Shell-and-tube heat exchanger

Abstract

The utility model relates to the technical field of heat exchangers, in particular to a shell-and-tube heat exchanger which comprises a shell, end sockets are arranged at the two ends of the shell, a spiral baffle plate and a heat exchange tube are arranged in the shell, and sawtooth baffle plates are arranged at the two ends of the spiral baffle plate. The rib has specific parameters such as rib height, screw pitch, rib thickness and an included angle between the rib and the axial direction of the heat exchange tube, the structure can destroy formation of a boundary layer when fluid flows in the tube, disturbance of the fluid is enhanced, and therefore the heat exchange efficiency between the fluid in the tube and the heat exchange tube is effectively improved. Meanwhile, the spiral baffle plates are arranged in the shell, and the sawtooth baffle plates are arranged at the two ends of the shell, so that the flowing state of shell pass fluid can be optimized, heat is promoted to be fully exchanged, and the heat exchange efficiency of the whole heat exchanger is remarkably improved compared with a traditional shell-and-tube heat exchanger; and the requirements of industrial application scenes with relatively high requirements on heat exchange efficiency are better met.

Description

Technical Field

[0001] This application relates to the technical field of heat exchangers, and in particular to a shell-and-tube heat exchanger. Background Technology

[0002] Heat exchangers, as a type of heat exchange equipment widely used in many fields such as industrial production and energy utilization, play a vital role. They enable the transfer of heat between different media, effectively improving energy utilization efficiency and ensuring the stable operation of process flows. For example, in chemical production, it is often necessary to heat or cool reactants to meet specific chemical reaction conditions. In the power industry, heat exchangers are used to cool the circulating water of generator sets. Shell-and-tube heat exchangers, with their robust structure, wide applicability, and high operational flexibility, have become one of the most widely used types of heat exchangers, and are widely distributed in many industrial sectors such as petroleum, chemical, power, and pharmaceutical industries.

[0003] During heat exchange, the surface of the heat exchange tubes in traditional shell-and-tube heat exchangers is relatively smooth. When the fluid flows inside the tubes, a boundary layer is easily formed, which hinders the efficient transfer of heat and makes it difficult to further improve the heat exchange efficiency. Moreover, if the baffle structure outside the tubes is not designed properly, it will also affect the flow state of the shell-side fluid, resulting in insufficient heat exchange. The overall heat exchange performance often cannot meet the needs of some industrial application scenarios with high requirements for heat exchange efficiency.

[0004] During long-term operation, due to the complex composition of the internal medium of the heat exchanger, scaling is prone to occur on the inner and outer walls of the heat exchange tubes. Scaling not only reduces the effective heat exchange area of ​​the heat exchange tubes, but also increases the flow resistance of the fluid, further affecting the heat exchange efficiency. At the same time, under some working conditions with corrosive media, the shell of the heat exchanger and other components such as the heat exchange tubes are prone to corrosion, reducing the service life of the equipment and increasing maintenance costs and safety risks. Utility Model Content

[0005] To further improve heat exchange efficiency, this application provides a shell-and-tube heat exchanger.

[0006] This application provides a shell-and-tube heat exchanger with the following technical solution: it includes a shell, both ends of which are provided with end caps, and a spiral baffle and heat exchange tubes are provided inside the shell. The spiral baffle has serrated baffles at both ends, and the heat exchange tubes pass through the spiral baffles and the serrated baffles. Both ends of the heat exchange tubes are mounted on the shell through tube sheets.

[0007] Optionally, the outer wall of the heat exchange tube is provided with a nano-hydrophobic coating, the thickness of which is 50-80 nm.

[0008] Optionally, the inner wall of the heat exchange tube is provided with a spiral rib, the rib height of which is 0.5-2.0 mm, the pitch of which is 5-20 mm, the thickness of which is 0.2-0.8 mm, the angle between which is ...) an angle of 30°-60° between which is which is which is which is which is which is which is which is which is which is which is which is which is which is which is) an angle of 30°-60° between which is which is which is which is which is which is which is which is which is which is which is which is which is which is which is) an angle of 30

[0009] Optionally, flanges are installed at both ends of the outer casing and on both end caps, and the flanges on the outer casing and the flanges on the end caps are connected by fixing bolts.

[0010] Optionally, a sealing ring is provided between the two flanges, and the sealing ring is configured as an "O" shape.

[0011] Optionally, the two end caps are respectively provided with a heat inlet and a heat outlet, the upper part of the outer shell is provided with a cold inlet and a cold outlet, the cold inlet and the cold outlet are located at opposite ends, and the lower part of the outer shell is provided with a drain outlet, which is located below the cold outlet.

[0012] Optionally, the outer shell has a double-layer design, with the outer shell base material being carbon steel and the outer shell surface layer being a corrosion-resistant alloy, and the layers are joined together by explosive welding.

[0013] In summary, this application includes the following beneficial technical effects:

[0014] 1. The heat exchange tube of this utility model has a spiral rib on its inner wall, which has specific parameters such as rib height, pitch, rib thickness and the angle with the heat exchange tube axis. This structure can disrupt the formation of the boundary layer when the fluid flows in the tube, enhance the turbulence of the fluid, and thus effectively improve the heat exchange efficiency between the fluid in the tube and the heat exchange tube. At the same time, the shell is provided with a spiral baffle and sawtooth baffles at both ends, which can optimize the flow state of the shell-side fluid and promote full heat exchange. All these factors combined make the heat exchange efficiency of the entire heat exchanger significantly improved compared with the traditional shell-and-tube heat exchanger, better meeting the needs of industrial application scenarios with high requirements for heat exchange efficiency.

[0015] 2. The heat exchange tube of this utility model is provided with a nano-hydrophobic coating on its outer wall, which can effectively reduce the adhesion of dirt on the outer wall of the heat exchange tube and reduce the impact of scaling on heat exchange efficiency; in addition, the shell adopts a double-layer design, with carbon steel as the base material and corrosion-resistant alloy as the surface layer, which is bonded by explosive welding, which can enhance the corrosion resistance of the shell under corrosive conditions, thereby extending the service life of the entire heat exchanger equipment, reducing maintenance costs caused by corrosion, scaling and other problems, and reducing safety risks. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure in an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the interior of the outer casing in an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of the spiral baffle and sawtooth baffle structure in the embodiments of this application;

[0019] Figure 4 This is a schematic diagram of the heat exchange tube structure in an embodiment of this application.

[0020] Reference numerals: 1. Outer shell; 2. End cap; 3. Heat inlet; 4. Heat outlet; 5. Cold inlet; 6. Cold outlet; 7. Drain; 8. Heat exchange tube; 9. Tube sheet; 10. Spiral baffle; 11. Serrated baffle; 12. Spiral rib; 13. Nano-hydrophobic coating; 14. Flange; 15. Fixing bolt; 16. Sealing ring. Detailed Implementation

[0021] The following is in conjunction with the appendix Figures 1-4 This application will be described in further detail.

[0022] This application discloses a shell-and-tube heat exchanger. For example... Figure 1 , Figure 2 As shown, the heat exchanger includes an outer shell 1, which is a double-layer design. The base material of the outer shell 1 is carbon steel, and the surface layer of the outer shell 1 is a corrosion-resistant alloy, which is bonded together by explosive welding. The excellent mechanical properties of carbon steel, such as its good strength and certain toughness, provide a stable support frame for the entire heat exchanger, ensuring the stability of its structure under different operating conditions. The corrosion-resistant alloy can greatly enhance the resistance of the outer shell 1 to various corrosive media, enabling it to work normally for a long time in relatively harsh chemical environments, avoiding damage to the outer shell 1 due to corrosion problems and affecting the overall service life of the heat exchanger. Both ends of the outer shell 1 are provided with end caps 2.

[0023] See Figure 2 As shown, flanges 14 are installed on both ends of the outer shell 1 and on the two end caps 2. The flanges 14 on the outer shell 1 and the flanges 14 on the end caps 2 are connected by fixing bolts 15. During the connection process.

[0024] The fixing bolts 15 can firmly fix the various components together, so that the whole structure remains stable. A sealing ring 16 is provided between the two flanges 14. The sealing ring 16 is set as an "O" shape. It is tightened by the fixing bolts 15 and the gap is filled by the sealing ring 16, which ensures the sealing of the entire heat exchanger structure, prevents the medium from leaking, and enables the above heat exchange process to proceed stably and continuously.

[0025] In this embodiment, the two end caps 2 are respectively provided with a heat inlet 3 and a heat outlet 4. The heat medium enters the heat exchanger from the heat inlet 3, and after a series of heat exchange processes, it flows out from the heat outlet 4, thereby realizing the transfer of heat.

[0026] The upper part of the outer shell 1 is provided with a cold inlet 5 and a cold outlet 6. The cold inlet 5 and the cold outlet 6 are located at both ends. The location at both ends is conducive to the cold medium entering and flowing out of the heat exchanger more evenly and smoothly, ensuring that the cold medium can fully contact the internal heat exchange components, thereby achieving a better heat exchange effect.

[0027] In this embodiment, a drain port 7 is provided at the lower part of the outer shell 1. The drain port 7 is located below the cold outlet 6. A one-way valve is provided on the drain port 7. During the long-term operation of the heat exchanger, some impurities and dirt will inevitably be generated. The existence of the drain port 7 provides convenience for regularly cleaning these impurities. Through the drain port 7, substances that may affect the normal operation and heat exchange efficiency of the heat exchanger can be discharged in a timely manner, ensuring the cleanliness of the heat exchanger and maintaining its good working condition.

[0028] See Figure 2 , Figure 3 As shown, the shell 1 is equipped with a spiral baffle 10 and a heat exchange tube 8. The spiral baffle 10 is equipped with serrated baffles 11 at both ends, which causes the flowing medium to continuously change its flow direction during the flow process, increasing the turbulence of the medium and thus improving the efficiency of heat exchange. The heat exchange tube 8 passes through the spiral baffle 10 and the serrated baffle 11.

[0029] See Figure 2 , Figure 4 As shown, the two ends of the heat exchange tube 8 are mounted on the outer shell 1 through the tube sheet 9. The tube sheet 9 plays a role in stabilizing the heat exchange tube 8 and reasonably distributing the medium flow direction. The outer wall of the heat exchange tube 8 is provided with a nano-hydrophobic coating 13.

[0030] The thickness of the nano-hydrophobic coating 13 is 50-80nm. The nano-hydrophobic coating 13 is made of polytetrafluoroethylene, which gives the outer wall of the heat exchange tube 8 good hydrophobic properties. It can prevent some water-containing media from condensing or adhering on the tube wall, reduce the negative impact of water accumulation on heat exchange efficiency, and also help extend the service life of the heat exchange tube 8 and avoid corrosion problems caused by long-term contact with water.

[0031] In this embodiment, the inner wall of the heat exchange tube 8 is provided with a spiral rib 12. The rib height of the spiral rib 12 is 0.5-2.0mm, the pitch of the spiral rib 12 is 5-20mm, the rib thickness of the spiral rib 12 is 0.2-0.8mm, and the axial angle between the spiral rib 12 and the heat exchange tube 8 is 30°-60°.

[0032] The spiral ribs 12 are 5-10 mm away from both ends of the heat exchange tube 8. This allows the medium flowing inside the heat exchange tube 8 to further enhance the turbulence effect under the action of the spiral ribs 12, expand the contact area between the medium and the inner wall of the heat exchange tube 8, and thus transfer heat more efficiently, improving the heat exchange performance of the entire heat exchanger.

[0033] The implementation principle of a shell-and-tube heat exchanger according to an embodiment of this application is as follows: First, the hot medium enters the heat exchanger through the heat inlets 3 respectively provided on the two end caps 2, and flows in the heat exchange tubes 8. The cold medium enters the shell-side space between the outer shell 1 and the heat exchange tubes 8 from the cold inlet 5 provided on the upper part of the outer shell 1. When the hot medium flows in the heat exchange tubes 8, the spiral ribs 12 provided on the inner wall of the heat exchange tubes 8 will disturb the flow of the hot medium and destroy the boundary layer formation, so that the hot medium and the tube wall of the heat exchange tubes 8 can fully exchange heat. In the heat exchange process, heat is transferred from the hot medium to the wall of the heat exchange tube 8. At the same time, the cold medium flows in the shell-side space. The shell-side is equipped with a spiral baffle 10 and serrated baffles 11 at both ends to guide the cold medium to flow in the shell-side in a reasonable flow state, so that the cold medium can fully contact the outer wall of the heat exchange tube 8, thereby absorbing the heat on the wall of the heat exchange tube 8 and realizing the heat exchange between the hot and cold media. After the heat exchange is completed, the hot medium flows out of the heat exchanger from the heat outlet 4 on the end cap 2, and the cold medium flows out from the cold outlet 6 at the top of the outer shell 1.

[0034] During operation, if impurities or other substances that need to be discharged appear inside the shell, they can be discharged through the drain port 7 located below the cold outlet 6 at the bottom of the shell 1.

[0035] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A shell-and-tube heat exchanger, comprising a shell (1), characterized in that: Both ends of the outer shell (1) are provided with end caps (2). Inside the outer shell (1) are spiral baffles (10) and heat exchange tubes (8). Both ends of the spiral baffles (10) are provided with serrated baffles (11). The heat exchange tubes (8) pass through the spiral baffles (10) and the serrated baffles (11). Both ends of the heat exchange tubes (8) are installed on the outer shell (1) through tube sheets (9).

2. A shell-and-tube heat exchanger according to claim 1, characterized in that: The outer wall of the heat exchange tube (8) is provided with a nano-hydrophobic coating (13), the thickness of which is 50-80 nm.

3. A shell-and-tube heat exchanger according to claim 1, characterized in that: The inner wall of the heat exchange tube (8) is provided with a spiral rib (12). The rib height of the spiral rib (12) is 0.5-2.0 mm, the pitch of the spiral rib (12) is 5-20 mm, the rib thickness of the spiral rib (12) is 0.2-0.8 mm, the axial angle between the spiral rib (12) and the heat exchange tube (8) is 30°-60°, and the distance between the two ends of the spiral rib (12) and the two ends of the heat exchange tube (8) is 5-10 mm.

4. A shell-and-tube heat exchanger according to claim 1, characterized in that: Flanges (14) are installed on both ends of the outer shell (1) and on the two end caps (2). The flanges (14) on the outer shell (1) and the flanges (14) on the end caps (2) are connected by fixing bolts (15).

5. A shell-and-tube heat exchanger according to claim 4, characterized in that: A sealing ring (16) is provided between the two flanges (14), and the sealing ring (16) is configured as an "O" shape.

6. A shell-and-tube heat exchanger according to claim 1, characterized in that: The two end caps (2) are respectively provided with a heat inlet (3) and a heat outlet (4). The upper part of the outer shell (1) is provided with a cold inlet (5) and a cold outlet (6). The cold inlet (5) and the cold outlet (6) are located at both ends. The lower part of the outer shell (1) is provided with a drain outlet (7). The drain outlet (7) is located below the cold outlet (6).

7. A shell-and-tube heat exchanger according to claim 1, characterized in that: The outer shell (1) is a double-layer design. The base material of the outer shell (1) is carbon steel, and the surface layer of the outer shell (1) is a corrosion-resistant alloy, which is bonded by explosive welding.

Images