Shell-and-tube heat exchanger and method of tube penetration thereof

Abstract

This invention provides a shell-and-tube heat exchanger and its tube insertion method, comprising a shell, heat exchange tubes, and baffles. Multiple baffles are spaced axially along the shell, and each baffle has a plurality of heat exchange tube holes. The heat exchange tubes are inserted into these holes, with the difference between the outer diameter of the heat exchange tubes and the inner diameter of the baffle holes being 0 mm to 0.7 mm. The heat exchange tube holes of the baffles have smoothed inner walls, and the heat exchange tubes have smoothed outer walls. By optimizing the surface roughness of the outer wall of the heat exchange tubes and the inner wall of the baffle holes, frictional resistance, jamming, and surface scratches during tube insertion are reduced, allowing for a smaller fit clearance between the heat exchange tubes and the holes. This reduced clearance not only reduces bypass leakage of the shell-side medium through the hole gap, improving flow field distribution and heat exchange efficiency, but also reduces collisions and fretting wear between the tubes and the hole walls. This contributes to extending the service life of the heat exchange tubes and improving the operational reliability of the heat exchanger.

Description

Technical Field

[0001] This invention relates to the field of thermochemical reaction technology, specifically to a shell-and-tube heat exchanger and its tube insertion method. Background Technology

[0002] Shell-and-tube heat exchangers typically consist of a shell, tube sheet, several baffles, and multiple heat exchange tubes. The heat exchange tubes pass through the tube sheet and the heat exchange tube holes of each baffle. The baffles are arranged at intervals along the shell side to change the flow direction of the shell-side medium, allowing the shell-side medium to flow laterally through the heat exchange tube bundle, thereby increasing the scouring of the outer wall of the heat exchange tubes by the medium and improving the shell-side heat exchange efficiency.

[0003] In existing heat exchangers, the diameter of the baffle tube orifice is typically larger than the outer diameter of the heat exchange tubes. For details, refer to the relevant provisions in GB / T 151-2014 "Heat Exchangers" regarding the outer diameter of the heat exchange tubes, the corresponding diameter of the heat exchange tube orifice, and their permissible deviations. A certain annular gap is formed between the inner wall of the baffle tube orifice and the outer wall of the heat exchange tubes. This annular gap between the baffle tube orifice and the outer wall of the heat exchange tubes constitutes a fluid channel, allowing some of the shell-side medium to flow from one side of the baffle to the other through this annular gap, instead of flowing fully laterally through the heat exchange tube bundle according to the predetermined flow path defined by the baffle. This results in leakage through the annular gap inside the shell side.

[0004] Although the annular leakage area formed by a single baffle tube hole is limited, heat exchangers usually have a large number of heat exchange tubes and multiple layers of baffles. When the leakage areas corresponding to the annular gaps of each tube hole are accumulated, they will form a large total leakage area.

[0005] The aforementioned leakage in the annular gaps of the tubes not only reduces the effective utilization rate of the shell-side medium but may also cause uneven distribution of the shell-side flow field. This weakens the medium velocity and scouring effect in some heat exchange areas, thereby reducing the shell-side heat transfer coefficient and causing a deviation between the actual heat exchange capacity and the design heat exchange capacity of the heat exchanger. To meet the specified heat exchange load, it may be necessary to increase the heat exchange area or increase the medium flow rate, thus increasing the volume of the heat exchanger, material consumption, and operating energy consumption.

[0006] To address the aforementioned issues, existing technologies, such as CN223005412U, propose a metal sealing sleeve and a shell-and-tube heat exchanger. This achieves physical sealing by inserting a metal sealing sleeve with a specific structure into the gap between the heat exchange tubes and the tube bores. However, this approach presents several problems in practical applications: First, an industrial heat exchanger may involve thousands or even tens of thousands of tube bores. Installing metal sealing sleeves one by one is not only cumbersome and inefficient, but also requires extremely high installation precision. Second, and more importantly, during long-term operation, heat exchangers are subject to temperature fluctuations, fluid pulsations, and vibrations, posing a serious risk of the metal sealing sleeve loosening or even detaching. If detached, this foreign metal object will travel with the fluid within the shell side, potentially impacting and abrading adjacent heat exchange tubes, causing thinning of the tube walls or stress concentration. It may also block the flow channels or become stuck deep within the tube bundle, leading to a sudden increase in pressure drop, deterioration of heat exchange performance, and even forcing the entire unit to shut down for maintenance. If the medium is high pressure or flammable and explosive, leakage caused by pipe wall wear will also pose a major safety hazard.

[0007] Therefore, it is necessary to provide a shell-and-tube heat exchanger and its tube insertion method to optimize the fit between the heat exchange tube holes of the baffle plate and the heat exchange tubes, reduce leakage of the shell-side medium through the annular gap of the tube holes, and allow more shell-side medium to flow laterally through the heat exchange tube bundle along a predetermined path, thereby improving the effective utilization rate of the shell-side medium and the heat exchange performance of the heat exchanger. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a shell-and-tube heat exchanger and its tube insertion method. By optimizing the surface roughness of the outer wall of the heat exchange tube and the inner wall of the baffle tube hole, the frictional resistance, jamming and surface scratches during the tube insertion process are reduced, so that a smaller fitting gap can be used between the heat exchange tube and the tube hole, thereby reducing the bypass leakage of the shell-side medium through the tube hole gap, improving the flow field distribution and increasing the heat exchange efficiency.

[0009] To achieve the above-mentioned technical objectives, the present invention provides a shell-and-tube heat exchanger, which includes a shell, heat exchange tubes, and baffles. A plurality of baffles are spaced apart along the axial direction of the shell. A plurality of heat exchange tube holes are distributed on the baffles. The heat exchange tubes pass through the heat exchange tube holes, and the difference between the outer diameter of the heat exchange tubes and the inner diameter of the heat exchange tube holes is 0 mm to 0.7 mm. The heat exchange tube holes have an inner wall formed by a finishing process, and the heat exchange tubes have an outer wall formed by a finishing process.

[0010] Preferably, the heat exchange tube is made of metal.

[0011] Preferably, the heat exchange tube is made of ferrous metal, or selected from any of the following metals or alloys: aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel, nickel alloy, zirconium, zirconium alloy.

[0012] Preferably, when the heat exchange tube is made of aluminum or aluminum alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.55 mm; when the heat exchange tube is made of copper, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.35 mm; when the heat exchange tube is made of copper alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.40 mm; when the heat exchange tube is made of any one of titanium, titanium alloy, nickel, nickel alloy, zirconium, or zirconium alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.60 mm.

[0013] Preferably, the baffle plate is made of metal.

[0014] Preferably, the baffle is a spiral baffle or an arc-shaped baffle.

[0015] The present invention also provides an application of the shell-and-tube heat exchanger as a heater, cooler, condenser, evaporator, reboiler or reactor.

[0016] The present invention also provides a method for inserting tubes into a shell-and-tube heat exchanger, which includes the following steps:

[0017] Ensure that the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole on the baffle plate is 0mm~0.7mm;

[0018] The heat exchange tube holes on the baffle plate have an inner wall formed by a smoothing process, and the heat exchange tubes have an outer wall formed by a smoothing process;

[0019] Multiple baffles are arranged side by side and coaxially positioned so that the heat exchange tube holes on each baffle correspond one-to-one along the axial direction.

[0020] An external force is applied to the heat exchange tubes to force them through multiple baffles in sequence.

[0021] Preferably, external force is applied to the heat exchange tube by any one or a combination of friction wheel continuous conveying, gripper reciprocating pushing, heat exchange tube front end traction, and heat exchange tube tail push.

[0022] Preferably, during the installation of the heat exchange tube, the suspended section of the heat exchange tube is limited to prevent the heat exchange tube from becoming unstable and bending or deforming.

[0023] Compared with the prior art, the beneficial effects of the present invention include:

[0024] By optimizing the surface roughness of the outer wall of the heat exchange tubes and the inner wall of the baffle tube holes, frictional resistance, jamming, and surface scratches during tube insertion are reduced, allowing for a smaller fit clearance between the heat exchange tubes and the tube holes. This smaller clearance not only reduces bypass leakage of the shell-side medium through the tube hole gap, allowing more medium to laterally flush the tube bundle in the designed direction, thus improving flow field distribution and heat exchange efficiency, but also enhances the lateral constraint of the baffle on the heat exchange tubes, limiting tube vibration and oscillation, and reducing collisions and fretting wear between the tube body and the hole wall. This contributes to extending the service life of the heat exchange tubes and improving the operational reliability of the heat exchanger.

[0025] Meanwhile, when applying external force to insert the tube, limiting the heat exchange tube increases the critical load for resisting instability, ensuring that the heat exchange tube remains straight throughout the entire insertion process, solving the problem of heat exchange tube instability and bending, and ensuring the smooth progress of the insertion operation. Attached Figure Description

[0026] Figure 1 It is a shell-and-tube heat exchanger with an arc-shaped baffle plate.

[0027] Figure 2 It is a spiral baffle shell-and-tube heat exchanger.

[0028] The meanings of the reference numerals in the attached figures are as follows:

[0029] 1. Shell; 2. Heat exchange tubes; 3. Bow-shaped baffle; 4. Spiral baffle. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] This invention provides a shell-and-tube heat exchanger, comprising a shell 1, heat exchange tubes 2, and baffles. Multiple baffles are spaced apart along the axial direction of the shell 1. Several heat exchange tube holes are distributed on the baffles, and the heat exchange tubes 2 pass through these holes. The standard GB / T 151-2014 "Heat Exchangers" specifies the outer diameter of the heat exchange tubes 2, the corresponding diameter of the heat exchange tube holes, and their permissible deviations. To reduce leakage of the shell-side medium through the gap between the heat exchange tube holes and the heat exchange tubes 2, the fit between the heat exchange tube holes and the heat exchange tubes 2 is optimized, making the difference between the outer diameter of the heat exchange tubes 2 and the inner diameter of the heat exchange tube holes 0 mm to 0.7 mm. By reducing the fit gap between the heat exchange tubes 2 and the heat exchange tube holes, bypass leakage caused by the shell-side medium through the gap is reduced, allowing more medium to laterally flush the heat exchange tube bundle in the preset direction of the baffles, thereby improving the flow field distribution and increasing heat exchange efficiency. The heat exchange tube 2 and the heat exchange tube hole are fitted with a small clearance. When the heat exchange tube 2 passes through the corresponding heat exchange tube hole on the multiple baffle plates in sequence, the insertion force needs to be appropriately increased, and external force may be required when necessary. In order to reduce frictional resistance and jamming during the insertion process, and also to minimize or reduce the degree of scratches on the tube wall of the heat exchange tube 2, the heat exchange tube hole has a smooth inner wall, and the heat exchange tube 2 has a smooth outer wall. That is, both the inner wall of the heat exchange tube hole and the outer wall of the heat exchange tube 2 are smooth surfaces.

[0032] In this invention, the baffle plate is made of metal, and the heat exchange tube 2 is made of metal.

[0033] Preferably, the heat exchange tube 2 is made of ferrous metal, such as stainless steel or carbon steel.

[0034] Alternatively, one of the following metals or alloys may be selected as the material for heat exchange tube 2: aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel, nickel alloy, zirconium, zirconium alloy.

[0035] The following table (unit: mm) shows the diameter and permissible deviation of the tube holes for Class I tube bundle baffles and support plates in GB / T 151-2014 Heat Exchangers:

[0036]

[0037] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and heat exchanger tube 2, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized. The gap between the baffle plate heat exchanger tube holes and heat exchanger tube 2 is smaller than the range specified in GB / T 151-2014 Heat Exchangers. The difference between the outer diameter of the Class I tube bundle heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0 mm to 0.70 mm. The diameters and allowable deviations (unit: mm) of the baffle plate and support plate tube holes of the Class I tube bundle heat exchanger tubes in this invention are shown in the following table:

[0038]

[0039] Specifically, interpreting the table above, for Class I tube bundles, when the outer diameter of the heat exchanger tube is less than or equal to 32 mm and the maximum unsupported span is greater than 900 mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube orifice is 0 mm to 0.40 mm; when the outer diameter of the heat exchanger tube is greater than 32 mm or the maximum unsupported span is less than or equal to 900 mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube orifice is 0 mm to 0.70 mm. Specifically, heat exchanger tubes 2 made of stainless steel or carbon steel can be used for Class I tube bundles, specifying the baffle and support plate tube orifice diameters and allowable deviations.

[0040] The following table (unit: mm) shows the diameter and permissible deviation of baffles and support plates for aluminum alloy heat exchange tubes in Table 6-24 of GB / T 151-2014 Heat Exchangers:

[0041]

[0042] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap range between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is aluminum alloy, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.55mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of the aluminum alloy heat exchanger tube in this invention are shown in the table below (unit: mm):

[0043]

[0044] Specifically, interpreting the table above, the material of heat exchanger tube 2 is aluminum alloy. When the outer diameter of the heat exchanger tube is 14mm or 16mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.40mm; when the outer diameter of the heat exchanger tube is 18mm, 22mm or 25mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.45mm; when the outer diameter of the heat exchanger tube is 30mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.50mm; when the outer diameter of the heat exchanger tube is 32mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.55mm.

[0045] The following table (unit: mm) shows the diameter and permissible deviation of baffles and support plates for aluminum heat exchange tubes in Table 6-25 of GB / T 151-2014 Heat Exchangers:

[0046]

[0047] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap range between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is aluminum, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.55mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of the aluminum heat exchanger tube in this invention are shown in the table below (unit: mm):

[0048]

[0049] Specifically, interpreting the table above, the material of heat exchanger tube 2 is aluminum. When the outer diameter of the heat exchanger tube is 14mm or 16mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.40mm; when the outer diameter of the heat exchanger tube is 18mm, 22mm or 25mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.45mm; when the outer diameter of the heat exchanger tube is 30mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.50mm; when the outer diameter of the heat exchanger tube is 32mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.55mm.

[0050] The following table (unit: mm) shows the diameter and permissible deviation of the baffles and support plates for copper heat exchange tubes in Table 6-26 of GB / T 151-2014 Heat Exchangers:

[0051]

[0052] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is copper, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.35mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of the copper heat exchanger tubes in this invention are shown in the table below (unit: mm):

[0053]

[0054] Specifically, interpreting the table above, the material of heat exchanger tube 2 is copper. When the outer diameter of the heat exchanger tube is 10mm or 12mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.20mm; when the outer diameter of the heat exchanger tube is 14mm or 16mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.25mm; when the outer diameter of the heat exchanger tube is 19mm or 22mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.30mm; when the outer diameter of the heat exchanger tube is 25mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.35mm.

[0055] The following table (unit: mm) shows the diameter and permissible deviation of the baffles and support plates for copper alloy heat exchange tubes in Table 6-27 of GB / T 151-2014 Heat Exchangers:

[0056]

[0057] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap range between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is copper alloy, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.40mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of the copper alloy heat exchanger tubes in this invention are shown in the table below (unit: mm):

[0058]

[0059] Specifically, interpreting the table above, the material of heat exchanger tube 2 is copper alloy. When the outer diameter of the heat exchanger tube is 10mm or 12mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.25mm; when the outer diameter of the heat exchanger tube is 14mm or 16mm, the difference is 0mm~0.30mm; when the outer diameter of the heat exchanger tube is 19mm or 22mm, the difference is 0mm~0.35mm; when the outer diameter of the heat exchanger tube is 25mm, 30mm or 32mm, the difference is 0mm~0.40mm.

[0060] The following table (unit: mm) shows the diameter and permissible deviation of the baffles and support plates for titanium and titanium alloy heat exchange tubes in Table 6-28 of GB / T 151-2014 Heat Exchangers:

[0061]

[0062] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is titanium or titanium alloy, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0 mm to 0.60 mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of titanium and titanium alloy heat exchanger tubes in this invention are shown in the table below (unit: mm):

[0063]

[0064] Specifically, interpreting the table above, the material of heat exchanger tube 2 is titanium or titanium alloy. When the outer diameter of the heat exchanger tube is 10mm or 12mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.30mm; when the outer diameter of the heat exchanger tube is 14mm, the difference is 0mm~0.40mm; when the outer diameter of the heat exchanger tube is 16mm, the difference is 0mm~0.45mm; when the outer diameter of the heat exchanger tube is 19mm, the difference is 0mm~0.50mm; when the outer diameter of the heat exchanger tube is 25mm or 30mm, the difference is 0mm~0.55mm; and when the outer diameter of the heat exchanger tube is 32mm, the difference is 0mm~0.60mm.

[0065] The following table (unit: mm) shows the diameter and permissible deviation of the baffles and support plates for nickel and nickel alloy heat exchange tubes in Table 6-29 of GB / T 151-2014 Heat Exchangers:

[0066]

[0067] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is nickel or nickel alloy, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0 mm to 0.60 mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of nickel and nickel alloy heat exchanger tubes in this invention are shown in the table below (unit: mm):

[0068]

[0069] Specifically, interpreting the table above, the material of heat exchanger tube 2 is nickel or nickel alloy. When the outer diameter of the heat exchanger tube is 10mm or 12mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.30mm; when the outer diameter of the heat exchanger tube is 14mm, the difference is 0mm~0.40mm; when the outer diameter of the heat exchanger tube is 16mm, the difference is 0mm~0.45mm; when the outer diameter of the heat exchanger tube is 19mm, the difference is 0mm~0.50mm; when the outer diameter of the heat exchanger tube is 25mm or 30mm, the difference is 0mm~0.55mm; and when the outer diameter of the heat exchanger tube is 32mm, the difference is 0mm~0.60mm.

[0070] The following table (unit: mm) shows the diameter and permissible deviation of the baffles and support plates for zirconium and zirconium alloy heat exchange tubes in GB / T 151-2014 Heat Exchangers:

[0071]

[0072] To reduce leakage of the shell-side medium through the gap between the baffle plate heat exchanger tube holes and the heat exchanger tubes, the fit between the baffle plate heat exchanger tube holes and the heat exchanger tubes is optimized so that the gap range between the baffle plate heat exchanger tube holes and the heat exchanger tubes is smaller than that specified in GB / T 151-2014 Heat Exchangers. When the material of heat exchanger tube 2 is zirconium or zirconium alloy, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0 mm to 0.60 mm. The diameter and allowable deviation of the baffle plate and support plate tube holes of zirconium and zirconium alloy heat exchanger tubes in this invention are shown in the table below (unit: mm):

[0073]

[0074] Specifically, interpreting the table above, the material of heat exchanger tube 2 is zirconium or zirconium alloy. When the outer diameter of the heat exchanger tube is 10mm, the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole is 0mm~0.25mm; when the outer diameter of the heat exchanger tube is 12mm, the difference is 0mm~0.30mm; when the outer diameter of the heat exchanger tube is 14mm, the difference is 0mm~0.40mm; when the outer diameter of the heat exchanger tube is 16mm... When the outer diameter of the heat exchange tube is 19 mm, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.45 mm; when the outer diameter of the heat exchange tube is 19 mm, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.50 mm; when the outer diameter of the heat exchange tube is 25 mm or 30 mm, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.55 mm; when the outer diameter of the heat exchange tube is 32 mm, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.60 mm.

[0075] In this invention, the heat exchange tube holes of the baffle plate have an inner wall formed by a smoothing process to reduce the surface roughness of the inner wall of the heat exchange tube holes and form a smooth surface. Specifically, the surface roughness Ra of the inner wall of the heat exchange tube holes of the baffle plate is ≤12.5μm.

[0076] When manufacturing the shell-and-tube heat exchanger described in this invention, baffles with heat exchange tube holes formed by finishing can be purchased directly, that is, baffles with a surface roughness Ra≤12.5μm on the inner wall of the heat exchange tube holes can be purchased directly.

[0077] Alternatively, the inner wall of the heat exchange tube holes in the baffle plate can be finished to achieve a surface roughness Ra ≤ 12.5 μm. Specifically, finishing processes for the inner wall of the heat exchange tube holes include, but are not limited to, honing, extrusion finishing, rolling, abrasive flow finishing, ultrasonic-assisted abrasive flow finishing, magnetic abrasive finishing, liquid magnetic abrasive finishing, or internal electromagnetic polishing, all of which can reduce the workpiece surface roughness to Ra ≤ 12.5 μm.

[0078] In this invention, the main function of the baffle is to provide support for the heat exchange tube 2 and guide the shell-side fluid to flow in a predetermined direction to enhance the heat transfer effect. Therefore, the specific structural form of the baffle is not limited. For example, an arc-shaped baffle 3 or a spiral baffle 4 can be used.

[0079] In this invention, the heat exchange tube 2 has an outer wall formed by a finishing process to reduce the surface roughness of the outer wall of the heat exchange tube and form a smooth surface. Specifically, the surface roughness Ra of the outer wall of the heat exchange tube is ≤1.6μm.

[0080] When manufacturing the shell-and-tube heat exchanger of the present invention, heat exchange tubes 2 with an outer wall formed by finishing can be purchased directly, that is, heat exchange tubes 2 with an outer wall surface roughness Ra≤1.6μm can be purchased directly.

[0081] Alternatively, the outer wall of the heat exchanger tube can be finished to achieve a surface roughness Ra≤1.6μm. Specifically, the finishing process for the outer wall of the heat exchanger tube includes, but is not limited to, mechanical polishing, grinding and belt polishing, ultrasonic vibration finishing, rolling and extrusion, or electrolytic polishing, which can reduce the surface roughness of the workpiece to Ra≤1.6μm or less.

[0082] The shell-and-tube heat exchanger provided by this invention significantly reduces the gap between the heat exchange tube holes of the baffle plate and the heat exchange tube 2, effectively suppressing the bypass leakage of the shell-side medium through the tube hole gap and greatly improving the heat transfer efficiency. Therefore, it can be widely used in various heat exchange and process treatment processes in industries such as petroleum, chemical, power, pharmaceutical, food and new energy.

[0083] For example, the shell-and-tube heat exchanger provided by the present invention can be used as any of the following devices according to actual process requirements:

[0084] When used as a heater, a high-temperature hot fluid (such as steam, heat transfer oil, or high-temperature process materials) can be used to heat the cold medium (such as crude oil, chemicals, or feedwater) in the tube side or shell side to a preset temperature by passing it through the outer wall of the heat exchange tube.

[0085] When used as a cooler, a low-temperature cooling medium (such as circulating cooling water, air, or chilled brine) can be used to cool or condense the process hot fluid (such as overhead oil and gas, reaction products) on the other side through the outer wall of the heat exchange tube to meet the temperature requirements of subsequent processes or storage.

[0086] When used as a condenser, a gaseous medium (such as steam from the top of a distillation column or turbine exhaust) can be introduced into one side of the heat exchanger, and condensed into a liquid state by a cooling medium (such as water or air) on the other side, while simultaneously releasing and recovering the latent heat of phase change.

[0087] When used as an evaporator or reboiler, a high-temperature heat source (such as steam or heat transfer oil) can be used to heat a low-boiling-point liquid medium (such as the bottom liquid of a distillation column or refrigerant), causing it to partially vaporize inside the heat exchanger, thereby providing the required gaseous material or rising steam for distillation, evaporation or refrigeration cycles.

[0088] When used as a reactor, this heat exchanger can be used as a reaction site to achieve efficient heat transfer while completing specific chemical reactions (such as heat extraction in exothermic reactions and heat supply in endothermic reactions). It is especially suitable for processes that require strict control of reaction temperature and need to quickly remove or replenish reaction heat (such as strongly exothermic polymerization reactions, hydrogenation reactions, or oxidation reactions).

[0089] The present invention also provides a method for inserting tubes into a shell-and-tube heat exchanger, comprising the following steps:

[0090] Ensure that the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole on the baffle plate is 0mm~0.7mm;

[0091] The heat exchange tube holes on the baffle plate have an inner wall formed by a smoothing process, and the heat exchange tube 2 has an outer wall formed by a smoothing process;

[0092] Multiple baffles are arranged side by side and coaxially positioned so that the heat exchange tube holes on the multiple baffles correspond one-to-one along the axial direction.

[0093] External force is applied to heat exchange tube 2 to pass it through multiple baffles in sequence.

[0094] To reduce leakage of the shell-side medium through the gap between the heat exchanger tube holes on the baffle plate and the heat exchanger tube 2, the fit between the heat exchanger tube holes on the baffle plate and the heat exchanger tube 2 is optimized so that the gap between the heat exchanger tube holes on the baffle plate and the heat exchanger tube 2 is smaller than that specified in "GBT 151-2014 Heat Exchangers". This ensures that the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole on the baffle plate is 0mm~0.7mm. The specific range of the difference between the outer diameter of the heat exchanger tube and the inner diameter of the heat exchanger tube hole on the baffle plate needs to be determined according to the material and outer diameter of the heat exchanger tube 2, which has been explained in detail in the aforementioned shell-and-tube heat exchanger section and will not be repeated here.

[0095] In this invention, the heat exchange tube holes of the baffle plate have an inner wall formed by a smoothing process to reduce the surface roughness of the inner wall of the heat exchange tube holes and form a smooth surface. Specifically, the surface roughness Ra of the inner wall of the heat exchange tube holes of the baffle plate is ≤12.5μm.

[0096] When manufacturing the shell-and-tube heat exchanger described in this invention, baffles with heat exchange tube holes formed by finishing can be purchased directly, that is, baffles with a surface roughness Ra≤12.5μm on the inner wall of the heat exchange tube holes can be purchased directly.

[0097] Alternatively, the inner wall of the heat exchange tube hole of the baffle plate can be finished to make the surface roughness Ra≤12.5μm. Specifically, the finishing process for the inner wall of the heat exchange tube hole includes, but is not limited to, honing, extrusion finishing, rolling, abrasive flow finishing, ultrasonic-assisted abrasive flow finishing, magnetic abrasive finishing, liquid magnetic abrasive finishing, or internal electromagnetic polishing, etc., which can reduce the surface roughness of the workpiece to Ra≤12.5μm or less.

[0098] In this invention, the main function of the baffle is to provide support for the heat exchange tube 2 and guide the shell-side fluid to flow in a predetermined direction to enhance the heat transfer effect. Therefore, the specific structural form of the baffle is not limited. For example, an arc-shaped baffle 3 or a spiral baffle 4 can be used.

[0099] In this invention, the heat exchange tube 2 has an outer wall formed by a finishing process to reduce the surface roughness of the outer wall of the heat exchange tube and form a smooth surface. Specifically, the surface roughness Ra of the outer wall of the heat exchange tube is ≤1.6μm.

[0100] When manufacturing the shell-and-tube heat exchanger of the present invention, heat exchange tubes 2 with an outer wall formed by finishing can be purchased directly, that is, heat exchange tubes 2 with an outer wall surface roughness Ra≤1.6μm can be purchased directly.

[0101] Alternatively, the outer wall of the heat exchanger tube can be finished to achieve a surface roughness Ra≤1.6μm. Specifically, the finishing process for the outer wall of the heat exchanger tube includes, but is not limited to, mechanical polishing, grinding and belt polishing, ultrasonic vibration finishing, rolling and extrusion, or electrolytic polishing, which can reduce the surface roughness of the workpiece to Ra≤1.6μm or less.

[0102] To reduce the probability of scratches on the heat exchange tube 2 during the tube insertion process, this embodiment uses coaxial positioning of multiple baffles to ensure that the heat exchange tube holes on each baffle correspond one-to-one along the axial direction. Specifically, tie rods and spacers are used to fix each baffle in series. This coaxial positioning ensures that the same heat exchange tube 2 can pass through all baffles sequentially with a uniform annular gap between it and the inner wall of the tube hole, avoiding excessively large (leaking) or excessively small (impeding tube insertion and causing stress concentration) gaps caused by tube hole eccentricity. On the other hand, it also reduces the scraping or squeezing between the heat exchange tube 2 and the inner wall of the baffle tube hole during tube insertion, reducing scratches on the outer wall of the heat exchange tube during the insertion process and effectively protecting the surface quality of the outer wall of the heat exchange tube.

[0103] Similarly, since the heat exchange tube 2 and the heat exchange tube holes adopt a small clearance fit, while ensuring that the heat exchange tube holes on each baffle plate correspond one-to-one along the axial direction, it is necessary to appropriately increase the tube insertion force. Therefore, it is necessary to apply external force to the heat exchange tube 2 for insertion, so that it passes through multiple baffle plates in sequence. Specifically, the methods of applying external force include: continuous conveying with friction wheels, reciprocating pushing with grippers, traction at the front end of the heat exchange tube, or pushing at the rear end of the heat exchange tube. When inserting the tube, one of the above methods can be selected, or multiple methods can be selected simultaneously and combined.

[0104] Since heat exchange tube 2 is a thin-walled tube with a large length-to-diameter ratio, the longer the tube, the weaker its resistance to bending. During the tube insertion process, heat exchange tube 2 is gradually fed towards the baffle plate. The tube section that has passed through the baffle plate is supported by the heat exchange tube holes, while the exposed tube section that has not yet entered the heat exchange tube holes of the baffle plate is in a suspended state. In the early stage of tube insertion, the length of this suspended section is too long. When external force is applied for tube insertion, heat exchange tube 2 is very prone to instability and bending, which greatly increases the tube insertion resistance.

[0105] To address the aforementioned issues, this embodiment limits the suspended section of the heat exchange tube 2 during the tube insertion process to prevent the heat exchange tube from bending and deforming due to instability. Specifically, a limiting fixture is added to the suspended section of the heat exchange tube 2 to restrict the tube body from bending and deforming off-axis, thereby increasing the critical load for the heat exchange tube 2 to resist instability. The heat exchange tube 2 can maintain a straight posture throughout the entire tube insertion process, solving the problem of instability and bending caused by an excessively long suspended section of the heat exchange tube 2, and ensuring the smooth progress of the tube insertion operation.

[0106] Furthermore, if the distance between adjacent baffles is large, a limiting fixture can be added between adjacent baffles to limit the heat exchange tube 2 section that passes through the front baffle to the rear baffle, so as to ensure that the heat exchange tube 2 always maintains a straight posture during the process of passing through the front baffle to the rear baffle.

[0107] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A shell-and-tube heat exchanger, characterized in that, The device includes a shell (1), a heat exchange tube (2), and baffles. Multiple baffles are spaced apart along the axial direction of the shell (1). Several heat exchange tube holes are distributed on the baffles. The heat exchange tube (2) passes through the heat exchange tube holes. The difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.7 mm. The heat exchange tube hole has an inner wall formed by a finishing process, and the heat exchange tube (2) has an outer wall formed by a finishing process.

2. The shell-and-tube heat exchanger as described in claim 1, characterized in that, The heat exchange tube (2) is made of metal.

3. The shell-and-tube heat exchanger as described in claim 2, characterized in that, The heat exchange tube (2) is made of ferrous metal, or selected from any of the following metals or alloys: aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel, nickel alloy, zirconium, zirconium alloy.

4. The shell-and-tube heat exchanger as described in claim 3, characterized in that, When the heat exchange tube (2) is made of aluminum or aluminum alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.55 mm; when the heat exchange tube (2) is made of copper, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.35 mm; when the heat exchange tube (2) is made of copper alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.40 mm; when the heat exchange tube (2) is made of any one of titanium, titanium alloy, nickel, nickel alloy, zirconium or zirconium alloy, the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole is 0 mm to 0.60 mm.

5. The shell-and-tube heat exchanger as described in claim 1, characterized in that, The baffle plate is made of metal.

6. The shell-and-tube heat exchanger as described in claim 1, characterized in that, The baffle is a spiral baffle (4) or an arc-shaped baffle (3).

7. The use of a shell-and-tube heat exchanger as described in any one of claims 1-6 as a heater, cooler, condenser, evaporator, reboiler, or reactor.

8. A method for inserting tubes into a shell-and-tube heat exchanger, characterized in that, Includes the following steps: Ensure that the difference between the outer diameter of the heat exchange tube and the inner diameter of the heat exchange tube hole on the baffle plate is 0mm~0.7mm; The heat exchange tube holes on the baffle plate have an inner wall formed by a smooth finish, and the heat exchange tube (2) has an outer wall formed by a smooth finish. Multiple baffles are arranged side by side and coaxially positioned so that the heat exchange tube holes on each baffle correspond one-to-one along the axial direction. External force is applied to the heat exchange tube (2) to make it pass through multiple baffles in sequence.

9. The tube-insertion method for a shell-and-tube heat exchanger as described in claim 8, characterized in that, External force is applied to the heat exchange tube (2) by any one or a combination of friction wheel continuous conveying, gripper reciprocating pushing, heat exchange tube front end traction, and heat exchange tube tail push.

10. The tube-insertion method for a shell-and-tube heat exchanger as described in claim 8, characterized in that, When inserting the tube, the suspended section of the heat exchange tube (2) is limited to prevent the heat exchange tube (2) from becoming unstable and bending.

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