A numerical simulation method for parameterizing design of autoclave

Abstract

This invention provides a numerical simulation method for parametric design of an autoclave. The autoclave includes a vessel body with an opening at one end and a lid disposed at the opening of the vessel body. First autoclave teeth are evenly spaced along the circumference of the opening in the vessel body, and second autoclave teeth are evenly spaced along the circumference of the edge of the lid. The first and second autoclave teeth abut against each other along the axial direction of the vessel body to close the opening. The numerical simulation method specifically includes the following steps: Step S1: Obtain the temperature distribution of the autoclave using the Fluent temperature calculation module in ANSYS; Step S2: Optimize the fillet size at the root of the autoclave teeth using the Direct Optimization module in ANSYS to obtain the fillet with the minimum equivalent stress and maximum fatigue life under the corresponding initial dimensions; In Step S2, calculate the equivalent stress and fatigue life at the fillet of the autoclave using the Static Structual module in ANSYS based on the temperature distribution.

Description

Technical Field

[0001] This invention relates to autoclaves, and more particularly to a numerical simulation method for parametric design of autoclaves. Background Technology

[0002] An autoclave, as a special pressure equipment, consists of an autoclave body, an autoclave flange, an autoclave cover, an autoclave cover flange, a swing device, and safety devices. It is widely used for heating concrete pipe piles, sand-lime bricks, and new lightweight wall materials such as microporous calcium carbonate boards and asbestos boards. It is also widely used in industries that require high-temperature and high-pressure processing, such as metal smelting and the production of chemical fiber products.

[0003] To facilitate rapid material loading and unloading processes involving repeated operations such as opening, pressurizing, steam curing, depressurizing, and closing, autoclaves typically employ a through-type or gear-type quick-opening door structure. However, due to the frequent changes in temperature and pressure parameters and the high number of opening and closing operations, the stress on the autoclave opening is constantly changing, leading to a significant reduction in the strength and service life of the opening and related gears. Therefore, utilizing numerical simulation calculations during the design and development phase to analyze the stress variation patterns of the autoclave under operating conditions and minimize the impact of unreasonable design parameters on its strength and service life is a crucial design step to ensure a reasonable structural design of the autoclave and prevent future production accidents. Summary of the Invention

[0004] The main objective of this invention is to provide a numerical simulation method for parametric design of autoclaves, which optimizes the dimensions at the point of maximum stress to minimize stress and maximize fatigue life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A numerical simulation method for parametric design of an autoclave, wherein the autoclave includes an autoclave body with an opening at one end and an autoclave lid disposed at the opening of the autoclave body. First autoclave teeth are evenly spaced along the circumference of the opening of the autoclave body, and second autoclave teeth are evenly spaced along the circumference of the edge of the autoclave lid. The first and second autoclave teeth abut against each other along the axial direction of the autoclave body to close the opening. The numerical simulation method specifically includes the following steps:

[0007] Step S1: Use the Fluent temperature calculation module in ANSYS to obtain the temperature distribution of the autoclave;

[0008] Step S2: Use the Direct Optimization module in ANSYS to optimize the fillet size at the root of the gear tooth, and obtain the fillet with the minimum equivalent stress and the maximum fatigue life under the corresponding initial size;

[0009] In step S2, the Static Structural module in ANSYS is used to calculate the equivalent stress and fatigue life at the rounded corners of the autoclave based on the temperature distribution.

[0010] Preferably, step 1 specifically includes the following steps:

[0011] Step S101: Determine the initial dimensions of the autoclave based on the design requirements and establish an autoclave model;

[0012] Step S102: Generate a fluid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation.

[0013] Step S103: Calculate the temperature distribution of the autoclave based on the temperature boundary conditions.

[0014] Preferably, step S2 specifically includes the following steps:

[0015] Step S201: Use the fillet size at the tooth root of the gear as the input variable of the Direct Optimization module, and use the equivalent stress and fatigue life as the output variables;

[0016] Step S202: In Direct Optimization, set the upper and lower limits of the input variable, the fillet size of the autoclave;

[0017] Step S203: Set the optimization objectives and constraints for the autoclave. The optimization objective for equivalent stress is to find the minimum value of equivalent stress, and the optimization objective for fatigue life is to find the maximum value.

[0018] Step S204: Change the fillet size within the upper and lower limits according to the predetermined variation law to obtain the equivalent stress and fatigue life corresponding to different fillet sizes;

[0019] Step S205: Plot the fillet size-equivalent stress curve and the fillet size-fatigue life curve based on the equivalent stress and fatigue life obtained in step S204;

[0020] Step S206: Based on the curve, select the fillet size at the point where the equivalent stress is minimum and the fatigue life is maximum.

[0021] Preferably, in step S204, the equivalent stress and fatigue life of the autoclave are calculated using the following steps:

[0022] Step 2041: Based on the design requirements, determine the initial dimensions of the autoclave, establish the autoclave model, and determine the corresponding materials;

[0023] Step 2042: Generate a solid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation.

[0024] Step 2043: Calculate the equivalent stress and fatigue life of the autoclave based on the temperature distribution;

[0025] Change the fillet size at the root of the autoclave tooth in the autoclave model according to the obtained fillet size.

[0026] Preferably, the equivalent stress is calculated using the following formula:

[0027]

[0028] σ e The equivalent stresses are σ1, σ2, and σ2, which are the first, second, and third principal stresses at the fillet, respectively, and are obtained from the stress calculation module Static Structual simulation.

[0029] Preferably, the fatigue life is calculated using the following formula:

[0030] σ e mN = C,

[0031] N represents fatigue life, and m and C are the material constants of the material selected for the autoclave.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The numerical simulation method of the present invention can calculate the fillet size of the corresponding overall design dimensions of the autoclave, so as to minimize the equivalent stress and maximize the fatigue life under the overall design dimensions. Attached Figure Description

[0034] Figure 1 This is an overall flowchart of the present invention;

[0035] Figure 2 This is a flowchart of step S1;

[0036] Figure 3 This is a flowchart of step S2;

[0037] Figure 4 This is a flowchart of step S3;

[0038] Figure 5 This is a stress distribution diagram on the autoclave;

[0039] Figure 6 It is a fillet-equivalent stress curve;

[0040] Figure 7 It is a fillet-fatigue life curve. Detailed Implementation

[0041] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0042] An autoclave consists of a vessel body and a lid located at the opening of the vessel body. Teeth are provided at the connection between the vessel body and the lid; these teeth abut against each other to secure the lid to the vessel body, similar to the fit between the pot body and lid of a pressure cooker. In practice, the greatest stress in an autoclave is concentrated at the root of the two teeth. Therefore, the simulation analysis primarily focuses on the tooth roots, optimizing the fillet radius at these roots to minimize stress and maximize fatigue life.

[0043] A numerical simulation method for parametric design of autoclaves specifically includes the following steps:

[0044] Step S1: Use the Fluent temperature calculation module in ANSYS to obtain the temperature distribution of the autoclave, which includes the following steps:

[0045] Step S101: Determine the initial dimensions of the autoclave based on the design requirements and establish an autoclave model;

[0046] Step S102: Generate a fluid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation.

[0047] Step S103: Calculate the temperature distribution of the autoclave based on the temperature boundary conditions;

[0048] Step S2: Optimize the fillet size at the root of the gear tooth using the Direct Optimization module in ANSYS to obtain the fillet with the minimum equivalent stress and maximum fatigue life under the corresponding initial dimensions. This includes the following steps:

[0049] Step S201: Use the fillet size at the tooth root of the gear as the input variable of the Direct Optimization module, and use the equivalent stress and fatigue life as the output variables;

[0050] Step S202: In Direct Optimization, set the upper and lower limits of the input variable, the fillet size of the autoclave;

[0051] Step S203: Set the optimization objectives and constraints for the autoclave. The optimization objective for equivalent stress is to find the minimum value of equivalent stress, and the optimization objective for fatigue life is to find the maximum value.

[0052] Step S204: Change the fillet size within the upper and lower limits according to the predetermined variation law to obtain the equivalent stress and fatigue life corresponding to different fillet sizes;

[0053] Step S205: Plot the fillet size-equivalent stress curve and the fillet size-fatigue life curve based on the equivalent stress and fatigue life obtained in step S204;

[0054] Step S206: Based on the curve, select the fillet size at the point where the equivalent stress is minimum and the fatigue life is maximum.

[0055] In step 204, the equivalent stress and fatigue life at the fillet radius of the autoclave teeth are calculated using the Static Structural module in ANSYS based on the temperature distribution, as detailed below:

[0056] Step 2041: Based on the design requirements, determine the initial dimensions of the autoclave, establish the autoclave model, and determine the corresponding materials;

[0057] Step 2042: Generate a solid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation.

[0058] Step 2043: Calculate the equivalent stress and fatigue life at the autoclave model based on the temperature distribution;

[0059] In step 2041, the autoclave model is modified sequentially based on the obtained multiple fillet dimensions.

[0060] The equivalent stress is calculated using the following formula:

[0061]

[0062] σ e The equivalent stress is represented by σ1, σ2, and σ2, which are the first, second, and third principal stresses at the fillet, corresponding to the stresses in the X, Y, and Z directions, respectively. In the optimization module, σ1, σ2, and σ2 are first simulated, and then the equivalent stress is calculated using the formula described above.

[0063] The fatigue life is calculated using the following formula:

[0064] σ e mN = C,

[0065] N is the stress cycle number, i.e. fatigue life, and m and C are the material constants of the material selected for the autoclave.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A numerical simulation method for parametric design of an autoclave, the autoclave comprising an autoclave body with an opening at one end and an autoclave lid disposed at the opening of the autoclave body, wherein first autoclave teeth are equally spaced along the circumferential direction of the opening of the autoclave body, and second autoclave teeth are equally spaced along the circumferential direction of the edge of the autoclave lid, the first autoclave teeth and the second autoclave teeth abut against each other in the axial direction of the autoclave body to close the opening, the numerical simulation method specifically comprising the following steps: Step S1: Use the Fluent temperature calculation module in ANSYS to obtain the temperature distribution of the autoclave; Step S2: Use the Direct Optimization module in ANSYS to optimize the fillet size at the root of the gear tooth, and obtain the fillet with the minimum equivalent stress and the maximum fatigue life under the corresponding initial size; In step S2, the Static Structual module in ANSYS is used to calculate the equivalent stress and fatigue life at the rounded corners of the autoclave based on the temperature distribution. Step S2 specifically includes the following steps: Step S201: Use the fillet size at the tooth root of the gear as the input variable of the Direct Optimization module, and use the equivalent stress and fatigue life as the output variables; Step S202: In Direct Optimization, set the upper and lower limits of the input variable, the fillet size of the autoclave; Step S203: Set the optimization objectives and constraints for the autoclave. The optimization objective for equivalent stress is to find the minimum value of equivalent stress, and the optimization objective for fatigue life is to find the maximum value. Step S204: Change the fillet size within the upper and lower limits according to the predetermined variation law to obtain the equivalent stress and fatigue life corresponding to different fillet sizes; Step S205: Plot the fillet size-equivalent stress curve and the fillet size-fatigue life curve based on the equivalent stress and fatigue life obtained in step S204; Step S206: Based on the curve, select the fillet size at the point where the equivalent stress is minimum and the fatigue life is maximum.

2. The numerical simulation method for parametric design of an autoclave according to claim 1, characterized in that, Step 1 specifically includes the following steps: Step S101: Determine the initial dimensions of the autoclave based on the design requirements and establish an autoclave model; Step S102: Generate a fluid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation. Step S103: Calculate the temperature distribution of the autoclave based on the temperature boundary conditions.

3. The numerical simulation method for parametric design of an autoclave according to claim 1, characterized in that, In step S204, the equivalent stress and fatigue life of the autoclave are calculated using the following steps: Step 2041: Based on the design requirements, determine the initial dimensions of the autoclave, establish the autoclave model, and determine the corresponding materials; Step 2042: Generate a solid mesh for the autoclave and optimize the mesh quality to improve the accuracy of the numerical simulation. Step 2043: Calculate the equivalent stress and fatigue life of the autoclave based on the temperature distribution; Change the fillet size at the root of the autoclave tooth in the autoclave model according to the obtained fillet size.

4. The numerical simulation method for parametric design of an autoclave according to claim 3, characterized in that, The equivalent stress is calculated using the following formula: ， For equivalent stress, These are the first, second, and third principal stresses at the rounded corners, obtained from simulations using the Static Structual stress calculation module.

5. The numerical simulation method for parametric design of an autoclave according to claim 4, characterized in that, The fatigue life is calculated using the following formula: ， For fatigue life, This is the material constant of the material selected for the autoclave.

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