A fuel oil boiler exhaust duct

Abstract

The utility model provides a kind of fuel oil boiler discharge pipeline, belong to waste gas emission technical field, this fuel oil boiler discharge pipeline includes: main discharge pipe body, exhaust regulating valve, support fixing frame, sealing connection component, condensing separator and anticorrosive coating;The main discharge pipe body is cylindrical barrel structure, the inner diameter of main discharge pipe body is 300 millimeters to 800 millimeters, wall thickness is 8 millimeters to 15 millimeters, main discharge pipe body is made of heat -resistant stainless steel material;One end of main discharge pipe body is equipped with gas inlet, the geometric center of gas inlet coincides with the axis of main discharge pipe body, gas inlet is fixedly connected with boiler discharge port by flange connection mode;Another end of main discharge pipe body is equipped with gas outlet, exhaust regulating valve is installed at gas outlet, exhaust regulating valve includes shaft and adjusting blade, adjusting blade is located inside main discharge pipe body, the utility model can solve the technical problem of low heat dissipation efficiency in prior art fuel oil boiler discharge pipeline.

Description

Technical Field

[0001] This utility model belongs to the field of exhaust gas emission technology, and specifically relates to an exhaust pipe for an oil-fired boiler. Background Technology

[0002] Oil-fired boilers are crucial equipment for industrial and residential heating, widely used in petrochemical, chemical, power, and heating industries. During combustion, these boilers produce large amounts of high-temperature exhaust gases containing water vapor, carbon dioxide, nitrogen oxides, and other components, requiring safe release into the atmosphere through a dedicated exhaust piping system. Existing oil-fired boiler exhaust piping systems primarily employ a straight-cylinder structure with a smooth inner surface, allowing for straight-line gas flow. However, in practical applications, existing exhaust piping systems suffer from several technical drawbacks: First, low heat dissipation efficiency. Due to the limited outer surface area of ​​the pipe, the high-temperature exhaust gases have a short residence time within the pipe, resulting in insufficient heat dissipation and excessively high outlet temperatures. This not only wastes significant thermal energy but also causes thermal pollution to the surrounding environment. Furthermore, the high temperature accelerates the aging and deformation of the pipe materials. Second, high flow resistance. While traditional straight-cylinder pipes offer a simple flow path, the exhaust gases easily form eddies and turbulence within the pipe, particularly at bends and connections, where flow resistance increases significantly, affecting exhaust efficiency and increasing boiler operating energy consumption. The most serious problem is insufficient condensate separation. During the cooling process of high-temperature exhaust gases within the pipeline, a large amount of condensate is generated. Existing pipelines lack effective moisture separation devices, causing the condensate to form a water film on the inner wall of the pipe. This film combines with acidic components in the exhaust gas to form a corrosive liquid, leading to severe corrosion of the pipe's inner wall over time, shortening its service life, and increasing maintenance costs. Current industry solutions mainly include passive protection measures such as increasing pipe wall thickness, using corrosion-resistant materials, and regularly replacing pipes. However, these methods cannot fundamentally solve the problems of heat dissipation, resistance, and corrosion, and significantly increase construction and operating costs. Utility Model Content

[0003] In view of this, the present invention provides a fuel oil boiler exhaust pipe that can solve the technical problems of low heat dissipation efficiency, high flow resistance of exhaust gas, and severe internal corrosion of fuel oil boiler exhaust pipes due to insufficient condensate separation in the prior art.

[0004] This utility model is implemented as follows: This utility model provides a fuel oil boiler exhaust pipe, comprising: a main exhaust pipe body, an exhaust regulating valve, a support bracket, a sealing connection assembly, a condensate separator, and an anti-corrosion coating; the main exhaust pipe body is a cylindrical structure with an inner diameter of 300 mm to 800 mm and a wall thickness of 8 mm to 15 mm, and is made of heat-resistant stainless steel; one end of the main exhaust pipe body is provided with an air inlet, the geometric center of which coincides with the axis of the main exhaust pipe body, and the air inlet is fixedly connected to the boiler exhaust port via a flange connection; the main exhaust pipe body... The other end is provided with an air outlet, and an exhaust regulating valve is installed at the air outlet. The exhaust regulating valve includes a rotating shaft and an adjusting blade. The adjusting blade is located inside the main exhaust pipe body. The geometric center of the adjusting blade is rotatably connected to the main exhaust pipe body through the rotating shaft. The axis of the rotating shaft is perpendicular to the axis of the main exhaust pipe body. The rotation of the adjusting blade realizes the adjustment of the exhaust volume. The support frame includes a base and columns. The base is a rectangular plate structure. The columns are vertically fixed on the base. There are 4 columns. The 4 columns are distributed in a rectangle on the base. The columns are fixed and supported by U-shaped clamps around the outer wall of the main exhaust pipe body.

[0005] The technical advantages of this utility model for a fuel-fired boiler exhaust pipe are as follows: The cylindrical structure of the main exhaust pipe ensures smooth gas flow, and the inner diameter range of 300 mm to 800 mm meets the exhaust requirements of boilers with different power ratings. The exhaust regulating valve achieves precise control of the exhaust volume by adjusting the rotation of the blades around the axis, effectively regulating the exhaust pressure and flow rate. The support frame adopts a four-column rectangular distribution structure, fixed by U-shaped clamps, providing stable support and good seismic performance. The sealing connection assembly ensures a reliable sealing connection with the boiler exhaust port. The condensate separator effectively separates moisture from the exhaust gas, preventing internal corrosion of the pipe. The anti-corrosion coating extends the overall service life of the equipment and reduces maintenance costs.

[0006] Based on the above technical solution, the exhaust pipe of the oil-fired boiler of this utility model can be further improved as follows: The sealing connection assembly includes a sealing ring and fastening bolts. The sealing ring has an annular structure, and its inner diameter matches the outer diameter of the main discharge pipe. The sealing ring is made of high-temperature resistant silicone material. The sealing ring is installed at the connection between the air inlet and the boiler discharge port. The upper surface of the sealing ring is in contact with the end face of the air inlet, and the lower surface of the sealing ring is in contact with the end face of the boiler discharge port. There are eight fastening bolts, which are evenly distributed along the circumference of the sealing ring. The fastening bolts pass through the flange connection holes to achieve a sealing connection.

[0007] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The sealing ring is made of high-temperature resistant silicone material, which has excellent heat resistance and sealing performance. Its precise matching design with the outer diameter of the main discharge pipe ensures a tight seal at the connection. The design of eight fastening bolts evenly distributed along the circumference ensures uniform distribution of sealing pressure, avoiding localized stress concentration and improving the reliability and durability of the connection. The design of the upper and lower surfaces of the sealing ring respectively fitting against the inlet and boiler outlet faces forms a double sealing protection, effectively preventing leakage of high-temperature exhaust gas and ensuring the safe operation of the system.

[0008] Furthermore, the condenser separator is installed in the middle section of the main discharge pipe. The condenser separator includes a separation chamber and a drain pipe. The separation chamber has a cylindrical structure, and its axis is perpendicular to the axis of the main discharge pipe. The separation chamber is connected to the side wall of the main discharge pipe through a connecting flange. A drain outlet is provided at the bottom of the separation chamber. One end of the drain pipe is threaded to the drain outlet, and the other end of the drain pipe extends to the outside of the main discharge pipe. The drain pipe has an L-shaped bending structure with a bending angle of 90 degrees. The drain pipe is made of carbon steel.

[0009] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The cylindrical separation chamber design of the condensate separator, with its axis perpendicular to the axis of the main discharge pipe, utilizes the principle of gravity separation, allowing condensate in the exhaust gas to naturally settle to the bottom of the separation chamber. The L-shaped curved drain pipe design, with a 90-degree bend angle, effectively prevents backflow of external air while ensuring smooth drainage of condensate. The drain pipe is made of carbon steel, possessing good corrosion resistance and mechanical strength. The threaded connection achieves the design goal of easy maintenance and replacement, effectively extending the service life of the condensate separator.

[0010] Furthermore, the adjusting blade has an elliptical plate-like structure, with a major axis length of 200 mm to 400 mm, a minor axis length of 150 mm to 300 mm, and a thickness of 5 mm to 10 mm. The major axis of the adjusting blade is perpendicular to the rotating shaft, and the adjusting blade is fixed to the rotating shaft by welding. Both ends of the rotating shaft are installed inside the side walls of the main discharge pipe body through bearings. The rotating shaft is made of stainless steel and has a diameter of 20 mm to 30 mm.

[0011] The beneficial effects of adopting the above-mentioned improved design are as follows: The elliptical plate-like structure design of the regulating blades, with a major axis ranging from 200 mm to 400 mm and a minor axis ranging from 150 mm to 300 mm, provides moderate flow resistance and good regulating performance. The blade thickness of 5 mm to 10 mm ensures sufficient mechanical strength and resistance to deformation. The design of the regulating blades' major axis being perpendicular to the rotating shaft allows the blades to generate maximum flow regulation effect during rotation. The rotating shaft diameter of 20 mm to 30 mm ensures sufficient torsional strength, and the bearing mounting within the side walls of the main discharge pipe achieves smooth rotation, reduces operating torque, and improves regulating accuracy and service life.

[0012] Furthermore, the inner surface of the main discharge pipe is provided with a spiral guide groove, which is spirally distributed along the axial direction of the main discharge pipe. The spiral angle of the spiral guide groove is 15 degrees to 45 degrees, the depth of the spiral guide groove is 3 mm to 8 mm, and the width of the spiral guide groove is 10 mm to 20 mm.

[0013] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The spiral guide groove design on the inner surface of the main discharge pipe, with a spiral angle of 15 to 45 degrees, creates a spiral flow state for the discharged gas within the pipe, enhancing the gas mixing effect and improving heat transfer efficiency. The spiral guide groove's dimensions of 3 to 8 mm depth and 10 to 20 mm width enhance the guiding effect while avoiding excessive flow resistance. The spiral flow state allows for more thorough contact between the gas and the pipe wall, effectively improving heat exchange efficiency. Simultaneously, the centrifugal force generated by the spiral flow helps concentrate particulate matter and moisture in the gas towards the pipe wall, facilitating subsequent separation and treatment, and improving the purification effect of the discharged gas.

[0014] Furthermore, the support frame also includes adjusting shims and shock-absorbing pads. The adjusting shims are installed between the base and the ground. There are four adjusting shims, which are located at the four corners of the base. The adjusting shims have a circular plate-like structure and a diameter of 80 mm to 120 mm. The adjusting shims are made of rubber material. The shock-absorbing pads are installed between the U-shaped clamp and the main discharge pipe. The shock-absorbing pads have a ring-shaped structure and the inner diameter of the shock-absorbing pads matches the outer diameter of the main discharge pipe. The shock-absorbing pads are made of polyurethane material.

[0015] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The adjusting shims are made of rubber material, with a circular plate structure ranging from 80 mm to 120 mm in diameter, and are installed at the four corners of the base, effectively adjusting the levelness of the support frame and adapting to the installation requirements of different ground conditions. The shock-absorbing pads are made of polyurethane material and are installed between the U-shaped clamps and the main discharge pipe. Their annular structure precisely matches the outer diameter of the main discharge pipe, effectively absorbing and mitigating the vibration and impact generated during the operation of the discharge pipeline, reducing noise levels. The polyurethane material has excellent elasticity and wear resistance, ensuring the stability of the shock absorption effect during long-term use and extending the service life of the overall equipment.

[0016] Furthermore, the outer surface of the main discharge pipe is provided with multiple heat dissipation protrusions, which are conical in shape, with a height of 10 mm to 25 mm and a bottom diameter of 15 mm to 30 mm.

[0017] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: Multiple conical heat dissipation protrusions, with a height of 10 mm to 25 mm and a base diameter of 15 mm to 30 mm, are designed on the outer surface of the main discharge pipe, significantly increasing the heat dissipation area of ​​the outer surface. The conical structure has excellent aerodynamic characteristics, effectively enhancing heat dissipation under both natural and forced convection conditions. The placement of the heat dissipation protrusions makes the surface temperature distribution of the pipe more uniform, avoiding localized overheating, effectively reducing the operating temperature of the pipe, reducing the impact of thermal stress on the pipe material, improving the reliability and service life of the equipment, and simultaneously reducing the impact of thermal radiation from the surrounding environment.

[0018] Compared with existing technologies, the beneficial effects of this utility model for an exhaust pipe of an oil-fired boiler are as follows: This utility model, through the innovative design of a spiral guide groove on the inner surface of the main exhaust pipe, enables the exhaust gas to form a stable spiral flow state within the pipe, significantly reducing flow resistance and improving exhaust efficiency. The centrifugal force generated by the spiral flow effectively promotes the separation of condensate in the gas. Combined with a specially designed condensate separator, this achieves thorough separation and discharge of moisture, fundamentally solving the problem of internal pipe corrosion. The spirally arranged heat dissipation protrusions on the outer surface of the main exhaust pipe, together with the internal spiral guide groove, form a synergistic heat transfer structure, greatly improving heat dissipation efficiency and effectively reducing the pipe's operating temperature. The exhaust regulating valve adopts an elliptical regulating blade design, achieving precise control of the exhaust volume and minimizing flow resistance. The support frame is equipped with shock-absorbing pads and adjusting shims, effectively absorbing operating vibrations and adapting to different installation conditions. The sealing connection components use high-temperature resistant silicone material and a multi-bolt evenly distributed design, ensuring reliable connection and sealing. The overall solution, through the synergistic effect of structural optimization and material selection, achieves comprehensive technical effects of efficient exhaust, reliable sealing, sufficient heat dissipation, and long-term stable operation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view of the exhaust pipe of an oil-fired boiler. Figure 2 A side view of the exhaust pipe of an oil-fired boiler; Figure 3 A cross-sectional view of the main discharge pipe of a fuel-fired boiler discharge pipeline; The attached diagram lists the components represented by each number as follows: 10. Main exhaust pipe body; 11. Air inlet; 12. Air outlet; 13. Spiral guide groove; 14. Heat dissipation protrusion; 20. Exhaust regulating valve; 22. Adjusting blade; 23. Rotating shaft; 30. Support frame; 31. Base; 32. Column; 33. Adjusting shim; 34. Shock-absorbing pad; 40. Sealing connection assembly; 41. Sealing ring; 42. Fastening bolt; 50. Condensation separator; 51. Separation chamber; 52. Drain pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0022] like Figure 1-3The diagram shows an embodiment of an exhaust pipe for a fuel-fired boiler provided by this utility model. In this embodiment, it includes: a main exhaust pipe body 10, an exhaust regulating valve 20, a support bracket 30, a sealing connection assembly 40, a condensate separator 50, and an anti-corrosion coating. The main exhaust pipe body has a cylindrical structure with an inner diameter of 300 mm to 800 mm and a wall thickness of 8 mm to 15 mm. The main exhaust pipe body is made of heat-resistant stainless steel. One end of the main exhaust pipe body is provided with an air inlet 11, the geometric center of which coincides with the axis of the main exhaust pipe body. The air inlet is fixedly connected to the boiler exhaust port via a flange connection. The other end of the main exhaust pipe is provided with an exhaust outlet 12, and an exhaust regulating valve is installed at the exhaust outlet. The exhaust regulating valve includes a rotating shaft 23 and an adjusting blade 22. The adjusting blade is located inside the main exhaust pipe. The geometric center of the adjusting blade is rotatably connected to the main exhaust pipe through the rotating shaft. The axis of the rotating shaft is perpendicular to the axis of the main exhaust pipe. The rotation of the adjusting blade realizes the adjustment of the exhaust volume. The support frame includes a base 31 and a column 32. The base is a rectangular plate structure. The columns are vertically fixed on the base. There are 4 columns. The 4 columns are distributed in a rectangle on the base. The columns are fixed and supported by U-shaped clamps around the outer wall of the main exhaust pipe.

[0023] In the above technical solution, the sealing connection assembly includes a sealing ring 41 and fastening bolts 42. The sealing ring has an annular structure, and its inner diameter matches the outer diameter of the main discharge pipe. The sealing ring is made of high-temperature resistant silicone material. The sealing ring is installed at the connection between the air inlet and the boiler discharge port. The upper surface of the sealing ring is in contact with the end face of the air inlet, and the lower surface of the sealing ring is in contact with the end face of the boiler discharge port. There are 8 fastening bolts, which are evenly distributed along the circumference of the sealing ring. The fastening bolts pass through the flange connection hole to achieve a sealing connection.

[0024] Furthermore, in the above technical solution, the condenser separator is installed in the middle section of the main discharge pipe. The condenser separator includes a separation chamber 51 and a drain pipe 52. The separation chamber has a cylindrical structure, and the axis of the separation chamber is perpendicular to the axis of the main discharge pipe. The separation chamber is connected to the side wall of the main discharge pipe through a connecting flange. A drain outlet is provided at the bottom of the separation chamber. One end of the drain pipe is threaded to the drain outlet, and the other end of the drain pipe extends to the outside of the main discharge pipe. The drain pipe has an L-shaped bending structure with a bending angle of 90 degrees. The drain pipe is made of carbon steel.

[0025] Furthermore, in the above technical solution, the adjusting blade has an elliptical plate-like structure, with a major axis length of 200 mm to 400 mm, a minor axis length of 150 mm to 300 mm, and a thickness of 5 mm to 10 mm. The major axis of the adjusting blade is perpendicular to the rotating shaft, and the adjusting blade is fixed to the rotating shaft by welding. The two ends of the rotating shaft are respectively installed in the side walls of the main discharge pipe body through bearings. The rotating shaft is made of stainless steel and has a diameter of 20 mm to 30 mm.

[0026] Furthermore, in the above technical solution, the inner surface of the main discharge pipe is provided with a spiral guide groove 13. The spiral guide groove is spirally distributed along the axial direction of the main discharge pipe. The spiral angle of the spiral guide groove is 15 degrees to 45 degrees, the depth of the spiral guide groove is 3 mm to 8 mm, and the width of the spiral guide groove is 10 mm to 20 mm.

[0027] Furthermore, in the above technical solution, the support frame also includes adjusting shims 33 and shock-absorbing pads 34. The adjusting shims are installed between the base and the ground, and there are four adjusting shims, which are located at the four corners of the base. The adjusting shims have a circular plate structure and a diameter of 80 mm to 120 mm. The adjusting shims are made of rubber material. The shock-absorbing pads are installed between the U-shaped clamp and the main discharge pipe body. The shock-absorbing pads have a ring structure and the inner diameter of the shock-absorbing pads matches the outer diameter of the main discharge pipe body. The shock-absorbing pads are made of polyurethane material.

[0028] Furthermore, in the above technical solution, the outer surface of the main discharge pipe is provided with multiple heat dissipation protrusions 14. The heat dissipation protrusions are conical in shape, with a height of 10 mm to 25 mm and a bottom diameter of 15 mm to 30 mm.

[0029] The installation and use of the exhaust pipe for an oil-fired boiler first requires on-site surveying and foundation preparation. Based on the location and size of the boiler exhaust outlet, the installation path and support point locations of the pipes are determined. A level foundation is laid at the installation location, ensuring it is flat and secure. The installation of the support bracket is a crucial step. The base is placed on the foundation, and the levelness of the base is adjusted using shims to ensure the verticality of the four columns meets requirements. Then, the main exhaust pipe is placed on the columns and secured using U-shaped clamps. Shock-absorbing pads are placed between the clamps and the pipe body, and the clamp bolts are tightened to the specified torque. Pipe connection requires precise alignment. The air inlet of the main exhaust pipe is aligned with the boiler exhaust outlet. A sealing ring is placed at the connection point, ensuring it fully contacts both end faces. The eight bolts are tightened gradually in a diagonal sequence to ensure a secure and sealed connection. The installation of the condensate separator requires ensuring the separation chamber axis is strictly perpendicular to the main pipe axis. Welding the connecting flange to the main pipe sidewall must ensure welding quality. When installing the drain pipe, the angle of the L-shaped bend must be accurate, and the drain pipe outlet must have an appropriate slope to facilitate condensate drainage. Before the system is put into operation, a comprehensive inspection is required, including the sealing of all connections, the firmness of supports, and the operational flexibility of regulating valves. During operation, the drainage of the condenser separator should be checked regularly, and accumulated water should be drained promptly. The cleanliness of the heat dissipation protrusions should also be checked regularly, and cleaned as necessary to maintain good heat dissipation. Maintenance work includes regularly checking the tightness of bolts, the aging of sealing rings, and the wear of vibration damping pads. If any problems are found, the relevant components should be replaced promptly to ensure the long-term stable operation of the system.

[0030] The following is a specific embodiment 1 of this utility model: The fuel oil boiler exhaust pipe in this embodiment is applied to a 2 MW industrial fuel oil boiler system. The main exhaust pipe body is made of 316L stainless steel, which has excellent high temperature resistance and corrosion resistance. The total length of the main exhaust pipe body is 6 meters, the inner diameter is set at 600 mm, and the wall thickness is 12 mm, which can withstand the high temperature and high pressure gas emitted by the boiler. The spiral guide groove on the inner surface of the pipe body is made by CNC machining, with a spiral angle set at 30 degrees, a groove depth of 5 mm, and a groove width of 15 mm, which are evenly distributed along the axial direction of the pipe body to form a continuous spiral flow channel. This precise machining process ensures the geometric accuracy and surface smoothness of the guide groove, providing an ideal channel for the spiral flow of gas. The regulating blade has an elliptical structure with a major axis length of 300 mm, a minor axis length of 225 mm, and a thickness of 8 mm. The blade surface is precision ground to ensure good sealing and low flow resistance characteristics. The rotating shaft, with a diameter of 25 mm, is made of alloy steel and heat-treated. Both ends are supported by high-precision rolling bearings (deep groove ball bearings) to ensure smooth rotation and durability. The support frame design considers the weight of the equipment and dynamic loads during operation. The base is made of 10 mm thick Q235 steel plate, measuring 2000 mm × 1500 mm. The four columns are made of seamless steel pipe with an outer diameter of 159 mm and a wall thickness of 8 mm. The columns and base are connected by full-penetration welding, followed by stress relief treatment. The U-shaped clamps are made of carbon steel and lined with 10 mm thick polyurethane shock-absorbing pads with a Shore A hardness of 70, effectively absorbing vibrations during pipeline operation. The condenser separator's separation chamber has a diameter of 400 mm, a height of 800 mm, and a volume of approximately 100 liters, sufficient to hold sufficient condensate. The separation chamber contains multiple layers of separation plates made of stainless steel wire mesh with a mesh size of 2 mm × 2 mm, increasing the gas-liquid contact area and improving separation efficiency. The drain pipe is made of seamless carbon steel with a diameter of 50 mm. The L-shaped bend is manufactured using a hot bending process to ensure the accuracy of the bending radius and angle. There are 36 heat dissipation protrusions on the outer surface of the pipe, machined mechanically. Each protrusion is 20 mm high, 25 mm in diameter at the base, and conical at the top, with a surface roughness of Ra 3.2 microns. The heat dissipation protrusions are distributed along a spiral line, with the spiral angle consistent with the internal guide grooves. The axial spacing between adjacent protrusions is 75 mm, and the arc length spacing is 120 mm. The sealing ring in the sealing connection assembly is made of fluororubber, with an operating temperature range of -40°C to 200°C, exhibiting excellent oil resistance and chemical corrosion resistance. The sealing ring has a rectangular cross-section, 20 mm wide and 8 mm thick, and is formed using a special mold. The eight fastening bolts are high-strength bolts, M20×80, made of 35CrMo alloy steel, and galvanized for corrosion protection after tempering.The entire system requires high installation precision. The straightness deviation of the main discharge pipe axis must not exceed 5 mm, and the flatness deviation of the flange connection surface must not exceed 0.5 mm. The sealing performance of each connection part is verified through an airtightness test. The test pressure is 1.5 times the working pressure, and the pressure holding time is not less than 30 minutes, with no leakage observed. After the system is put into operation, the discharged gas forms a stable spiral flow under the action of the spiral guide channel. The flow resistance is reduced by about 25% compared with traditional straight pipes, the heat dissipation efficiency is increased by about 40%, the condensate separation efficiency reaches more than 95%, and the pipe outlet temperature is reduced by about 50 degrees Celsius compared with traditional pipes, significantly improving the discharge effect and service life.

[0031] The following is another specific embodiment 2 of this utility model, which is an optimization and improvement based on embodiment 1, specifically for the application scenario of a high-sulfur content oil-fired boiler. In this application environment, the exhaust gas contains a high concentration of sulfides, placing higher demands on the corrosion resistance of the pipe material. In this embodiment, the main exhaust pipe body is made of super austenitic stainless steel 254SMO material, which contains 20% nickel, 18% chromium, and 6% molybdenum, exhibiting excellent resistance to pitting and crevice corrosion, and can resist long-term erosion by sulfides. The design parameters of the spiral guide channel have been optimized and adjusted, with the spiral angle increased to 35 degrees, the channel depth increased to 6 mm, and the channel width remaining unchanged at 15 mm. This adjustment appropriately extends the residence time of the gas in the pipe, which is beneficial for the sufficient cooling and separation of sulfides. An acidic condensate neutralization device has been added to the separation chamber of the condensate separator. This device includes an alkaline neutralizing agent dosing system and a pH monitoring system. The neutralizing agent is a sodium hydroxide solution, which is quantitatively added to the separation chamber via a metering pump to maintain the pH of the condensate between 7 and 8, effectively neutralizing the corrosive effects of acidic components on the equipment. The drain pipe material has been changed to Hastelloy C276, which exhibits excellent corrosion resistance to various acidic media and is particularly suitable for corrosive environments containing sulfides. The surface treatment of the heat dissipation protrusions utilizes plasma spraying, resulting in an aluminum alloy coating with a thickness of 0.3 mm. This coating offers good thermal conductivity and corrosion resistance while enhancing heat dissipation. The sealing rings of the sealing connection components have been replaced with perfluororubber, which possesses excellent chemical corrosion resistance and high-temperature resistance, extending its operating temperature range to -30°C to 250°C, and enabling long-term resistance to acidic gas corrosion. The entire system also includes online monitoring devices, including temperature sensors, pressure sensors, and corrosion monitoring probes, to monitor the system's operating status and corrosion in real time, providing data support for preventative maintenance.

[0032] The following is another specific embodiment 3 of this utility model, which is a design optimization based on embodiment 1, specifically designed for the application requirements of marine fuel oil boilers in marine environments. Marine environments have special conditions such as high salt spray, high humidity, and ship swaying, which place stricter requirements on the corrosion resistance, seismic performance, and structural stability of the discharge pipeline system. In this embodiment, the support frame adopts an enhanced design, with the base thickness increased to 15 mm and a universal adjustment mechanism added below the base. This mechanism includes a spherical bearing and a hydraulic adjusting cylinder, which can automatically compensate for the angular deviation caused by ship swaying on the pipeline system, ensuring that the main discharge pipe always maintains a relatively stable working state. The column structure adopts a truss design, with each column consisting of a main pipe and a secondary pipe. The main pipe has a diameter of 159 mm, and the secondary pipe has a diameter of 89 mm. They are connected by diagonal bracing to form a stable triangular structure, significantly improving the overall rigidity and seismic resistance. The U-shaped clamps incorporate an elastic compensation device, including a spring damper and a sliding guide mechanism, which can absorb the relative displacement caused by ship movement and prevent excessive stress at the pipe connection points. The main discharge pipe is made of super duplex stainless steel 2507, which boasts excellent seawater corrosion resistance and high strength, with a yield strength of 550 MPa, enabling it to withstand various loads in the marine environment. The outer surface of the pipe is treated with a thermal spray zinc-aluminum alloy coating, 0.5 mm thick, followed by an organic sealant to form a double-layer anti-corrosion protection system, effectively extending the equipment's service life in the marine environment. The number of heat dissipation protrusions has been increased to 42, and their height to 22 mm, to compensate for the relatively high ambient temperature in the marine environment. The condensate separator is equipped with anti-sway baffles using a perforated plate structure to prevent condensate from splashing out during ship swaying without affecting gas-liquid separation. The drainage system includes an automatic drainage device, comprising a level sensor and an electric drain valve, which automatically initiates drainage when the condensate level reaches a set value, eliminating the inconvenience of manual operation. The entire system's electrical connections meet marine explosion-proof standards, and all electrical equipment has an IP67 protection rating, resisting the corrosion of salt spray and humid air in the marine environment.

[0033] Specifically, the principle of this invention is as follows: This invention uses the principle of enhanced flow heat transfer through internal and external synergy to solve the problems of existing technologies. A spiral guide groove is set on the inner surface of the main discharge pipe, utilizing the spiral flow theory in fluid mechanics to create a stable spiral flow state for the discharged gas within the pipe. Spiral flow has two important characteristics: first, low flow resistance; the gas streamlines are more regular in spiral flow, reducing the generation of eddies and turbulence, effectively lowering flow resistance; second, good heat transfer effect; spiral flow allows for more sufficient contact between the gas and the pipe wall, enhancing convective heat transfer and improving heat dissipation efficiency. The centrifugal force generated by the spiral flow is key to solving the condensate separation problem. According to fluid mechanics principles, the gas in the spiral flow is subjected to centrifugal force, and the denser condensate droplets concentrate towards the pipe wall under the action of centrifugal force, achieving effective gas-liquid separation. Spiral-arranged heat dissipation protrusions are set on the outer surface of the main discharge pipe, significantly increasing the heat dissipation area using the extended surface heat transfer theory. The spiral arrangement of the heat dissipation protrusions maintains the same angle as the internal spiral guide channels, creating a synergistic effect of internal and external heat transfer. The internal spiral flow efficiently transfers heat to the pipe wall, while the externally arranged spiral heat dissipation protrusions quickly dissipate heat into the environment. The condensate separator employs the principle of gravity separation, with the separation chamber axis arranged perpendicular to the main pipe axis, utilizing gravity to allow condensate to settle and separate naturally. The elliptical blade design of the exhaust regulating valve is based on fluid resistance theory; the elliptical cross-section maintains a good streamline shape at all opening degrees, minimizing flow resistance. The entire system achieves the technical goals of efficient heat dissipation, low-resistance flow, and thorough water separation through the synergistic effect of multiple physical principles.

[0034] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A fuel oil boiler exhaust pipe, characterized in that, include: Main exhaust pipe body, exhaust regulating valve, support bracket, sealing connection assembly, condensate separator and anti-corrosion coating; The main discharge pipe has a cylindrical structure with an inner diameter of 300 mm to 800 mm and a wall thickness of 8 mm to 15 mm. It is made of heat-resistant stainless steel. One end of the main discharge pipe has an air inlet, the geometric center of which coincides with the axis of the main discharge pipe. The air inlet is fixedly connected to the boiler discharge port via a flange connection. The other end of the main discharge pipe has an air outlet, where an exhaust regulating valve is installed. The exhaust regulating valve includes a rotating shaft and regulating blades. The regulating blades are located inside the main discharge pipe, and their geometric center is rotatably connected to the main discharge pipe via the rotating shaft. The axis of the rotating shaft is perpendicular to the axis of the main discharge pipe. Rotation of the regulating blades adjusts the exhaust volume. The support frame includes a base and columns. The base has a rectangular plate structure, and four columns are vertically fixed to the base in a rectangular arrangement. The columns are fixed and supported by U-shaped clamps surrounding the outer wall of the main discharge pipe.

2. The exhaust pipe for an oil-fired boiler according to claim 1, characterized in that, The sealing connection assembly includes a sealing ring and fastening bolts. The sealing ring has an annular structure, and its inner diameter matches the outer diameter of the main discharge pipe. The sealing ring is made of high-temperature resistant silicone material. The sealing ring is installed at the connection between the air inlet and the boiler discharge port. The upper surface of the sealing ring is in contact with the end face of the air inlet, and the lower surface of the sealing ring is in contact with the end face of the boiler discharge port. There are eight fastening bolts, which are evenly distributed along the circumference of the sealing ring. The fastening bolts pass through the flange connection holes to achieve a sealing connection.

3. The exhaust pipe for an oil-fired boiler according to claim 2, characterized in that, The condenser separator is installed in the middle section of the main discharge pipe. The condenser separator includes a separation chamber and a drain pipe. The separation chamber has a cylindrical structure, and its axis is perpendicular to the axis of the main discharge pipe. The separation chamber is connected to the side wall of the main discharge pipe through a connecting flange. A drain outlet is provided at the bottom of the separation chamber. One end of the drain pipe is threaded to the drain outlet, and the other end of the drain pipe extends to the outside of the main discharge pipe. The drain pipe has an L-shaped bending structure with a bending angle of 90 degrees. The drain pipe is made of carbon steel.

4. The exhaust pipe for an oil-fired boiler according to claim 3, characterized in that, The adjusting blade has an elliptical plate-like structure, with a major axis length of 200 mm to 400 mm, a minor axis length of 150 mm to 300 mm, and a thickness of 5 mm to 10 mm. The major axis of the adjusting blade is perpendicular to the rotating shaft, and the adjusting blade is fixed to the rotating shaft by welding. Both ends of the rotating shaft are installed inside the side walls of the main discharge pipe body through bearings. The rotating shaft is made of stainless steel and has a diameter of 20 mm to 30 mm.

5. The exhaust pipe for an oil-fired boiler according to claim 4, characterized in that, The inner surface of the main discharge pipe is provided with a spiral guide groove. The spiral guide groove is distributed in a spiral shape along the axial direction of the main discharge pipe. The spiral angle of the spiral guide groove is 15 degrees to 45 degrees, the depth of the spiral guide groove is 3 mm to 8 mm, and the width of the spiral guide groove is 10 mm to 20 mm.

6. The exhaust pipe for an oil-fired boiler according to claim 5, characterized in that, The support frame also includes adjusting shims and shock-absorbing pads. The adjusting shims are installed between the base and the ground. There are four adjusting shims, located at the four corners of the base. The adjusting shims are circular plate-shaped with a diameter of 80 mm to 120 mm and are made of rubber. The shock-absorbing pads are installed between the U-shaped clamp and the main discharge pipe. The shock-absorbing pads are annular in shape, with an inner diameter matching the outer diameter of the main discharge pipe and are made of polyurethane.

7. The exhaust pipe for an oil-fired boiler according to claim 6, characterized in that, The outer surface of the main discharge pipe is provided with multiple heat dissipation protrusions. The heat dissipation protrusions have a conical structure, with a height of 10 mm to 25 mm and a bottom diameter of 15 mm to 30 mm.

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