface material of the airbag 335 to complete the surface purification without causing secondary damage to the pipe wall. In the aforementioned triple effect, the mechanical scraping of the rigid scraper 334 is an active forced peeling, while the deformation and shaking of the airbag 335 is a fluid-driven dynamic peeling. The two are coupled through the air path formed by the connecting pipe 336 to achieve adaptive distribution of cleaning force. When the dirt on the pipe wall is thick and the water flow resistance is high, the airbag 335 is compressed more, the amount of gas transferred increases, and the expansion degree and fan-shaped opening and closing amplitude of the rear airbag 335 increase accordingly, thus enhancing the flexible cleaning effect. When the dirt on the pipe wall is thin and the water flow resistance is low, the deformation amplitude of the airbag 335 decreases, and the scraping force of the rigid scraper 334 becomes dominant. This adaptive cleaning force distribution mechanism based on fluid pressure feedback is a key technical feature that distinguishes it from the simple superposition of rigid scraping and flexible cleaning in existing technologies.

[0027] Reference Figure 5 and Figure 6 The flow drive component 32 includes a reciprocating screw sleeve 321 that is adapted to drive one of the transmission disc frames 331, and a drive shaft 322 is coaxially sleeved inside the reciprocating screw sleeve 321. The drive shaft 322 is rotatably connected at both ends between the cold liquid inlet end 12 and the cold liquid outlet end 13, and the shaft body of the drive shaft 322 moves through the entire structure of the heat exchange tube bundle 20; the drive shaft 322 and the two floating head end plates 23 are rotatably sealed at their penetration positions through wear-resistant sealing pairs, effectively preventing leakage of the heat exchange medium; the wear-resistant sealing pairs can adopt mechanical seals or packing seals to ensure good sealing performance under long-term rotational operation of the drive shaft 322; A turbine structure 323 is fixedly connected to the outside of the drive shaft 322. The inlet end of the turbine structure 323 is sealed and fixed to the inner wall of the cold liquid inlet end 12 through a variable diameter pipe 324. The medium flow rate is increased by the variable diameter and pressurization, providing stable power for the operation of the turbine structure 323. The inner diameter of the inlet end of the variable diameter pipe 324 is larger than the inner diameter of the outlet end. When the cooling medium flows into the variable diameter pipe 324 from the cold liquid inlet end 12, the medium flow rate increases due to the gradual decrease in the flow cross-sectional area, forming a jet effect that impacts the blades of the turbine structure 323 and drives the turbine structure 323 to rotate. The outlet end of the turbine structure 323 is fixedly connected to a spray ring 325, which is sleeved on the outside of the drive shaft 322 and the guide frame 31. The spray ring 325 has high-pressure spray holes evenly opened on its surface, which can high-pressure flush the outer wall of the drive shaft 322 and the guide frame 31. The power output end of the drive shaft 322 is connected to the outer tube bundle wall cleaning component 34 for transmission, providing rotational driving force for the outer wall cleaning operation.

[0028] This shell-and-tube heat exchanger with a cleaning structure converts the fluid power of the cooling medium into the rotational mechanical energy of the drive shaft 322 through the turbine structure 323 in the flow drive component 32. At the same time, the rotational motion is converted into the linear reciprocating motion of the inner tube bundle wall cleaning component 33 through the reciprocating screw sleeve 321. The rotational power is then transmitted to the outer tube bundle wall cleaning component 34 through the drive shaft 322, achieving the technical effect of synchronously driving the inner and outer wall cleaning operations with a single power source.

[0029] Reference Figure 6 , Figure 9 and Figure 10 The outer tube bundle wall cleaning component 34 is composed of an extrusion bushing 341 and multiple cleaning units 342 sleeved on the outside of the extrusion bushing 341. The extrusion sleeve 341 is sleeved on the outside of the drive shaft 322 and rotates synchronously with it. It is used to connect and constrain and link the cleaning units 342 to operate synchronously. Each cleaning unit 342 consists of a rigid scraping ring frame 343, a rigid extrusion ring 344, and a sliding column 345 fixedly connected to the inner wall of the rigid extrusion ring 344. Among them, the rigid scraping ring 343 is sleeved on the outside of the heat exchange tube bundle 20 to form a sliding fit structure, and the inner ring of the rigid scraping ring 343 and the outer ring of the rigid extrusion ring 344 are fixedly connected as one piece; the rigid extrusion ring 344 is sleeved on the outside of the extrusion bushing 341 for sliding fit, and the sliding column 345 and the cam groove opened on the outside of the extrusion bushing 341 form a sliding extrusion fit structure. The outer wall of the extrusion sleeve 341 is provided with a cam groove, and the end of the slide column 345 is slidably embedded in the cam groove. When the drive shaft 322 drives the extrusion sleeve 341 to rotate, the dynamic extrusion engagement between the cam groove and the slide column 345 drives the rigid extrusion ring 344 and the rigid scraping ring frame 343 to reciprocate linearly along the axis of the heat exchange tube 21, thereby realizing continuous reciprocating scraping and cleaning of the outer wall of the heat exchange tube bundle 20. The trajectory shape of the cam groove determines the reciprocating stroke and speed curve of the cleaning unit 342, which can be optimized according to actual cleaning needs.

[0030] This shell-and-tube heat exchanger with a cleaning structure, through the cooperation structure between the extrusion sleeve 341 and the cleaning unit 342 in the outer tube bundle wall cleaning component 34, converts the rotational motion of the drive shaft 322 into the reciprocating linear motion of the rigid scraping ring 343 along the axis of the heat exchange tube 21, thereby realizing continuous reciprocating scraping and cleaning of the outer wall of the heat exchange tube bundle 20, effectively solving the problem of difficult cleaning of impurities in the tube bundle gaps and baffle connection positions in the prior art; Furthermore, the cam groove on the outer wall of the extrusion sleeve 341 in the outer tube bundle wall cleaning component 34 adopts a double-stroke symmetrical cam groove structure design, that is, the trajectory of the cam groove is symmetrically distributed in the circumferential direction of the extrusion sleeve 341, so that the cleaning unit 342 completes a complete reciprocating stroke during one rotation of the extrusion sleeve 341—the first half of the stroke drives the cleaning unit 342 to move forward along the axis of the heat exchange tube 21, and the second half of the stroke drives the cleaning unit 342 to move backward and return to its original position; the ratio of the axial stroke length of the cam groove to the spacing of the baffle plate 22 is 1:1.2~1:1.5. This ensures that the reciprocating motion of the cleaning unit 342 can cover the entire outer wall area of ​​the tube bundle between adjacent baffles 22, avoiding cleaning dead zones at the connection points of the baffles 22. In addition, multiple media flow channels are evenly distributed circumferentially on the ring body of the rigid scraping ring 343. When the rigid scraping ring 343 reciprocates along the axis of the heat exchange tube 21, the media flow channels allow the shell-side medium to pass smoothly, avoiding significant obstruction to the normal flow of the shell-side medium caused by the movement of the cleaning unit 342, and ensuring that the normal operation of the heat exchanger is not affected during the cleaning operation.

[0031] Reference Figure 9 and Figure 10 Both the rigid scraping ring 343 and the rigid extrusion ring 344 have beveled grooves on their ring edges for scraping off hard impurities. A high-density soft brush ring is fixedly connected to the beveled groove of the rigid extrusion ring 344. The soft brush ring is flexibly attached to the outer wall of the heat exchange tube 21, which can clean up fine flocculent and dust impurities, and achieve a layered cleaning effect that combines hard scraping and soft cleaning. The inclined groove of the rigid scraping ring 343 is mainly used to scrape off the hard scale and crystalline impurities attached to the outer wall of the heat exchange tube 21. Its inclined angle is preferably 30° to 60° to obtain the best scraping effect. The high-density soft bristle brush ring (not shown in the figure) fixedly connected to the inclined groove of the rigid extrusion ring 344 is used to clean the fine flocculent matter and dust impurities remaining after being scraped by the rigid scraping ring 343. The soft bristle brush ring can be made of nylon bristles or polyester bristles, and the bristle density and length can be adjusted according to the actual cleaning needs.

[0032] This shell-and-tube heat exchanger with a cleaning structure achieves an organic combination of hard scraping and soft cleaning through the layered cleaning design of rigid scraping ring 343 and rigid extrusion ring 344. It can effectively remove stubborn scale adhering to the tube wall and thoroughly clean fine impurities, significantly improving the cleaning effect of the outer tube bundle wall.

[0033] Reference Figure 8A miniature one-way pressure regulating valve is installed on the middle part of the connecting pipe 336. The one-way pressure regulating valve is used to maintain the balanced and stable air pressure inside the two airbags 335, avoid excessive deformation of one airbag 335, ensure the smooth movement of the scraper 333 on the inner wall of the heat exchange tube bundle 20, and at the same time prevent the medium inside the pipe from flowing back into the cavity of the airbag 335. The opening pressure of the miniature one-way pressure regulating valve can be set according to the actual working conditions. When the pressure difference inside the two airbags 335 exceeds the set value, the one-way pressure regulating valve opens to exchange gases and restore the pressure balance on both sides. This design effectively avoids the problem of the scraper 333 shifting or getting stuck due to the over-expansion or over-compression of one side of the airbag 335, ensuring the smooth movement of the scraper 333 on the inner wall of the heat exchange tube 21 for cleaning. At the same time, the one-way conduction characteristic of the one-way pressure regulating valve can effectively prevent the medium in the tube from flowing back into the cavity of the airbag 335, and prevent water from entering the airbag 335 and affecting its normal expansion and contraction function.

[0034] This shell-and-tube heat exchanger with a cleaning structure performs the following three functions in this embodiment by installing a miniature one-way pressure regulating valve (not shown in the figure) on the connecting pipe 336: Firstly, the air pressure equalization function: When the scraper 333 moves back and forth on the inner wall of the heat exchange tube 21, due to the pulsation and change in direction of the water flow pressure inside the tube, the pressure on the two air bags 335 is not completely symmetrical; when the air pressure difference inside the two air bags 335 exceeds the set value, the one-way pressure regulating valve opens to exchange gas, so that the air pressure on both sides is restored to balance, avoiding excessive expansion of one air bag 335 leading to excessive contact force with the tube wall, or excessive compression leading to separation from the tube wall; Secondly, the backflow prevention function: the one-way flow characteristic of the one-way pressure regulating valve can effectively prevent the medium in the pipe from flowing back into the cavity of the airbag 335, avoiding water entering the airbag 335 and affecting its normal expansion and contraction function, thus ensuring the reliability and service life of the airbag 335 under long-term operating conditions. Third, damping and buffering function: The throttling characteristics of the miniature one-way pressure regulating valve produce a certain damping effect on the gas transfer between the airbags 335. This damping effect can suppress the violent shaking of the airbags 335 caused by sudden changes in water pressure, making the deformation process of the airbags 335 more stable and controllable, thereby improving the smoothness of operation and the consistency of cleaning of the scraper 333 during the inner wall cleaning process.

[0035] In summary, the shell-and-tube heat exchanger with a cleaning structure provided in this embodiment achieves synchronous adaptive cleaning of the inner and outer walls of the heat exchange tube bundle 20 through its cleaning mechanism 30 via the following technical approach: Integrated drive path: The turbine structure 323 in the flow drive component 32 uses the cooling medium fluid power as a single drive source. Through the drive shaft 322, the rotational power is simultaneously transmitted to the reciprocating screw sleeve 321 (driving the linear reciprocating motion of the inner tube bundle wall cleaning component 33) and the extrusion bushing 341 (driving the reciprocating linear motion of the outer tube bundle wall cleaning component 34). This realizes a linkage cleaning architecture with a single power source and dual execution paths, eliminating the need for external power input and reducing equipment energy consumption and operating costs. Adaptive cleaning of inner wall: The rigid scraper 334 and the airbag 335 in the scraper 333 form a closed air passage through the connecting pipe 336, which enables the scraper 333 to adaptively adjust the scraping force and the ratio of cleaning methods according to the change of water pressure in the heat exchange pipe 21 during the movement of the scraper 333 on the inner wall of the heat exchange pipe 21. This achieves an organic combination of effective scraping of hard and thick scale and flexible peeling of fine impurities. All-round cleaning of the outer wall: The sliding fit structure of the cam groove of the extrusion sleeve 341 and the slide column 345 in the outer tube bundle wall cleaning component 34 converts the rotational motion of the drive shaft 322 into the continuous reciprocating linear motion of the cleaning unit 342 along the axis of the heat exchange tube 21. Combined with the hard scraping of the rigid scraping ring 343 and the flexible cleaning layering design of the rigid extrusion ring 344, all-round, dead-angle-free cleaning of the outer wall of the heat exchange tube bundle 20 is achieved.

[0036] The above three technical features work together and are indispensable, together constituting a complete technical solution that distinguishes this application from the prior art, rather than a simple superposition of individual technical features.

[0037] The working principle of a shell-and-tube heat exchanger with a cleaning structure according to the present invention is as follows: Under normal heat exchange operation: the cooling medium enters the sealed heat exchange cavity of the outer shell 10 from the medium flow interface of the cold liquid inlet end 12. Part of the cooling medium flows through the tube side of the heat exchange tube 21, and the other part of the cooling medium flows through the shell side of the heat exchange tube 21. The two media exchange heat with the heat medium inside the heat exchange tube 21. During this process, the cleaning mechanism 30 is in standby mode. The turbine structure 323 of the flow drive component 32 rotates at a low speed under the continuous flow of the cooling medium. However, due to the transmission characteristics of the reciprocating screw sleeve 321, the inner tube bundle wall cleaning component 33 does not produce obvious axial displacement under the low speed rotation state. The cleaning unit 342 of the outer tube bundle wall cleaning component 34 only produces a small amplitude reciprocating vibration under the low speed rotation of the cam groove, which is not enough to interfere with the normal heat exchange of the heat exchange tube bundle 20. In cleaning operation mode: When cleaning is required, the flow rate or pressure of the cooling medium at the inlet of the cold liquid inlet 12 can be adjusted to achieve the set values ​​for the cleaning condition. At this time, the cooling medium, after being pressurized by the reducer 324, impacts the blades of the turbine structure 323, driving the turbine structure 323 to rotate at its rated speed. The turbine structure 323 drives the drive shaft 322 to rotate synchronously. The rotational motion of the drive shaft 322 drives the inner tube bundle wall cleaning component 33 and the outer tube bundle wall cleaning component 34 through two paths respectively. Path 1: The drive shaft 322 converts the rotational motion into the axial reciprocating linear motion of the transmission disc frame 331 through the reciprocating screw sleeve 321. The transmission disc frame 331 drives the traction rod 332 and each scraper 333 fixed on the traction rod 332 to reciprocate inside the heat exchange tube 21. During the movement of each scraper 333, the rigid scraper 334 scrapes off the hard scale on the tube wall, and the air bag 335 undergoes periodic deformation under the pressure of the water in the tube. Through deformation vibration and micro-jet effect, the scraped residual impurities are peeled off from the tube wall. When the transmission disc frame 331 moves to the end of its stroke, the concave structure of the floating head end plate 23 provides it with clearance space. At the same time, the elastic element generates a reverse buffer force on the transmission disc frame 331 to avoid rigid impact. Path Two: The drive shaft 322 drives the extrusion sleeve 341 to rotate synchronously. The cam groove on the outer wall of the extrusion sleeve 341, through sliding extrusion with the sliding column 345, converts the rotational motion into the reciprocating linear motion of the cleaning unit 342 along the axis of the heat exchange tube 21. The rigid scraping ring 343 moves reciprocally with the cleaning unit 342, and its inclined groove scrapes away the hard scale on the outer wall of the heat exchange tube 21. The high-density soft brush ring at the inclined groove of the rigid extrusion ring 344 gently cleans the fine flocculent and dust impurities remaining after scraping. At the same time, the injection ring 325 connected to the outlet end of the turbine structure 323 sprays high-pressure medium into the gap of the outer wall of the tube bundle through the high-pressure injection hole to assist in flushing and removing the scraped impurities. In the shutdown and reset state: when the shell and tube heat exchanger stops running or the cooling medium supply stops, the turbine structure 323 stops rotating and the drive shaft 322 stops rotating; the inner tube bundle wall cleaning component 33 resets to the initial position under the elastic restoring force of the elastic component; the cleaning unit 342 of the outer tube bundle wall cleaning component 34 stops reciprocating and stays at the end or middle of the stroke; the entire cleaning mechanism 30 stops running and the heat exchanger returns to the normal heat exchange standby state.

[0038] In the description of this invention, it should be understood that the terms "center", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the foregoing; the descriptions above and in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A shell-and-tube heat exchanger with a cleaning structure, characterized in that, Includes an outer casing (10), a heat exchange tube bundle (20), and a cleaning mechanism (30); The outer shell (10) is composed of a heat exchange cylinder (11) and a cold liquid inlet end (12) and a cold liquid outlet end (13) detachably connected to both ends of the heat exchange cylinder (11). The heat exchange cylinder (11), the cold liquid inlet end (12), and the cold liquid outlet end (13) enclose a closed heat exchange cavity. The cold liquid inlet end (12) and the cold liquid outlet end (13) are both provided with a medium flow interface for the heat exchange medium to flow in and out. The heat exchange tube bundle (20) is adapted to be installed inside the sealed heat exchange cavity of the outer shell (10). It consists of multiple heat exchange tubes (21), multiple baffles (22) sleeved on the outside of the multiple heat exchange tubes (21), and two floating end plates (23) fixedly connected to both ends of the multiple heat exchange tubes (21). The baffles (22) are arranged at equal intervals perpendicular to the axis of the heat exchange tubes (21) to disturb the flow direction of the shell side medium. The cleaning mechanism (30) is an integrated structure adapted to the synchronous cleaning of the inner and outer walls of the heat exchange tube bundle (20), including a guide frame (31), a flow drive component (32), an inner tube bundle wall cleaning component (33), and an outer tube bundle wall cleaning component (34). The guide frame (31) is fixedly connected to the inside of the cold liquid inlet end (12) and is set with a hollow frame structure. It is used to connect and support the flow supply drive component (32) and at the same time constrain the linear displacement path of the inner tube bundle wall cleaning component (33). The flow drive component (32) is fixedly connected to the middle of the guide frame (31) and is sealed and fixedly connected to the internal medium channel of the cold liquid inlet end (12). It uses the fluid power of the cooling medium as the driving source to synchronously drive the inner tube bundle wall cleaning component (33) and the outer tube bundle wall cleaning component (34) to operate in conjunction. The inner tube bundle wall cleaning component (33) includes two symmetrically arranged transmission disc frames (331), and a plurality of traction rods (332) are fixedly connected between the two transmission disc frames (331). The plurality of traction rods (332) are arranged in a ring array at equal intervals. A plurality of scraping components (333) for cleaning the inner wall of the heat exchange tube bundle (20) are connected to the outside of the traction rods (332). The scraping component (333) includes a rigid scraper (334), which is a semi-circular cylindrical structure that fits the inner wall of the heat exchange tube bundle (20). The rigid scraper (334) of the semi-circular cylindrical structure has two symmetrically opened inclined grooves on its outside, and an airbag (335) that can open and close in a fan-shaped structure is fixedly connected in the inclined groove. A connecting pipe (336) is fixedly connected between the two airbags (335). The connecting pipe (336) is set through the interior of the rigid scraper (334) to form a closed connecting air passage. The gas inside the airbag (335) is transferred to each other by the squeezing of water in the pipe, which drives the airbag (335) to adapt to volume expansion and contraction and fan-shaped opening and closing, and works with the rigid scraper (334) to scrape off the dirt on the tube wall. At the same time, residual impurities are peeled off by deformation and shaking.

2. A shell-and-tube heat exchanger with a cleaning structure according to claim 1, characterized in that: The two floating head end plates (23) are arranged symmetrically. The surface of the floating head end plate (23) is provided with fixed through holes corresponding to the openings of each heat exchange tube (21). The outer side of the floating head end plate (23) facing the inner tube bundle wall cleaning component (33) is set with an inward structure, which can adapt to the reciprocating stroke of the inner tube bundle wall cleaning component (33), reduce the dead angle of medium flow, and at the same time play a role in limiting protection.

3. A shell-and-tube heat exchanger with a cleaning structure according to claim 1, characterized in that: One of the transmission disc frames (331) is connected to the flow drive component (32) and slides with the inner wall of the guide frame (31) to achieve directional reciprocating movement; the other transmission disc frame (331) is sleeved on the outside of the flow drive component (32) and forms an elastic constraint with the corresponding side floating head end plate (23) through the circumferentially arranged elastic element to achieve the reset buffer of the cleaning mechanism.

4. A shell-and-tube heat exchanger with a cleaning structure according to claim 1, characterized in that: The flow drive (32) includes a reciprocating screw sleeve (321) that is adapted to drive one of the transmission disc frames (331), and a drive shaft (322) is coaxially sleeved inside the reciprocating screw sleeve (321). The drive shaft (322) is rotatably connected at both ends between the cold liquid inlet end (12) and the cold liquid outlet end (13), and the shaft of the drive shaft (322) moves through the entire structure of the heat exchange tube bundle (20). The drive shaft (322) and the two floating head end plates (23) are rotatably sealed and connected by wear-resistant sealing pairs at their penetration positions.

5. A shell-and-tube heat exchanger with a cleaning structure according to claim 4, characterized in that: The drive shaft (322) is externally fixedly connected to a turbine structure (323). The inlet end of the turbine structure (323) is sealed and fixed to the inner wall of the cold liquid inlet end (12) through a variable diameter pipe (324). The variable diameter pressurization increases the flow rate of the medium, providing power for the operation of the turbine structure (323).

6. A shell-and-tube heat exchanger with a cleaning structure according to claim 5, characterized in that: The outlet end of the turbine structure (323) is fixedly connected to a spray ring (325). The spray ring (325) is sleeved on the outside of the drive shaft (322) and the guide frame (31). The spray ring (325) has high-pressure spray holes evenly opened on its surface, which can flush impurities in the gap between the outer wall of the tube bundle under high pressure. The power output end of the drive shaft (322) is connected to the outer tube bundle wall cleaning component (34) for transmission, providing rotational driving force for the outer wall cleaning operation.

7. A shell-and-tube heat exchanger with a cleaning structure according to claim 4, characterized in that: The outer tube bundle wall cleaning component (34) consists of an extrusion bushing (341) and multiple cleaning units (342) sleeved on the outside of the extrusion bushing (341); The extrusion bushing (341) is sleeved on the outside of the drive shaft (322) and rotates synchronously with it. It is used to connect and constrain and link each group of cleaning units (342) to operate synchronously. Each group of cleaning units (342) consists of a rigid scraping ring frame (343), a rigid extrusion ring (344), and a sliding column (345) fixedly connected to the inner wall of the rigid extrusion ring (344). The rigid scraper ring (343) is sleeved on the outside of the heat exchange tube bundle (20) to form a sliding fit structure, and the inner ring of the rigid scraper ring (343) and the outer ring of the rigid extrusion ring (344) are fixedly connected as one piece; the rigid extrusion ring (344) is sleeved on the outside of the extrusion bushing (341) for sliding fit, and the sliding column (345) and the cam groove opened on the outside of the extrusion bushing (341) form a sliding extrusion fit structure.

8. A shell-and-tube heat exchanger with a cleaning structure according to claim 7, characterized in that: The outer wall of the extrusion sleeve (341) is provided with a cam groove, and the end of the slide column (345) is slidably embedded in the cam groove. When the drive shaft (322) drives the extrusion sleeve (341) to rotate, the rigid extrusion ring (344) and the rigid scraping ring frame (343) are driven to reciprocate linearly along the axis of the heat exchange tube (21) through the dynamic extrusion cooperation between the cam groove and the slide column (345), so as to realize continuous reciprocating scraping and cleaning of the outer wall of the heat exchange tube bundle (20).

9. A shell-and-tube heat exchanger with a cleaning structure according to claim 7, characterized in that: Both the rigid scraping ring frame (343) and the rigid extrusion ring (344) have inclined grooves at their edges for scraping away hard impurities. A high-density soft brush ring is fixedly connected to the inclined groove of the rigid extrusion ring (344). The soft brush ring is flexibly attached to the outer wall of the heat exchange tube (21) and can clean up fine flocculent and dust impurities, achieving layered cleaning that combines hard scraping with flexible cleaning.

10. A shell-and-tube heat exchanger with a cleaning structure according to claim 1, characterized in that: A miniature one-way pressure regulating valve is installed on the middle tube of the connecting pipe (336). The one-way pressure regulating valve is used to maintain the balanced and stable air pressure inside the two airbags (335), avoid excessive deformation of one airbag (335), ensure the smooth movement of the scraper (333) on the inner wall of the heat exchange tube bundle (20), and at the same time prevent the medium inside the tube from flowing back into the cavity of the airbag (335).

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