Novel efficient energy-saving tubular gas preheater

Abstract

The utility model discloses a novel efficient energy-saving tubular gas preheater which comprises a preheater barrel, an upper tube plate, a lower tube plate and a heat exchange module. The upper tube plate and the lower tube plate are respectively arranged at two ends of the preheater cylinder and seal the internal space of the cylinder, the upper tube plate is connected with a gas inlet, and the lower tube plate is connected with a gas outlet; a smoke inlet is formed in the lower portion of the front side of the preheater barrel, and a smoke outlet is formed in the upper portion of the rear side of the preheater barrel. A plurality of heat exchange modules are arranged, and the plurality of heat exchange modules are arranged in the internal space of the preheater cylinder; the heat exchange module comprises a sealing box body and a heat exchange tube bundle, the heat exchange tube bundle is arranged in the sealing box body, and the two ends of the heat exchange tube bundle are connected with the upper tube plate and the lower tube plate respectively; the coal gas passes through the interior of the heat exchange tube bundle, and the flue gas passes through the space between the exterior of the heat exchange tube bundle and the interior of the preheater barrel. The gas preheater of the device is high in pure countercurrent operation heat exchange efficiency, small in flow resistance, convenient to install, free of vibration risk and very suitable for efficient preheating of gas due to the adoption of modular design.

Description

Technical Field

[0001] The utility model relates to the technical field of gas preheating equipment, in particular to a novel high-efficiency energy-saving tubular gas preheater. Background Art

[0002] Blast furnace gas preheaters play a key role in the ironmaking process of steel mills' blast furnaces. Their main functions include increasing gas temperature, promoting smelting reactions, improving energy efficiency, reducing thermal shock, and protecting equipment from particulate corrosion. Through the heat transfer process, the low-temperature state of gas generated from the top of the blast furnace is preheated to a higher temperature, which helps to improve the reduction performance of iron ore in the blast furnace. The low-temperature gas is heated by the waste heat of the exhaust flue gas. Such a preheating process not only improves production efficiency and reduces fuel consumption, but also ensures the smooth operation of the blast furnace. When preheating gas through flue gas, the current traditional heat pipe gas preheater uses spiral finned tubes to enhance the heat exchange effect. However, due to the harsh working environment, the heat exchange tubes are in contact with blast furnace gas for a long time. The particulate matter and corrosive components contained in the blast furnace gas may accumulate in the heat pipes, resulting in serious corrosion and blockage of the equipment and performance degradation, increasing the instability of operation and maintenance costs; at the same time, the heat transfer medium inside the heat pipe is limited by temperature and pressure, and its heat transfer effect is also significantly reduced. Utility Model Content

[0003] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and provide a new type of high-efficiency and energy-saving tubular gas preheater.

[0004] The utility model is realized through the following technical scheme: a novel high-efficiency and energy-saving tubular coal gas preheater, comprising a preheater cylinder, an upper tube plate, a lower tube plate and a heat exchange module; the upper tube plate and the lower tube plate are respectively arranged at both ends of the preheater cylinder and close the internal space of the cylinder, the upper tube plate is connected with a coal gas inlet, and the lower tube plate is connected with a coal gas outlet; a smoke inlet is arranged at the lower front part of the preheater cylinder, and a smoke outlet is arranged at the upper rear part of the preheater cylinder; a plurality of heat exchange modules are provided, and the plurality of heat exchange modules are arranged in the internal space of the preheater cylinder; the heat exchange module comprises a sealed box and a heat exchange tube bundle, the heat exchange tube bundle is arranged inside the sealed box, and the two ends of the heat exchange tube bundle are respectively connected with the upper tube plate and the lower tube plate; the coal gas flows inside the heat exchange tube bundle, and the smoke flows outside the heat exchange tube bundle and in the space between the inside of the preheater cylinder.

[0005] The adjacent heat exchange modules are spaced equally apart and sealed and isolated by partitions, which are used to guide the smoke into the sealed box to prevent cross-flow.

[0006] The heat exchange tube bundle is formed by a plurality of high-efficiency HP heat exchange tubes arranged in parallel; the heat exchange tube bundle is integrally bundled and fixed with a bundle every 1-2 m. The heat exchange tube bundle is integrally bundled and fixed with a bundle to achieve mutual support.

[0007] The high-efficiency HP heat exchange tube is a spirally deformed tube, the cross section of which is nearly elliptical, and the spirally deformed tube is twisted through multiple processing to form a spiral structure; a plurality of high-efficiency HP heat exchange tubes are mutually supported by convex point contact to form an axial multi-channel flow channel. The axial multi-channel flow channel formed between the heat exchange tube bundles has a three-dimensional variable space turbulent flow design, which can reduce the heat exchange end difference, reduce energy loss, and improve heat exchange efficiency.

[0008] The cross section of the heat exchange tube bundle is arranged in a square to form a grid-like integrated structure.

[0009] The upper end of the heat exchange tube bundle extends out of the upper tube plate by 30 mm, and the lower end of the heat exchange tube bundle extends out of the lower tube plate by 30 mm. The heat exchange tube bundle is fixed to the upper tube plate and the lower tube plate by welding.

[0010] The smoke inlet is provided with an anti-collision baffle, which can ensure that the smoke enters the heat exchanger cylinder uniformly and prevent the smoke from directly impacting the tube wall of the heat exchange tube bundle.

[0011] An expansion joint is arranged in the middle of the preheater cylinder.

[0012] The lower part of the preheater cylinder is also equipped with supporting legs.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] (1) The operation mode of the hot and cold fluids at the heat transfer interface of the heat pipe is changed to high-speed friction flow, which increases the gas flow rate, reduces the process resistance, and has better "heat transfer-pressure reduction" performance. Under the same resistance, the gas flow rate is fast and the heat exchange effect is good. The special three-dimensional structure of the heat exchange tube bundle reduces the dust accumulation on the heat exchange surface.

[0015] (2) The supporting structures such as the bow-shaped baffles used in traditional heat exchangers are eliminated. The high-efficiency HP heat exchange tubes rely on the outside of the tubes to achieve multi-point self-support. The tube bundles are fixed with strapping tapes, which enhances the overall rigidity and eliminates the risk of vibration.

[0016] (3) The coal gas and flue gas exchange heat in pure countercurrent in the heat exchange module, which has a simple structure, clear flow channels, and no dead zones in the airflow. The heat exchange tubes are assembled in a modular manner, which has a compact structure and reduces the total flow resistance. It is also convenient for equipment manufacturing and transportation, and the on-site hoisting and installation operation cycle is short and maintenance is convenient.

[0017] (4) Flue gas directly impacts the tube bundle, which can easily affect the durability of the heat exchange tube. By setting an anti-impact baffle at the flue gas inlet, the flue gas is prevented from directly impacting the heat exchange tube wall, thereby improving the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the heat exchange tube bundle and the preheater cylinder of the embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the connection between the heat exchange tube bundle and the tube sheet in the embodiment of the utility model;

[0021] Figure 4 This is a schematic diagram of the structure of the heat exchange module baffle of the embodiment of the utility model;

[0022] Figure 5 This is a schematic structural diagram of an anti-collision baffle according to an embodiment of the utility model;

[0023] Figure 6 This is a schematic diagram of the structure of the heat exchange tube bundle in an embodiment of the utility model;

[0024] Figure 7 A schematic diagram of wear when conventional round tubes are used in the heat exchange tube bundle of the prior art;

[0025] Figure 8 This is a schematic diagram of the anti-wear principle when the heat exchange tube bundle adopts spirally deformed tubes in the embodiment of the utility model.

[0026] The meanings of the reference numerals in the figure are as follows: 1. gas inlet; 2. gas outlet; 3. flue gas inlet; 4. flue gas outlet; 5. upper tube sheet; 6. lower tube sheet; 7. partition; 8. high-efficiency HP heat exchange tube; 9. sealing box; 10. preheater cylinder; 11. expansion joint; 12. support leg; 13. anti-collision baffle. DETAILED DESCRIPTION

[0027] The content of the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Example

[0029] See also Figures 1 to 6, which is a new type of high-efficiency and energy-saving tubular gas preheater, including a preheater barrel 10, an upper tube sheet 5, a lower tube sheet 6 and a heat exchange module; the upper tube sheet 5 and the lower tube sheet 6 are respectively arranged at both ends of the preheater barrel 10 and close the internal space of the barrel, the upper tube sheet 5 is connected to the gas inlet 1, and the lower tube sheet 6 is connected to the gas outlet 2; a flue gas inlet 3 is provided at the lower front part of the preheater barrel 10, and a flue gas outlet 4 is provided at the upper rear part of the preheater barrel 10; a plurality of heat exchange modules are provided, and the plurality of heat exchange modules are arranged in the internal space of the preheater barrel 10; the heat exchange module includes a sealed box 9 and a heat exchange tube bundle, the heat exchange tube bundle is arranged inside the sealed box 9, and the two ends of the heat exchange tube bundle are respectively connected to the upper tube sheet 5 and the lower tube sheet 6; the gas goes inside the heat exchange tube bundle, and the flue gas goes between the outside of the heat exchange tube bundle and the inside of the preheater barrel 10.

[0030] The adjacent heat exchange modules are spaced equally apart and sealed and isolated by partitions 7. The partitions 7 are provided to guide the smoke into the sealed box 9 to prevent cross-flow.

[0031] The heat exchange tube bundle is formed by a plurality of high-efficiency HP heat exchange tubes 8 arranged in parallel; the heat exchange tube bundle is integrally bundled and fixed with a bundle of strapping tape at intervals of 1-2 m, preferably 1.5 m. The heat exchange tube bundle is integrally bundled and fixed with a bundle of strapping tape to achieve mutual support.

[0032] The high-efficiency HP heat exchange tube 8 is a spirally deformed tube, and the cross section of the spirally deformed tube is nearly elliptical. The spirally deformed tube is twisted through multiple processing to form a spiral structure; a number of high-efficiency HP heat exchange tubes 8 support each other through convex point contact to form an axial multi-channel flow channel. An axial multi-channel flow channel is formed between the heat exchange tube bundles, which has a three-dimensional variable space turbulent flow design, can reduce the heat exchange end difference, reduce energy loss, and improve heat exchange efficiency. The heat exchange tube bundles rely on the convex sections of adjacent heat exchange tubes to support and block each other at multiple points, forming an integrated structure similar to a grid, realizing a self-supporting design, which can stabilize the structure and form a flow channel.

[0033] The cross section of the heat exchange tube bundle is arranged in a square shape to form a grid-like integrated structure.

[0034] The upper end of the heat exchange tube bundle extends out of the upper tube sheet 5 by 30 mm, and the lower end of the heat exchange tube bundle extends out of the lower tube sheet 6 by 30 mm. The heat exchange tube bundle is fixed to the upper tube sheet 5 and the lower tube sheet 6 by welding.

[0035] An anti-collision baffle 13 is provided at the flue gas inlet 3. The provision of the anti-collision baffle 13 can enable the flue gas to enter the heat exchanger cylinder uniformly, and prevent the flue gas from directly impacting the tube wall of the heat exchange tube bundle.

[0036] An expansion joint 11 is provided in the middle of the preheater cylinder 10 .

[0037] A support leg 12 is also installed at the lower part of the preheater cylinder 10.

[0038] The working principle of the utility model is as follows: low-temperature coal gas enters the high-efficiency HP heat exchange tube 8 from the coal gas inlet 1, is quickly preheated by the high-temperature flue gas and then discharged from the coal gas outlet 2; high-temperature flue gas enters from the flue gas inlet 3, passes through the anti-collision baffle 13 and evenly enters the preheater cylinder 10, enters each heat exchange module through the partition 7, and is absorbed by the coal gas in the high-efficiency HP heat exchange tube 8, and then is discharged from the flue gas outlet 4. The inside of the heat exchange tube bundle is the tube side, and the space between the outside of the heat exchange tube bundle and the inside of the preheater cylinder 10 is the shell side. The shell side flue gas and the tube side coal gas are pure countercurrent flow, maximizing heat exchange. The special spiral structure of the high-efficiency HP heat exchange tube 8 enhances the disturbance of the boundary layer of the fluid inside and outside the tube, reduces dust accumulation and strengthens the heat exchange process. Since the baffles in the existing equipment are eliminated, the heat exchange module presents a self-supporting grid-like multi-channel structure, and the shell side forms a longitudinal flow channel. The flue gas entering the sealed box 9 can flow smoothly along the tube bundle, effectively reducing the process resistance.

[0039] In this embodiment, HP heat exchange tube refers to High Performance spirally deformed tube. In this application, the heat exchange tube bundle uses a spirally deformed tube with a cross section that is nearly elliptical and is twisted multiple times to form a spiral structure. Figure 7 As shown, the traditional heat exchange tube is a round tube. When the gas passes through the round tube, a vortex will be generated. As shown in the figure, a black spot is formed at the 60° angle of the round tube, indicating that the round tube has a 60° wear angle at this point. There is a vortex structure on the right side of the figure, indicating that there is a vortex here. Figure 8 This is the anti-wear principle diagram of the HP heat exchange tube used in the embodiment of the utility model. As shown in the figure, there is no black spot on the HP heat exchange tube at 60°, indicating that there is no 60° wear angle. There is no vortex structure at 180° on the right side of the figure, indicating that no eddy current is generated there. The HP heat exchange tube has anti-wear characteristics. Generally, the largest wear point of a round tube appears at the 60° angle, which is the first to be worn through. There is a vortex at the 180° angle (that is, the back of the round tube along the flow direction), and the speed decreases, which is the most likely to cause dust accumulation. According to the wear law of the round tube heat exchange tube in the flue gas flow field, the largest wear position appears at the 60° angle of the circular cross section, while the cross section of the HP heat exchange tube is nearly elliptical, there is no 60° wear angle, and there are no vortex points on the back, so there will be no dust accumulation.

[0040] The above detailed description is a specific description of a feasible embodiment of the utility model. The embodiment is not intended to limit the patent scope of the utility model. Any equivalent implementation or modification that does not deviate from the utility model should be included in the patent scope of this case.

Claims

1. A new type of high-efficiency and energy-saving tubular gas preheater, characterized by: It comprises a preheater cylinder, an upper tube sheet, a lower tube sheet and a heat exchange module; the upper tube sheet and the lower tube sheet are respectively arranged at both ends of the preheater cylinder and close the internal space of the cylinder, the upper tube sheet is connected with a gas inlet, and the lower tube sheet is connected with a gas outlet; a smoke inlet is arranged at the lower front part of the preheater cylinder, and a smoke outlet is arranged at the upper rear part of the preheater cylinder; a plurality of heat exchange modules are provided, and the plurality of heat exchange modules are arranged in the internal space of the preheater cylinder; the heat exchange module comprises a sealed box and a heat exchange tube bundle, the heat exchange tube bundle is arranged inside the sealed box, and the two ends of the heat exchange tube bundle are respectively connected with the upper tube sheet and the lower tube sheet; the gas flows inside the heat exchange tube bundle, and the smoke flows outside the heat exchange tube bundle and in the space inside the preheater cylinder.

2. The novel high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: The adjacent heat exchange modules are spaced equally apart and are sealed and isolated by partitions.

3. The new high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: The heat exchange tube bundle is formed by a plurality of high-efficiency HP heat exchange tubes arranged in parallel; the heat exchange tube bundle is integrally bundled and fixed with a bundling belt every 1-2 m.

4. The novel high-efficiency and energy-saving tubular gas preheater according to claim 3 is characterized in that: The high-efficiency HP heat exchange tube is a spirally deformed tube, the cross section of which is nearly elliptical, and the spirally deformed tube is twisted through multiple processing to form a spiral structure; a plurality of high-efficiency HP heat exchange tubes are mutually supported by convex point contact to form an axial multi-channel flow channel.

5. The novel high-efficiency and energy-saving tubular gas preheater according to claim 3 is characterized in that: The cross section of the heat exchange tube bundle is arranged in a square to form a grid-like integrated structure.

6. The novel high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: The upper end of the heat exchange tube bundle extends out of the upper tube plate by 30 mm, and the lower end of the heat exchange tube bundle extends out of the lower tube plate by 30 mm. The heat exchange tube bundle is fixed to the upper tube plate and the lower tube plate by welding.

7. The novel high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: An anti-collision baffle is arranged at the smoke inlet.

8. The novel high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: An expansion joint is arranged in the middle of the preheater cylinder.

9. The novel high-efficiency and energy-saving tubular gas preheater according to claim 1 is characterized in that: The lower part of the preheater cylinder is also equipped with supporting legs.

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