A heat exchanger processing method capable of improving heat transfer performance

Abstract

The present application aims to provide a heat exchanger processing method capable of improving heat transfer performance, which seals the edges of the baffle plates in contact with the inner wall of the shell, avoids the heat medium in the shell from flowing through the gaps of the baffle plates, and thus improves the heat transfer performance.

Description

Technical Field

[0001] This invention relates to the field of shell-and-tube heat exchangers, specifically to a heat exchanger manufacturing method that can improve heat transfer performance. Background Technology

[0002] Shell-and-tube (or tube-and-shell) heat exchangers are the most widely used traditional heat exchangers. Their basic structure consists of a circular shell containing numerous small tubes for heat exchange. Shell-and-tube heat exchangers are widely used in heat exchange equipment in the petrochemical, pharmaceutical, and other fields.

[0003] High-efficiency heat transfer in heat exchangers has always been a challenge for industry technicians, especially for heat exchangers handling easily crystallizing media. Low heat transfer efficiency leads to scale formation on the inner walls of the heat exchange tubes. In existing shell-and-tube heat exchangers, the heat exchange tube bundle and baffles are first assembled as a single unit, and then the entire bundle and baffles are assembled into the shell. Due to manufacturing errors, there will inevitably be a gap of approximately 3.5 mm between the outer edge of the baffles and the inner wall of the shell. This gap causes some of the medium in the shell side to flow directly through the gap between the baffles and the inner wall of the shell, instead of following the serpentine flow pattern restricted by the baffles. This results in cross-flow of the shell-side heat medium, causing heat loss and hindering the improvement of heat transfer efficiency. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a heat exchanger processing method that can improve heat transfer performance by sealing the edge of the baffle plate in contact with the inner wall of the shell, thereby preventing the heat medium in the shell side from flowing through the gap of the baffle plate and thus improving the heat transfer performance.

[0005] This invention is achieved through the following technical solution: A method for manufacturing a heat exchanger that can improve heat transfer performance includes the following steps: S01. Make a square cylindrical body, the square cylindrical body including an elongated base plate, and side plates are provided on the left and right sides of the base plate; S02. Prepare multiple baffles, each with several mounting holes on its surface. Place the baffles inside the square cylinder, with the upper edge of the baffles extending above the upper edge of the side plates. Make one side of the baffle fit against the inner wall of the side plate, and seal the gap formed between the side of the baffle and the side plate, and the gap formed between the bottom edge of the baffle and the bottom plate, so that all the baffles are connected to the two side plates in an alternating manner. S03. Several heat exchange tubes are inserted into the mounting holes of the baffle plate to form a heat exchange tube bundle. S04. Fabricate a cylinder cover plate, wherein the cylinder cover plate is machined with grooves equal in number to the baffles; Assemble the cylinder cover plate assembly onto the upper edge of the long cylinder, so that the upper edge of the baffle plate is inserted into each groove one by one. The gaps formed by the upper edge of the baffle plate and the groove, and the gaps formed by the upper edge of the elongated cylinder and the cylinder cover plate are sealed by welding.

[0006] Furthermore, it also includes: S05. An insert assembly is installed inside the heat exchange tube along its axial direction, wherein the outer diameter of the insert assembly is smaller than the inner diameter of the heat exchange tube.

[0007] Furthermore, the insert assembly includes an insert housing, a support member, a counterweight round steel bar, and a drainage cone; A drainage cone is fixed at the rear end of the plug housing, and then a counterweight round steel is assembled inside the plug housing from the front end of the plug housing. Multiple positioning parts are fixed on the outer wall of the plug housing. Fix the support to the front end of the insert housing, insert the insert housing into the inlet end of the heat exchange tube, fix the insert housing inside the heat exchange tube by the positioning component, and finally fix the support to the inlet end of the heat exchange tube.

[0008] Furthermore, in step S01, the square cylinder is made of metal sheet by stamping and bending.

[0009] Furthermore, in step S04, the left and right sides of the cylinder cover plate are processed with vertically downward folded edges in a bending manner, and one end of all the grooves alternately extends through the folded edges on the left and right sides of the cylinder cover plate.

[0010] Furthermore, the number of baffles is 25-30, the baffles are square, and the spacing between adjacent baffles is 650-700mm.

[0011] The beneficial effects achieved by this invention compared with the prior art are as follows: 1. The heat exchanger processing method described in this invention first seals the baffle plate onto the square cylinder, then installs the heat exchange tubes, and finally welds the cylinder cover plate onto the upper edge of the square cylinder, and seals the upper edge of the baffle plate with the groove to achieve a fully enclosed baffle system, which avoids cross-flow of the shell-side heat medium and heat loss, greatly improves the heat transfer performance of the heat exchanger, and avoids the problem of easily crystallizing media crystallizing into scale in the heat exchange tubes; 2. An internal insertion component is installed inside the heat exchange tube along its axial direction. While ensuring the heat exchange area of ​​the heat exchange tube, it can reduce the flow area and increase the medium flow velocity in the tube. By increasing the flow velocity, it prevents easily crystallizing media from scaling and clogging the tube. 3. A counterweight round steel bar is installed inside the plug housing. This round steel bar is in a movable state and acts as a counterweight. Under the action of the medium flow on the plug housing, it will vibrate on its own to achieve a reaction with the medium flow, improve the contact rate between the medium and the heat exchange tube wall, and further improve the heat exchange and scale inhibition effect. 4. The flow-guiding cone can achieve the function of guiding the flow, and at the same time, the diameter of the heat exchange tube outlet position can be increased sharply, which can reduce the resistance at the heat exchange tube outlet and allow the medium inside the heat exchange tube to flow out smoothly. 5. The left and right sides of the cylinder cover plate are processed with vertical downward folded edges by bending. The lower edge of the folded edge is assembled with the upper edge of the square cylinder and then sealed by welding, making the welding process easier and more convenient. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the fabrication of the square cylinder, baffles, and heat exchange tubes described in this embodiment. Figure 2 This is a schematic diagram of the cylinder cover plate described in this embodiment; Figure 3 This is a schematic diagram of the interpolation component described in this embodiment; Figure 4 This is a schematic diagram showing the square cylinder and its cover plate after being sealed and welded together. In the figure: 1. Square cylinder, 2. Baffle plate, 3. Heat exchange tube, 4. Cylinder cover plate, 5. Groove, 6. Internal component, 61. Insert shell, 62. Support component, 63. Counterweight circle, 64. Drain cone, 65. Positioning component. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0014] In the description of the invention, it should be understood that the terms "front," "rear," "upper," "lower," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention. The invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Phenol is prone to crystallization and blockage in the tubes of heat exchangers due to low heat exchange efficiency or slow flow rate. Taking the manufacture of a heat exchanger suitable for phenol as an example, this paper provides a heat exchanger processing method that can improve heat transfer performance. The heat exchanger is designed with a square structure, with the outer shell having a main body size of 1100mm×1100mm×11430mm. The heat exchange tubes are Φ25×2, L=10000mm, with 800 tubes / unit. The heat exchange tubes are polished inside. The heat exchanger processing method that can improve heat transfer performance described in this embodiment specifically includes the following steps: S01. Make a square cylinder 1, as follows: Figure 1 As shown, the square cylinder 1 is made of a 10mm thick metal plate by stamping and bending. The square cylinder 1 mainly includes a long bottom plate, and the left and right sides of the bottom plate are bent into vertically upward side plates. The cross-sectional dimensions of the square cylinder 1 are 1100mm×950mm. S02. Prepare 28 baffle plates 2, which are square and have a size of 1090mm (height) × 750mm (width). Each baffle plate 2 has 800 arrayed mounting holes on its surface. Place the baffle plate 2 inside the square cylinder 1. The upper edge of the baffle plate 2 is 150mm higher than the upper edge of the side plate. Make one side of the baffle plate 2 fit against the inner wall of the side plate, seal the gap formed by the side of the baffle plate 2 and the side plate, and the gap formed by the bottom edge of the baffle plate 2 and the bottom plate, so that all the baffle plates 2 are connected to the two side plates in an alternating manner, and the spacing between adjacent baffle plates 2 is controlled to be 650mm. S03. 800 heat exchange tubes 3 are inserted into the mounting holes of 28 baffles 2 to form a heat exchange tube bundle. The sequence of this fitting process differs from that of conventional heat exchanger manufacturing processes, where the heat exchange tube bundle is fabricated as a whole and then fitted into the cylinder. S04. Fabricate cylinder cover plate 4, such as Figure 2 As shown, the left and right sides of the cylinder cover plate 4 are processed with vertically downward folded edges by bending, so that the width of the cylinder cover plate 4 is 1100mm and the height of the folded edges on both sides is 150mm; one end of all the grooves 5 alternately extends and penetrates the folded edges on the left and right sides of the cylinder cover plate 4. Four sets of cylinder cover plates are assembled on the upper edge of the long cylinder, so that the upper edge of the baffle plate 2 is inserted into each groove 5 in a corresponding manner. Finally, the gap formed by the upper edge of the baffle plate 2 and the groove 5, and the gap formed by the upper edge of the elongated cylinder and the lower edge of the folded edge of the cylinder cover plate 4 are sealed and welded together. The elongated cylinder and the cylinder cover plate 4 are sealed and welded together to form the outer shell of the heat exchanger. The three outer edges of the baffle plate 2 are completely sealed and welded to the inner wall of the outer shell, thus completely avoiding gaps. S05. An inner insertion component 6 is installed inside the heat exchange tube 3 along its axial direction. The outer diameter of the inner insertion component 6 is smaller than the inner diameter of the heat exchange tube. like Figure 3-4As shown, the insert assembly 6 includes an insert housing 61, a support 62, a counterweight circle 63, and a flow-guiding cone 64. The insert housing 61 is a Φ12×1 stainless steel tube, and the counterweight circle has a diameter of Φ6. The counterweight circle is placed inside the housing 6-2 and primarily serves as a counterweight to prevent excessive disturbance of the insert assembly 6 by the medium, which could cause wear to the inner wall of the heat exchange tube. Simultaneously, the counterweight circle has room to move within the insert housing 61, allowing it to generate micro-vibrations in the insert assembly 6, which in turn react with the medium inside the heat exchange tube, ensuring more thorough contact between the medium and the inner wall of the heat exchange tube.

[0016] The front end of the insert housing 61 is welded to the support 62. The support can be clipped onto the inlet end of the heat exchange tube to support the entire insert assembly 6. The support 62 is made into a curved structure, which allows the medium to enter the heat exchange tube in a swirling state. The overall height of the support is 30mm, the width is 35mm, and the thickness is 3mm. Multiple positioning elements 65 are fixed on the outer wall of the plug-in housing 61. The positioning elements 65 are evenly distributed around the plug-in housing 61. There are groups of 3 positioning elements, and 1 group is set every 2m, for a total of 4 groups. They are made of 1mm thick stainless steel plate, with a width of 4mm and a length of 15mm. The corners at both ends are removed to prevent resistance to the medium. The positioning elements are located between the heat exchange tube and the inner plug-in component 6 to position the inner plug-in component 6 and keep the inner plug-in component 6 always in a centered state.

[0017] A flow-guiding cone is located at the tail of the insert housing 61. It is made of Φ12 round steel machined into a cone shape to seal the tail of the insert housing 61. Its structure allows for a significant increase in the space at the outlet section of the heat exchange tube, reducing the resistance at the outlet section and allowing the medium inside the tube to flow out smoothly. S06. Heat exchanger tube boxes are installed at the front and rear ends of the square cylinder 1, and the heat exchanger is completed.

[0018] The heat exchanger manufactured using the heat exchanger processing method described in this embodiment, which improves heat transfer performance, was compared with that of a conventional heat exchanger of the same specifications under liquid-liquid heat exchange conditions. The conventional heat exchanger has a gap of 3.5 mm between the baffle 2 and the outer shell, while the heat exchanger manufactured by this method has a gap of 0 mm. The fluid flow rate fraction through the gap between the baffle 2 and the inner wall of the outer shell decreased from 12% to 0%, the heat exchange area margin increased from 1.06 to 1.17, and the heat exchange efficiency increased by 9.4%. The heat exchanger tubes manufactured by this method are Φ25mm×2mm, and the cross-section of the inner component 6 is Φ12mm. After inserting the inner component 6, the cross-section of a single heat exchange tube is 377mm². Based on a medium flow rate of 50m³ / h, the flow velocity of the Φ25mm heat exchange tube is 28.29m / s. After inserting the inner component 6, the flow velocity is 37.21m / s, which significantly increases the flow velocity inside the tube.

[0019] Taking phenol as an example, the medium inside the heat exchanger tube bundle has a melting point of 43℃. Above 60℃, it is miscible with water in any proportion. The process operation requires strict control at 55℃±1℃. Lowering the temperature easily leads to crystallization and tube blockage, while raising the temperature easily leads to oxidation of the medium. Measurements show that phenol crystallizing for 1mm on the inner wall of the heat exchanger tube reduces heat exchange efficiency by 15%, severely affecting temperature control and accelerating crystallization and tube blockage. The heat exchanger manufactured using this method achieves a fully enclosed baffled system, avoiding cross-flow of the shell-side heat medium, reducing heat loss, and improving the heat transfer efficiency of the heat exchanger. The phenol temperature is controlled at 55℃±1℃, and the internal insertion components increase the flow rate, effectively flushing away slight crystals on the tube wall to prevent blockage and ensure stable process operation.

Claims

1. A method for processing a heat exchanger that can improve heat transfer performance, characterized in that, Includes the following steps: S01. Make a square cylindrical body, the square cylindrical body including an elongated base plate, and side plates are provided on the left and right sides of the base plate; S02. Prepare multiple baffles, each with several mounting holes on its surface. Place the baffles inside the square cylinder, with the upper edge of the baffles extending above the upper edge of the side plates. Make one side of the baffle fit against the inner wall of the side plate, and seal the gap formed between the side of the baffle and the side plate, and the gap formed between the bottom edge of the baffle and the bottom plate, so that all the baffles are connected to the two side plates in an alternating manner. S03. Several heat exchange tubes are inserted into the mounting holes of the baffle plate to form a heat exchange tube bundle. S04. Fabricate a cylinder cover plate, wherein the cylinder cover plate is machined with grooves equal in number to the baffles; Assemble the cylinder cover plate assembly onto the upper edge of the elongated cylinder, so that the upper edges of the baffles are inserted into each groove one by one. Seal the gaps formed between the upper edge of the baffle plate and the groove, and the gaps formed between the upper edge of the elongated cylinder and the cylinder cover plate. S05. An insert assembly is installed inside the heat exchange tube along its axial direction. The outer diameter of the insert assembly is smaller than the inner diameter of the heat exchange tube. The insert assembly includes an insert housing, a support, a counterweight round steel, and a flow-guiding cone. A drainage cone is fixed at the rear end of the plug housing, and then a counterweight round steel is assembled inside the plug housing from the front end of the plug housing. Multiple positioning parts are fixed on the outer wall of the plug housing. Fix the support to the front end of the insert housing, insert the insert housing into the inlet end of the heat exchange tube, fix the insert housing inside the heat exchange tube by the positioning component, and finally fix the support to the inlet end of the heat exchange tube.

2. The heat exchanger processing method according to claim 1, characterized in that, In step S01, the square cylinder is made of metal sheet by stamping and bending.

3. The heat exchanger processing method according to claim 2, characterized in that, In step S04, the left and right sides of the cylindrical cover plate are processed with vertically downward folded edges in a bending manner, and one end of all the grooves alternately extends through the folded edges on the left and right sides of the cylindrical cover plate.

4. The heat exchanger processing method according to any one of claims 1-3, characterized in that, The number of baffles is 25-30, the baffles are square, and the spacing between adjacent baffles is 650-700mm.

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