Tube sheet thickness design method and vertical heat exchanger

Abstract

The application provides a tube sheet thickness design method and a vertical heat exchanger, and relates to the technical field of heat exchangers. The tube sheet thickness design method comprises the following steps: S1, determining the thicknesses of an upper tube box cylinder, a lower tube box cylinder, a heat exchange tube and a shell side cylinder according to the design conditions of the vertical heat exchanger; S2, determining the thickness of an upper tube sheet δ1 according to the design conditions; S3, setting the thickness difference between the upper tube sheet and a lower tube sheet as d; S4, determining the thickness of the lower tube sheet δ2, δ2=δ1+d; S5, performing finite element analysis on the vertical heat exchanger according to the design conditions, the thickness of the upper tube box cylinder determined in step S1, the thickness of the lower tube box cylinder determined in step S1, the thickness of the heat exchange tube determined in step S1, the thickness of the shell side cylinder determined in step S1, the thickness of the upper tube sheet δ1 determined in step S2 and the thickness of the lower tube sheet δ2 determined in step S4; and S6, evaluating the result of the finite element analysis according to the allowable stress evaluation index. The tube sheet thickness design method can save tube sheet materials and reduce material costs.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more specifically, to a tube sheet thickness design method and a vertical heat exchanger. Background Technology

[0002] The upper and lower tube sheets are important components in vertical heat exchangers, mainly serving to support the heat exchange tubes. Therefore, the design of the upper and lower tube sheets is particularly important.

[0003] Currently, in the design of vertical heat exchangers, the upper and lower tube sheets are often designed to have the same thickness. This can lead to one of the tube sheets having a thickness that exceeds the actual requirements. The excessive thickness of this tube sheet results in the use of more material and can easily lead to waste of material costs. Summary of the Invention

[0004] The problem this invention addresses is: how to reduce material costs.

[0005] To address the above problems, this invention provides a tube sheet thickness design method applied to a vertical heat exchanger. The vertical heat exchanger includes an upper tube box shell, a lower tube box shell, heat exchange tubes, a shell-side shell, an upper tube sheet, and a lower tube sheet. The tube sheet thickness design method includes:

[0006] S1. Determine the thickness of the upper tube box shell, the lower tube box shell, the heat exchange tubes, and the shell-side shell according to the design conditions of the vertical heat exchanger;

[0007] S2. Determine the thickness δ1 of the upper tube sheet according to the design conditions;

[0008] S3. Set the thickness difference between the upper tube sheet and the lower tube sheet as d;

[0009] S4. Determine the thickness δ2 of the lower tube sheet, where δ2 = δ1 + d;

[0010] S5. Based on the design conditions, the thickness of the upper tube box cylinder determined in step S1, the thickness of the lower tube box cylinder determined in step S1, the thickness of the heat exchange tube determined in step S1, the thickness of the shell-side cylinder determined in step S1, the thickness δ1 of the upper tube sheet determined in step S2, and the thickness δ2 of the lower tube sheet determined in step S4, perform finite element analysis on the vertical heat exchanger.

[0011] S6. Evaluate the results of the finite element analysis according to the allowable stress evaluation index. If the evaluation is passed, the thickness difference d between the upper tube sheet and the lower tube sheet set in step S3 is determined as the thickness difference value between the upper tube sheet and the lower tube sheet. If the evaluation is not passed, return to step S3 to reset the thickness difference d between the upper tube sheet and the lower tube sheet.

[0012] Optionally, the thickness difference d between the upper tube sheet and the lower tube sheet set in step S3 satisfies the following condition:

[0013] d = uδ1, where u is greater than or equal to 0.2 and less than or equal to 0.3.

[0014] Optionally, u is 0.25.

[0015] Optionally, step S2 includes:

[0016] Determine whether the inner diameter of the vertical heat exchanger is greater than 4000 mm;

[0017] When the inner diameter of the vertical heat exchanger is less than or equal to 4000 mm, the thickness δ1 of the upper tube sheet shall be determined in accordance with the GB / T151-2014 standard.

[0018] When the inner diameter of the vertical heat exchanger is greater than 4000 mm, the thickness δ1 of the upper tube sheet is determined according to the following formula: δ1 = ηδ3, where η is greater than or equal to 1 and less than or equal to 2, and δ3 is the thickness value of the shell-side cylinder determined in step S1.

[0019] Optionally, η is 1.5.

[0020] Optionally, boundary conditions are set according to non-uniform loads during the finite element analysis process, including differential pressure loads, mass loads, and pressure drop loads.

[0021] Optionally, the non-uniform load is set according to the load experienced by the vertical heat exchanger when it is under simultaneous pressure in both the tube and shell sides.

[0022] Optionally, the finite element simulation model of the vertical heat exchanger may be established using a GUI method or an APDL method during the finite element analysis process.

[0023] Optionally, the allowable stress evaluation index includes the allowable limit of overall film stress intensity, the allowable limit of local film stress intensity, the allowable limit of film stress intensity plus bending stress, the allowable limit of stress intensity plus secondary stress, and the allowable limit of peak stress intensity.

[0024] The present invention also provides a vertical heat exchanger, comprising an upper tube box shell, a lower tube box shell, heat exchange tubes, a shell-side shell, an upper tube sheet, and a lower tube sheet, wherein the thickness of the upper tube sheet and the lower tube sheet is obtained by the tube sheet thickness design method described above.

[0025] Compared with the prior art, the tube sheet thickness design method provided by the present invention has, but is not limited to, the following technical effects:

[0026] In the tube sheet thickness design method provided by this invention, the thicknesses of the upper tube box shell, the lower tube box shell, the heat exchange tubes, and the shell-side shell are first determined according to the design conditions of the vertical heat exchanger to facilitate subsequent finite element analysis. Then, the thickness δ1 of the upper tube sheet is determined according to the design conditions, and the thickness δ1 of the upper tube sheet can serve as the basis for determining the thickness δ2 of the lower tube sheet. Next, the thickness difference between the upper and lower tube sheets is set to d to provide an initial assumed value for the thickness difference between the upper and lower tube sheets. Finally, the thickness δ2 of the lower tube sheet is determined to obtain a thickness of δ2 for the upper tube sheet. The initial assumptions for the lower tube sheet thickness are described. Next, a finite element analysis (FEM) is performed on the vertical heat exchanger to obtain the FEM results under the combined parameters of the above design conditions, upper tube box thickness, lower tube box thickness, heat exchange tube thickness, shell-side thickness, upper tube sheet thickness δ1, and lower tube sheet thickness δ2. Finally, the results of the FEM are evaluated according to the allowable stress assessment index. If the evaluation fails, the process returns to step S3 to reset the d value until the evaluation passes, continuously adjusting and optimizing to find a suitable d value. Once the d value is determined, the lower tube sheet thickness δ2 can be obtained. This tube sheet thickness design method can simultaneously determine the thickness of both the upper and lower tube sheets. The determination of the lower tube sheet thickness is based on the optimal thickness difference d. The thicknesses of the upper and lower tube sheets, while having a thickness difference, also meet the allowable stress assessment index, thus ensuring that one of the upper and lower tube sheets is thinner while meeting actual requirements, avoiding both being too thick, saving tube sheet material, and reducing material costs. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the tube sheet thickness design method according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of a vertical heat exchanger according to an embodiment of the present invention;

[0029] Figure 3 This is a finite element simulation model in the tube sheet thickness design method of this invention.

[0030] Figure 4 The results are from the finite element simulation analysis of the tube sheet thickness design method in this embodiment of the invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1-Upper tube box shell, 2-Lower tube box shell, 3-Heat exchange tube, 4-Shell side shell, 5-Upper tube sheet, 6-Lower tube sheet. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] In the description of this invention, it should be understood that if the terms "upper", "lower", "front", "rear", "left", and "right" are used, they indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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 limitations on this invention.

[0035] Furthermore, in the description of this invention, the Z-axis in the accompanying drawings represents the vertical direction, that is, the up and down position, and the positive direction of the Z-axis represents the top, and correspondingly, the negative direction of the Z-axis represents the bottom. It should be noted that the aforementioned representation of the Z-axis is only for the convenience of describing this invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0036] Traditional vertical heat exchanger design often assumes that the upper and lower tube sheets have the same load conditions. Therefore, the upper and lower tube sheets designed using this method have the same thickness. However, in actual operating conditions, the loads on the upper and lower tube sheets differ. For vertical heat exchangers where the shell-side design pressure is greater than the tube-side design pressure, the lower tube sheet experiences a greater load. Therefore, to meet actual operating conditions, the optimal design is for the upper tube sheet to be thinner and the lower tube sheet thicker. If the traditional design method prioritizes performance and results in upper and lower tube sheets of the same thickness, while this might allow the lower tube sheet to meet actual requirements, it inevitably leads to an upper tube sheet thickness far exceeding the actual requirements, resulting in material waste and increased material costs.

[0037] Therefore, embodiments of the present invention provide a tube sheet thickness design method, which is applied to vertical heat exchangers, such as... Figure 1 As shown, the vertical heat exchanger includes an upper tube box shell 1, a lower tube box shell 2, heat exchange tubes 3, a shell-side shell 4, an upper tube sheet 5, and a lower tube sheet 6, as follows. Figure 2 As shown, the tube sheet thickness design method includes:

[0038] S1. Determine the thickness of the upper tube box shell 1, lower tube box shell 2, heat exchange tube 3, and shell-side shell 4 according to the design conditions of the vertical heat exchanger.

[0039] Specifically, the design conditions for a vertical heat exchanger may include the inner diameter of the equipment, design pressure, design temperature, corrosion allowance, and the materials of each component, etc., which are given before the design. The specific method for designing the thickness of the upper tube box 1, lower tube box 2, heat exchange tubes 3, and shell-side tube 4 according to the design conditions is a conventional method in this field and will not be described in detail here.

[0040] S2. Determine the thickness δ1 of the upper tube sheet 5 according to the design conditions.

[0041] S3. Set the thickness difference between the upper tube sheet 5 and the lower tube sheet 6 as d.

[0042] It should be noted that the thickness difference d is the difference between the thickness of the lower tube sheet 6 and the thickness of the upper tube sheet 5.

[0043] S4. Determine the thickness δ2 of the lower tube sheet 6, where δ2 = δ1 + d.

[0044] S5. Based on the design conditions, the thickness of the upper tube box 1 determined in step S1, the thickness of the lower tube box 2 determined in step S1, the thickness of the heat exchange tube 3 determined in step S1, the thickness of the shell-side tube 4 determined in step S1, the thickness δ1 of the upper tube sheet 5 determined in step S2, and the thickness δ2 of the lower tube sheet 6 determined in step S4, perform finite element analysis on the vertical heat exchanger.

[0045] Specifically, the design conditions, the thickness of the upper tube box 1 determined in step S1, the thickness of the lower tube box 2 determined in step S1, the thickness of the heat exchange tube 3 determined in step S1, the thickness of the shell-side tube 4 determined in step S1, the thickness δ1 of the upper tube sheet 5 determined in step S2, and the thickness δ2 of the lower tube sheet 6 determined in step S4 are input into the finite element analysis software to perform finite element analysis.

[0046] S6. Evaluate the results of the finite element analysis according to the allowable stress evaluation index. If the evaluation is passed, the thickness difference d between the upper tube sheet 5 and the lower tube sheet 6 set in step S3 is determined as the thickness difference value between the upper tube sheet 5 and the lower tube sheet 6. If the evaluation is not passed, return to step S3 to reset the thickness difference d between the upper tube sheet 5 and the lower tube sheet 6.

[0047] Specifically, when the result of the finite element analysis is less than or equal to the corresponding allowable stress, the result is deemed to meet the allowable stress evaluation index and the evaluation is passed; otherwise, the evaluation is failed. When the evaluation is passed, the thickness δ2 value of the lower tube sheet 6 corresponding to the thickness difference d value is determined as the thickness value of the lower tube sheet 6.

[0048] In this embodiment, the thicknesses of the upper tube sheet 1, lower tube sheet 2, heat exchange tubes 3, and shell-side tube sheet 4 are first determined according to the design conditions of the vertical heat exchanger to facilitate subsequent finite element analysis. Then, the thickness δ1 of the upper tube sheet 5 is determined according to the design conditions, and the thickness δ1 of the upper tube sheet 5 can serve as the basis for determining the thickness δ2 of the lower tube sheet 6. Next, the thickness difference between the upper tube sheet 5 and the lower tube sheet 6 is set to d to provide an initial assumed value for the thickness difference between the upper tube sheet 5 and the lower tube sheet 6. After that, the thickness δ2 of the lower tube sheet 6 is determined to obtain a lower tube sheet under the above initial assumed value. 6. Thickness value; Next, the vertical heat exchanger is subjected to finite element analysis to obtain the finite element analysis results under the above design conditions, the thickness of the upper tube box shell 1, the thickness of the lower tube box shell 2, the thickness of the heat exchange tube 3, the thickness of the shell-side shell 4, the thickness of the upper tube sheet 5 δ1, and the thickness of the lower tube sheet 6 δ2. Finally, the results of the finite element analysis are evaluated according to the allowable stress evaluation index. If the evaluation fails, the process returns to step S3 to reset the d value until the evaluation passes, so as to continuously adjust and optimize to find a suitable d value. After the d value is determined, the thickness δ2 of the lower tube sheet 6 can be obtained. The above-mentioned tube sheet thickness design method can simultaneously determine the thickness of the upper tube sheet 5 and the lower tube sheet 6. The determination of the thickness of the lower tube sheet 6 is based on the optimal thickness difference d. The thicknesses of the upper tube sheet 5 and the lower tube sheet 6, while having a thickness difference, also meet the allowable stress evaluation index. This allows one of the upper tube sheet 5 and the lower tube sheet 6 to be thinner while meeting actual requirements, avoiding both being too thick, saving tube sheet materials and reducing material costs.

[0049] Optionally, the thickness difference d between the upper tube sheet 5 and the lower tube sheet 6 set in step S3 satisfies the following condition: d = uδ1, where u is greater than or equal to 0.2 and less than or equal to 0.3.

[0050] In this embodiment, u is greater than or equal to 0.2 and less than or equal to 0.3, that is, the value of d is within the following range: 0.2δ1≤d≤0.3δ1. Within this range, the value of d conforms to the actual load difference between the upper tube sheet 5 and the lower tube sheet 6, thus the thickness of the lower tube sheet 6 more accurately meets the actual requirements, the thickness of the lower tube sheet 6 is closer to the optimal thickness, and the material of the lower tube sheet 6 is saved.

[0051] Optionally, u is 0.25. That is, d is 0.25 times the thickness of the upper tube sheet 5. In this embodiment, by setting u to 0.25, the value of d is made to better reflect the actual load difference between the upper tube sheet 5 and the lower tube sheet 6, resulting in lower material costs for the lower tube sheet 6.

[0052] Optionally, step S2 includes:

[0053] S21. Determine whether the inner diameter of the vertical heat exchanger is greater than 4000mm.

[0054] Specifically, the inner diameter of the vertical heat exchanger is one of the design conditions.

[0055] S22. When the inner diameter of the vertical heat exchanger is less than or equal to 4000 mm, the thickness δ1 of the upper tube sheet 5 shall be determined in accordance with GB / T151-2014 standard.

[0056] S23. When the inner diameter of the vertical heat exchanger is greater than 4000mm, the thickness δ1 of the upper tube sheet 5 is determined according to the following formula: δ1=ηδ3, where η is greater than or equal to 1 and less than or equal to 2, and δ3 is the thickness value of the shell-side cylinder 4 determined in step S1.

[0057] In this embodiment, the thickness of the upper tube sheet 5 is designed in two ways, with the inner diameter of the equipment (4000mm) as the dividing point. The designed thickness of the upper tube sheet 5 is more in line with reality, increasing the reliability of the upper tube sheet 5. At the same time, η is greater than or equal to 1 and less than or equal to 2, that is, the value of δ1 is within the following range: δ3≤δ1≤2δ3. Within this range, the value of δ1 conforms to the actual load of the upper tube sheet 5. The thickness of the upper tube sheet 5 obtained thus more accurately meets the actual requirements, is closer to the optimal thickness, and saves material of the upper tube sheet 5.

[0058] Optionally, η is 1.5. That is, η is 1.5 times the thickness of the shell-side cylinder 4. In this embodiment, by setting η to 1.5, the value of δ1 is made more consistent with the actual load of the upper tube sheet 5, and the material cost of the upper tube sheet 5 is lower.

[0059] Optionally, boundary conditions are set according to non-uniform loads during the finite element analysis process. Non-uniform loads include differential pressure loads, mass loads, and pressure drop loads.

[0060] Specifically, the pressure differential load refers to the shell-and-tube side pressure differential load, and the pressure drop load refers to the tube-side pressure drop load. In actual engineering cases, the loads on the upper tube sheet 5 and lower tube sheet 6 mainly include: shell-and-tube side pressure differential load, mass load, and tube-side pressure drop load. For vertical heat exchangers where the shell-side design pressure is greater than the tube-side design pressure, the shell-and-tube side pressure differential load, mass load, and tube-side pressure drop load on the lower tube sheet 6 all act downwards, resulting in a superimposed effect. The shell-and-tube side pressure differential load on the upper tube sheet 5 acts upwards, while the mass load and tube-side pressure drop load act downwards, thus canceling out their effects. Therefore, the load conditions on the lower tube sheet 6 of a vertical heat exchanger are more severe than those on the upper tube sheet 5.

[0061] In this embodiment, the boundary conditions set during the finite element analysis process simultaneously consider non-uniform loads such as differential pressure load, mass load, and pressure drop load, making the simulation environment of the finite element analysis more consistent with actual working conditions and improving the accuracy of the finite element analysis results.

[0062] Optionally, the non-uniform load is set according to the load experienced by the vertical heat exchanger when it is under pressure in both the tube and shell sides.

[0063] Specifically, the loads experienced by the vertical heat exchanger under simultaneous tube-side and shell-side pressurization include: pressure on the inner wall of the upper tube box 1, tube sheet, heat exchange tube 3 cross section and the inner wall of heat exchange tube 3; equivalent pressure on the inner wall of the lower tube box 2, tube sheet and heat exchange tube 3 cross section; equivalent load on the end face of the tube box; pressure on the inner wall of the shell-side tube 4 and pressure on the outer wall of heat exchange tube 3; gravity; displacement constraint on the end face of the lower tube box 2; and displacement constraint on the symmetrical cross section.

[0064] In this embodiment, the load under the condition of simultaneous pressurization of the tube side and shell side is used as the boundary condition for finite element analysis, which can accurately reflect the actual situation of the vertical heat exchanger and make the results of finite element analysis more accurate.

[0065] Optionally, a GUI method or APDL method can be used to establish a finite element simulation model of the vertical heat exchanger during the finite element analysis process.

[0066] GUI stands for Graphical User Interface; APDL stands for ANSYS Parametric Design Language.

[0067] In this embodiment, the finite element analysis process uses the GUI method or APDL method to establish the finite element simulation model, which can obtain an accurate finite element simulation model. This not only improves the accuracy of finite element analysis, but also enhances its efficiency and saves analysis time.

[0068] Optionally, the allowable stress evaluation index includes the allowable limit of overall membrane stress intensity, the allowable limit of local membrane stress intensity, the allowable limit of membrane stress intensity plus bending stress, the allowable limit of stress intensity plus secondary stress, and the allowable limit of peak stress intensity.

[0069] Specifically, when the allowable stress evaluation index includes the above five allowable limits, the evaluation is passed if the result of the finite element analysis meets the five allowable limits; the evaluation is failed if the result of the finite element analysis does not meet any of the five allowable limits.

[0070] In this embodiment, the allowable stress evaluation index considers five allowable limits simultaneously: the allowable limit of overall membrane stress intensity, the allowable limit of local membrane stress intensity, the allowable limit of membrane stress intensity plus bending stress intensity, the allowable limit of stress intensity plus secondary stress intensity, and the allowable limit of peak stress intensity. This makes the evaluation of the finite element analysis results more accurate, and the obtained d value is more consistent with the actual load difference between the upper tube sheet 5 and the lower tube sheet 6, which is more conducive to reducing the tube sheet material.

[0071] This invention also provides a vertical heat exchanger, including an upper tube sheet 1, a lower tube sheet 2, heat exchange tubes 3, a shell-side tube sheet 4, an upper tube sheet 5, and a lower tube sheet 6. The thicknesses of the upper tube sheet 5 and the lower tube sheet 6 are obtained by the tube sheet thickness design method described above. Since the thicknesses of the upper tube sheet 5 and the lower tube sheet 6 of this vertical heat exchanger are obtained by the tube sheet thickness design method described above, it possesses all the beneficial effects brought by the above embodiments, which will not be elaborated further here.

[0072] The following specific examples further illustrate the tube sheet thickness design method and the effect of the vertical heat exchanger. A vertical heat exchanger has a tube-side design pressure of 2.3 MPa and a design temperature of 330°C, a shell-side design pressure of 5.8 MPa and a design temperature of 274°C, an inner diameter of 7250 mm, and a tube-side pressure drop load of 0.27 MPa. Following the aforementioned tube sheet thickness design method, the thicknesses of the upper tube sheet 5 and the lower tube sheet 6 are designed. The thickness δ1 of the upper tube sheet 5 is 240 mm, the thickness δ2 of the lower tube sheet 6 is 300 mm, and the thickness difference d between the upper tube sheet 5 and the lower tube sheet 6 is 60 mm. The finite element simulation model is shown below. Figure 3 As shown, the finite element simulation analysis results are as follows: Figure 4 As shown, the upper tube sheet 5 and the lower tube sheet 6 have different thicknesses, with a difference between them. Each thickness can meet the actual requirements, avoiding the need to design them with the same thickness, thus avoiding waste of tube sheet materials and reducing material costs.

[0073] In the description of this invention, the term "embodiment" refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation that is included in at least one embodiment or implementation of the invention. In this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0074] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for designing tube sheet thickness, characterized in that, This is applied to a vertical heat exchanger, which includes an upper tube box shell (1), a lower tube box shell (2), heat exchange tubes (3), a shell-side shell (4), an upper tube sheet (5), and a lower tube sheet (6). The tube sheet thickness design method includes: S1. Determine the thickness of the upper tube box shell (1), the lower tube box shell (2), the heat exchange tube (3), and the shell-side shell (4) according to the design conditions of the vertical heat exchanger; S2. Determine the thickness of the upper tube sheet (5) according to the design conditions. ; S3. Set the thickness difference between the upper tube sheet (5) and the lower tube sheet (6) to d; S4. Determine the thickness of the lower tube sheet (6). , = +d; S5. Based on the design conditions, the thickness of the upper tube box shell (1) determined in step S1, the thickness of the lower tube box shell (2) determined in step S1, the thickness of the heat exchange tube (3) determined in step S1, the thickness of the shell-side shell (4) determined in step S1, and the thickness of the upper tube sheet (5) determined in step S2. The thickness of the lower tube sheet (6) determined in step S4 Finite element analysis was performed on the vertical heat exchanger. S6. Evaluate the results of the finite element analysis according to the allowable stress evaluation index. If the evaluation is passed, the thickness difference d between the upper tube sheet (5) and the lower tube sheet (6) set in step S3 is determined as the thickness difference between the upper tube sheet (5) and the lower tube sheet (6). If the evaluation is not passed, return to step S3 to reset the thickness difference d between the upper tube sheet (5) and the lower tube sheet (6). The thickness difference d between the upper tube sheet (5) and the lower tube sheet (6) set in step S3 satisfies the following condition: d = u Where u is greater than or equal to 0.2 and less than or equal to 0.3; Step S2 includes: Determine whether the inner diameter of the vertical heat exchanger is greater than 4000 mm; When the inner diameter of the vertical heat exchanger is less than or equal to 4000 mm, the thickness of the upper tube sheet (5) shall be determined in accordance with GB / T 151-2014 standard. ; When the inner diameter of the vertical heat exchanger is greater than 4000 mm, the thickness of the upper tube sheet (5) is determined according to the following formula. : = ,in, Greater than or equal to 1 and less than or equal to 2, The thickness value of the shell-side cylinder (4) determined in step S1.

2. The tube sheet thickness design method according to claim 1, characterized in that, u is 0.

25.

3. The tube sheet thickness design method according to claim 1, characterized in that, It is 1.

5.

4. The tube sheet thickness design method according to claim 1, characterized in that, In the finite element analysis process, boundary conditions are set according to non-uniform loads, including differential pressure loads, mass loads, and pressure drop loads.

5. The tube sheet thickness design method according to claim 4, characterized in that, The non-uniform load is set according to the load experienced by the vertical heat exchanger when it is under pressure in both the tube and shell sides.

6. The tube sheet thickness design method according to claim 1, characterized in that, The finite element simulation model of the vertical heat exchanger is established using either the GUI method or the APDL method during the finite element analysis process.

7. The tube sheet thickness design method according to claim 1, characterized in that, The allowable stress evaluation indicators include the allowable limit of overall film stress intensity, the allowable limit of local film stress intensity, the allowable limit of film stress intensity plus bending stress, the allowable limit of stress intensity plus secondary stress, and the allowable limit of peak stress intensity.

8. A vertical heat exchanger, characterized in that, It includes an upper tube box shell (1), a lower tube box shell (2), heat exchange tubes (3), a shell-side shell shell (4), an upper tube sheet (5), and a lower tube sheet (6), wherein the thickness of the upper tube sheet (5) and the lower tube sheet (6) is obtained by the tube sheet thickness design method as described in any one of claims 1 to 7.

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