Anti-clogging horizontal flue gas heat exchange device

Abstract

The application discloses a kind of anti-clogging horizontal flue gas heat exchange device, belong to boiler waste heat recovery technical field, by composite cleaning plate integration phase change heat storage function, in high-temperature ash deposition area, hollow heat conduction plate body absorbs flue gas waste heat, by phase change heat storage core body storage, after moving to turning air chamber, heat is transferred to cold air by heat conduction fin, realize waste heat secondary recovery, and rely on cleaning slide sleeve to clean the surface of heat exchange tube bundle of flue dust in the moving process of composite cleaning plate, utilize scraping, wiping and knocking etc. Many means improve the cleaning effect of heat exchange tube bundle, to ensure heat exchange efficiency, simultaneously introduce heat induction baffle to monitor high-temperature area caused by ash deposition in real time, trigger composite cleaning plate to stay and remove ash, realize targeted tube bundle cleaning and waste heat recovery, compared with traditional device heat recovery utilization rate significantly improves, prolongs the overall service life of device.

Description

Technical Field

[0001] This invention relates to the field of boiler waste heat recovery technology, and more specifically, to a blockage-resistant horizontal flue gas heat exchanger. Background Technology

[0002] Horizontal flue gas heat exchangers are core equipment for industrial waste heat recovery. They recover heat from high-temperature flue gas in boilers, kilns, etc., to heat air or water, achieving cascaded energy utilization and reducing enterprise energy consumption and carbon emissions. They are widely used in industries such as chemical, power, and metallurgy. However, the large amount of soot, dust, and sticky impurities contained in industrial flue gas easily adheres and accumulates on the surface of the heat exchange tube bundle, forming an ash layer. This problem has become a major bottleneck restricting the efficient and stable operation of heat exchangers, and traditional horizontal flue gas heat exchangers and ash removal technologies have many insurmountable defects.

[0003] The core pain point of traditional equipment is the reduction in heat exchange efficiency and the risk of blockage caused by ash accumulation. The thermal conductivity of the ash layer is only a fraction of that of metal. Once it adheres to the surface of the heat exchange tube bundle, it severely hinders heat transfer, preventing the residual heat in the flue gas from being effectively transferred to the heated medium, resulting in a significant decrease in heat exchange efficiency. Existing ash removal technologies struggle to achieve efficient and thorough online cleaning. Early manual cleaning methods required a complete shutdown, with operators entering the unit to clean using high-pressure water or mechanical tools. This was labor-intensive, involved harsh working environments (high temperature, high dust), and had long cleaning cycles, severely impacting production continuity. Some units are equipped with steam or sonic soot blowing systems, which have significant limitations. Steam soot blowing easily leads to corrosion of the heat exchange tube bundle and is ineffective at removing sticky ash, only able to remove loose ash. Sonic soot blowing only loosens the ash through vibration, failing to completely remove it. The loosened ash easily accumulates at the bottom of the unit, causing secondary blockages, and sonic waves pose a risk of fatigue damage to the unit structure. Summary of the Invention

[0004] The purpose of this invention is to provide a horizontal flue gas heat exchanger that prevents clogging, so as to solve the above-mentioned problems.

[0005] To achieve the above objectives, an embodiment of the present invention provides the following technical solution:

[0006] A horizontal flue gas heat exchanger with anti-clogging features includes multiple heat exchange tube boxes arranged in parallel horizontally, and interconnected by connecting boxes. Connecting air outlets and inlets are fixedly installed at the beginning and end of each heat exchange tube box. Turning air chambers are fixedly installed at the left and right ends of each heat exchange tube box. Connecting flues are fixedly installed between adjacent heat exchange tube boxes. A composite cleaning plate parallel to the flue gas direction is slidably installed inside each heat exchange tube box. Multiple arrayed tube bundle through holes are opened on the composite cleaning plate, and matching cleaning sleeves are fixedly installed within each tube bundle through hole.

[0007] As a further improvement of the present invention, the heat exchange tube box includes a box body, in which multiple arrayed heat exchange tube bundles are horizontally arranged, and the two ends of the heat exchange tube bundles pass through the box body and are connected to the turning air chamber. The cleaning sleeve is slidably sleeved on the heat exchange tube bundles. Air, as the heat exchange medium, passes through the heat exchange tube bundles and then fully exchanges heat with the flue gas outside the heat exchange tube bundles. During the movement of the composite cleaning plate, the cleaning sleeve can clean the dust on the surface of the heat exchange tube bundles, avoiding the dust from adhering to the heat exchange tube bundles and forming a "heat insulation layer" that would affect the heat exchange efficiency.

[0008] As a further improvement of the present invention, a pair of slide rails are fixedly installed on the inner wall of the box, and a matching slider is slidably installed on the slide rails, and the slider is fixedly connected to the composite cleaning plate.

[0009] As a further improvement of the present invention, the turning chamber includes a hollow cavity with multiple air inlets matching the heat exchange tube bundle. Multiple electromagnets are fixedly installed at the corners of the hollow cavity, and multiple uniformly distributed heat-conducting fins are fixedly installed on the inner wall of the hollow cavity, with the heat-conducting fins located on the side close to the heat exchange tube bundle. By intermittently applying a magnetic field to the electromagnets in the turning chamber, the composite cleaning plate is attracted and moves along the direction of the heat exchange tube bundle inside the heat exchange tube box. The cleaning sleeve cleans the dust on the heat exchange tube bundle, preventing it from adhering to the heat exchange tube bundle and affecting the heat exchange efficiency. Furthermore, the composite cleaning plate can absorb the residual heat in the flue gas in the high-temperature area and contact and adhere to the turning chamber at the edge, transferring heat to the air inside the hollow cavity through the heat-conducting fins.

[0010] As a further improvement of the present invention, the composite cleaning plate includes a hollow heat-conducting plate body, the inner cavity of which is filled with a phase change heat storage core. Magnetic suction plates are embedded at both the upper and lower edges of the hollow heat-conducting plate body. When the heat exchange efficiency of the heat exchange tube bundle decreases, the flue gas heat in this area cannot be fully exchanged and maintain a high temperature. At this time, the hollow heat-conducting plate body can help absorb heat and transfer it to the phase change heat storage core for storage. Finally, it moves to the turning wind chamber to release the heat.

[0011] As a further improvement of the present invention, the cleaning sleeve includes an outer ring, on which a concentrically arranged flexible inner wiping sleeve and a pair of rigid edge scraping rings are fixedly installed. The flexible inner wiping sleeve is located between the pair of rigid edge scraping rings. During the movement of the rigid edge scraping rings, the rigid edge scraping rings scrape off the heavily adhered dust or stains, and the flexible inner wiping sleeve then sweeps them off and they fall off at the edge.

[0012] As a further improvement of the present invention, annular hidden grooves are provided at both the front and rear ends of the outer sleeve ring. Matching telescopic striking elements are slidably installed in the annular hidden grooves. When the flue gas passes through the telescopic striking elements, it will cause them to vibrate. The vibration effect triggers the striking action on the heat exchange tube bundle, thereby achieving a good dust removal effect.

[0013] As a further improvement of the present invention, the telescopic striking component includes a movable slip ring, a compression spring is fixedly installed between the movable slip ring and the bottom wall of the annular hidden groove, a plurality of circumferentially distributed vibrating plates are fixedly installed at the outer end of the movable slip ring, and a striking block is fixedly installed at the outer end of the vibrating plates. Under normal conditions, the elastic force of the compression spring ensures that the vibrating plates and striking blocks are located in the external area, which can cooperate with the flue gas to achieve the effect of vibrating and striking the heat exchange tube bundle. At the same time, when it moves to the turning wind chamber, it can be squeezed to enter the annular hidden groove for avoidance, ensuring that the composite cleaning plate can fit against the wall of the turning wind chamber for sufficient heat exchange.

[0014] As a further improvement of the present invention, a heat-sensing baffle is fixedly installed at the top of the box body in the direction of flue gas passage, and the lower end surface of the heat-sensing baffle is higher than the upper end surface of the hollow heat-conducting plate. The heat-sensing baffle can sense the high-temperature area in the movement path of the composite cleaning plate, thereby triggering the blocking action to restrict the composite cleaning plate from continuing to move and keep it in that area. On the one hand, it can absorb and store heat, and on the other hand, it can specifically concentrate on cleaning the heat exchange tube bundle in that area, thereby restoring the heat exchange effect.

[0015] As a further improvement of the present invention, the heat-sensing baffle includes a heat-collecting plate, at least three bimetallic strips are fixedly installed at the lower end of the heat-collecting plate, and an extension baffle is fixedly installed at the lower expansion end of the bimetallic strip. The heat-sensing baffle can detect the global temperature in real time. When the heat exchange effect is reduced and the local temperature rises due to the adhesion of dust on the surface of the heat exchange tube bundle or the flow field distribution, usually in the middle area of ​​the heat exchange tube box where the flue gas flow is the largest, the bimetallic strips will expand when the temperature is higher than the normal heat exchange temperature due to the difference in the material expansion coefficient, thereby driving the extension baffle to move downward and block and stop it on the moving path of the composite cleaning plate.

[0016] Compared with the prior art, the advantages of this invention are:

[0017] (1) The composite cleaning plate of this device integrates phase change heat storage function. In the high temperature ash accumulation area, the hollow heat-conducting plate absorbs the waste heat of flue gas and stores it through the phase change heat storage core. After moving to the turning wind chamber, the heat is transferred to the cold air through the heat-conducting fins, realizing the secondary recovery of waste heat. This realizes the conversion of the "waste heat" caused by ash accumulation into usable energy, reducing the boiler's additional fuel consumption. Compared with traditional devices, the energy utilization rate is significantly improved, which meets the requirements of energy saving and consumption reduction.

[0018] (2) The flexible inner wiping sleeve and telescopic striking parts of the cleaning sleeve of this device are made of elastic material to avoid hard contact damage to the heat exchange tube bundle; the composite cleaning plate is guided by the slide rail and the slider, and moves smoothly without collision, without the need for frequent manual intervention, reducing the labor intensity of maintenance personnel; the ash removal is thorough, which extends the service life of the heat exchange tube bundle, reduces the cost of equipment maintenance and replacement, and at the same time reduces the safety hazards caused by ash accumulation, improving the reliability of the device operation.

[0019] (3) This device monitors the high-temperature area caused by ash accumulation in real time through the heat-sensing baffle, triggers the composite cleaning plate to stay and remove ash, can actively absorb and store the waste heat of flue gas in the temperature abnormal area, and then realize the secondary heat transfer through the fit with the hollow cavity, fully recovering the local excess heat that might have been wasted, forming a synergistic effect of primary heat exchange and secondary heat storage recovery. Attached Figure Description

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

[0021] Figure 2 This is a schematic diagram of the heat exchanger tube box part of the present invention;

[0022] Figure 3 This is a schematic diagram of the internal structure of the heat exchanger tube box of the present invention;

[0023] Figure 4 This is a partial cross-sectional view of the turning chamber of the present invention;

[0024] Figure 5 For the present invention Figure 3 Enlarged view of point A in the middle;

[0025] Figure 6 This is a partial structural cross-sectional view of the cleaning sleeve portion of the present invention;

[0026] Figure 7 This is a partial structural cross-sectional view of the composite cleaning plate of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of the heat-sensitive baffle of the present invention.

[0028] Explanation of the labels in the diagram:

[0029] 1. Heat exchanger tube box; 11. Box body; 12. Heat exchanger tube bundle; 13. Slide rail; 14. Slider; 2. Turning air chamber; 21. Hollow cavity; 22. Electromagnet; 23. Air inlet; 24. Heat-conducting fins; 3. Connecting box; 4. Air outlet; 5. Air inlet; 6. Connecting flue; 7. Composite cleaning plate; 71. Hollow heat-conducting plate body; 72. Tube bundle through hole; 73. Phase change heat storage core; 74. Magnetic suction plate; 8. Cleaning sleeve; 81. Outer ring; 82. Flexible inner wiping sleeve; 83. Hard edge scraper ring; 84. Telescopic striking component; 841. Moving slip ring; 842. Compression spring; 843. Vibrating plate; 844. Striking block; 9. Thermal induction baffle; 91. Heat-concentrating plate; 92. Bimetallic strip; 93. Extension block. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] Please see Figures 1-7 A horizontal flue gas heat exchanger for clogging prevention includes multiple parallel horizontally arranged heat exchange tube boxes 1, which are connected by a connecting box 3. The ends of the multiple heat exchange tube boxes 1 are respectively connected by an air outlet 4 and an air inlet 5. The left and right ends of the heat exchange tube boxes 1 are respectively fixedly installed with a turning air chamber 2. Adjacent heat exchange tube boxes 1 are connected by a connecting flue duct 6. A composite cleaning plate 7 parallel to the flue gas direction is slidably installed in the inner cavity of the heat exchange tube box 1. The composite cleaning plate 7 has multiple arrayed tube bundle through holes 72. Matching cleaning sleeves 8 are fixedly installed in the tube bundle through holes 72.

[0033] The heat exchange tube box 1 includes a box body 11, in which multiple arrayed heat exchange tube bundles 12 are horizontally arranged. The two ends of the heat exchange tube bundles 12 pass through the box body 11 and are connected to the turning air chamber 2. The cleaning sleeve 8 is slidably sleeved on the heat exchange tube bundles 12. Air, as the heat exchange medium, passes through the heat exchange tube bundles 12 and then fully exchanges heat with the flue gas outside the heat exchange tube bundles 12. During the movement of the composite cleaning plate 7, the dust on the surface of the heat exchange tube bundles 12 can be cleaned by the cleaning sleeve 8, so as to prevent the dust from adhering to the heat exchange tube bundles 12 and forming a "heat insulation layer" that would affect the heat exchange efficiency.

[0034] A pair of slide rails 13 are fixedly installed on the inner wall of the housing 11. Matching sliders 14 are slidably installed on the slide rails 13, and the sliders 14 are fixedly connected to the composite cleaning plate 7.

[0035] The turning chamber 2 includes a hollow chamber 21. The hollow chamber 21 has multiple air inlets 23 that match the heat exchange tube bundle 12. Multiple electromagnets 22 are fixedly installed at the corners of the hollow chamber 21. Multiple uniformly distributed heat-conducting fins 24 are fixedly installed on the inner wall of the hollow chamber 21, and the heat-conducting fins 24 are located on the side close to the heat exchange tube bundle 12. By intermittently applying a magnetic field to the electromagnets 22 in the turning chamber 2, the composite cleaning plate 7 is attracted and moves along the direction of the heat exchange tube bundle 12 in the heat exchange tube box 1. The cleaning sleeve 8 cleans the dust on the heat exchange tube bundle 12, preventing it from adhering to the heat exchange tube bundle 12 and affecting the heat exchange efficiency. The composite cleaning plate 7 can absorb the residual heat in the flue gas in the high-temperature area and contact and adhere to the turning chamber 2 when it moves to the edge. The heat is transferred to the air in the hollow chamber 21 through the heat-conducting fins 24.

[0036] Electromagnet 22 is a DC high-temperature electromagnet, adapted to the temperature environment inside the air chamber. Its outer shell is sealed with stainless steel, achieving an IP65 waterproof and dustproof rating to prevent smoke and dust from affecting its magnetic properties. Electromagnet 22 is fixed to the inner wall of the chamber via a bracket. Its magnetic field strength is designed to stably attract the magnetic suction plate 74 of the composite cleaning plate 7, enabling the reciprocating drive of the cleaning plate. The heat-conducting fins 24 on the inner wall of the hollow chamber 21 are made of copper, which has a high thermal conductivity. They are arranged in an array and close to the ports of the heat exchange tube bundle 12. When the composite cleaning plate 7 is in contact with the chamber, the fins can quickly conduct the heat stored in the cleaning plate to the air medium. The air inlet 23 on the chamber is precisely aligned with the heat exchange tube bundle 12, ensuring smooth airflow into the inner cavity of the heat exchange tube bundle 12.

[0037] The composite cleaning plate 7 includes a hollow heat-conducting plate body 71, the inner cavity of which is filled with a phase change heat storage core 73. Magnetic suction plates 74 are embedded at both the upper and lower edges of the hollow heat-conducting plate body 71. When the heat exchange efficiency of the heat exchange tube bundle 12 decreases, the flue gas in this area cannot be fully exchanged and maintain a high temperature. At this time, the hollow heat-conducting plate body 71 can help absorb heat and transfer it to the phase change heat storage core 73 for storage. Finally, it moves to the turning wind chamber 2 to release the heat.

[0038] The hollow heat-conducting plate 71 is made of aluminum alloy sheet by stamping, which is lightweight and has good thermal conductivity. The hollow structure inside the plate is used to fill the phase change heat storage core 73. The core is made of high-temperature phase change material such as molten salt-based composite material. The phase change temperature is adapted to the flue gas waste heat recovery range. It can absorb and store the heat of flue gas in the high-temperature area and release heat in the low-temperature area to achieve secondary waste heat recovery. The magnetic suction plates 74 at the top and bottom of the plate are neodymium iron boron permanent magnets, which are embedded in the edge of the plate and magnetically matched with the electromagnet 22 of the turning wind chamber 2 to ensure that the electromagnet 22 can stably drive the cleaning plate to move. The tube bundle through holes 72 on the composite cleaning plate 7 correspond one-to-one with the heat exchange tube bundle 12. The hole diameter is slightly larger than the outer diameter of the heat exchange tube bundle 12 to provide installation space for the cleaning sliding sleeve 8.

[0039] The cleaning sleeve 8 includes an outer ring 81, on which a concentrically arranged flexible inner wiping sleeve 82 and a pair of rigid edge scraping rings 83 are fixedly installed. The flexible inner wiping sleeve 82 is located between the pair of rigid edge scraping rings 83. During the movement, the rigid edge scraping rings 83 scrape off the more heavily adhered dust or stains, and the flexible inner wiping sleeve 82 then sweeps them off and they fall off at the edge.

[0040] Both ends of the outer ring 81 are provided with annular hidden grooves. Matching telescopic striking parts 84 are slidably installed in the annular hidden grooves. When the flue gas passes through the telescopic striking parts 84, it will cause the parts to vibrate. The vibration effect will trigger the striking action on the heat exchange tube bundle 12, thereby achieving a good dust removal effect.

[0041] The telescopic striking component 84 includes a movable slip ring 841. A compression spring 842 is fixedly installed between the movable slip ring 841 and the bottom wall of the annular hidden groove. Multiple circumferentially distributed vibrating plates 843 are fixedly installed at the outer end of the movable slip ring 841. A striking block 844 is fixedly installed at the outer end of the vibrating plate 843. Under normal conditions, the elastic force of the compression spring 842 ensures that the vibrating plate 843 and the striking block 844 are located in the external area, which can cooperate with the flue gas to achieve the effect of vibrating and striking the heat exchange tube bundle 12. At the same time, when it moves to the turning chamber 2, it can be squeezed to enter the annular hidden groove for avoidance, ensuring that the composite cleaning plate 7 can fit with the wall of the turning chamber 2 for sufficient heat exchange.

[0042] The outer ring 81 is made of polytetrafluoroethylene, which is high temperature resistant and self-lubricating. It is fixed with the through hole by interference fit to prevent loosening during movement. The hard edge scraper ring 83 on the inner wall of the outer ring is made of wear-resistant alloy material such as tungsten steel. It is hardened by quenching treatment to improve hardness. Its inner diameter is precisely matched with the outer diameter of the heat exchange tube bundle 12. It is used to scrape off stubborn dust and hard scale adhering to the surface of the heat exchange tube bundle 12. The flexible inner wiping sleeve 82 located in the middle is made of high temperature resistant silicone rubber. It is elastic and wear-resistant. It fits tightly with the surface of the heat exchange tube bundle 12 and can sweep away the fine dust remaining on the scraper ring, forming a "scraping-wiping" dual dust removal effect. The telescopic striking parts 84 at both ends of the outer ring are auxiliary ash removal structures. The movable slip ring 841 is made of stainless steel and is slidably installed in the annular hidden groove. It cooperates with the compression spring 842 at the bottom of the groove to realize the telescopic function. The vibrating plate 843 at the outer end of the movable slip ring 841 is made of elastic alloy steel sheet, which is easily excited by the flow of flue gas. The striking block 844 at the outer end is made of wear-resistant ceramic material. When vibrating, it can lightly tap the surface of the heat exchange tube bundle 12 and use the vibration wave to peel off the tightly attached ash. At the same time, when the cleaning plate moves to the turning air chamber 2, the telescopic striking parts 84 are squeezed and contracted into the annular hidden groove by the chamber wall, which does not affect the heat exchange between the cleaning plate and the chamber.

[0043] Example 2:

[0044] Please see Figure 7 and Figure 8 Based on Example 1, a heat-sensing baffle 9 is fixedly installed at the top of the box 11 in the direction of flue gas passage, and the lower end of the heat-sensing baffle 9 is higher than the upper end of the hollow heat-conducting plate 71. The heat-sensing baffle 9 can sense the high-temperature area in the moving path of the composite cleaning plate 7, thereby triggering the blocking action to restrict the composite cleaning plate 7 from continuing to move and keep it in the area. On the one hand, it can absorb and store heat, and on the other hand, it can specifically concentrate on cleaning the heat exchange tube bundle 12 in that area, thereby restoring the heat exchange effect.

[0045] The heat-sensing baffle 9 includes a heat-collecting plate 91, at least three bimetallic strips 92 are fixedly installed at the lower end of the heat-collecting plate 91, and an extension baffle 93 is fixedly installed at the lower expansion end of the bimetallic strip 92. The heat-sensing baffle 9 can detect the global temperature in real time. When the heat exchange effect is reduced and the local temperature rises due to the adhesion of smoke and dust on the surface of the heat exchange tube bundle 12 or the flow field distribution, usually in the middle area of ​​the heat exchange tube box 1, where the flue gas flow is the largest, the bimetallic strip 92 will expand when the temperature is higher than the normal heat exchange temperature due to the difference in the material expansion coefficient of the bimetallic strip 92. This will drive the extension baffle 93 to move downward and block and stop it on the moving path of the composite cleaning plate 7.

[0046] The heat-collecting plate 91 is made of copper, which has high heat absorption efficiency and can quickly sense changes in flue gas temperature. The lower bimetallic strip 92 is made of two metals with large differences in thermal expansion coefficients, such as copper and iron-nickel alloy. It is horizontal at room temperature. When the local flue gas temperature is higher than the normal heat exchange temperature, the bimetallic strip 92 expands and bends due to heat, which drives the extension block 93 to extend downward, blocking the composite cleaning plate 7 from moving and keeping it in the high-temperature ash accumulation area to enhance ash removal and heat storage. When the temperature drops to the normal range, the bimetallic strip 92 returns to straight, the extension block 93 resets, and the composite cleaning plate 7 continues to move.

[0047] It should be noted that this device uses a PLC controller as its core, integrating an electromagnet 22 control module and a temperature monitoring module. It can be connected to the existing temperature sensor of the heat exchange system to achieve automated control of "temperature monitoring - ash removal triggering - reciprocating drive". When the temperature sensor detects that the temperature at the flue gas outlet is higher than the threshold, the PLC controls the electromagnets 22 on both sides of the turning chamber 2 to intermittently switch on and off, driving the composite cleaning plate 7 to reciprocate through magnetic field adsorption.

[0048] Working principle:

[0049] Medium Flow and Basic Heat Exchange: High-temperature flue gas discharged from the industrial boiler enters the housing 11 of multiple heat exchange tube boxes 1 sequentially through the connecting flue 6. The flue gas flows through the outside of the heat exchange tube bundle 12 in the housing and exchanges heat with the air flowing inside the heat exchange tube bundle 12. Room temperature air enters the turning air chamber 2 of the first heat exchange tube box from the air inlet 5, enters the heat exchange tube bundle 12 through the air inlet 23, absorbs the heat of the flue gas and becomes hot air, and is distributed to the subsequent heat exchange tube boxes 1 through the connecting box 3 to continue to heat up, and finally is discharged from the air outlet 4 for production or heating use; the low-temperature flue gas after heat exchange is discharged from the end of the device.

[0050] Ash accumulation monitoring and ash removal triggering: As heat exchange continues, ash in the flue gas gradually adheres to the surface of the heat exchange tube bundle 12, forming an insulation layer that leads to a decrease in local heat exchange efficiency, manifested as an increase in flue gas temperature in that area. The heat-sensing baffle 9 at the top of the housing 11 senses temperature changes in real time. The high-temperature flue gas causes the heat-collecting plate 91 to absorb heat, which is then transferred to the bimetallic strip 92. Due to the difference in thermal expansion coefficients between the two metals, the bimetallic strip 92 bends, causing the extension baffle 93 to extend downwards onto the moving path of the composite cleaning plate 7.

[0051] Intelligent Ash Removal and Waste Heat Storage: When the temperature sensor detects a high outlet flue gas temperature, the PLC controller initiates the ash removal program, controlling the intermittent switching of the electromagnets 22 at both ends of the heat exchange tube box 1 in the turning air chambers 2. When one electromagnet is energized, its magnetic field attracts the magnetic suction plate 74 of the composite cleaning plate 7, causing the cleaning plate to move along the slide rail 13 to that side. During the movement, the rigid edge scraper ring 83 of the cleaning sleeve 8 first scrapes away the stubborn ash accumulated on the surface of the heat exchange tube bundle 12, and the flexible inner wiping sleeve 82 then sweeps away the residual dust. The dust falls to the bottom of the box under gravity and can be discharged through the subsequent ash removal structure. At the same time, the flue gas flow excites the telescopic striking pieces 84 at both ends of the cleaning sleeve 8. The vibrating plate 843 vibrates due to the airflow impact, causing the striking block 844 to gently tap the surface of the heat exchange tube bundle 12, using vibration waves to peel off the tightly attached ash and enhance the ash removal effect. When the cleaning plate moves to the high-temperature area, it is blocked and stopped by the extension block 93. At this time, the hollow heat-conducting plate 71 absorbs the residual heat of the flue gas and transfers it to the internal phase change heat storage core 73. The core undergoes a phase change to store heat. During the stop, the striking part continues to vibrate to remove ash until the ash accumulation in the area is removed, the flue gas temperature drops to the normal range, the bimetallic strip 92 returns to straight, the extension block resets, and the cleaning plate continues to move.

[0052] Waste heat release and cleaning plate reset: When the composite cleaning plate 7 moves to the turning air chamber 2 near the energized electromagnet 22, its surface is in contact with the inner wall of the hollow chamber 21. At this time, the telescopic striking piece 84 is squeezed by the chamber wall, and the moving slip ring 841 compresses the spring 842, causing the vibrating plate 843 and the striking block 844 to retract into the annular hidden groove of the outer ring 81, ensuring that the cleaning plate is in close contact with the chamber. The waste heat stored in the composite cleaning plate is transferred to the heat-conducting fins 24 on the inner wall of the chamber through the hollow heat-conducting plate 71. The fins conduct the heat to the air flowing through the air chamber, realizing secondary recovery of waste heat. After the waste heat on one side is released, the PLC controls the electromagnet 22 on that side to be de-energized, and the electromagnet 22 on the other side to be energized, driving the cleaning plate to move in the opposite direction, repeating the ash removal and heat storage process; when the flue gas temperature returns to normal, the PLC controls the composite cleaning plate 7 to reset to one end of the box, the ash removal program is paused, and the device returns to the basic heat exchange state.

Claims

1. A horizontal flue gas heat exchanger with anti-clogging properties, characterized in that: The system includes multiple horizontally arranged heat exchange tube boxes (1) and interconnected connecting boxes (3) fixedly installed between them. Each heat exchange tube box (1) has a connected air outlet (4) and an air inlet (5) fixedly installed at its head and tail. A turning air chamber (2) is fixedly installed at each end of the heat exchange tube box (1). A connecting flue (6) is fixedly installed between adjacent heat exchange tube boxes (1). A composite cleaning plate (7) parallel to the flue gas direction is slidably installed inside the heat exchange tube box (1). Multiple arrayed tube bundle through holes (72) are opened on the composite cleaning plate (7). Matching cleaning sleeves (8) are fixedly installed inside the tube bundle through holes (72). The heat exchange tube box (1) includes a box body (11). Multiple arrayed heat exchange tube bundles (12) are horizontally arranged inside the box body (11). The two ends of the bundle (12) pass through the box (11) and are connected to the turning air chamber (2). The cleaning sleeve (8) is slidably sleeved on the heat exchange tube bundle (12). The turning air chamber (2) includes a hollow cavity (21). The hollow cavity (21) is provided with multiple air inlets (23) that match the heat exchange tube bundle (12). Multiple electromagnets (22) are fixedly installed at the corners of the hollow cavity (21). Multiple uniformly distributed heat-conducting fins (24) are fixedly installed on the inner wall of the hollow cavity (21). The heat-conducting fins (24) are located on the side close to the heat exchange tube bundle (12). The composite cleaning plate (7) includes a hollow heat-conducting plate body (71). The inner cavity of the hollow heat-conducting plate body (71) is filled with a phase change heat storage core (73). Magnetic suction plates (74) are embedded at the upper and lower edges of the hollow heat-conducting plate body (71).

2. The anti-clogging horizontal flue gas heat exchanger according to claim 1, characterized in that: A pair of slide rails (13) are fixedly installed on the inner wall of the box (11), and a matching slider (14) is slidably installed on the slide rails (13), and the slider (14) is fixedly connected to the composite cleaning plate (7).

3. The anti-clogging horizontal flue gas heat exchanger according to claim 1, characterized in that: The cleaning sleeve (8) includes an outer ring (81), on which a concentrically arranged flexible inner wiping sleeve (82) and a pair of hard edge scraping rings (83) are fixedly installed. The flexible inner wiping sleeve (82) is located between the pair of hard edge scraping rings (83).

4. The anti-clogging horizontal flue gas heat exchanger according to claim 3, characterized in that: The outer ring (81) has annular hidden grooves at both the front and rear ends, and a matching telescopic striking element (84) is slidably installed in the annular hidden groove.

5. The anti-clogging horizontal flue gas heat exchanger according to claim 4, characterized in that: The telescopic striking component (84) includes a movable slip ring (841), a compression spring (842) is fixedly installed between the movable slip ring (841) and the bottom wall of the annular hidden groove, a plurality of circumferentially distributed vibrating plates (843) are fixedly installed at the outer end of the movable slip ring (841), and a striking block (844) is fixedly installed at the outer end of the vibrating plate (843).

6. The anti-clogging horizontal flue gas heat exchanger according to claim 5, characterized in that: A heat-sensitive baffle (9) is fixedly installed at the top of the box (11) in the direction of flue gas passage, and the lower end of the heat-sensitive baffle (9) is higher than the upper end of the hollow heat-conducting plate (71).

7. A horizontal flue gas heat exchanger for clogging prevention according to claim 6, characterized in that: The heat-sensitive baffle (9) includes a heat-collecting plate (91), at least three bimetallic strips (92) are fixedly installed at the lower end of the heat-collecting plate (91), and an extension block (93) is fixedly installed at the lower expansion end of the bimetallic strips (92).

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