Efficient compact air preheater and control method thereof

Abstract

The invention relates to the technical field of air preheaters, and discloses an efficient compact type air preheater and a control method thereof.The efficient compact type air preheater comprises a preheater body, a plurality of heat exchange pipes are arranged in the preheater body, multiple sets of heat exchange pipes are distributed in the transverse direction, and each set of heat exchange pipes are connected through bent pipes to form a continuous water passing pipeline; the water inlet ends of the multiple sets of water passing pipelines communicate with a water inlet header pipe, the water outlet ends of the multiple sets of water passing pipelines communicate with a water outlet header pipe, a medium input pipeline and a medium output pipeline are arranged on one side of the preheater body, an air outlet is formed in the top of the preheater body, an air inlet is formed in the bottom of the preheater body, and an air circulation device covering the air outlet and the air inlet is arranged on the preheater body. The air circulation device comprises a flow expanding body and a flow gathering cover, the top air outlet end of the flow gathering cover is communicated with the air inlet position of a burner of the heating furnace, and a flow meter, a thermometer and a flow control valve are arranged on the medium input pipeline and the medium output pipeline. The waste heat utilization device has the effect of efficiently utilizing waste heat energy.

Description

Technical Field

[0001] The present application relates to the technical field of air preheaters, and in particular to a high-efficiency compact air preheater and a control method thereof. Background Art

[0002] In the oil refining and chemical industry, various types of heating furnaces such as oil refining heating furnaces and ethylene cracking furnaces are key production equipment, and their energy consumption accounts for an important proportion of the total energy consumption of the entire plant. In order to ensure the normal operation of these heating furnaces, high-temperature air must be continuously supplied, which usually relies on a large amount of fuel combustion to achieve. However, this traditional method has a significant energy waste problem, because a large amount of heat generated by fuel combustion is not effectively utilized, resulting in low energy utilization. In addition, a large amount of high-temperature media such as steam and hot water generated during the production process are often directly discharged into the environment due to the lack of effective recycling methods, further exacerbating energy waste and environmental pollution.

[0003] In order to solve this problem, the industry has taken some measures to improve the effect of air preheating. Common methods include using traditional heat exchangers, increasing the thickness of the insulation layer, and optimizing the design of the burner. Among them, the traditional heat exchanger achieves heat transfer through direct or indirect means, but its heat exchange efficiency is low and it occupies a large space; adding an insulation layer can reduce heat loss to a certain extent, but it cannot fundamentally solve the problem of waste heat recovery; and improving the burner design mainly focuses on optimizing the combustion process, and it is difficult to fully take into account the effective use of waste heat. Although these methods have improved energy efficiency to a certain extent, they are still far from meeting the requirements of modern industry for high efficiency and energy saving.

[0004] The main problems of existing air preheating technology are low heat exchange efficiency, large equipment size and incomplete waste heat recovery. These problems make the energy utilization rate still low, increase the operating costs of enterprises, and also have a negative impact on environmental protection. Therefore, there is an urgent need for a new air preheating technology that can improve the heat exchange efficiency, reduce the equipment size and effectively utilize the waste heat to overcome the shortcomings of the existing technology. Summary of the invention

[0005] In order to achieve efficient utilization of waste heat energy, the present application provides a high-efficiency compact air preheater and a control method thereof.

[0006] The present application provides a highly efficient and compact air preheater and a control method thereof, which adopts the following technical solutions: A high-efficiency compact air preheater comprises a preheater body, wherein a plurality of heat exchange tubes are arranged in the preheater body, wherein the heat exchange tubes are distributed in a plurality of groups in the transverse direction, and each group of heat exchange tubes is connected through a bend to form a continuous water pipe, wherein the water inlet ends of the plurality of water pipes are connected to a water inlet main pipe, and the water outlet ends are connected to a water outlet main pipe, and a medium input pipeline connected to the water inlet main pipe and a medium output pipeline connected to the water outlet main pipe are arranged on one side of the preheater body, an air outlet is arranged on the top of the preheater body, an air inlet is arranged on the bottom of the preheater body, and an air circulation device covering the air outlet and the air inlet is arranged on the preheater body, wherein the air circulation device comprises a diffuser connected to the air inlet and a focusing hood connected to the air outlet, wherein the top air outlet end of the focusing hood is connected to the air inlet of the burner of the heating furnace, and a flow meter, a thermometer and a flow control valve are arranged on the medium input pipeline and the medium output pipeline.

[0007] By adopting the above technical solution, the continuous water pipeline formed by connecting multiple groups of heat exchange tubes through elbows not only enhances the uniformity and stability of the water flow, but also significantly improves the heat conduction effect. At the same time, the flowmeter, thermometer and flow control valve installed on the medium input pipeline and the medium output pipeline can monitor and adjust the medium flow parameters in the system in real time to ensure the optimal working state of the system. In addition, the air preheater cleverly integrates the diffuser, the flow hood and the preheater body, which not only greatly reduces the overall volume of the equipment, but also optimizes the air flow path and reduces the resistance loss, thereby improving the stability and uniformity of the airflow, further improving the heat transfer efficiency, and also providing great convenience for the installation and maintenance of the equipment.

[0008] Optionally, a plurality of fins are provided on the outside of the heat exchange tube, and the fins are densely arranged along the length direction of the heat exchange tube.

[0009] By adopting the above technical solution, the multiple fins arranged on the outside of the heat exchange tube can significantly increase the heat exchange area and improve the heat transfer efficiency. The fins are densely arranged along the length of the heat exchange tube, so that the air and the surface of the heat exchange tube are in more complete contact, thereby enhancing the speed and effect of heat transfer. Specifically, this structure can effectively improve the overall heat exchange performance of the air preheater, reduce energy consumption, and reduce the size of the equipment, making it more compact.

[0010] Optionally, the diffuser is in an inverted cone shape and has a plurality of diversion channels arranged inside. The air inlet ends of the diversion channels are evenly distributed at the inlet end of the diffuser and extend to the inlet end wall of the diffuser. The air outlet ends of the diversion channels are evenly distributed at the outlet end of the diffuser and gradually bend in a direction away from the central axis of the diffuser.

[0011] By adopting the above technical solution, the inverted cone design of the diffuser can effectively expand the area of ​​the air inlet, making the air entering the preheater more evenly distributed, thereby increasing the contact area between the air and the heat exchange tube and the heat exchange efficiency. At the same time, the design of multiple diversion channels allows the air to disperse quickly after entering the preheater, further enhancing the uniformity and stability of the air flow and reducing the occurrence of local overheating. In addition, the outlet end of the diversion channel is bent in a direction away from the central axis, which helps to avoid mutual interference of airflows, ensures smooth air flow, and improves the stability and reliability of the overall system.

[0012] Optionally, a shunt tube is inserted into each shunt channel, the shunt tube is plugged into the shunt channel, and sealing rings are respectively sleeved on both ends of the shunt tube, the sealing rings abut against the end wall of the diffuser fluid, and the inlet end of the shunt tube is also sleeved with an abutment edge, and the sealing ring located at the inlet end of the diffuser fluid abuts between the abutment edge and the side wall of the diffuser fluid.

[0013] By adopting the above technical solution, the detachable setting of the shunt pipe not only makes the air more evenly distributed in the diffuser, but also facilitates the regular cleaning of the accumulated dirt in the shunt pipe, ensuring that the gas flow path is unobstructed. In addition, the sealing rings sleeved on both ends of the shunt pipe can fix the relative position of the shunt pipe and the diffuser, effectively preventing the accumulation of dirt between the shunt channel and the shunt pipe during the air circulation process, and ensuring the long-term stable operation of the preheater under high pressure conditions.

[0014] Optionally, a cyclone separation device is provided at the bottom of the diffuser, and the cyclone separation device includes a cylindrical body connected to the diffuser, a conical body coaxially connected to the bottom of the cylindrical body, an exhaust pipe arranged in the center of the top of the cylindrical body, an air intake pipe arranged on the side wall of the cylindrical body, and a dust exhaust pipe connected to the bottom of the conical body, the body of the air intake pipe is spirally wound on the exhaust pipe, and the air intake end thereof is tangentially arranged on the side wall of the cylindrical body and connected to the outside air.

[0015] By adopting the above technical solution, after the dusty air enters the cyclone separation device from the air inlet pipe, it flows downward along a spiral path in the cylindrical and conical cylinders. Under the action of centrifugal force, the dust particles are thrown to the inner wall of the cylinder and slide down along the inner wall to the dust exhaust pipe for discharge. At the same time, the purified gas forms an ascending internal vortex in the central area and finally enters the diffuser from the exhaust pipe at the top. The cyclone separation device effectively removes the dust carried in the air, improves the quality of the air entering the preheater body, and reduces the problems of reduced heat exchange efficiency and frequent equipment maintenance caused by dust accumulation.

[0016] Optionally, a guide pipe is arranged between the diffuser and the cyclone separation device, and two parallel support rods are distributed axially in the guide pipe, and the support rods are connected to the pipe wall of the guide pipe perpendicular to the axial direction of the guide pipe, and a support shaft is rotatably connected between the two support rods, and the support shaft coincides with the axis of the guide pipe, and a plurality of inclined swirl blades are connected to the side walls of the support shaft, and the diameter length of the swirl blades gradually increases from bottom to top.

[0017] By adopting the above technical solution, the gas that has been initially separated from the dust will be guided to produce a rotating motion when passing through the swirl blades. Under the action of centrifugal force, the remaining dust particles are thrown to the surrounding walls to achieve further dust removal. At the same time, the rotating airflow will gradually disperse with the diffusion of the swirl blades before entering the diffuser, so that the gas is evenly distributed on the air inlet end of the diffuser.

[0018] Optionally, a fixed plate is connected between the focus hood and the diffuser, and one fixed plate is arranged on each side of the length direction of the heat exchange tube. A U-shaped shell that surrounds the preheater body is arranged between the focus hood, the diffuser and the fixed plate, and a handle is also arranged on the outer wall of the fixed plate to facilitate the transfer of the air preheater.

[0019] By adopting the above technical solution, a fixing plate is provided on each side along the length direction of the heat exchange tube, and is surrounded by a U-shaped casing, so that the preheater body can slide and fit, which is convenient for disassembly and cleaning. At the same time, the hinged handle on the inner wall of the through hole further improves the convenience of operation, making it easier for technicians to move or adjust the position of the preheater.

[0020] Optionally, the handle is hingedly arranged between the handle and the fixed plate, and a through hole is opened on the fixed plate corresponding to the movable side of the handle, a torsion spring is sleeved on the hinge axis between the handle and the fixed plate, a positioning rod is provided on the side wall of the handle facing the through hole, and a hemispherical positioning protrusion is provided on the end of the positioning rod extending out of the through hole, and a positioning hole is opened on the outer side wall of the preheater body corresponding to the positioning protrusion, and the positioning protrusion corresponds to the positioning hole one by one and is plugged into and matched.

[0021] By adopting the above technical solution, under the action of the torsion spring, when the preheater body is slidably inserted into the casing, the positioning protrusion and the positioning hole can be quickly and accurately docked, which not only improves the assembly speed and efficiency of the air preheater, but also ensures a stable connection between the preheater body and the casing, thereby enhancing the overall stability and reliability of the equipment.

[0022] A control method for a high-efficiency compact air preheater comprises the following steps: S1. Configure a corresponding number of air preheaters according to the number of burners equipped with the heating furnace, connect the medium input pipelines to the water inlet mains of multiple air preheaters, connect the medium output pipelines to the water outlet mains of multiple air preheaters, and connect the top air outlet end of the focusing hood to the air inlet of the corresponding burner; S2. Open the flow meter, thermometer and flow control valve on the medium input pipeline and the medium output pipeline to allow the heat source to flow into the heat exchange tube of the air preheater; S3, start the heating furnace, and use the suction force of the heating furnace to guide the ambient air into the preheater body to exchange heat with the heat exchange tubes densely covered with fins; S4. Monitor the thermometer on the outlet end of the focusing hood, record the air outlet temperature, and adjust the suction force of the heating furnace according to actual needs; S5. Monitor the flowmeter, thermometer and flow control valve on the medium output pipeline, record the temperature of the heat source flowing out after heat exchange, and adjust the flow of the medium input pipeline and the medium output pipeline according to actual needs; S6. When shutting down, first close the flow control valve on the medium input pipeline, then close the flow control valve on the medium output pipeline, and finally stop the heating furnace from sucking air.

[0023] By adopting the above technical solution, not only can a single air preheater provide high-heat air to the heating furnace, but also multiple air preheaters can work together to improve the stability and reliability of the system. At the same time, through real-time monitoring and adjustment of the flowmeter, thermometer and flow control valve on the medium input pipeline and the medium output pipeline, the flow of the heat source and the heat exchange process can be accurately controlled to ensure the efficiency and quality of air preheating. In addition, the control method can also dynamically adjust the suction force and medium flow of the heating furnace according to actual needs, further optimize energy utilization, reduce energy consumption, and improve the overall system performance.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. The continuous water pipeline formed by connecting multiple groups of heat exchange tubes through elbows not only enhances the uniformity and stability of the water flow, but also significantly improves the heat conduction effect. At the same time, the flowmeter, thermometer and flow control valve installed on the medium input pipeline and the medium output pipeline can monitor and adjust the medium flow parameters in the system in real time to ensure the optimal working state of the system. In addition, the air preheater cleverly integrates the diffuser, the flow hood and the preheater body, which not only greatly reduces the overall volume of the equipment, but also optimizes the air flow path and reduces the resistance loss, thereby improving the stability and uniformity of the airflow, further improving the heat transfer efficiency, and also providing great convenience for the installation and maintenance of the equipment; 2. The multiple fins arranged on the outside of the heat exchange tube can significantly increase the heat exchange area and improve the heat transfer efficiency. The fins are densely arranged along the length of the heat exchange tube, so that the air and the surface of the heat exchange tube are in more complete contact, thereby enhancing the speed and effect of heat transfer. Specifically, this structure can effectively improve the overall heat exchange performance of the air preheater, reduce energy consumption, and reduce the size of the equipment, making it more compact; 3. The inverted cone design of the diffuser can effectively expand the area of ​​the air inlet, making the air entering the preheater more evenly distributed, thereby increasing the contact area between the air and the heat exchange tube and the heat exchange efficiency. At the same time, the design of multiple diversion channels allows the air to disperse quickly after entering the preheater, further enhancing the uniformity and stability of the air flow and reducing the occurrence of local overheating. In addition, the outlet end of the diversion channel is bent in a direction away from the central axis, which helps to avoid mutual interference of airflows, ensures smooth air flow, and improves the stability and reliability of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the embodiment of the present application during actual use.

[0026] Figure 2 It is a cross-sectional view showing the internal structure of a single air preheater in an embodiment of the present application.

[0027] Figure 3 It is a cross-sectional view showing the connection relationship between the diffuser, the guide tube and the cyclone separation device in the embodiment of the present application.

[0028] Figure 4 It is a cross-sectional view showing the positional relationship between the positioning rod and the positioning hole in the embodiment of the present application.

[0029] Description of reference numerals: 1. Preheater body; 11. Air outlet; 12. Air inlet; 13. Heat exchange tube; 131. Fin; 132. Bend pipe; 133. Water inlet main pipe; 134. Water outlet main pipe; 14. Positioning hole; 2. Air circulation device; 21. Diffuser; 211. Diverter channel; 212. Diverter pipe; 2121. Sealing ring; 2122. Abutment edge; 22. Focusing cover; 23. Fixing plate; 231. Through hole; 3. Leg; 31. Universal positioning wheel; 4. , handle; 41, torsion spring; 42, positioning rod; 421, positioning protrusion; 5, guide tube; 51, support rod; 511, bearing; 512, support shaft; 52, swirl blade; 6, cyclone separation device; 61, cylindrical body; 62, conical body; 63, exhaust pipe; 64, air inlet pipe; 65, dust exhaust pipe; 7, medium input pipeline; 71, flow control valve; 72, flow meter; 73, thermometer; 8, medium output pipeline; 9, bypass valve. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-4 This application is described in further detail.

[0031] The embodiment of the present application discloses a high-efficiency compact air preheater and a control method thereof.

[0032] Reference Figure 1 and Figure 2 A high-efficiency compact air preheater comprises a preheater body 1 and an air circulation device 2 sleeved and mounted on the preheater body 1. The top of the preheater body 1 is provided with an air outlet 11, and the bottom is provided with an air inlet 12. The air circulation device 2 covers the air outlet 11 and the air inlet 12 of the preheater body 1, and is fixedly connected to the air outlet 11 and the air inlet 12 of the preheater body 1 through a sealing gasket and bolts. A plurality of legs 3 are fixedly arranged at the bottom of the air circulation device 2, and a universal positioning wheel 31 is installed at the bottom end of each leg 3, and a handle 4 is hinged on the side walls of the air circulation device 2 on both sides parallel to the length direction of the preheater body 1.

[0033] Reference Figure 2 A plurality of heat exchange tubes 13 are installed in the preheater body 1, and a plurality of fins 131 are fixedly sleeved on each heat exchange tube 13, and the plurality of fins 131 are densely arranged along the length direction of the heat exchange tube 13. The fins 131 can be made of aluminum, copper or silver-plated copper. The present embodiment takes the silver-plated copper material as an example, and the shape of the fins 131 can be circular, square or regular hexagonal. The present embodiment adopts a circular arrangement.

[0034] Reference Figure 1 and Figure 2 There are multiple groups of heat exchange tubes 13 distributed in the transverse direction. Each group of heat exchange tubes 13 extends out of the end of the preheater body 1 and is connected through a bend pipe 132 to form a continuous water pipeline. The water inlet ends of the multiple groups of water pipelines are connected to a water inlet main pipe 133, and the water outlet ends are connected to a water outlet main pipe 134.

[0035] Reference Figure 1 , Figure 2 and Figure 3The air circulation device 2 includes a diffuser 21, a focusing cover 22 and a fixing plate 23. The diffuser 21 covers the air inlet 12 of the preheater body 1 and is arranged in an inverted cone shape. A plurality of diverter channels 211 are arranged inside the diffuser. The air inlet ends of these diverter channels 211 are evenly distributed at the inlet end of the diffuser 21 and extend to the inlet end wall of the diffuser 21, while the air outlet ends are evenly distributed at the outlet end of the diffuser 21 and gradually bend in a direction away from the central axis of the diffuser 21. A plurality of diverter pipes 212 are arranged inside the diffuser 21. The diverter pipes 212 correspond to the diverter channels 211 one by one, and each diverter pipe 212 is plugged into the diverter channel 211. The diverter pipes 212 in this embodiment are made of high-plasticity plastic pipes that are bendable and resistant to high temperatures. The two ends of the diverter pipes 212 extending out of the diverter channels 211 are respectively provided with sealing rings 2121 made of rubber material, and the sealing rings 2121 are tightly pressed against the end walls of the diffuser 21. An abutting edge 2122 is integrally formed on the outer side wall of the inlet end of the flow divider 212 , and a sealing ring 2121 located at the inlet end of the diffuser 21 is pressed tightly between the abutting edge 2122 and the side wall of the diffuser 21 .

[0036] Reference Figure 2 and Figure 3 The bottom of the diffuser 21 is provided with a guide tube 5 through an external threaded sleeve, and two parallel support rods 51 are distributed in the axial direction of the guide tube 5. The support rods 51 are fixedly connected to the tube wall of the guide tube 5 perpendicular to the axial direction of the guide tube 5, and a support shaft 512 is rotatably connected between the two support rods 51 through a bearing 511, and the support shaft 512 coincides with the axis of the guide tube 5. A plurality of obliquely arranged swirl blades 52 are installed on the side wall of the support shaft 512, and the diameter length of the swirl blades 52 gradually increases from bottom to top. Before entering the diffuser 21, the dust-carrying air first flows through the swirl blades 52, and will be guided by the rotating swirl blades 52 to produce a rotating motion.

[0037] Reference Figure 3 Under the action of centrifugal force, dust particles in the air entering the guide tube 5 are thrown to the surrounding wall surface, and the rotating airflow is gradually dispersed as the swirl blades 52 diffuse, so that the gas is evenly distributed on the air inlet end of the diffuser 21.

[0038] Reference Figure 2 and Figure 3The bottom of the guide pipe 5 is provided with a cyclone separation device 6 through an internal thread sleeve, and the cyclone separation device 6 includes a cylindrical body 61, a conical body 62, an exhaust pipe 63, an air intake pipe 64 and a dust exhaust pipe 65. The conical body 62 is located below the cylindrical body 61, and the two are coaxially arranged and integrally formed. The top outer wall of the cylindrical body 61 and the bottom inner wall of the guide pipe 5 are rotatably connected by threads. The exhaust pipe 63 is coaxially fixedly arranged at the top center of the cylindrical body 61, the air intake end of the exhaust pipe 63 is located in the cylindrical body 61, and the air outlet end extends out of the cylindrical body 61 and is inserted into the guide pipe 5. The air intake pipe 64 is spirally coiled downward in the cylindrical body 61 and wound around the circumference of the exhaust pipe 63. The air intake end of the air intake pipe 64 is tangentially arranged on the side wall of the cylindrical body 61 and communicates with the outside air.

[0039] Reference Figure 2 and Figure 3 After the dust-laden air enters the cyclone separation device 6 from the air inlet pipe 64, it flows downward along a spiral path in the cylindrical body 61 and the conical body 62. Under the action of centrifugal force, the dust particles are thrown to the inner wall of the cylinder and slide down along the inner wall to the dust exhaust pipe 65 for discharge. At the same time, the purified gas forms an ascending internal vortex in the central area and finally enters the guide pipe 5 from the exhaust pipe 63 at the top.

[0040] Reference Figure 1 and Figure 2 The focusing hood 22 covers the top air outlet 11 of the preheater body 1, and its top air outlet end is connected to the burner air inlet of the heating furnace. The function of the focusing hood 22 is to guide the preheated air to the burner, ensure that the high-temperature air can smoothly enter the combustion chamber, and improve the combustion efficiency.

[0041] Reference Figure 1 and Figure 4, one fixed plate 23 is provided on each side along the length direction of the heat exchange tube 13, and a U-shaped casing is formed between the flow collector 22, the diffuser 21 and the fixed plate 23, which is sleeved on the preheater body 1. One handle 4 is provided for each fixed plate 23, and the handle 4 is hinged on the outer wall of the fixed plate 23. A through hole 231 is opened on the side wall of the fixed plate 23 corresponding to the movable side of each handle 4, and the hinge axis between the handle 4 and the fixed plate 23 is vertically arranged, and a torsion spring 41 is sleeved at the hinge axis between the handle 4 and the fixed plate 23, and the torsion spring 41 connects the fixed plate 23 and the handle 4. A plurality of positioning rods 42 are fixedly provided on the side wall of the handle 4 facing the through hole 231, and the positioning rods 42 are arranged perpendicular to the side wall of the handle 4, and the end of the positioning rod 42 extending out of the through hole 231 is integrally formed with a hemispherical positioning protrusion 421. In this embodiment, two are taken as an example, and the two positioning rods 42 are distributed vertically. A positioning hole 14 is provided on the outer wall of the preheater body 1 corresponding to each positioning protrusion 421 , and the positioning protrusions 421 correspond to the positioning holes 14 one by one and are plug-fitted.

[0042] Reference Figure 1 , a medium input pipeline 7 and a medium output pipeline 8 are provided on one side of the air preheater. Multiple air preheaters are provided according to the number of burners equipped in the heating furnace. This embodiment takes three as an example. The medium input pipeline 7 is commonly connected to the water inlet main pipe 133 of multiple air preheaters, and the medium output pipeline 8 is commonly connected to the water outlet main pipe 134 of multiple air preheaters. A flow control valve 71, a flow meter 72 and a thermometer 73 are sequentially installed on the main pipeline of the medium input pipeline 7 and the water inlet end of the branch pipeline along the conveying direction. Only a flow control valve 71 is installed on the branch pipeline of the medium output pipeline 8, and a bypass valve 9 is installed at the end of its main pipeline. A thermometer 73 is plugged and installed on the bypass valve 9, and the bypass valve 9 is connected to the water inlet end of the medium input pipeline 7. A thermometer 73 is also installed at the outlet of the focusing hood 22.

[0043] Reference Figures 1 to 4 , a control method for a high-efficiency compact air preheater, comprising the following steps: S1. Configure a corresponding number of air preheaters according to the number of burners equipped with the heating furnace, connect the medium input pipeline 7 to the water inlet main pipe 133 of multiple air preheaters, connect the medium output pipeline 8 to the water outlet main pipe 134 of multiple air preheaters, and connect the top air outlet end of the focusing hood 22 to the corresponding burner air inlet; S2, open the flow meter 72, the thermometer 73 and the flow control valve 71 on the medium input pipeline 7 and the medium output pipeline 8, so that the heat source flows into the heat exchange tube 13 of the air preheater; S3, start the heating furnace, and use the suction force of the heating furnace to guide the ambient air into the preheater body 1 to exchange heat with the heat exchange tubes 13 densely covered with fins 131; S4, monitoring the thermometer 73 on the outlet end of the focusing hood 22, recording the air outlet temperature, and adjusting the suction force of the heating furnace according to actual needs; S5, monitoring the flow meter 72, the thermometer 73 and the flow control valve 71 on the medium output pipeline 8, recording the temperature of the heat source flowing out after heat exchange, and adjusting the flow of the medium input pipeline 7 and the medium output pipeline 8 according to actual needs; S6. When shutting down, first close the flow control valve 71 on the medium input pipeline 7, then close the flow control valve 71 on the medium output pipeline 8, and finally stop the heating furnace from sucking air.

[0044] The implementation principle of an efficient and compact air preheater and its control method in the embodiment of the present application is as follows: during the production process of the heating furnace, under the control of the intelligent control system, the flow meter 72, the thermometer 73 and the flow control valve 71 on the medium input pipeline 7 and the medium output pipeline 8 are first opened to allow the heat source to flow into the heat exchange tube 13 of the air preheater. Then the heating furnace is started, and the suction force of the heating furnace is used to guide the ambient air into the preheater body 1 to exchange heat with the heat exchange tube 13 densely covered with fins 131. Finally, the air heated to the standard temperature enters the burner equipped with the heating furnace to play a combustion-supporting effect. When the heat source output in the medium output pipeline 8 still has a relatively high temperature, it enters the medium input pipeline 7 again through the bypass valve 9 to participate in the heat exchange process.

[0045] During the air circulation process, the dusty air first enters the cyclone separation device 6 from the air inlet pipe 64, and flows downward along the spiral path in the cylindrical body 61 and the conical body 62. Under the action of centrifugal force, the dust particles are thrown to the inner wall of the cylinder, and slide down along the inner wall to the dust exhaust pipe 65 for discharge. At the same time, the purified gas forms an ascending internal vortex in the central area, and enters the guide pipe 5 from the exhaust pipe 63 at the top; and then the gas that has been initially separated from the dust will be guided to produce a rotating motion when passing through the swirl blades 52. And under the action of centrifugal force, the remaining dust particles are thrown to the surrounding wall surface to achieve further dust removal. At the same time, the rotating airflow will gradually disperse with the diffusion of the swirl blades 52 before entering the diffuser 21, so that the gas is evenly distributed on the air inlet end of the diffuser 21; the air after dust removal does not interfere with each other under the guidance of several diverter pipes 212, and further diffuses into the preheater body 1, and fully exchanges heat with the heat exchange tube 13 densely covered with fins 131.

[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-efficiency compact air preheater, comprising a preheater body (1), wherein a plurality of heat exchange tubes (13) are arranged in the preheater body (1), wherein the heat exchange tubes (13) are arranged in a plurality of groups in a transverse direction, wherein each group of heat exchange tubes (13) is connected via an elbow (132) to form a continuous water pipe, wherein the water inlet ends of the plurality of water pipes are connected to a water inlet main pipe (133), and the water outlet ends are connected to a water outlet main pipe (134), wherein the plurality of water pipes are characterized in that: A medium input pipeline (7) connected to a water inlet main pipe (133) and a medium output pipeline (8) connected to a water outlet main pipe (134) are provided on one side of the preheater body (1); an air outlet (11) is provided on the top of the preheater body (1), and an air inlet (12) is provided on the bottom; and an air circulation device (2) covering the air outlet (11) and the air inlet (12) is provided on the preheater body (1); the air circulation device (2) comprises a diffuser (21) connected to the air inlet (12) and a focusing hood (22) connected to the air outlet (11); the top air outlet end of the focusing hood (22) is connected to the air inlet of the burner of the heating furnace; and a flow meter (72), a thermometer (73) and a flow control valve (71) are provided on the medium input pipeline (7) and the medium output pipeline (8).

2. A highly efficient and compact air preheater according to claim 1, characterized in that A plurality of fins (131) are provided on the outside of the heat exchange tube (13), and the fins (131) are densely arranged along the length direction of the heat exchange tube (13).

3. A highly efficient and compact air preheater according to claim 1, characterized in that The diffuser (21) is in an inverted cone shape and is provided with a plurality of flow diversion channels (211) therein; the air inlet ends of the flow diversion channels (211) are evenly distributed at the inlet end of the diffuser (21) and extend to the inlet end wall of the diffuser (21); the air outlet ends of the flow diversion channels (211) are evenly distributed at the outlet end of the diffuser (21) and gradually bend in a direction away from the central axis of the diffuser (21).

4. A highly efficient and compact air preheater according to claim 3, characterized in that A shunt tube (212) is inserted into each shunt channel (211), the shunt tube (212) is plugged into and matched with the shunt channel (211), and sealing rings (2121) are respectively sleeved on both ends of the shunt tube (212), and the sealing rings (2121) abut against the end wall of the diffuser (21), and the inlet end of the shunt tube (212) is also sleeved with an abutting edge (2122), and the sealing ring (2121) located at the inlet end of the diffuser (21) abuts between the abutting edge (2122) and the side wall of the diffuser (21).

5. A highly efficient and compact air preheater according to claim 1, characterized in that A cyclone separation device (6) is arranged at the bottom of the diffuser (21), and the cyclone separation device (6) comprises a cylindrical body (61) connected to the diffuser (21), a conical body (62) coaxially connected to the bottom of the cylindrical body (61), an exhaust pipe (63) arranged at the center of the top of the cylindrical body (61), an air intake pipe (64) arranged on the side wall of the cylindrical body (61), and a dust exhaust pipe (65) connected to the bottom of the conical body (62), wherein the body of the air intake pipe (64) is spirally wound around the exhaust pipe (63), and the air intake end of the air intake pipe (64) is tangentially arranged on the side wall of the cylindrical body (61) and communicates with the outside air.

6. A highly efficient and compact air preheater according to claim 5, characterized in that A flow guide tube (5) is arranged between the diffuser (21) and the cyclone separation device (6), and two parallel support rods (51) are distributed in the flow guide tube (5) along the axial direction. The support rods (51) are connected to the tube wall of the flow guide tube (5) perpendicular to the axial direction of the flow guide tube (5), and a support shaft (512) is rotatably connected between the two support rods (51). The support shaft (512) coincides with the axis of the flow guide tube (5), and a plurality of obliquely arranged swirl blades (52) are connected to the side wall of the support shaft (512), and the diameter length of the swirl blades (52) gradually increases from bottom to top.

7. A highly efficient and compact air preheater according to claim 1, characterized in that A fixing plate (23) is connected between the focusing hood (22) and the diffuser (21), and one fixing plate (23) is provided on each side of the length direction of the heat exchange tube (13). A U-shaped casing is formed between the focusing hood (22), the diffuser (21) and the fixing plate (23) to enclose the preheater body (1). A handle (4) is also provided on the outer wall of the fixing plate (23) to facilitate the transfer of the air preheater.

8. A highly efficient and compact air preheater according to claim 7, characterized in that The handle (4) is hingedly arranged with the fixing plate (23), and a through hole (231) is opened on the fixing plate (23) corresponding to the movable side of the handle (4), a torsion spring (41) is sleeved at the hinge axis between the handle (4) and the fixing plate (23), a positioning rod (42) is arranged on the side wall of the handle (4) facing the through hole (231), and a hemispherical positioning protrusion (421) is arranged at the end of the positioning rod (42) extending out of the through hole (231), and a positioning hole (14) is opened on the outer wall of the preheater body (1) corresponding to the positioning protrusion (421), and the positioning protrusion (421) corresponds to the positioning hole (14) one by one and is plug-fitted.

9. A control method for a high-efficiency compact air preheater, characterized in that: The following steps are involved: S1. A corresponding number of air preheaters are configured according to the number of burners equipped in the heating furnace, and the medium input pipeline (7) is connected to the water inlet main pipe (133) of multiple air preheaters, the medium output pipeline (8) is connected to the water outlet main pipe (134) of multiple air preheaters, and the top air outlet end of the focusing hood (22) is connected to the air inlet of the corresponding burner; S2, opening the flow meter (72), the thermometer (73) and the flow control valve (71) on the medium input pipeline (7) and the medium output pipeline (8) to allow the heat source to flow into the heat exchange tube (13) of the air preheater; S3, starting the heating furnace, using the suction force of the heating furnace to guide ambient air into the preheater body (1) to exchange heat with the heat exchange tubes (13) densely covered with fins (131); S4, monitoring the thermometer (73) on the outlet end of the focusing hood (22), recording the air outlet temperature, and adjusting the suction force of the heating furnace according to actual needs; S5, monitoring the flow meter (72), the thermometer (73) and the flow control valve (71) on the medium output pipeline (8), recording the temperature of the heat source flowing out after heat exchange, and adjusting the flow of the medium input pipeline (7) and the medium output pipeline (8) according to actual needs; S6. When shutting down, first close the flow control valve (71) on the medium input pipeline (7), then close the flow control valve (71) on the medium output pipeline (8), and finally stop the heating furnace from sucking air.

Images