A waste heat utilization recovery device and method applied to flue gas of a boiler

Abstract

The application relates to the technical field of flue gas waste heat recovery devices, and discloses a waste heat utilization and recovery device and method applied to boiler combustion flue gas, wherein the waste heat utilization and recovery device applied to boiler combustion flue gas comprises a chassis, heat absorption mechanisms fixed and installed on the top of the chassis in sequence, a middle section partition plate and heat release components, and multiple pipe body components arranged in the heat absorption mechanisms and the heat release components, when the temperature of the flue gas is relatively high, the heat absorption fins can absorb part of heat and conduct the heat to a medium storage cavity, the medium in the medium storage cavity absorbs heat and evaporates into gas which fills the air-filled heat conduction film through a gaseous flow cavity, the air-filled heat conduction film expands to store the gaseous medium, and the gaseous medium is discharged when the temperature of the flue gas is relatively low, the gaseous medium is condensed into liquid after heat dissipation and is absorbed by a liquid absorption core plate to return to the medium storage cavity, thereby helping heat transfer and buffering, and reducing the damage of heat shock to device components.

Description

Technical Field

[0001] This invention relates to the technical field of flue gas waste heat recovery devices, and in particular to a waste heat recovery device and method for boiler combustion flue gas. Background Technology

[0002] Marine boilers are critical equipment in ship operations, and the flue gas they produce contains a significant amount of waste heat. Direct emission of this waste heat not only results in enormous energy waste but also exacerbates environmental pollution. Traditional waste heat recovery methods are inefficient and struggle to fully extract heat from the flue gas. Furthermore, the marine environment is complex and variable, with large fluctuations in boiler load, placing extremely high demands on the stability and adaptability of the recovery device. While heat pipe technology, as a highly efficient heat transfer method, has some applications in waste heat recovery, existing heat pipe-based marine boiler waste heat recovery devices suffer from insufficient regulation capacity and poor thermal shock resistance when dealing with complex operating conditions, failing to achieve efficient and stable waste heat recovery.

[0003] Patent publication number CN220061804U discloses a boiler waste heat recovery device, including a base. The filter box assembly consists of an annular sliding groove, an annular sliding block, a return spring, an arc-shaped filter screen, a rotating shaft, a cam, and a drive motor. The arc-shaped filter screen moves back and forth, and vibrates in conjunction with the impact of the cam. Impurities are filtered through the arc-shaped filter screen. The filtered impurities, due to the vibration of the arc-shaped filter screen, fall into the impurity recovery box through the impurity discharge pipe. This achieves filtration of impurities in the flue gas and self-cleaning of the arc-shaped filter screen, preventing pipe blockage. Simultaneously, it collects incompletely burned materials for reprocessing, improving the combustion utilization rate of materials. The purified gas is discharged through the exhaust pipe, achieving dust reduction and condensation of the flue gas, preventing the direct emission of impurities and heat carried in the flue gas, thus preventing environmental damage.

[0004] The existing technology has the following drawbacks:

[0005] Lack of an effective thermal buffering mechanism: Existing devices lack an effective thermal buffering mechanism. Rapid rises or falls in heat pipe temperature can lead to unstable heat recovery efficiency, affecting the overall performance of the waste heat recovery device. Frequent thermal shocks can also cause fatigue damage to components such as pipes and seals, shortening the equipment's lifespan. Therefore, it is necessary to incorporate a structure with a thermal buffering mechanism to stabilize the heat pipe temperature, prevent rapid rises and falls, significantly improve heat recovery efficiency, make the waste heat recovery device more stable, fully utilize the value of waste heat, and at the same time, greatly reduce the damage of thermal shocks to device components, extend the overall service life of the equipment, reduce replacement and maintenance costs, and ultimately improve the sustainability and reliability of energy recovery.

[0006] The existing equipment cannot automatically adjust the heat absorption range and exhaust resistance according to changes in flue gas flow rate. The resistance value is fixed and does not consider flow rate variations. When the flue gas flow rate is high, the heat absorption range is small and the exhaust resistance is high, resulting in some heat being discharged without being absorbed. When the flue gas flow rate is low, the heat absorption range is large and the exhaust resistance is low, easily leading to heat waste and unstable thermal efficiency. Furthermore, inappropriate exhaust resistance subjectes the equipment to abnormal pressure for extended periods, accelerating component aging and damage. Therefore, a structure that can automatically adjust the heat absorption range and exhaust resistance according to changes in flue gas flow rate is needed. This ensures sufficient heat exchange regardless of flue gas flow rate, avoiding heat waste or incomplete absorption, improving overall thermal efficiency. Simultaneously, appropriate exhaust resistance reduces the impact of abnormal pressure on the equipment, slowing down component aging and damage, and ensuring continuous and efficient production processes. Summary of the Invention

[0007] Given the lack of an effective heat buffering mechanism and the inability to automatically adjust the heat absorption range and exhaust resistance according to changes in flue gas flow rate in existing technologies, a waste heat recovery device and method for boiler combustion flue gas is proposed.

[0008] This application provides a waste heat recovery device for boiler combustion flue gas. Its purpose is to stabilize the heat pipe temperature through a designed heat absorption mechanism and pipe assembly, preventing rapid temperature fluctuations and significantly improving heat recovery efficiency. This results in more stable performance of the waste heat recovery device, fully utilizing the value of waste heat, and significantly reducing thermal shock damage to device components, extending the overall service life of the equipment, reducing replacement and maintenance costs, and improving the sustainability and reliability of energy recovery. Simultaneously, it ensures sufficient heat exchange regardless of flue gas flow rate, preventing heat waste or incomplete absorption, thus improving overall thermal efficiency. Furthermore, appropriate exhaust resistance reduces the impact of abnormal pressure on the equipment, slowing down component aging and damage, and ensuring continuous and efficient production processes.

[0009] The technical solution of the present invention is as follows: a waste heat recovery device for boiler combustion flue gas, comprising a base frame, a heat absorption mechanism, a middle section partition and a heat release component that are sequentially fixedly installed on the top of the base frame, and a plurality of tube components disposed inside the heat absorption mechanism and the heat release component. The heat absorption mechanism includes a waste heat recovery chamber fixedly installed on the top of the base frame, and a heat buffer component and an adjustment component are disposed inside the waste heat recovery chamber.

[0010] The heat buffer assembly includes a sealed buffer cavity fixedly connected to the inner wall of the waste heat recovery chamber and two limiting frames. The two limiting frames are symmetrically arranged inside the sealed buffer cavity. A liquid-absorbing core plate and multiple heat-absorbing fins are fixedly connected between the two limiting frames. The tops of the multiple heat-absorbing fins are all fixedly connected to the inner wall of the sealed buffer cavity. A medium storage cavity is formed between two adjacent heat-absorbing fins. A gas flow cavity is also opened inside the sealed buffer cavity. The gas flow cavity is connected to the medium storage cavity. Multiple inflatable heat-conducting films are fixedly connected to the bottom of the sealed buffer cavity. After the medium in the medium storage cavity evaporates, it is guided to the inner surface of the inflatable heat-conducting films through the gas flow cavity.

[0011] By adopting the above scheme, when the flue gas temperature is high, the heat-absorbing fins absorb some heat and conduct it to the medium storage chamber. The medium in the medium storage chamber absorbs heat and evaporates into gas, which fills the gas-filled heat-conducting film through the gas flow chamber. This causes the gas-filled heat-conducting film to expand and store the gaseous medium. When the flue gas temperature is low, the gaseous medium dissipates and condenses into liquid after dissipating heat. It is then absorbed by the liquid-absorbing core plate and returned to the medium storage chamber, forming a cycle. Furthermore, when the gas-filled heat-conducting film expands, even if the flue gas flow rate is small, the gas-filled heat-conducting film can also compress the regulating component to expand the heat absorption range. This helps with heat transfer and buffering, reducing the damage of thermal shock to the device components.

[0012] Furthermore, the adjustment assembly includes multiple storage slots opened inside the base frame, with telescopic springs fixedly connected to the inner walls of the storage slots, and lifting plates fixedly connected between the tops of the multiple telescopic springs. The outer walls of the lifting plates are slidably connected to the inner walls of the waste heat recovery chamber.

[0013] By adopting the above scheme, through the setting of the regulating components, when the boiler load is high, the flue gas flow is large, and a large amount of flue gas will squeeze the lifting plate, causing it to descend. The descent of the lifting plate expands the heat absorption range, allowing more heat pipes to participate in the heat absorption process, ensuring that the heat in the flue gas can be fully absorbed, and preventing some heat from being discharged without being absorbed.

[0014] Furthermore, the two ends of the waste heat recovery chamber are respectively connected to a flue gas inlet pipe and a flue gas outlet pipe, and the inside of the flue gas outlet pipe is connected to an auxiliary exhaust pipe, which is connected to the waste heat recovery chamber.

[0015] By adopting the above scheme, the auxiliary exhaust pipe will be exposed when the lifting plate descends. The auxiliary exhaust pipe guides the flue gas to flow evenly, avoids excessive local resistance, and ensures that the device can maintain stable exhaust resistance under different flue gas flow rates, thereby improving heat exchange efficiency.

[0016] Furthermore, the tube assembly includes a second tube shell fixedly connected to the inner wall of the middle section partition, and a first tube shell slidably connected to the inner wall of the second tube shell, forming a heat exchange cavity between the second tube shell and the first tube shell.

[0017] Furthermore, a second sealing ring is fixedly connected to the inner wall of the second tube shell, and a first sealing ring is fixedly connected to the outer wall of the first tube shell. The second tube shell and the first tube shell are sealed together by the second sealing ring and the first sealing ring.

[0018] Furthermore, the inner wall of the sealed buffer cavity is provided with multiple through grooves, the inner walls of the multiple through grooves are slidably connected to the outer walls of the multiple first tube shells, and the bottom of the multiple first tube shells abuts against the top of the lifting plate.

[0019] Using the above scheme, through the set tube assembly, the lifting plate descends while the first tube shell slides downward in the second tube shell, expanding the heat absorption range. The heat in the flue gas is conducted to the heat exchange chamber through the first tube shell, causing the medium in the heat exchange chamber to evaporate. The gaseous medium carries the heat and rises to the second tube shell, preparing for the subsequent heat release process. After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber under the action of gravity, forming a cyclic heat exchange process.

[0020] Furthermore, the heat dissipation assembly includes a heat dissipation cavity fixedly connected to the top of the middle section partition. The inner wall of the heat dissipation cavity is fixedly connected to a plurality of heat dissipation fins, and the inner walls of the plurality of heat dissipation fins are respectively fixedly connected to the outer walls of a plurality of second tube shells.

[0021] Furthermore, the two ends of the heat dissipation chamber are respectively connected to a cold air input pipe and a hot air output pipe, with the cold air input pipe located above the flue gas output pipe and the hot air output pipe located above the flue gas input pipe.

[0022] Using the above scheme, through the heat dissipation component, cold air is introduced into the heat dissipation chamber through the cold air inlet pipe. The heat dissipation fins in the heat dissipation chamber are tightly connected to the second shell. The cold air exchanges heat with the second shell through the heat dissipation fins, absorbing the heat in the gaseous medium. The flue gas after heat dissipation is discharged through the flue gas outlet pipe, while the cold air after heat absorption is discharged through the hot air outlet pipe, thus realizing the effective recovery and utilization of waste heat.

[0023] Another aspect of this application provides a method for recovering waste heat from boiler combustion flue gas using a waste heat recovery device, comprising the following steps:

[0024] Step 1: Introduce the flue gas generated by the marine boiler combustion into the waste heat recovery chamber through the flue gas inlet pipe;

[0025] Step 2: When the boiler load is less than 1.5 tons / hour and the flue gas flow is low, heat is absorbed only through the upper part of the waste heat recovery chamber via heat pipes.

[0026] Step 3: When the boiler load is higher than 1.5 tons / hour, the flue gas flow rate is high, and the lifting plate is squeezed to expand the heat absorption range;

[0027] Step 4: The heat buffer component absorbs and stores some of the heat to prevent the heat pipe temperature from rising and falling sharply, thus reducing thermal shock;

[0028] Step 5: When the lifting plate descends, the auxiliary exhaust pipe leaks out to guide the smoke to flow evenly and avoid excessive local resistance;

[0029] Step 6: The heat from the flue gas is conducted through the first tube shell to the evaporating medium inside the heat exchange chamber, and the gaseous medium carries the heat up to the second tube shell;

[0030] Step 7: Cold air is introduced through the cold air inlet pipe and exchanges heat with the second pipe shell through the heat dissipation fins;

[0031] Step 8: After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber under the action of gravity;

[0032] Step 9: The released flue gas is discharged through the flue gas output pipe, and the absorbed cold air is discharged through the hot air output pipe.

[0033] Using the above scheme, the flue gas generated by the marine boiler combustion is introduced into the waste heat recovery chamber through the flue gas inlet pipe, providing a heat source for subsequent heat recovery. When the boiler load is low, the flue gas flow rate is small. At this time, heat absorption by the heat pipes only occurs in the upper part of the waste heat recovery chamber, and the small heat absorption range is sufficient to complete the heat absorption, avoiding heat waste. When the boiler load is high, the flue gas flow rate is large, and a large amount of flue gas will squeeze the lifting plate, causing it to descend. The descent of the lifting plate expands the heat absorption range, allowing more heat pipes to participate in the heat absorption process, ensuring that the heat in the flue gas is fully absorbed and preventing some heat from being discharged without being absorbed. When the flue gas temperature is high, the heat buffer component absorbs and stores some heat to prevent the heat pipe temperature from rising sharply. The lowering plate reduces thermal shock. When the lifting plate descends, the auxiliary exhaust pipe leaks out, guiding the flue gas to flow evenly and avoiding excessive local resistance. This ensures that the device maintains stable exhaust resistance under different flue gas flow rates, improving heat exchange efficiency. Cold air is introduced into the heat release chamber through the cold air inlet pipe. The heat dissipation fins in the heat release chamber are tightly connected to the second shell. The cold air exchanges heat with the second shell through the heat dissipation fins, absorbing heat from the gaseous medium. After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber under gravity, forming a cyclic heat exchange process. The flue gas that has released heat is discharged through the flue gas outlet pipe, while the cold air that has absorbed heat is discharged through the hot air outlet pipe, realizing the effective recovery and utilization of waste heat.

[0034] The beneficial effects of this invention are:

[0035] 1. Through the set heat buffer component, when the flue gas temperature is high, the heat-absorbing fins will absorb some heat and conduct it to the medium storage chamber. The medium in the medium storage chamber absorbs heat and evaporates into gas, which fills the gas-filled heat-conducting film through the gas flow chamber. This causes the gas-filled heat-conducting film to expand and store the gaseous medium. When the flue gas temperature is low, the gaseous medium dissipates and condenses into liquid, which is then absorbed by the liquid-absorbing core plate and returned to the medium storage chamber, forming a cycle. Moreover, when the gas-filled heat-conducting film expands, even if the flue gas flow rate is small, the gas-filled heat-conducting film can also squeeze the regulating component to expand the heat absorption range, thereby helping to transfer and buffer heat and reduce the damage of thermal shock to the device components.

[0036] 2. Through the set adjustment components, when the boiler load is high, the flue gas flow rate is large. A large amount of flue gas will squeeze the lifting plate, causing it to descend. The descent of the lifting plate expands the heat absorption range, allowing more heat pipes to participate in the heat absorption process. This ensures that the heat in the flue gas can be fully absorbed, preventing some heat from being discharged without being absorbed. Furthermore, when the lifting plate descends, the auxiliary exhaust pipe will leak out. The auxiliary exhaust pipe guides the flue gas to flow evenly, avoiding excessive local resistance. This ensures that the device can maintain stable exhaust resistance under different flue gas flow rates, thereby improving heat exchange efficiency.

[0037] 3. Through the set tube assembly, as the lifting plate descends, the first tube shell slides downward in the second tube shell, expanding the heat absorption range. The heat in the flue gas is conducted to the inside of the heat exchange chamber through the first tube shell, causing the medium in the heat exchange chamber to evaporate. The gaseous medium carries the heat and rises to the second tube shell, preparing for the subsequent heat release process. After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber under the action of gravity, forming a cycle of heat exchange process. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the heat dissipation component of the present invention;

[0040] Figure 3 This is a schematic diagram of the heat absorption mechanism of the present invention;

[0041] Figure 4 This is a schematic diagram of the auxiliary exhaust pipe structure of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of the heat buffer assembly of the present invention;

[0043] Figure 6 This is a schematic diagram of the structure of the medium storage cavity in this invention;

[0044] Figure 7 This is a schematic diagram of the structure of the inflatable heat-conducting film of the present invention;

[0045] Figure 8 This is a schematic diagram of the heat absorption process of the heat buffer component of the present invention;

[0046] Figure 9 This is a schematic diagram of the structure of the gas flow cavity in this invention;

[0047] Figure 10 This is a schematic diagram of the structure of the adjustment component of the present invention;

[0048] Figure 11 This is a schematic diagram of the structure of the tube assembly of the present invention;

[0049] Figure 12 This is a schematic diagram of the flue gas flow rate change process of the present invention.

[0050] In the picture:

[0051] 1. Base frame; 2. Heat absorption mechanism; 21. Flue gas inlet pipe; 22. Waste heat recovery chamber; 23. Flue gas outlet pipe; 24. Auxiliary exhaust pipe; 25. Heat buffer assembly; 251. Sealed buffer chamber; 252. Limiting frame; 253. Liquid absorption core plate; 254. Penetration groove; 255. Heat absorption fins; 256. Medium storage chamber; 257. Gas flow chamber; 258. Inflatable heat-conducting film; 26. Adjustment assembly; 261. Lifting plate; 262. Telescopic spring; 263. Storage groove; 3. Middle section partition; 4. Heat release assembly; 41. Cold air inlet pipe; 42. Heat release chamber; 43. Hot air outlet pipe; 44. Heat dissipation fins; 5. Pipe body assembly; 51. First pipe shell; 52. Heat exchange chamber; 53. First sealing ring; 54. Second pipe shell; 55. Second sealing ring. Detailed Implementation

[0052] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0053] Example 1, referring to Figure 1 - Figure 12 The first embodiment of the present invention provides a waste heat recovery device for boiler combustion flue gas, including a base frame 1, a heat absorption mechanism 2, a middle section partition 3 and a heat release component 4 which are fixedly installed on the top of the base frame 1 in sequence, and a plurality of tube components 5 disposed inside the heat absorption mechanism 2 and the heat release component 4. The heat absorption mechanism 2 includes a waste heat recovery chamber 22 fixedly installed on the top of the base frame 1, and a heat buffer component 25 and an adjustment component 26 are disposed inside the waste heat recovery chamber 22.

[0054] Reference Figure 4 - Figure 9 The heat buffer assembly 25 includes a sealed buffer cavity 251 fixedly connected to the inner wall of the waste heat recovery cavity 22 and two limiting frames 252. The two limiting frames 252 are symmetrically arranged inside the sealed buffer cavity 251. A liquid-absorbing core plate 253 and multiple heat-absorbing fins 255 are fixedly connected between the two limiting frames 252. The tops of the multiple heat-absorbing fins 255 are all fixedly connected to the inner wall of the sealed buffer cavity 251. A medium storage cavity 256 is formed between two adjacent heat-absorbing fins 255. A gas flow cavity 257 is also provided inside the sealed buffer cavity 251. The gas flow cavity 257 communicates with the medium storage cavity 256. Multiple inflatable heat-conducting films 258 are fixedly connected to the bottom of the sealed buffer cavity 251. After the medium in the medium storage cavity 256 evaporates, it is guided to the inner surface of the inflatable heat-conducting film 258 through the gas flow cavity 257.

[0055] Specifically, the liquid-absorbing core plate 253 has excellent liquid absorption performance, enabling it to store and transfer the medium required for heat exchange. Multiple heat-absorbing fins 255 significantly increase the contact area with flue gas, improving the efficiency of heat absorption. The medium storage cavity 256 is an important location for heat storage and exchange. When the flue gas temperature is high, the medium absorbs heat and undergoes a state change in the medium storage cavity 256. When the flue gas temperature decreases, the stored heat can be released, thus stabilizing the heat pipe temperature. The gas-filled heat-conducting film 258 has excellent thermal conductivity and expandability. When the medium absorbs heat, becomes gaseous, and fills the cavity, it expands, further enhancing heat transfer and buffering effects, effectively reducing thermal shock damage to the device components.

[0056] With the heat buffer component 25 in place, when the flue gas temperature is high, the heat-absorbing fins 255 absorb some heat and conduct it to the medium storage chamber 256. The medium in the medium storage chamber 256 absorbs heat and evaporates into gas, which fills the gas-filled heat-conducting film 258 through the gas flow chamber 257. This causes the gas-filled heat-conducting film 258 to expand and store the gaseous medium. When the flue gas temperature is low, the gaseous medium dissipates and condenses into liquid after dissipating heat. It is then absorbed back into the medium storage chamber 256 by the liquid-absorbing core plate 253, forming a cycle. Furthermore, when the gas-filled heat-conducting film 258 expands, even if the flue gas flow rate is small, the gas-filled heat-conducting film 258 can also compress the regulating component 26 to expand the heat absorption range. This helps with heat transfer and buffering, reducing the damage of thermal shock to the device components.

[0057] Reference Figure 4 - Figure 10 The adjustment component 26 includes multiple storage slots 263 opened inside the base frame 1. The inner wall of the storage slots 263 is fixedly connected to a telescopic spring 262. The tops of the multiple telescopic springs 262 are fixedly connected to a lifting plate 261. The outer wall of the lifting plate 261 is slidably connected to the inner wall of the waste heat recovery chamber 22.

[0058] With the adjustment component 26, when the boiler load is high, the flue gas flow is large, and a large amount of flue gas will squeeze the lifting plate 261, causing it to descend. The descent of the lifting plate 261 expands the heat absorption range, allowing more heat pipes to participate in the heat absorption process, ensuring that the heat in the flue gas can be fully absorbed, and preventing some heat from being discharged without being absorbed.

[0059] Reference Figure 3 The two ends of the waste heat recovery chamber 22 are respectively connected to the flue gas inlet pipe 21 and the flue gas outlet pipe 23. The inside of the flue gas outlet pipe 23 is connected to the auxiliary exhaust pipe 24, which is connected to the waste heat recovery chamber 22.

[0060] When the lifting plate 261 descends, the auxiliary exhaust pipe 24 will be exposed. The auxiliary exhaust pipe 24 guides the flue gas to flow evenly, avoids excessive local resistance, and ensures that the device can maintain stable exhaust resistance under different flue gas flow rates, thereby improving heat exchange efficiency.

[0061] Reference Figure 10 - Figure 11 The tube assembly 5 includes a second tube shell 54 fixedly connected to the inner wall of the middle section partition 3. A first tube shell 51 is slidably connected to the inner wall of the second tube shell 54. A heat exchange chamber 52 is formed between the second tube shell 54 and the first tube shell 51. A second sealing ring 55 is fixedly connected to the inner wall of the second tube shell 54. A first sealing ring 53 is fixedly connected to the outer wall of the first tube shell 51. The second tube shell 54 and the first tube shell 51 are sealed by the second sealing ring 55 and the first sealing ring 53. The inner wall of the sealing buffer chamber 251 is also provided with a plurality of through grooves 254. The inner walls of the plurality of through grooves 254 are slidably connected to the outer walls of the plurality of first tube shells 51 respectively. The bottom of the plurality of first tube shells 51 abuts against the top of the lifting plate 261.

[0062] Specifically, during operation, the heat absorbed from the flue gas generated by boiler combustion is conducted through the first shell 51 to the interior of the heat exchange chamber 52. The medium inside the heat exchange chamber 52 absorbs the heat and evaporates, storing the heat in gaseous form to prepare for the subsequent heat release process. To ensure the airtightness of the heat exchange chamber 52 and prevent medium leakage, a second sealing ring 55 is fixedly connected to the inner wall of the second shell 54, and a first sealing ring 53 is fixedly connected to the outer wall of the first shell 51. These two sealing rings fit tightly together, effectively preventing medium leakage and ensuring the high efficiency and stability of the heat exchange process.

[0063] As the lifting plate 261 descends via the tube assembly 5, the first tube shell 51 slides downward within the second tube shell 54, expanding the heat absorption range. The heat in the flue gas is conducted through the first tube shell 51 to the interior of the heat exchange chamber 52, causing the medium inside the heat exchange chamber 52 to evaporate. The gaseous medium carries the heat and rises to the second tube shell 54, preparing for the subsequent heat release process. After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber 52 under the action of gravity, forming a cyclic heat exchange process.

[0064] Reference Figure 2 - Figure 3 The heat dissipation assembly 4 includes a heat dissipation cavity 42 fixedly connected to the top of the middle section partition 3. Multiple heat dissipation fins 44 are fixedly connected to the inner wall of the heat dissipation cavity 42. The inner walls of the multiple heat dissipation fins 44 are fixedly connected to the outer walls of multiple second tube shells 54 respectively. The two ends of the heat dissipation cavity 42 are respectively connected to a cold air inlet pipe 41 and a hot air outlet pipe 43. The cold air inlet pipe 41 is located above the flue gas outlet pipe 23, and the hot air outlet pipe 43 is located above the flue gas inlet pipe 21.

[0065] Through the heat dissipation component 4, cold air is input into the heat dissipation chamber 42 through the cold air inlet pipe 41. The heat dissipation fins 44 in the heat dissipation chamber 42 are tightly connected to the second shell 54. The cold air exchanges heat with the second shell 54 through the heat dissipation fins 44, absorbing the heat in the gaseous medium. The flue gas after heat dissipation is discharged through the flue gas outlet pipe 23, while the cold air after heat absorption is discharged through the hot air outlet pipe 43, realizing the effective recovery and utilization of waste heat.

[0066] During operation, the flue gas generated by the marine boiler combustion is introduced into the waste heat recovery chamber 22 through the flue gas inlet pipe 21, providing a heat source for subsequent heat recovery. When the boiler load is low, the flue gas flow rate is small. At this time, only the upper half of the waste heat recovery chamber 22 absorbs heat through the heat pipes. The small heat absorption range is sufficient to complete the heat absorption, avoiding heat waste. When the boiler load is high, the flue gas flow rate is large. A large amount of flue gas will squeeze the lifting plate 261, causing it to descend. The descent of the lifting plate 261 expands the heat absorption range, allowing more heat pipes to participate in the heat absorption process, ensuring that the heat in the flue gas is fully absorbed and preventing some heat from being discharged without being absorbed. When the flue gas temperature is high, the heat buffer component 25 absorbs and stores some heat, preventing the heat pipe temperature from rising and falling sharply, and reducing heat loss. Impact; When the lifting plate 261 descends, the auxiliary exhaust pipe 24 will leak out. The auxiliary exhaust pipe 24 guides the flue gas to flow evenly, avoiding excessive local resistance, and ensuring that the device can maintain stable exhaust resistance under different flue gas flow rates, thereby improving heat exchange efficiency; Cold air is input into the heat dissipation chamber 42 through the cold air input pipe 41. The heat dissipation fins 44 in the heat dissipation chamber 42 are tightly connected to the second shell 54. The cold air exchanges heat with the second shell 54 through the heat dissipation fins 44, absorbing the heat in the gaseous medium. After the medium is heated, it condenses into a liquid and falls back to the bottom of the heat exchange chamber 52 under the action of gravity, forming a cycle of heat exchange process. The flue gas after heat release is discharged through the flue gas output pipe 23, while the cold air after heat absorption is discharged through the hot air output pipe 43, realizing the effective recovery and utilization of waste heat.

[0067] Example 2, refer to Figure 1 - Figure 12 The second embodiment of the present invention provides a method for recovering waste heat from boiler combustion flue gas using a waste heat recovery device, comprising the following steps:

[0068] Step 1: Introduce the flue gas generated by the marine boiler combustion into the waste heat recovery chamber 22 through the flue gas inlet pipe 21;

[0069] Step 2: When the boiler load is less than 1.5 tons / hour and the flue gas flow is low, heat is absorbed by the heat pipes only through the upper part of the waste heat recovery chamber 22.

[0070] Step 3: When the boiler load is higher than 1.5 tons / hour and the flue gas flow is high, the compression lifting plate 261 expands the heat absorption range;

[0071] Step 4: The heat buffer assembly 25 absorbs and stores some of the heat to prevent the heat pipe temperature from rising and falling sharply and to reduce thermal shock;

[0072] Step 5: When the lifting plate 261 descends, the auxiliary exhaust pipe 24 leaks out to guide the smoke to flow evenly and avoid excessive local resistance;

[0073] Step 6: The heat from the flue gas is conducted through the first tube shell 51 to the evaporating medium inside the heat exchange chamber 52, and the gaseous medium carries the heat to the second tube shell 54.

[0074] Step 7: Cold air is introduced through the cold air inlet pipe 41 and exchanges heat with the second pipe shell 54 through the heat dissipation fins 44;

[0075] Step 8: After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber 52 under the action of gravity;

[0076] Step 9: The released flue gas is discharged through the flue gas output pipe 23, and the absorbed cold air is discharged through the hot air output pipe 43.

[0077] Working principle of the invention:

[0078] During operation, the flue gas generated by the marine boiler combustion is introduced into the waste heat recovery chamber 22 through the flue gas inlet pipe 21 to provide a heat source for subsequent heat recovery.

[0079] When the boiler load is low, the flue gas flow rate is small. At this time, heat is absorbed by the heat pipe only through the upper half of the waste heat recovery chamber 22. Due to the presence of the extension spring 262, the lifting plate 261 abuts against the first tube shell 51, preventing the first tube shell 51 from sliding down and ensuring the initial heat absorption range. The initial small heat absorption range is sufficient to complete the heat absorption and avoid heat waste.

[0080] When the boiler load is high, the flow velocity and dynamic pressure of the flue gas in the waste heat recovery chamber 22 will increase significantly. A large amount of flue gas flows in the waste heat recovery chamber 22 and squeezes the lifting plate 261, causing it to descend. At the same time as the lifting plate 261 descends, the first tube shell 51 slides downward in the second tube shell 54, expanding the heat absorption range and allowing more heat pipes to participate in the heat absorption process, ensuring that the heat in the flue gas can be fully absorbed and avoiding the discharge of some heat without being absorbed.

[0081] When the temperature of the flue gas is high, the heat-absorbing fins 255 absorb some heat and conduct it to the medium storage cavity 256. The medium in the medium storage cavity 256 absorbs heat and evaporates into gas, which fills the gas-filled heat-conducting film 258 through the gas flow cavity 257. This causes the gas-filled heat-conducting film 258 to expand and store the gaseous medium. When the flue gas temperature is low, the gaseous medium dissipates heat and condenses into liquid, which is then absorbed by the liquid-absorbing core plate 253 and returned to the medium storage cavity 256, forming a cycle.

[0082] Furthermore, when the inflatable heat-conducting film 258 expands, even if the flue gas flow rate is small, the inflatable heat-conducting film 258 can squeeze the lifting plate 261 to expand the heat absorption range, thereby helping to transfer and buffer heat and reduce the damage of thermal shock to the device components.

[0083] When the lifting plate 261 descends, the auxiliary exhaust pipe 24 will be exposed. The auxiliary exhaust pipe 24 guides the flue gas to flow evenly, avoids excessive local resistance, and ensures that the device can maintain stable exhaust resistance under different flue gas flow rates, thereby improving heat exchange efficiency.

[0084] The heat in the flue gas is conducted through the first shell 51 to the heat exchange chamber 52, causing the medium inside the heat exchange chamber 52 to evaporate. The gaseous medium carries the heat and rises to the second shell 54, preparing for the subsequent heat release process. Cold air is introduced into the heat release chamber 42 through the cold air inlet pipe 41. The heat dissipation fins 44 inside the heat release chamber 42 are tightly connected to the second shell 54. The cold air exchanges heat with the second shell 54 through the heat dissipation fins 44, absorbing the heat in the gaseous medium and achieving waste heat recovery.

[0085] After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber 52 under the action of gravity, forming a cyclic heat exchange process. The flue gas that releases heat is discharged through the flue gas output pipe 23, while the cold air that absorbs heat is discharged through the hot air output pipe 43, thus realizing the effective recovery and utilization of waste heat.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A waste heat recovery device for boiler combustion flue gas, comprising a base frame (1), a heat absorption mechanism (2), a middle section partition (3), and a heat release assembly (4) sequentially fixedly installed on the top of the base frame (1), and a plurality of tube assemblies (5) disposed inside the heat absorption mechanism (2) and the heat release assembly (4), characterized in that: The heat absorption mechanism (2) includes a waste heat recovery chamber (22) fixedly installed on the top of the base frame (1), and the waste heat recovery chamber (22) is provided with a heat buffer assembly (25) and an adjustment assembly (26); The heat buffer assembly (25) includes a sealed buffer cavity (251) fixedly connected to the inner wall of the waste heat recovery cavity (22) and two limiting frames (252). The two limiting frames (252) are symmetrically arranged inside the sealed buffer cavity (251). A liquid-absorbing core plate (253) and multiple heat-absorbing fins (255) are fixedly connected between the two limiting frames (252). The tops of the multiple heat-absorbing fins (255) are all fixedly connected to the inner wall of the sealed buffer cavity (251). Adjacent two A medium storage cavity (256) is formed between the heat-absorbing fins (255). A gas flow cavity (257) is also provided inside the sealed buffer cavity (251). The gas flow cavity (257) is connected to the medium storage cavity (256). A plurality of gas-filled heat-conducting films (258) are fixedly connected to the bottom of the sealed buffer cavity (251). After the medium in the medium storage cavity (256) evaporates, it is guided to the inner surface of the gas-filled heat-conducting film (258) through the gas flow cavity (257).

2. The waste heat recovery device for boiler combustion flue gas according to claim 1, characterized in that: The adjustment assembly (26) includes multiple storage slots (263) opened inside the base frame (1). The inner wall of the storage slots (263) is fixedly connected with a telescopic spring (262). The tops of the multiple telescopic springs (262) are fixedly connected with a lifting plate (261). The outer wall of the lifting plate (261) is slidably connected to the inner wall of the waste heat recovery chamber (22).

3. The waste heat recovery device for boiler combustion flue gas according to claim 2, characterized in that: The two ends of the waste heat recovery chamber (22) are respectively connected to a flue gas inlet pipe (21) and a flue gas outlet pipe (23). An auxiliary exhaust pipe (24) is connected inside the flue gas outlet pipe (23), and the auxiliary exhaust pipe (24) is connected to the waste heat recovery chamber (22).

4. The waste heat recovery device for boiler combustion flue gas according to claim 3, characterized in that: The tube assembly (5) includes a second tube shell (54) fixedly connected to the inner wall of the middle section partition (3), and a first tube shell (51) is slidably connected to the inner wall of the second tube shell (54). A heat exchange cavity (52) is formed between the second tube shell (54) and the first tube shell (51).

5. The waste heat recovery device for boiler combustion flue gas according to claim 4, characterized in that: The inner wall of the second tube shell (54) is fixedly connected with a second sealing ring (55), and the outer wall of the first tube shell (51) is fixedly connected with a first sealing ring (53). The second tube shell (54) and the first tube shell (51) are sealed by the second sealing ring (55) and the first sealing ring (53).

6. The waste heat recovery device for boiler combustion flue gas according to claim 5, characterized in that: The inner wall of the sealed buffer cavity (251) is also provided with a plurality of through grooves (254), the inner walls of the plurality of through grooves (254) are slidably connected to the outer walls of the plurality of first tube shells (51), and the bottom of the plurality of first tube shells (51) abuts against the top of the lifting plate (261).

7. The waste heat recovery device for boiler combustion flue gas according to claim 6, characterized in that: The heat dissipation assembly (4) includes a heat dissipation cavity (42) fixedly connected to the top of the middle section partition (3). The inner wall of the heat dissipation cavity (42) is fixedly connected to a plurality of heat dissipation fins (44), and the inner walls of the plurality of heat dissipation fins (44) are respectively fixedly connected to the outer walls of a plurality of second tube shells (54).

8. The waste heat recovery device for boiler combustion flue gas according to claim 7, characterized in that: The two ends of the heat release chamber (42) are respectively connected to a cold air input pipe (41) and a hot air output pipe (43). The cold air input pipe (41) is located above the flue gas output pipe (23), and the hot air output pipe (43) is located above the flue gas input pipe (21).

9. A method for recovering waste heat from boiler combustion flue gas using a waste heat recovery device as described in claim 8, characterized in that, Includes the following steps: Step 1: Introduce the flue gas generated by the combustion of the marine boiler into the waste heat recovery chamber (22) through the flue gas inlet pipe (21); Step 2: When the boiler load is less than 1.5 tons / hour and the flue gas flow is low, heat is absorbed by the heat pipe only through the upper part of the waste heat recovery chamber (22); Step 3: When the boiler load is higher than 1.5 tons / hour and the flue gas flow is high, the lifting plate (261) is squeezed to expand the heat absorption range; Step 4: The heat buffer assembly (25) absorbs and stores some of the heat to prevent the heat pipe temperature from rising and falling sharply and to reduce thermal shock; Step 5: When the lifting plate (261) descends, the auxiliary exhaust pipe (24) leaks out to guide the flue gas to flow evenly and avoid excessive local resistance; Step 6: The heat from the flue gas is conducted through the first tube shell (51) to the evaporating medium inside the heat exchange chamber (52), and the gaseous medium carries the heat to the second tube shell (54); Step 7: Cold air is introduced through the cold air inlet pipe (41) and exchanges heat with the second pipe shell (54) through the heat dissipation fins (44); Step 8: After the medium absorbs heat, it condenses into a liquid and falls back to the bottom of the heat exchange chamber (52) under the action of gravity; Step 9: The flue gas after heat release is discharged through the flue gas output pipe (23), and the cold air after heat absorption is discharged through the hot air output pipe (43).

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