A waste heat recovery device and method for a steam boiler

Abstract

The application discloses a waste heat recycling device and method of a steam boiler and relates to the technical field of steam boiler waste heat equipment, which comprises a steam boiler shell, a steam boiler support fixedly installed on the outer side of the steam boiler shell, a steam boiler main body fixedly installed on the inner side of the steam boiler shell, a waste heat recycling device fixedly connected to the flue gas output end of the steam boiler main body on the side of the steam boiler support close to the steam boiler main body, and a plurality of smoke pipes arranged in the steam boiler main body along the horizontal direction. The application dynamically balances the flue gas flow and temperature entering each smoke pipe, ensures that the flue gas distributed uniformly and the temperature field is stable when finally discharged from the boiler and entering the waste heat recycling device. The application changes the condition that the traditional boiler flue gas outlet exists serious 'flue gas deviation' (namely local high temperature and high speed), so that each part of the waste heat recycling device can work efficiently and safely under the design condition.

Description

Technical Field

[0001] This invention relates to the field of waste heat equipment for steam boilers, specifically a waste heat recovery and utilization device and method for steam boilers. Background Technology

[0002] A steam boiler is a thermal power device that converts the chemical energy of fuel into thermal energy, thereby heating water into steam at a certain temperature and pressure. The flue gas emitted during steam boiler operation carries a large amount of underutilized waste heat; directly discharging this waste heat would result in serious energy waste. Waste heat recovery and utilization devices can convert this heat into a reusable form of energy through heat exchange, heat conduction, and other methods.

[0003] Traditional boiler furnaces are mostly rectangular in cross-section, and the furnace outlet (connecting to the horizontal flue or the tail shaft) often has an asymmetrical geometry due to the arrangement of burners. For example, in a boiler with burners arranged on one side, the flame center will be biased to one side, and the high-temperature flue gas will create a flow deviation effect at the furnace outlet, resulting in uneven distribution of flue gas during flow. Consequently, the airflow entering the flue tubes will also be uneven. If the temperature of some flue tubes is too high or the temperature difference between them is too large, it will lead to uneven heating of the tube walls of the high-temperature flue tubes, generating significant thermal stress. Over time, this can easily lead to tube wall deformation, cracking, or even leakage. At the same time, the flue tubes and waste heat recovery surfaces generally accumulate a lot of ash, which exacerbates equipment blockage, wear, and corrosion, requiring frequent and costly cleaning and maintenance. Furthermore, the rigid connection between the flue tubes and the boiler body cannot effectively absorb thermal stress and vibration, which restricts the axial and radial expansion of the flue tubes. This generates tensile or shear stress at the weld joint between the flue tubes and the boiler body. Long-term hot and cold cycles will cause repeated stress accumulation, leading to fatigue cracks in the weld metal, eventually resulting in cracking and leakage.

[0004] Therefore, those skilled in the art provide a waste heat recovery and utilization device and method for a steam boiler to solve the problems mentioned in the background art. Summary of the Invention

[0005] The purpose of this invention is to provide a waste heat recovery and utilization device and method for a steam boiler to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A waste heat recovery device for a steam boiler includes a steam boiler shell, a steam boiler support fixedly installed on the outer side of the steam boiler shell, and a steam boiler body fixedly installed on the inner side of the steam boiler shell. A waste heat recovery device is fixedly connected to the flue gas output end of the steam boiler support near the steam boiler body. Multiple flue pipes are arranged horizontally inside the steam boiler body. A self-adjusting flow guiding mechanism is provided on the inner side of each flue pipe. The self-adjusting flow guiding mechanism includes a metal folding plate, which is installed on the inner side of the multiple flue pipes near the flue gas inlet. The deformation of the metal folding plate is used to change the flow at the flue gas inlet of the flue pipe it is located in. The area includes multiple flue pipes with a turbulence-disrupting mechanism located near their center. The turbulence-disrupting mechanism includes two second springs, which are installed on the inner wall of the flue pipe near the upper part. The lower ends of the two second springs are fixedly connected to thin metal plates. The vibration of the second springs and the thin metal plates is used to disturb the inner wall of the flue pipe. Flexible connection mechanisms are provided at the connection points between the two ends of the multiple flue pipes and the main body of the steam boiler. The flexible connection mechanisms include metal bellows, which are sealed to the ends of the flue pipes and the main body of the steam boiler, respectively. The metal bellows are used to compensate for the thermal deformation difference between the flue pipes and the main body of the steam boiler.

[0008] As a further aspect of the present invention: the self-adjusting flow guiding mechanism further includes a first fixing block, which is fixedly connected to the inner side of multiple smoke tubes. A base is fixedly connected to the inner side of the first fixing block near its smoke inlet. The metal folding plate is vertically fixedly connected to the base. A fixing rod is fixedly connected to the upper side of the metal folding plate. A slider is fixedly connected to both ends of the fixing rod. The two sliders are slidably adapted to the adjacent bases. A first spring is fixedly connected between the two sliders and the bases. A medicine box is installed between the first fixing block and the bases. A cylindrical box is threaded into the medicine box. A movable cover is rotatably connected to the upper surface of the medicine box. A connecting rope is fixedly connected between the movable cover and the fixing rod.

[0009] As a further embodiment of the present invention: the self-adjusting flow guiding mechanism further includes a miniature electric telescopic rod, which is fixedly installed on the outside of the steam boiler shell. A sealing sliding block is fixedly connected to the telescopic end of the miniature electric telescopic rod. A heat insulation cover is fixedly connected to the steam boiler shell near the miniature electric telescopic rod. The heat insulation cover is connected to the nearby flue pipe. A through groove is opened on the inner side of the heat insulation cover. The sealing sliding block is limited and slidably connected inside the heat insulation cover. A traction rope is fixedly installed on the side of the sealing sliding block away from the miniature electric telescopic rod. The traction rope is fixedly connected to the slider.

[0010] As a further aspect of the present invention: the self-adjusting flow guiding mechanism further includes a temperature sensor, which is fixedly installed on the first fixing block near the medicine box.

[0011] As a further embodiment of the present invention: the turbulence mechanism further includes a second fixing block, which is fixedly connected to the inner side of the flue near its middle position, and two guide blocks are fixedly connected at equal intervals on the inner side of the second fixing block.

[0012] As a further embodiment of the present invention: the turbulence mechanism further includes two thin metal plates, which are fixedly connected to one end of two second springs. The two second springs are fixedly connected at equal distances to the inner side of the second fixed block, respectively close to the two sets of guide blocks. The two second springs are in an uncompressed state by default.

[0013] As a further aspect of the present invention, the flexible connection mechanism further includes multiple protective blocks, which are fixedly connected to the outer side of the steam boiler body near multiple flue pipes. Each of the multiple protective blocks has a fixed retaining ring fixedly connected to its inner side. Each of the multiple protective blocks has three second spring rods fixedly connected at equal distances to its inner side away from the fixed retaining ring. The other end of each of the three second spring rods is fixedly connected to a movable retaining ring.

[0014] As a further aspect of the present invention, the flexible connection mechanism also includes a locking block, which is fixedly connected to the outer side of the metal corrugated pipe near the end of the flue, and the locking block engages with the adjacent movable locking ring and fixed locking ring.

[0015] A method for waste heat recovery and utilization from a steam boiler includes the following steps:

[0016] S1. Start the main body of the steam boiler, so that the high-temperature flue gas it generates enters the inside of the flue pipe through the flue pipe inlet. When the temperature inside a flue pipe is higher than the preset value, it means that more flue gas has passed through that flue pipe than the preset value. The temperature sensor is exposed to a temperature higher than the preset value, which drives the metal folding plate to open through the mini electric telescopic rod, thereby adjusting the flow area at the flue pipe inlet, so that the flue gas passes through other pipes, realizing adaptive control of flue gas flow rate.

[0017] S2. As the high-temperature flue gas flows inside the flue pipe, it impacts the thin metal plate in the turbulence mechanism, causing the second spring to vibrate. The vibration disturbs the inner wall of the flue pipe, while simultaneously enhancing the contact between the flue gas and the inner wall of the flue pipe, thus improving the waste heat transfer efficiency.

[0018] S3. During the flow of flue gas in the flue pipe and the operation of the device, when the flue pipe and the main body of the steam boiler undergo thermal deformation due to temperature differences, the metal bellows in the flexible connection mechanism adapts to the expansion and contraction. Combined with the elastic buffering effect of the second spring rod, it compensates for the thermal deformation difference between the two. At the same time, through the snap-fit ​​cooperation of the snap-fit ​​block with the movable snap-fit ​​ring and the fixed snap-fit ​​ring, it ensures the sealing stability of the connection.

[0019] S4. The low-temperature flue gas after heat exchange in the flue is discharged from the flue and enters the waste heat recovery device for subsequent waste heat recovery treatment, thus completing the entire waste heat recovery and utilization process.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The self-regulating flow guiding mechanism balances the flow rate and temperature of flue gas entering each flue tube, ensuring uniform distribution and stable temperature field of the flue gas ultimately discharged from the boiler and entering the waste heat recovery device. This changes the situation of severe "flue gas deviation" (i.e., localized high temperature and high speed) at the flue gas outlet of traditional boilers, enabling each part of the heat-receiving surface of the waste heat recovery device to operate efficiently and safely under design conditions. It avoids equipment damage and reduced heat exchange efficiency caused by localized overheating and overspeeding, and also reduces uneven heating of the tube walls of high-temperature flue tubes, which can generate large thermal stress and easily lead to tube wall deformation, cracking, or even leakage during long-term operation.

[0022] Through the continuous self-cleaning effect of the turbulence mechanism, the deposition of fly ash in the flue gas inside the boiler body flue tube is significantly reduced, thereby reducing the ash concentration and ash particle stickiness of the flue gas entering the downstream waste heat recovery device from the source. This effectively alleviates the problems of ash accumulation, blockage and wear of the waste heat recovery device, and extends its cleaning cycle and service life.

[0023] The flexible connection mechanism effectively eliminates the thermal stress fatigue and vibration damage caused by traditional rigid connections. It can effectively reduce the tensile or shear stress generated at the connection weld between the flue and the body, and greatly reduce the risk of unplanned shutdowns such as leaks and tube ruptures in the boiler flue system, especially near the interface with the waste heat recovery device.

[0024] The alkaline slow-release agent (such as magnesium oxide and calcium hydroxide) built into the cylindrical box can slowly release alkaline ions, which can neutralize the acidic condensate on the pipe wall surface, reducing the formation of hard scale on the inner wall of the flue. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a waste heat recovery and utilization device for a steam boiler.

[0026] Figure 2 This is a schematic diagram of the structure of the main body of the steam boiler and the flue in a waste heat recovery and utilization device for a steam boiler.

[0027] Figure 3 This is a cross-sectional schematic diagram of the turbulence mechanism in a waste heat recovery and utilization device for a steam boiler.

[0028] Figure 4 This is a schematic diagram of the self-regulating flow guiding mechanism in a waste heat recovery and utilization device for a steam boiler.

[0029] Figure 5 This is a schematic diagram of the structure of a waste heat recovery device for a steam boiler, including a miniature electric telescopic rod and a base.

[0030] Figure 6 This is a schematic diagram of the structure of a waste heat recovery device for a steam boiler, including metal folding plates and fixing rods.

[0031] Figure 7 This is a schematic diagram of the flexible connection mechanism in a waste heat recovery and utilization device for a steam boiler.

[0032] Figure 8 This is a cross-sectional schematic diagram of the flexible connection mechanism in a waste heat recovery and utilization device for a steam boiler.

[0033] Figure 9 This is a schematic diagram of the structure of a waste heat recovery device for a steam boiler, including a thin metal plate and a flow guide block.

[0034] Figure 10 In a waste heat recovery and utilization device for a steam boiler Figure 4 A magnified structural diagram of region A in the middle.

[0035] In the picture:

[0036] 1. Steam boiler outer shell; 11. Steam boiler support frame; 12. Steam boiler main body; 13. Flue pipe;

[0037] 21. First fixing block; 22. Base; 23. Metal folding plate; 24. First spring; 25. Slider; 26. Fixing rod; 27. Miniature electric telescopic rod; 271. Sealing sliding block; 272. Traction rope; 273. Insulation cover; 28. Medicine box; 281. Cylindrical box; 282. Connecting rope; 283. Movable cover; 29. ​​Temperature sensor;

[0038] 31. Second fixing block; 32. Guide block; 34. Second spring; 35. Metal sheet;

[0039] 41. Locking block; 42. Metal bellows; 43. Movable retaining ring; 44. Fixed retaining ring; 45. Spring rod; 46. Protective block;

[0040] 5. Waste heat recovery device. Detailed Implementation

[0041] The technical solutions of the embodiments 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] like Figures 1 to 9 As shown, this embodiment of the invention provides a waste heat recovery and utilization device and method for a steam boiler, including a steam boiler shell 1, a steam boiler support 11 fixedly installed on the outer side of the steam boiler shell 1, a steam boiler body 12 fixedly installed on the inner side of the steam boiler shell 1, a waste heat recovery device 5 fixedly connected to the flue gas output end of the steam boiler support 11 near the steam boiler body 12, and multiple flue pipes 13 arranged horizontally inside the steam boiler body 12. Self-adjusting flow guiding mechanisms are provided on the inner side of the multiple flue pipes 13 and the outer side of the steam boiler body 12, i.e., multiple self-adjusting flow guiding mechanisms are provided. Each self-adjusting flow guiding mechanism includes a metal folding plate 23, which is installed inside the multiple flue pipes 13. On the side, the shape of the metal folding plate 23 is changed to change the flow area at the inlet of the flue pipe 13. A turbulence mechanism is provided on the inner side of the multiple flue pipes 13 near the middle position. The turbulence mechanism includes a second spring 34, which is installed in the middle position of the inner side of the flue pipe 13. The vibration of the second spring 34 is used to disturb the inner wall of the flue pipe 13. A flexible connection mechanism is provided at the connection between the two ends of the multiple flue pipes 13 and the steam boiler body 12. The flexible connection mechanism includes a metal corrugated pipe 42. The two ends of the metal corrugated pipe 42 are respectively sealed to the end of the flue pipe 13 and the steam boiler body 12. The metal corrugated pipe 42 is used to compensate for the thermal deformation difference between the flue pipe 13 and the steam boiler body 12.

[0043] It should be noted that the steam boiler body 12, flue pipe 13, and waste heat recovery device 5 in this embodiment are all existing technologies. The steam boiler body 12 specifically consists of two flue gas headers, a combustion pipe, a burner, and an exhaust box. The burner is connected to the combustion pipe, and multiple flue pipes 13 are sequentially connected to the two flue gas headers, forming a series S-shaped passage arrangement between the two flue gas headers and the exhaust box. The high-temperature flue gas generated by the combustion of the boiler furnace burner enters the flue pipe through the combustion pipe and the flue gas header. After completing the main heat exchange through the flue pipe 13, it enters the tail waste heat recovery device 5. The waste heat recovery device 5 can be an economizer, an air preheater, or a condensing heat exchanger, etc., used to further recover waste heat from the flue gas discharged from the steam boiler and use the heat from the flue gas to preheat the boiler feedwater. The above are the waste heat recovery and utilization steps of existing steam boilers.

[0044] Specifically, such as Figure 1 , Figure 2 , Figures 4 to 6 and Figure 10As shown, the self-adjusting flow guiding mechanism also includes a first fixing block 21, which is fixedly connected to the inner side of the smoke pipe 13. A base 22 is fixedly connected to the inner side of the first fixing block 21 near its smoke inlet. A metal folding plate 23 is vertically fixedly connected to the base 22. A fixing rod 26 is fixedly connected to the upper side of each metal folding plate 23. Slider blocks 25 are fixedly connected to both ends of the fixing rod 26. A vertical sliding groove is provided on the inner side of the base 22, and the two sliders 25 slide appropriately with the sliding groove. The two sliders 25 are fixedly connected to the wall of the sliding groove by a first spring 24. A medicine box 28 is installed between the first fixing block 21 and the base 22. A cylindrical box 281 is connected to the medicine box 28 by an internal thread. A movable cover 283 is rotatably connected to the upper surface of the medicine box 28. A connecting rope 282 is fixedly connected between the movable cover 283 and the fixing rod 26. The outer surface of the smoke pipe 13 is provided with a through hole through which the cylindrical box 281 can pass, and the cylindrical box 281 is threadedly connected to the threaded ring in the through hole.

[0045] It should be noted that the metal folding plate 23 is a corrugated metal plate structure that can be elastically stretched. When it is unfolded, it can guide and constrain the flue gas flow channel. When it is contracted, it does not affect the flue gas flow channel, thereby realizing the adaptive adjustment of the flow channel cross-sectional area. A torsion spring is provided at the rotating connection between the movable cover 283 and the agent box 28. A filter screen plate is fixedly connected to the upper surface of the agent box 28. An alkaline slow-release agent is placed inside the cylindrical box 281, and the alkaline slow-release agent is located below the filter screen plate.

[0046] like Figure 1 , Figure 2 , Figure 4 , Figure 5 and Figure 6 As shown, optionally, the self-adjusting flow guiding mechanism also includes a miniature electric telescopic rod 27, which is fixedly installed on the outside of the steam boiler shell 1. A sealing sliding block 271 is fixedly connected to the telescopic end of the miniature electric telescopic rod 27. A heat insulation cover 273 is fixedly connected to the steam boiler shell 1 near the miniature electric telescopic rod 27. The heat insulation cover 273 penetrates into the inside of the steam boiler shell 1 and is fixedly connected to the outer surface of the flue pipe 13. A through groove is provided on the inner side of the heat insulation cover 273. The sealing sliding block 271 is limited and slidably connected to the inside of the heat insulation cover 273 to prevent the flue gas in 13 from leaking. A traction rope 272 is fixedly installed on the side of the sealing sliding block 271 away from the miniature electric telescopic rod 27. The traction rope 272 is fixedly connected to the adjacent slider 25. The self-adjusting flow guiding mechanism also includes a temperature sensor 29, which is fixedly installed on the first fixed block 21 near the reagent box 28.

[0047] It should be noted that the temperature sensor 29 is a high-temperature resistant temperature sensor, and the temperature sensor 29 is preset based on the temperature of the flue pipe 13 when it is working normally during the test. The traction rope 272 and the connecting rope 282 are made of high-temperature resistant and low-elongation material.

[0048] In this embodiment, when the main body 12 of the steam boiler is started to heat the water inside the outer shell 1 of the steam boiler normally, the fuel in the main body 12 of the steam boiler is burned in the combustion tube. The flue gas from the combustion first enters the flue gas header, and then enters multiple flue pipes 13 from the flue gas header. When a large amount of flue gas flows in a flue pipe 13, the temperature in this flue pipe 13 rises relatively. When the temperature rise in this flue pipe 13 is greater than the preset temperature of the temperature sensor 29, the output end of the miniature electric telescopic rod 27 corresponding to the temperature sensor 29 pulls the sealing sliding block 271 closer. The sealing sliding block 271 pulls the traction rope 272, the traction rope 272 drives the slider 25 to move, and the slider 25 drives the fixed rod 26 to move (the two ends of the fixed rod 26 slide on the base 22, so there will be no uneven sliding, and the first spring 24 is stretched). The fixed rod 26 drives the metal folding plate 23 to unfold. With the metal folding plate 23 unfolded, the flow area of ​​the smoke pipe 13 becomes smaller, and there are still gaps for smoke flow in the smoke pipe 13. Due to the reduced flow area, the local resistance of the "overheated" smoke pipe 13 increases. According to the principle of fluid mechanics, the subsequent smoke will naturally flow to the adjacent smoke pipe 13 with relatively less resistance, that is, to other smoke pipes 13 where the metal folding plate 23 has not unfolded. When the smoke in the "overheated" smoke pipe 13 decreases, the temperature will drop. After it drops below the preset temperature of the temperature sensor 29, the output end of the miniature electric telescopic rod 27 pushes the sealing sliding block 271 away from the miniature electric telescopic rod 27. At the same time, the traction rope 272 loosens, and the first spring 24 stretched at both ends of the two sliders 25 drives the two sliders 25 to return to their positions. The two sliders 25 drive the metal folding plate 23 to fold up, while tightening the loosened traction rope 272.

[0049] This method allows the excessive flow of flue gas in the original flue 13 to be distributed to other flue 13s, reducing the uneven flow among multiple flue 13s. This ensures that the flue gas is evenly discharged into the waste heat recovery device 5, thereby improving the efficiency of waste heat recovery. Simultaneously, the temperatures of multiple flue 13s tend to be similar, allowing for uniform heating of the water in the boiler. When the fixing rod 26 moves the metal folding plate 23 to unfold, the flue gas flow in this flue 13 decreases. The fixing rod 26 moves the connecting rope 282 to open the movable cover 283 of the agent box 28. The movable cover 283 rotates and causes the torsion spring to contract, allowing the alkaline slow-release agent inside the agent box 28 to volatilize into this flue 13. If the boiler feedwater treatment is incomplete, calcium and magnesium ions in the water will adhere with the water vapor circulation. Hard scale forms on the inner wall of the flue. At this time, the alkaline slow-release agent is slowly released onto the inner wall surface of the flue 13, forming a protective film to neutralize the acidic substances in the flue gas or inhibit the growth of scale crystals. The agent box 28 can also be opened by the mini electric telescopic rod 27 to release the alkaline slow-release agent. When the fixing rod 26 drives the metal folding plate 23 to fold up, the flue gas flows normally in the flue 13. The fixing rod 26 has no tension on the connecting rope 282. At this time, the movable cover 283 of the agent box 28 closes under the action of the torsion spring, stopping the release of the alkaline slow-release agent into the flue 13. In addition, since the cylindrical box 281 and the flue 13 are threaded together, the alkaline slow-release agent can be added inside the cylindrical box 281 after it is removed.

[0050] like Figure 3 and Figure 9 As shown, optionally, the second fixing block 31 is fixedly connected to the inner side of the flue pipe 13 near its middle position, and two guide blocks 32 are fixedly connected at equal intervals on the inner side of the second fixing block 31.

[0051] like Figure 3 and Figure 9 As shown, optionally, the turbulence mechanism also includes two metal plates 35, which are fixedly connected to one end of two second springs 34. The two second springs 34 are in an undeformed state by default. When the flue gas passes through the two sets of guide blocks 32, the guide blocks 32 guide the flue gas onto the metal plates 35, so that the flue gas is blown onto the metal plates 35 in a more concentrated manner.

[0052] It should be noted that both the metal plate 35 and the second spring 34 are made of high-temperature resistant metal materials. The metal plate 35 is very thin. When the high-temperature flue gas impacts the metal plate 35, the metal plate 35 is forced to drive the second spring 34 to reciprocate and expand and contract. The vibration frequency matches the flue gas flow frequency, forming a resonance turbulence effect. The vibration is transmitted to the inner wall of the flue pipe 13.

[0053] In this embodiment, when the high-temperature flue gas flows through the flue pipe 13 to the position of the second fixed block 31, it flows through two sets of symmetrically arranged guide blocks 32. The flue gas guided by the guide blocks 32 impacts the smoke-facing surface of the metal plate 35. Due to its thin thickness and light weight, the metal plate 35 shifts away from the second spring 34 under the impact force of the flue gas. When the metal plate 35 shifts, it causes the second spring 34 to be stretched. The elastic restoring force of the second spring 34 interacts with the continuous impact force of the flue gas, causing the metal plate 35 to move away from the second spring 34. Spring 34 reciprocates and extends at a frequency that matches the flue gas flow frequency, creating a resonant turbulence effect. This vibration is transmitted to the inner wall of flue pipe 13. As the flue gas flows within pipe 13, viscosity causes it to adhere to the inner wall, forming a very low-velocity laminar boundary layer. This boundary layer acts as a thermal barrier between the flue gas and the pipe wall, enhancing heat transfer by disrupting the laminar thermal boundary layer near the pipe wall. Furthermore, the vibration prevents ash particle deposition and dislodging existing ash layers, keeping the heat exchange surface clean. The second spring 34 is made of a high-temperature resistant alloy material, ensuring long-term elasticity under flue gas temperatures.

[0054] like Figure 2 , Figure 7 and Figure 8 As shown, optionally, each flue pipe 13 is provided with a flexible connection mechanism at both ends. The flexible connection mechanism also includes multiple protective blocks 46. The multiple protective blocks 46 are fixedly connected to the outer side of the steam boiler body 12 near the multiple flue pipes 13. The inner side of each of the multiple protective blocks 46 is fixedly connected with a fixing ring 44. The inner side of each of the multiple protective blocks 46 away from the fixing ring 44 is fixedly connected with three second spring rods 45 at equal distances. The other end of each of the three second spring rods 45 is fixedly connected to a movable ring 43.

[0055] It should be noted that the second spring rod 45 can provide axial elastic preload for the movable retaining ring 43, while allowing a certain radial float, which can both ensure the clamping force required for sealing and adapt to the multidimensional thermal displacement of the flue 13.

[0056] like Figure 2 , Figure 7 and Figure 8 As shown, optionally, the flexible connection mechanism also includes a locking block 41, which is fixedly connected to the outer side of the metal bellows 42 near the end of the smoke pipe 13, and the locking block 41 is engaged with the adjacent movable locking ring 43 and fixed locking ring 44.

[0057] It should be noted that the locking block 41 is specifically an annular fixing block installed on the outside of the metal bellows 42. The annular fixing block engages with the corresponding slots on the inner sides of the movable retaining ring 43 and the fixed retaining ring 44. The metal bellows 42 is made of multi-layer heat-resistant stainless steel, and its corrugated structure effectively absorbs the axial, lateral, and angular displacement differences between the flue pipe 13 and the steam boiler body 12, eliminating thermal stress. The slots on the inner sides of the fixed retaining ring 44 and the movable retaining ring 43 corresponding to the locking block 41 are slightly larger than the annular fixing block of the locking block 41. This ensures that when the fixed retaining ring 44 and the movable retaining ring 43 are engaged with the locking block 41, the locking block 41 cannot be longitudinally limited, but can only move slightly laterally.

[0058] In this embodiment, during the boiler start-up and heating phase, the flue pipe 13 undergoes axial thermal elongation due to heating by the high-temperature flue gas; the metal bellows 42 subsequently compresses and deforms to compensate for the axial thermal displacement of the flue pipe 13. Given that the thermal elongation of the flue pipe 13 is within a small range, the locking block 41 is confined within the clamping space formed by the fixed locking ring 44 and the movable locking ring 43, and can undergo slight lateral displacement within this space. The preload of the second spring rod 45 continuously acts on the movable locking ring 43, ensuring that the movable locking ring 43 and the fixed locking ring 44 always maintain a reliable engagement with the locking block 41. During boiler operation, if the system vibrates or the flue pipe 13 experiences slight radial displacement, the sliding characteristics of the movable locking ring 43, the elastic extension and contraction properties of the second spring rod 45, and the flexible deformation capability of the metal bellows 42 can form a synergistic compensation mechanism to jointly absorb the aforementioned vibrations and displacements. The movable retaining ring 43 and the fixed retaining ring 44 can support and limit the metal bellows 42, preventing it from sagging and loosening when the boiler is shut down for cooling. Throughout the entire thermal expansion and contraction cycle, the connection between the flue pipe 13 and the tube sheet maintains excellent sealing performance, and no stress concentration occurs at this location, providing a reliable guarantee for the long-term, stable, and efficient operation of the waste heat recovery system.

[0059] A method for recovering and utilizing waste heat from a steam boiler includes the following steps:

[0060] S1. Start the main body of the steam boiler 12, so that the high-temperature flue gas generated by it enters the interior of the flue pipe 13 through the flue inlet. When the temperature inside the flue pipe 13 is higher than the preset value, it means that more flue gas passes through the flue pipe 13 than the preset value. The temperature sensor 29 receives a temperature higher than the preset value, and drives the metal folding plate 23 to open through the micro electric telescopic rod 27, thereby adjusting the flow area at the flue pipe 13 inlet, so that the flue gas passes through other pipes, realizing adaptive control of flue gas flow rate.

[0061] S2. During the flow of high-temperature flue gas in the flue pipe 13, it impacts the metal plate 35 in the turbulence mechanism, causing the second spring 34 to vibrate. The vibration causes disturbance to the inner wall of the flue pipe 13, while enhancing the contact between the flue gas and the inner wall of the flue pipe 13 and improving the waste heat transfer efficiency.

[0062] S3. During the flow of flue gas in the flue pipe 13 and the operation of the device, when the flue pipe 13 and the main body of the steam boiler 12 undergo thermal deformation due to temperature difference, the metal bellows 42 in the flexible connection mechanism adapts to the expansion and contraction. With the elastic buffering effect of the second spring rod 45, it compensates for the thermal deformation difference between the two. At the same time, through the snap-fit ​​cooperation of the snap-fit ​​block 41 with the movable snap-fit ​​ring 43 and the fixed snap-fit ​​ring 44, the sealing stability of the connection is ensured.

[0063] S4. The low-temperature flue gas after heat exchange through the flue pipe 13 is discharged from the flue pipe 13 and enters the waste heat recovery device 5 for subsequent waste heat recovery treatment, thus completing the entire waste heat recovery and utilization process.

[0064] It should be noted that the parts used in this invention are all made of high-temperature resistant materials, which are suitable for steam boilers.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A waste heat recovery and utilization device for a steam boiler, characterized in that, include: Steam boiler shell (1), and a steam boiler bracket (11) is fixedly installed on the outside of the steam boiler shell (1); The main body of the steam boiler (12) is fixedly installed on the inner side of the outer shell (1) of the steam boiler. A waste heat recovery device (5) is fixedly connected to the flue gas output end of the steam boiler support (11) near the main body of the steam boiler (12). Multiple flue pipes (13) are arranged horizontally inside the main body of the steam boiler (12). A self-adjusting flow guiding mechanism is provided on the inner side of multiple smoke pipes (13). The self-adjusting flow guiding mechanism includes a metal folding plate (23). The metal folding plate (23) is installed on the inner side of the smoke pipe (13) near the smoke inlet. The deformation of the metal folding plate (23) is used to change the flow area at the smoke inlet of the smoke pipe (13) where it is located. A flow disturbance mechanism is provided on the inner side of the plurality of smoke pipes (13) near the middle position. The flow disturbance mechanism includes two second springs (34). The two second springs (34) are installed on the inner side wall of the smoke pipe (13) near the upper part. The lower ends of the two second springs (34) are fixedly connected to metal plates (35). The vibration of the second springs (34) and the metal plates (35) is used to disturb the inner wall of the smoke pipe (13) where they are located. A flexible connection mechanism is provided at the connection between the two ends of the multiple flue pipes (13) and the main body of the steam boiler (12). The flexible connection mechanism includes two metal corrugated pipes (42). The two ends of the two metal corrugated pipes (42) are respectively sealed to the end of the flue pipe (13) and the main body of the steam boiler (12). The metal corrugated pipes (42) are used to compensate for the thermal deformation difference between the flue pipe (13) and the main body of the steam boiler (12).

2. The waste heat recovery and utilization device for a steam boiler according to claim 1, characterized in that, The self-adjusting flow guiding mechanism also includes a first fixing block (21), which is fixedly connected to the inner side of the flue (13). A base (22) is fixedly connected to the inner side of the first fixing block (21) near its smoke inlet. The metal folding plate (23) is vertically fixedly connected to the base (22). A fixing rod (26) is fixedly connected to the upper side of the metal folding plate (23). Slider blocks (25) are fixedly connected to both ends of the fixing rod (26). 25) and the adjacent base (22) are slidably adapted, and a first spring (24) is fixedly connected between the two sliders (25) and the base (22). A medicine box (28) is installed between the first fixing block (21) and the base (22). A cylindrical box (281) is internally threaded to the medicine box (28). A movable cover (283) is rotatably connected to the upper surface of the medicine box (28). A connecting rope (282) is fixedly connected between the movable cover (283) and the fixing rod (26).

3. The waste heat recovery and utilization device for a steam boiler according to claim 2, characterized in that, The self-adjusting flow guiding mechanism also includes a miniature electric telescopic rod (27), which is fixedly installed on the outside of the steam boiler shell (1). The telescopic end of the miniature electric telescopic rod (27) is fixedly connected to a sealing sliding block (271). The steam boiler shell (1) is fixedly connected to a heat insulation cover (273) near the miniature electric telescopic rod (27). The heat insulation cover (273) is connected to the nearby flue pipe (13). A through groove is opened on the inner side of the heat insulation cover (273). The sealing sliding block (271) is limited and slidably connected inside the heat insulation cover (273). A traction rope (272) is fixedly installed on the side of the sealing sliding block (271) away from the miniature electric telescopic rod (27). The traction rope (272) is fixedly connected to the slider (25).

4. The waste heat recovery and utilization device for a steam boiler according to claim 3, characterized in that, The self-adjusting flow guiding mechanism also includes a temperature sensor (29), which is fixedly installed on the first fixing block (21) near the medicine box (28).

5. The waste heat recovery and utilization device for a steam boiler according to claim 1, characterized in that, The turbulence mechanism also includes a second fixing block (31), which is fixedly connected to the inner side of the flue (13) near its middle position. Two guide blocks (32) are fixedly connected at equal distances to the inner side of the second fixing block (31).

6. The waste heat recovery and utilization device for a steam boiler according to claim 1, characterized in that, The flexible connection mechanism also includes multiple protective blocks (46), which are fixedly connected to the outer side of the steam boiler body (12) near multiple flue pipes (13). Each of the multiple protective blocks (46) is fixedly connected to a retaining ring (44). Each of the multiple protective blocks (46) is fixedly connected to three second spring rods (45) at equal distances on the inner side away from the retaining rings (44). The other end of each of the three second spring rods (45) is fixedly connected to a movable retaining ring (43).

7. The waste heat recovery and utilization device for a steam boiler according to claim 6, characterized in that, The flexible connection mechanism also includes a locking block (41), which is fixedly connected to the outside of the multiple metal corrugated pipes (42) near the end of the smoke pipe (13). The locking block (41) is engaged with the adjacent movable locking ring (43) and fixed locking ring (44).

8. A method for waste heat recovery and utilization of a steam boiler, applied to the waste heat recovery and utilization device of a steam boiler as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Start the main body of the steam boiler (12) so that the high temperature flue gas generated by it enters the inside of the flue pipe (13) through the flue inlet. When the temperature inside the flue pipe (13) is higher than the preset value, it means that the flue gas passing through the flue pipe (13) is more than the preset value. The temperature sensor (29) is subjected to a temperature higher than the preset value. The metal folding plate (23) is opened by the micro electric telescopic rod (27), thereby adjusting the flow area at the flue pipe (13) inlet so that the flue gas passes through other pipes and realizes the adaptive control of the flue gas flow rate. S2. During the flow of high-temperature flue gas in the flue pipe (13), it impacts the metal plate (35) in the turbulence mechanism, causing the second spring (34) to vibrate. The vibration causes disturbance to the inner wall of the flue pipe (13), while enhancing the contact between the flue gas and the inner wall of the flue pipe (13) and improving the waste heat transfer efficiency. S3. When flue gas flows in the flue pipe (13) and the device is in operation, the flue pipe (13) and the main body of the steam boiler (12) undergo thermal deformation due to temperature difference. The metal bellows (42) in the flexible connection mechanism expands and contracts adaptively. With the elastic buffering effect of the second spring rod (45), the thermal deformation difference between the two is compensated. At the same time, the locking block (41) and the movable locking ring (43) and the fixed locking ring (44) are engaged to ensure the sealing stability of the connection. S4. The low-temperature flue gas after heat exchange through the flue pipe (13) is discharged from the flue pipe (13) and enters the waste heat recovery device (5) for subsequent waste heat recovery treatment, thus completing the entire waste heat recovery and utilization process.

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