Air duct steam heater integrated with zero-thermal-resistance spiral finned tube

Abstract

The invention provides an air duct steam heater integrated with zero-thermal-resistance spiral finned tubes. The air duct steam heater of the integrated zero-thermal-resistance spiral finned tube comprises a sealed air duct of a box structure, a finned tube bundle arranged in the sealed air duct, an inlet header and an outlet header which are located outside the sealed air duct, and a flow guide mechanism arranged in the sealed air duct. The inlet header is connected with the inlet end of the finned tube bundle through a plurality of steam distributing tubes penetrating through the top wall of the sealed air channel, and the outlet header is connected with the outlet end of the finned tube bundle through a gas collecting tube penetrating through the bottom wall of the sealed air channel. The finned tube bundle comprises a plurality of zero-thermal-resistance spiral finned tubes, and the zero-thermal-resistance spiral finned tubes are arranged in a staggered mode. The air duct steam heater integrated with the zero-thermal-resistance spiral finned tube has the advantages that lower-load dry-state operation of a boiler can be achieved, the SCR inlet smoke temperature is effectively increased, and the modification cost is controllable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal-fired thermal power generation technology, and particularly relates to a wind channel steam heater integrated with zero-thermal-resistance spiral finned tubes. BACKGROUND

[0002] In the field of deep load regulation of coal-fired thermal power units, with the increasing proportion of new energy power generation, thermal power units need to bear deeper load regulation tasks. However, the units face two key technical problems when operating at low load: first, the safety problem of the boiler wide-load denitration system operation, when the unit load decreases, the flue gas temperature at the outlet of the economizer decreases, resulting in the SCR denitration system being unable to operate normally; second, the stability problem of the boiler low-load stable combustion, the temperature in the furnace decreases at low load, and the combustion stability decreases. The existing wind channel heating technology generally has problems such as low heat exchange efficiency, uneven airflow distribution, high maintenance cost, etc. In particular, the traditional finned tube adopts a welding process to connect the base pipe and the fin, which has defects such as large contact thermal resistance and easy to fall off, seriously affecting the service life and heat exchange efficiency of the equipment. In addition, the existing wind channel heater has poor adjustment accuracy of the flow guide device, and it is difficult to adapt to the large range of load changes under the deep load regulation condition, resulting in large fluctuations in hot air temperature, which seriously affects the low-load stable combustion performance of the boiler.

[0003] Therefore, it is necessary to provide a new wind channel steam heater integrated with zero-thermal-resistance spiral finned tubes to solve the above technical problems. SUMMARY

[0004] The technical problem solved by the present application is to provide a wind channel steam heater integrated with zero-thermal-resistance spiral finned tubes, which can realize lower load dry operation of the boiler, effectively improve the SCR inlet flue gas temperature, and has controllable modification cost.

[0005] To solve the above technical problems, the wind channel steam heater integrated with zero-thermal-resistance spiral finned tubes provided by the present application comprises: a sealed wind channel in a box structure, a finned tube bundle arranged inside the sealed wind channel, an inlet header and an outlet header located outside the sealed wind channel, and a flow guide mechanism arranged in the sealed wind channel. The inlet header is connected with the inlet end of the finned tube bundle through a plurality of steam distribution pipes penetrating the top wall of the sealed wind channel, and the outlet header is connected with the outlet end of the finned tube bundle through a gas collection pipe penetrating the bottom wall of the sealed wind channel. The finned tube bundle comprises a plurality of zero-thermal-resistance spiral finned tubes, and the plurality of zero-thermal-resistance spiral finned tubes are arranged in a staggered manner. The base pipe and the spiral fin of each zero-thermal-resistance spiral finned tube are integrally formed by a medium-frequency extrusion process.

[0006] Preferably, the height of the spiral fin of the zero-thermal-resistance spiral finned tube is 20 mm, the fin thickness is 4 mm, the fin outer diameter is 75 mm, the base pipe inner diameter is 28 mm, and the base pipe material is 12Cr1MoV alloy steel.

[0007] Preferably, the guide mechanism is located at the inlet section of the sealing air duct, the guide mechanism comprises a plurality of guide plates in the sealing air duct, a rotating shaft is rotatably arranged on the guide plate, both ends of the rotating shaft extend to the outside of the sealing air duct, the rotating shaft is rotatably connected with the sealing air duct, both ends of the rotating shaft are fixedly sleeved with a connecting block, a connecting rod is fixedly installed on the connecting block, a clamping block is fixedly installed on the connecting block, the clamping block is fixedly connected with the guide plate, connecting strips are arranged on both sides of the sealing air duct, both ends of the connecting rod are rotatably arranged on the two connecting strips, a same moving rod is fixedly installed between the two connecting strips, the moving rod is located above the sealing air duct, a hydraulic cylinder is fixedly installed on the top of the sealing air duct, a connecting frame is fixedly installed on the output shaft of the hydraulic cylinder, and the moving rod penetrates the connecting block.

[0008] Preferably, a plurality of rotating holes and a plurality of arc-shaped holes are arranged on the side wall of the sealing air duct, the rotating shaft penetrates the rotating hole and is rotatably connected with the inner wall of the rotating hole, and the clamping block penetrates the rotating hole.

[0009] Preferably, a sealing frame is fixedly installed on the outer wall of the sealing air duct, and the guide mechanism is located in the sealing frame.

[0010] Preferably, a wind guide plate is arranged on the side, away from the finned tube bundle, of the guide mechanism, a plurality of wind guide holes are formed in the wind guide plate, and the wind guide holes are horizontally arranged.

[0011] Preferably, a filter screen is arranged on the side, away from the guide mechanism, of the wind guide plate.

[0012] Preferably, a supporting seat is arranged below the sealing air duct, and the supporting seat is fixedly connected with the sealing air duct.

[0013] Preferably, temperature sensors and pressure sensors are arranged in the inlet header and the outlet header, and signal lines of the temperature sensors and the pressure sensors are led out through waterproof junction boxes and connected with an external intelligent temperature control system.

[0014] Preferably, an air inlet flange is arranged on the inlet header, an air outlet flange is arranged in the outlet header, and a drain valve is connected with the air outlet flange.

[0015] Compared with the related art, the air duct steam heater with integrated zero-thermal-resistance spiral finned tube provided by the application has the following beneficial effects: This invention provides a steam heater for air ducts with integrated zero-thermal-resistance spiral finned tubes. It employs a one-piece molding design with zero-thermal-resistance spiral finned tubes, achieving a seamless connection between the base tube and the spiral fins, completely eliminating contact thermal resistance and improving heat exchange efficiency by more than 25% compared to traditional structures. The optimized design of fin height (20mm) and thickness (4mm) maximizes the heat exchange area within a limited space. The flow guiding mechanism, driven by a hydraulic cylinder, links the connecting frame, moving rod, and connecting rod, enabling precise angle adjustment of the guide plate to ensure uniform airflow distribution and control of flow velocity deviation within ±5%. The coordinated design of the sealing plate and sealing frame effectively prevents air leakage, significantly improving the equipment's sealing performance. Temperature and pressure sensors are installed in the inlet and outlet headers respectively, enabling precise temperature control through an intelligent temperature control system. The combined use of the air guide plate and filter effectively purifies the intake air quality and extends the equipment's service life. The optimized design of the support base ensures the equipment's operational stability, and the drain valve, combined with a 5° inclined pipe arrangement, effectively prevents water hammer. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a preferred embodiment of the duct steam heater with integrated zero thermal resistance spiral finned tube provided by the present invention. Figure 2 for Figure 1 A structural schematic diagram from another perspective is shown; Figure 3 for Figure 1 The diagram shown is a structural schematic after the sealing frame has been removed. Figure 4 for Figure 3 The diagram shown is a structural schematic after the sealing duct has been removed. Figure 5 for Figure 4 The diagram shows the connection structure between the inlet header, outlet header, and finned tube bundle. Figure 6 for Figure 5 A structural schematic diagram from another perspective is shown; Figure 7 for Figure 5 The diagram shows the structure of a zero thermal resistance spiral finned tube. Figure 8 for Figure 4 The diagram shows the structure of the flow guiding mechanism; Figure 9 for Figure 8 An enlarged structural diagram of part A shown; Figure 10 for Figure 8 An enlarged structural diagram of part B is shown; Figure 11 for Figure 4 The diagram shows the structure of the air guide plate. Figure 12 Fig. 1 is a structural schematic diagram of a sealing air duct according to the present application. Figure 1 Fig. 2 is a structural schematic diagram of a sealing air duct according to the present application.

[0017] Fig. 1 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 2 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 3 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 4 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 5 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 6 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 7 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 8 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 9 is a structural schematic diagram of a sealing air duct according to the present application. Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. DETAILED DESCRIPTION

[0018] The present application will be further described below in conjunction with the drawings and embodiments.

[0019] Please refer to Figures 1-12 Fig. 1 is a structural schematic diagram of a sealing air duct according to the present application. Figure 1 Fig. 1 is a structural schematic diagram of a sealing air duct according to the present application. Figure 2 Fig. 2 is a structural schematic diagram of a sealing air duct according to the present application. Figure 1 Fig. 2 is a structural schematic diagram of a sealing air duct according to the present application. Figure 3 Fig. 3 is a structural schematic diagram of a sealing air duct according to the present application. Figure 1 Fig. 3 is a structural schematic diagram of a sealing air duct according to the present application. Figure 4 Fig. 4 is a structural schematic diagram of a sealing air duct according to the present application. Figure 3 Fig. 4 is a structural schematic diagram of a sealing air duct according to the present application. Figure 5 Fig. 5 is a structural schematic diagram of a sealing air duct according to the present application. Figure 4 Fig. 5 is a structural schematic diagram of a sealing air duct according to the present application. Figure 6 Fig. 6 is a structural schematic diagram of a sealing air duct according to the present application. Figure 5 Fig. 6 is a structural schematic diagram of a sealing air duct according to the present application. Figure 7 Fig. 7 is a structural schematic diagram of a sealing air duct according to the present application. Figure 5 Fig. 7 is a structural schematic diagram of a sealing air duct according to the present application. Figure 8 Fig. 8 is a structural schematic diagram of a sealing air duct according to the present application. Figure 4 Fig. 8 is a structural schematic diagram of a sealing air duct according to the present application. Figure 9 Fig. 9 is a structural schematic diagram of a sealing air duct according to the present application. Figure 8 Fig. 9 is a structural schematic diagram of a sealing air duct according to the present application. Figure 10 Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. Figure 8 Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. Figure 11 Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. Figure 4 Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. Figure 12 Fig. 10 is a structural schematic diagram of a sealing air duct according to the present application. Figure 1The structure diagram of the sealing air duct is shown. The air duct steam heater integrated with zero-thermal-resistance spiral finned tube comprises a sealing air duct 5 in the form of a box structure, a finned tube bundle 3 arranged inside the sealing air duct 5, an inlet header 1 and an outlet header 2 arranged outside the sealing air duct 5, and a flow guide mechanism 4 arranged inside the sealing air duct 5; The inlet header 1 is connected with the inlet end of the finned tube bundle 3 through a plurality of steam distribution pipes 6 penetrating the top wall of the sealing air duct 5, and the outlet header 2 is connected with the outlet end of the finned tube bundle 3 through a gas collection pipe 7 penetrating the bottom wall of the sealing air duct 5; The finned tube bundle 3 comprises a plurality of zero-thermal-resistance spiral finned tubes 31, and the plurality of zero-thermal-resistance spiral finned tubes 31 are arranged in a staggered manner. The base pipe 311 and the spiral fin 312 of each zero-thermal-resistance spiral finned tube 31 are integrally formed by a medium-frequency extrusion process.

[0020] The height of the spiral fin 312 of the zero-thermal-resistance spiral finned tube 31 is 20 mm, the fin thickness is 4 mm, the fin outer diameter is 75 mm, the base pipe 311 inner diameter is 28 mm, and the base pipe material is 12Cr1MoV alloy steel.

[0021] The flow guide mechanism 4 is located at the inlet section of the sealing air duct 5. The flow guide mechanism 4 comprises a plurality of flow guide plates 401 arranged inside the sealing air duct 5. A rotating shaft 404 is rotatably arranged on each flow guide plate 401. Both ends of the rotating shaft 404 extend out of the sealing air duct 5 and are rotatably connected to the sealing air duct 5. Both ends of the rotating shaft 404 are fixedly sleeved with a connecting block 403. A connecting rod 402 is fixedly arranged on the connecting block 403. A clamping block 405 is fixedly arranged on the connecting block 403. The clamping block 405 is fixedly connected to the flow guide plate 401. Connecting strips 407 are arranged on both sides of the sealing air duct 5. Both ends of the connecting rod 402 are rotatably arranged on the two connecting strips 407. A same moving rod 408 is fixedly arranged between the two connecting strips 407. The moving rod 408 is located above the sealing air duct 5. A hydraulic cylinder 409 is fixedly arranged on the top of the sealing air duct 5. A connecting frame 410 is fixedly arranged on the output shaft of the hydraulic cylinder 409. The moving rod 408 penetrates the connecting frame 410.

[0022] A plurality of rotating holes 501 and a plurality of arc-shaped holes 502 are arranged on the side wall of the sealing air duct 5. The rotating shaft 404 penetrates the rotating hole 501 and is rotatably connected to the inner wall of the rotating hole 501. The clamping block 405 penetrates the rotating hole 501. A sealing plate 406 is fixedly arranged on the connecting block 403. The sealing plate 406 is matched with the rotating hole 501. One side of the sealing plate 406 is in contact with the outer wall of the sealing air duct 5.

[0023] The outer wall of the sealing air duct 5 is fixedly provided with a sealing frame, and the flow guide mechanism 4 is located in the sealing frame.

[0024] The flow guide mechanism 4 is provided with a wind guide plate 9 away from the finned tube bundle 3, and a plurality of wind guide holes are formed in the wind guide plate 9.

[0025] The wind guide plate 9 is provided with a filter screen 10 away from the flow guide mechanism 4.

[0026] The lower portion of the sealing air duct 5 is provided with a supporting seat 8 which is fixedly connected with the sealing air duct 5.

[0027] Temperature sensors and pressure sensors are arranged in the inlet header 1 and the outlet header 2, and the signal lines of the temperature sensors and the pressure sensors are led out through waterproof junction boxes and connected with an external intelligent temperature control system.

[0028] The inlet header 1 is provided with an air inlet flange 101, and the outlet header 2 is provided with an air outlet flange 201 which is connected with a drain valve 202.

[0029] The working principle of the integrated zero-thermal-resistance spiral finned tube air duct steam heater is as follows: The steam-air heat exchange mechanism is as follows: the main steam enters the inlet header 1 through the air inlet flange 101, is evenly distributed to the finned tube bundle 3 through the plurality of steam distribution pipes 6, and in the zero-thermal-resistance spiral finned tube 31, the steam transfers heat to the spiral fin 312 through the base pipe 311 wall, which fully utilizes the high-efficiency heat transfer characteristics of the finned tube, and the heat-exchanged steam enters the outlet header 2 through the gas collection pipe 7 and is finally discharged from the system through the drain valve 202.

[0030] The working process of the air side is as follows: the hot secondary air is purified through the filter screen 10, is preliminarily distributed through the wind guide holes of the wind guide plate 9, and then enters the flow guide mechanism 4, the flow guide plate 401 is driven by the hydraulic cylinder 409, the linkage of the rotating shaft 404 and the connecting block 403 realizes accurate angle adjustment, and the air flow uniformly passes through the finned tube bundle 3, and when the air flow passes through the finned tube bundle 3, the air absorbs the heat transferred by the fin surface, and the temperature is significantly increased. The whole system is monitored in real time through the temperature and pressure sensors arranged on the inlet header 1 and the outlet header 2, the data is transmitted to the intelligent temperature control system through the waterproof junction boxes, the system automatically adjusts the steam flow and the angle of the flow guide plate according to the load change, the accuracy of the air temperature control is ensured, and in particular, the special sealing design of the flow guide mechanism 4 ensures that the equipment does not leak air during long-term operation, the supporting seat 6 provides stable support for the whole system, and the operation stability of the equipment under various working conditions is ensured.

[0031] Compared with the related art, the integrated zero-thermal-resistance spiral fin tube air duct steam heater has the following beneficial effects: The integrated zero-thermal-resistance spiral fin tube air duct steam heater is integrally formed by using the zero-thermal-resistance spiral fin tube 31, seamless connection is achieved between the base pipe 311 and the spiral fin 312, the contact thermal resistance is completely eliminated, the heat exchange efficiency is improved by more than 25% compared with the conventional structure, the optimization design of the fin height of 20 mm and the fin thickness of 4 mm realizes the maximization of the heat exchange area in the limited space, the linkage mechanism of the connecting frame 410, the moving rod 408 and the connecting rod 402 is driven by the hydraulic cylinder 409, the precise angle adjustment of the guide plate 401 is realized, the uniform distribution of the airflow is ensured, the flow rate deviation is controlled within ± 5%, the sealing plate 406 is matched with the sealing frame, the air leakage is effectively prevented, the sealing performance of the equipment is significantly improved, the temperature sensor and the pressure sensor are arranged on the inlet header 1 and the outlet header 2 respectively, the precise temperature control is realized through the intelligent temperature control system, the combination of the air deflector 9 and the filter screen 10 effectively purifies the air quality and prolongs the service life of the equipment, the optimization design of the support seat 6 ensures the stability of the equipment, the drain valve 202 is matched with the 5° inclined pipeline, and the water hammer phenomenon is effectively prevented.

[0032] The above-mentioned is only the embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent flow transformation obtained by using the content of the specification and the drawings, or direct or indirect application in other related technical fields, is also included in the patent protection range of the present application.

Claims

1. A duct steam heater integrating a zero thermal resistance spiral finned tube, characterized in that, include: The sealed air duct has a box-shaped structure, a finned tube bundle installed inside the sealed air duct, an inlet header and an outlet header located outside the sealed air duct, and a flow guiding mechanism installed inside the sealed air duct. The inlet header is connected to the inlet end of the finned tube bundle through multiple steam distribution pipes penetrating the top wall of the sealed air duct, and the outlet header is connected to the outlet end of the finned tube bundle through a gas collection pipe penetrating the bottom wall of the sealed air duct. The finned tube bundle includes multiple zero thermal resistance spiral finned tubes, which are arranged in a staggered manner. The base tube and spiral fins of each zero thermal resistance spiral finned tube are integrally formed by medium frequency extrusion process.

2. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 1, characterized in that, The zero thermal resistance spiral finned tube has a spiral fin height of 20mm, a fin thickness of 4mm, a fin outer diameter of 75mm, a base tube inner diameter of 28mm, and a base tube material of 12Cr1MoV alloy steel.

3. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 1, characterized in that, The flow guiding mechanism is located at the inlet section of the sealed air duct. The flow guiding mechanism includes multiple flow guiding plates inside the sealed air duct. A rotating shaft is rotatably mounted on the flow guiding plate. Both ends of the rotating shaft extend outside the sealed air duct and are rotatably connected to the sealed air duct. Connecting blocks are fixedly sleeved on both ends of the rotating shaft. Connecting rods are fixedly mounted on the connecting blocks. Clamping blocks are fixedly mounted on the connecting blocks and are fixedly connected to the flow guiding plates. Connecting strips are provided on both sides of the sealed air duct. The two ends of the connecting rod are rotatably mounted on two connecting strips respectively. A common moving rod is fixedly mounted between the two connecting strips. The moving rod is located above the sealed air duct. A hydraulic cylinder is fixedly mounted on the top of the sealed air duct. A connecting frame is fixedly mounted on the output shaft of the hydraulic cylinder. The moving rod passes through the connecting block.

4. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 3, characterized in that, The sidewall of the sealed air duct is provided with multiple rotating holes and multiple arc-shaped holes. The rotating shaft passes through the rotating holes and is rotatably connected to the inner wall of the rotating holes. The clamping block passes through the rotating holes. A sealing plate is fixedly installed on the connecting block. The sealing plate is adapted to the rotating holes. One side of the sealing plate is in contact with the outer wall of the sealed air duct.

5. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 4, characterized in that, A sealing frame is fixedly installed on the outer wall of the sealed air duct, and the flow guiding mechanism is located inside the sealing frame.

6. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 1, characterized in that, The air guiding mechanism has an air guide plate on the side away from the finned tube bundle, and the air guide plate has multiple air guide holes, which are horizontally arranged.

7. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 6, characterized in that, A filter screen is provided on the side of the air guide plate away from the airflow guiding mechanism.

8. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 1, characterized in that, A support base is provided below the sealed air duct, and the support base is fixedly connected to the sealed air duct.

9. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 1, characterized in that, Temperature sensors and pressure sensors are installed in both the inlet and outlet headers. The signal lines of the temperature sensors and pressure sensors are led out through a waterproof junction box and connected to an external intelligent temperature control system.

10. The duct steam heater with integrated zero thermal resistance spiral finned tube according to claim 9, characterized in that, The inlet header is equipped with an inlet flange, and the outlet header is equipped with an outlet flange, which is connected to a drain valve.

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