Anti-corrosion and anti-scale flue gas waste heat recovery device

Abstract

The invention provides an anti-corrosion and anti-scale flue gas waste heat recovery device which comprises a shell and a heat exchange tube bundle arranged in the shell, the heat exchange tube bundle is provided with a flue gas flow channel and a heat exchange working medium flow channel, the inner wall of the flue gas flow channel is provided with a nanometer hydrophobic and deashing coating, and the contact angle is larger than or equal to 120 degrees; the device further comprises a cleaning pipe and an air supply system, the cleaning pipe is arranged in the shell, a plurality of nozzles are arranged on the cleaning pipe, jet orifices of the nozzles extend into the flue gas flow channel, and an air inlet of the cleaning pipe is connected with the air supply system. According to the anti-corrosion and anti-scaling flue gas waste heat recovery device, a dual anti-scaling and anti-scaling mechanism of active protection and online cleaning is constructed, the problem of dust deposition-corrosion coupling degradation of a traditional device can be solved, the long-term stability of heat exchange efficiency is remarkably improved, the service life of equipment is prolonged, meanwhile, frequent shutdown maintenance is avoided, and the operation cost is greatly reduced.

Description

Technical Field

[0001] This application relates to the fields of energy conservation, environmental protection and thermal energy engineering technology, and more specifically, to a flue gas waste heat recovery device that is corrosion-resistant and scale-resistant. Background Technology

[0002] In industrial processes such as coal-fired power generation, biomass utilization, waste incineration, and chemical production, high-temperature flue gas carries a large amount of recoverable heat energy. Flue gas waste heat recovery devices, as core energy-saving and environmental protection equipment, can convert this heat energy into usable energy, reducing enterprise energy consumption and carbon emissions. Existing flue gas waste heat recovery devices mostly adopt finned tube, shell-and-tube, or coaxial tube heat exchanger structures, but they have the following prominent technical defects in actual operation: 1. The problem of ash and scale accumulation is prominent: fly ash, alkali metal salts, tar and acidic media contained in flue gas are prone to physical deposition and chemical reaction on the wall of low temperature heat exchange tubes, forming a dense and difficult-to-remove scale layer, which leads to a significant increase in heat transfer resistance, a continuous decline in waste heat recovery efficiency, and in severe cases, even blockage of heat exchange channels, forcing the equipment to shut down. 2. High dust cleaning and maintenance costs: Traditional equipment has a fixed structure and lacks online dust cleaning capability. It requires periodic shutdown for manual dust cleaning or high-pressure water washing, which not only interrupts the production process, but also has problems such as incomplete dust cleaning, high labor intensity, and long maintenance cycle, significantly increasing operating costs. 3. Significant contradiction between corrosion and economy: Acidic media in flue gas can easily cause corrosion to heat exchange tubes. Ordinary carbon steel has poor corrosion resistance and short service life, while stainless steel or corrosion-resistant alloy materials can improve corrosion resistance, but the material cost is high and it is difficult to promote and apply on a large scale. 4. Lack of active protection and intelligent adaptation: Existing technologies such as ND steel materials and enamel coatings can only alleviate corrosion or ash accumulation problems individually, and cannot solve the problem of "corrosion-ash accumulation" coupled deterioration. Furthermore, they lack intelligent monitoring and active cleaning triggering mechanisms, making it difficult to adapt to flue gas parameter fluctuation scenarios, resulting in unstable protection effects. Summary of the Invention

[0003] This application provides at least one anti-corrosion and anti-scaling flue gas waste heat recovery device, which constructs a dual anti-scaling and anti-corrosion mechanism of "active protection + online cleaning". It can solve the problem of "ash accumulation-corrosion" coupled deterioration faced by traditional devices, significantly improve the long-term stability of heat exchange efficiency, extend equipment life, and avoid frequent shutdown maintenance, thereby greatly reducing operating costs.

[0004] This application provides a corrosion-resistant and scale-resistant flue gas waste heat recovery device. The device includes a shell and a heat exchange tube bundle disposed within the shell. The heat exchange tube bundle has a flue gas flow channel and a heat exchange working fluid flow channel. The inner wall of the flue gas flow channel is provided with a nano-hydrophobic and dust-repellent coating with a contact angle ≥120°. The device also includes a cleaning pipe and a gas supply system. The cleaning pipe is disposed within the shell and has multiple nozzles. The nozzles extend into the flue gas flow channel, and the gas inlet of the cleaning pipe is connected to the gas supply system.

[0005] In one alternative embodiment, the cleaning tube extends axially along the heat exchange tube bundle, and the nozzles are spaced apart axially along the cleaning tube.

[0006] In one alternative embodiment, the cleaning tube is mounted to the housing via a fixing assembly.

[0007] In one optional embodiment, the fixing component includes a mounting base and a first clamp, the mounting base being mounted on the housing, the first clamp being disposed on the mounting base, and the cleaning tube passing through the first clamp.

[0008] In one optional embodiment, the mounting base is a T-shaped support plate, and the mounting base is configured to be fixed to the housing by bolts.

[0009] In one optional embodiment, the fixing component further includes a second clamp connected between the mounting base and the first clamp, and the heat exchange tube bundle passes through the second clamp.

[0010] In one optional embodiment, the gas supply system includes a gas storage tank, a solenoid valve, and an air compressor. The outlet of the gas storage tank is connected to the inlet of the cleaning pipe. The solenoid valve is located at the outlet of the gas storage tank or the inlet of the cleaning pipe. The air compressor is connected to the inlet of the gas storage tank and is used to supply high-pressure gas to the gas storage tank.

[0011] In an optional embodiment, the device further includes an intelligent control system, which includes a first temperature sensor, a second temperature sensor, and a controller. The first temperature sensor and the second temperature sensor are respectively disposed at the flue gas inlet and flue gas outlet of the flue gas duct, and are used to collect the flue gas inlet and flue gas outlet temperatures in real time. The controller is communicatively connected to the first temperature sensor and the second temperature sensor and is configured to calculate the temperature difference between the flue gas inlet and the flue gas outlet, and control the start and stop of the gas supply system according to the temperature difference.

[0012] In one alternative implementation, the controller is specifically configured to start the gas supply system when the temperature difference between the flue gas inlet and the flue gas outlet is lower than a set threshold.

[0013] The above-mentioned technical solution of this application has the following beneficial technical effects: The anti-corrosion and anti-scaling flue gas waste heat recovery device of this application integrates a cleaning pipe connected to the inside of the flue gas duct and the gas supply system on the heat exchange tube bundle, and combines it with a highly hydrophobic nano-coating on the inner wall of the inner tube to construct a dual anti-scaling and anti-corrosion mechanism of "active protection + online cleaning". Its beneficial effects are twofold: firstly, the nano-hydrophobic and ash-repellent coating with a contact angle ≥120° significantly reduces the adhesion and wettability of pollutants such as fly ash and tar in the flue gas to the core heat exchange surface (inner wall of the inner tube) from the source, delaying the occurrence of ash accumulation, scaling, and corrosion; secondly, when the heat exchange efficiency is detected to decrease due to ash accumulation, the intelligent system can automatically trigger high-pressure gas to precisely purge through nozzles, removing the deposits online without interrupting operation. The synergistic effect of these two mechanisms fundamentally solves the "ash accumulation-corrosion" coupled degradation problem faced by traditional devices, significantly improving the long-term stability of heat exchange efficiency, extending equipment life, and avoiding frequent downtime for maintenance, thus greatly reducing operating costs.

[0014] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this application and, together with the specification, serve to explain the technical solutions of this application. It should be understood that the following drawings only show some embodiments of this application and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This illustration shows a structural schematic diagram of a corrosion-resistant and scale-resistant flue gas waste heat recovery device provided in an embodiment of this application; Figure 2 It shows Figure 1 Internal assembly diagram; Figure 3 It shows Figure 2 A cross-sectional view of the heat exchanger tube bundle in the middle; Figure 4 It shows Figure 2 A schematic diagram of the cleaning tube in the diagram; Figure 5 It shows Figure 2 A magnified view of part A in the image; Figure 6 It shows Figure 5 Schematic diagram of the structure of the fixed component; In the diagram: 1. Shell; 11. Insulation layer; 12. Door panel; 2. Heat exchange tube bundle; 21. Inner tube; 22. Outer tube; 23. Water inlet; 24. Water outlet; 3. Cleaning pipe; 31. Nozzle; 32. Air inlet; 4. Fixing assembly; 41. Mounting base; 42. First clamp; 43. Second clamp. Detailed Implementation

[0017] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0018] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0019] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0020] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] refer to Figures 1 to 6 This application provides a corrosion-resistant and scale-resistant flue gas waste heat recovery device. The device includes a shell 1 and a heat exchange tube bundle 2 disposed within the shell 1. An insulation layer 11, which can be foam, is provided on the inner wall of the shell 1. An openable and closable sealing door 12 is installed at the open end of the shell 1 via a hinge or latch, and a U-shaped handle is fixedly installed on the sealing door 12. The heat exchange tube bundle 2 has a flue gas flow channel and a heat exchange medium flow channel. During use, high-temperature flue gas flows through the flue gas flow channel and exchanges heat with the heat exchange medium (such as water) flowing through the heat exchange medium flow channel, thereby realizing the recovery of flue gas waste heat.

[0023] Optionally, the heat exchange tube bundle 2 has an inclined angle within the shell 1. For example, the heat exchange tube bundle 2 gradually slopes downwards at 10-45° from the flue gas inlet to the flue gas outlet, so that the flue gas can carry away as much dust as possible from the flue gas flow channel when flowing through the tube bundle. Of course, when cleaning the scale in the flue gas flow channel, the cleaned dust can also slide down along the flue gas flow channel.

[0024] Optionally, the heat exchanger tube bundle 2 is composed of an inner tube 21 and an outer tube 22. For example, the inner cavity of the inner tube 21 is used for the flow of high-temperature flue gas, and the annular flow channel formed between the inner tube 21 and the outer tube 22 is used for the flow of the heat exchange working fluid, which exchanges heat with the high-temperature flue gas in the inner tube 21. During operation, the high-temperature flue gas flows in the inner tube 21, while the heat exchange working fluid (such as water, heat transfer oil, etc.) flows in the same or opposite direction in the annular flow channel between the inner and outer tubes 22. The heat of the high-temperature flue gas is transferred to the working fluid in the annular flow channel through the tube wall of the inner tube 21, achieving efficient heat exchange. The heat exchanger tube bundle 2 designed in this way has a compact structure, a large heat exchange area per unit volume, and high heat transfer efficiency. Moreover, the annular flow channel design makes the working fluid flow uniform and the boundary layer thin, further enhancing heat transfer. Most importantly, this structure structurally separates the flue gas side (inner wall of inner tube 21) which is subject to high temperature, corrosion and ash accumulation risks from the pressurized working fluid side (annular flow channel), allowing the selection of the most economical material combination for different working conditions (such as using corrosion-resistant and high-temperature-resistant materials for inner tube 21 and pressure-resistant materials for outer tube 22). While ensuring safety and service life, it effectively controls manufacturing costs and resolves the contradiction between "corrosion resistance" and "economy" faced by a single material.

[0025] Optionally, the outer tube 22 is provided with an inlet 23 and an outlet 24 at both ends. Specifically, the inlet 23 is located at the end of the outer tube 22 closest to the flue gas outlet, and the outlet 24 is located at the end of the outer tube 22 closest to the flue gas inlet. During operation, cold water enters the annular flow channel formed between the inner tube 21 and the outer tube 22 through the inlet 23, and exchanges heat counter-currently with the high-temperature flue gas flowing inside the inner tube 21. The hot water after heat exchange is discharged from the outlet 24. In other words, the heat exchange tube bundle 2 adopts a jacketed counter-current heat exchange structure with an inner tube 21 and an outer tube 22, which maximizes the heat exchange temperature difference and improves waste heat recovery efficiency.

[0026] Optionally, the inner wall of the flue gas duct (i.e., inner tube 21) is coated with a nano-hydrophobic and ash-repellent coating with a contact angle ≥120°. For example, the nano-hydrophobic and ash-repellent coating is a SiO2-TiO2 composite sol-gel coating. This coating can significantly reduce the adhesion of fly ash and tar in the flue gas to the tube wall, reducing the initial formation of ash and scale. At the same time, it has good high-temperature resistance and corrosion resistance, and can block the corrosion of the tube material by acidic flue gas, solving the "corrosion-ash accumulation" coupled deterioration problem from the source. Compared with traditional devices, the heat exchange efficiency decay rate is reduced by more than 60%, and the service life of the tube material is extended. On this basis, the heat exchange tube material can be ordinary carbon steel. Compared with the all-stainless steel solution, the combination of ordinary carbon steel base + nano-coating reduces the material cost by more than 50%, balancing corrosion resistance and economy.

[0027] Optionally, the device also includes a cleaning pipe 3 and an air supply system (not shown in the figure). The cleaning pipe 3 is disposed inside the housing 1 and is equipped with multiple nozzles 31. The nozzles 31 extend into the flue gas flow channel (i.e., the nozzles pass through the outer pipe 22 and are connected to the inner cavity of the inner pipe 21), and the air inlet 32 ​​of the cleaning pipe 3 is connected to the air supply system. During the operation of the device, the flue gas exchanges heat with the heat exchange tube bundle 2. When the inner wall of the inner pipe 21 shows a tendency to accumulate ash and scale, high-pressure gas is supplied to the cleaning pipe 3 through the air supply system. The high-pressure gas is injected at high speed into the flue gas flow channel through the nozzles 31, directly impacting and blowing away the ash accumulation on the inner wall of the inner pipe 21, achieving online cleaning without shutting down the machine. This design, by setting up the cleaning pipe 3 and the air supply system, realizes active, online cleaning of the heat exchange tube bundle 2, effectively reducing ash and scale accumulation, avoiding the problem of decreased heat transfer efficiency and channel blockage caused by ash accumulation, and reducing the frequency of shutdown for cleaning and maintenance costs.

[0028] Optionally, the cleaning pipe 3 extends along the axial direction of the heat exchange tube bundle 2, and the nozzles 31 are spaced apart along the axial direction of the cleaning pipe 3. During use, high-pressure gas can be sprayed synchronously or sequentially from multiple axially distributed nozzles 31, which can cover the entire length of the heat exchange tube bundle 2, ensuring the uniformity and comprehensiveness of the cleaning, avoiding local cleaning dead corners, and improving the overall dust removal effect and efficiency.

[0029] Optionally, the cleaning pipe 3 is installed on the housing 1 by means of the fixing component 4. The fixing component 4 is used to position and fix the cleaning pipe 3, which can keep the cleaning pipe 3 stable during operation, ensure the structural stability of the cleaning pipe 3 and the nozzle 31 under the flushing of flue gas and the reaction force of high pressure gas, prevent displacement or vibration, and ensure the reliability of the cleaning effect and the stability of the device operation.

[0030] Optionally, the fixing component 4 includes a mounting base 41 and a first clamp 42. The mounting base 41 is mounted on the housing 1, and the first clamp 42 is disposed on the mounting base 41. The cleaning tube 3 passes through the first clamp 42. During installation, the mounting base 41 is fixed to the housing 1, and the first clamp 42 is used to hold the cleaning tube 3 tightly. This design provides a simple, robust, and reliable installation method, facilitating the installation, disassembly, and maintenance of the cleaning tube 3, while ensuring connection strength.

[0031] Optionally, the mounting base 41 is a T-shaped support plate, which is fixed to the inner cavity bottom wall of the housing 1 by bolts. In use, the T-shaped structure can provide good support strength and stability, and the bolts can be used to fasten the T-shaped support plate to the housing 1, which facilitates on-site installation and adjustment, and enhances the flexibility and reliability of installation.

[0032] Optionally, the fixing assembly 4 also includes a second clamp 43, which is connected between the mounting base 41 and the first clamp 42, and the heat exchange tube bundle 2 passes through the second clamp 43. In use, the fixing assembly 4 can connect the cleaning tube 3 and the heat exchange tube bundle 2 into one unit, realizing the relative fixation of the cleaning tube 3 and the heat exchange tube bundle 2, further enhancing the stability of the overall structure, and may also simplify the internal support structure, which is beneficial for resisting vibration and thermal stress.

[0033] Optionally, the air supply system includes an air tank, a solenoid valve, and an air compressor. The outlet of the air tank is connected to the inlet 32 ​​of the cleaning pipe 3. The solenoid valve is located at the outlet of the air tank or the inlet 32 ​​of the cleaning pipe 3 (used to control the opening and closing of the cleaning pipe 3 to achieve timed or on-demand dust removal). The air compressor is connected to the inlet of the air tank to provide high-pressure gas (pressure range 0.6-1.0MPa) to the air tank. During operation, the air compressor continuously or intermittently charges the air tank with energy. When dust removal is required, the controller (or manually) opens the solenoid valve, and the high-pressure gas in the air tank is rapidly released into the cleaning pipe 3. The instantaneous high-flow-rate high-pressure gas provided by the air tank can ensure the intensity and suddenness of the dust removal and improve the dust removal effect.

[0034] Optionally, the device also includes an intelligent control system (not shown in the figure). The intelligent control system includes a first temperature sensor, a second temperature sensor, and a controller (PLC). The first and second temperature sensors are respectively installed at the flue gas inlet and outlet of the flue gas duct to collect the flue gas inlet and outlet temperatures in real time. The controller is communicatively connected to the first and second temperature sensors and is configured to calculate the temperature difference between the flue gas inlet and outlet, and control the start and stop of the gas supply system based on the temperature difference. During operation, the controller monitors the temperature difference changes in real time. When the temperature difference decreases due to ash accumulation, it automatically determines and triggers the ash removal action. This design realizes intelligent monitoring and automatic control of ash removal based on thermal performance (heat transfer temperature difference), making the ash removal operation more scientific, timely, and efficient, avoiding the blindness of ash removal based on experience or timed ash removal, and saving gas consumption while ensuring effectiveness.

[0035] Optionally, the controller is specifically configured to start the gas supply system when the temperature difference between the flue gas inlet and outlet is lower than a set threshold. Specifically, the controller calculates the temperature difference between the flue gas inlet and outlet to determine the degree of ash and scale buildup in the heat exchange tube bundle 2. When the temperature difference is lower than the set threshold, it can automatically trigger the solenoid valve to open and start the soot blowing process, thereby achieving intelligent and precise ash cleaning and avoiding ineffective ash cleaning and energy waste.

[0036] In practical use: 1. Heat exchange operation process High-temperature industrial flue gas (200-400℃) enters the inner tube 21 through the flue gas inlet and flows towards the flue gas outlet. Simultaneously, cold water enters the annular flow channel formed between the inner tube 21 and the outer tube 22 through the water inlet 23, where it exchanges heat counter-currently with the high-temperature flue gas inside the inner tube 21. After absorbing heat, the cold water heats up to 80-120℃ and is discharged from the water outlet 24 for subsequent use. The high-temperature flue gas, after heat exchange, cools down to 80-120℃ and is discharged from the flue gas outlet, completing the waste heat recovery process. The nano-coating on the inner wall of the inner tube 21 reduces the adhesion of fly ash and tar in the flue gas, delaying the formation of scale and deposits.

[0037] 2. Intelligent dust removal process During operation, the first and second temperature sensors collect the flue gas inlet and outlet temperatures in real time and transmit the data to the controller. When the heat exchange efficiency decreases due to ash and scale buildup on the inner wall of the inner tube 21 and the temperature difference between the flue gas inlet and outlet falls below the set threshold of 50°C, the controller automatically starts the cleaning program, controls the solenoid valve to open, and the 0.8MPa high-pressure gas in the gas storage tank enters the cleaning pipe 3 through the conduit, and then impacts the inner wall of the inner tube 21 in a fan-shaped spray pattern through the nozzle 31, blowing off the attached ash and scale. Due to the inclined setting of the heat exchange tube bundle 2, the blown-off dust can be discharged to the outside of the shell 1 along the flue gas flow channel. After the 30-second cleaning is completed, the solenoid valve closes, and the controller continues to monitor the temperature difference. If the temperature difference rises above the threshold, the device resumes normal heat exchange. If the temperature difference is still below the threshold, the cleaning can be repeated once to ensure the cleaning effect.

[0038] The anti-corrosion and anti-scaling flue gas waste heat recovery device of this application integrates a cleaning pipe connected to the inside of the flue gas duct and the gas supply system on the heat exchange tube bundle, and combines it with a highly hydrophobic nano-coating on the inner wall of the inner tube to construct a dual anti-scaling and anti-corrosion mechanism of "active protection + online cleaning". Its beneficial effects are twofold: firstly, the nano-hydrophobic and ash-repellent coating with a contact angle ≥120° significantly reduces the adhesion and wettability of pollutants such as fly ash and tar in the flue gas to the core heat exchange surface (inner wall of the inner tube) from the source, delaying the occurrence of ash accumulation, scaling, and corrosion; secondly, when the heat exchange efficiency is detected to decrease due to ash accumulation, the intelligent system can automatically trigger high-pressure gas to precisely purge through nozzles, removing the deposits online without interrupting operation. The synergistic effect of these two mechanisms fundamentally solves the "ash accumulation-corrosion" coupled degradation problem faced by traditional devices, significantly improving the long-term stability of heat exchange efficiency, extending equipment life, and avoiding frequent downtime for maintenance, thus greatly reducing operating costs.

[0039] One or more embodiments in this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this specification should be included within the protection scope of this application.

[0040] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A corrosion-resistant and scale-resistant flue gas waste heat recovery device, the device comprising a shell and a heat exchange tube bundle disposed within the shell, the heat exchange tube bundle having a flue gas flow channel and a heat exchange working fluid flow channel, characterized in that, The inner wall of the flue gas duct is provided with a nano-hydrophobic and dust-repellent coating with a contact angle ≥120°; the device also includes a cleaning pipe and an air supply system. The cleaning pipe is disposed inside the housing and is provided with multiple nozzles. The nozzles extend into the flue gas duct, and the air inlet of the cleaning pipe is connected to the air supply system.

2. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 1, characterized in that, The cleaning tube extends axially along the heat exchange tube bundle, and the nozzles are spaced apart axially along the cleaning tube.

3. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 1, characterized in that, The cleaning tube is mounted to the housing via a fixing assembly.

4. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 3, characterized in that, The fixing component includes a mounting base and a first clamp. The mounting base is installed on the housing, the first clamp is disposed on the mounting base, and the cleaning tube passes through the first clamp.

5. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 4, characterized in that, The mounting base is a T-shaped support plate, and the mounting base is configured to be fixed to the housing by bolts.

6. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 4, characterized in that, The fixing component also includes a second clamp, which is connected between the mounting base and the first clamp, and the heat exchange tube bundle passes through the second clamp.

7. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 1, characterized in that, The gas supply system includes a gas storage tank, a solenoid valve, and an air compressor. The outlet of the gas storage tank is connected to the inlet of the cleaning pipe. The solenoid valve is located at the outlet of the gas storage tank or the inlet of the cleaning pipe. The air compressor is connected to the inlet of the gas storage tank and is used to supply high-pressure gas to the gas storage tank.

8. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 1, characterized in that, The device also includes an intelligent control system, which includes a first temperature sensor, a second temperature sensor, and a controller. The first temperature sensor and the second temperature sensor are respectively installed at the flue gas inlet and flue gas outlet of the flue gas flow channel to collect the flue gas inlet and flue gas outlet temperatures in real time. The controller is communicatively connected to the first temperature sensor and the second temperature sensor and is configured to calculate the temperature difference between the flue gas inlet and the flue gas outlet and control the start and stop of the gas supply system based on the temperature difference.

9. The anti-corrosion and anti-scaling flue gas waste heat recovery device according to claim 8, characterized in that, The controller is specifically configured to start the gas supply system when the temperature difference between the flue gas inlet and the flue gas outlet is lower than a set threshold.

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