Electric heater stress analysis method and device, electronic equipment and storage medium

Abstract

The invention provides an electric heater stress analysis method and device, electronic equipment and a storage medium, and relates to the technical field of electric heaters, and the electric heater stress analysis method comprises the following steps: determining a temperature field of a first local model of an electric heater based on a fluid-solid conjugate heat exchange relationship, the electric heater comprises a first local model and a second local model; the temperature field is mapped to an electric heater model, the temperature boundary condition of the electric heater model is obtained, and the electric heater model is obtained by combining a first local model and a second local model; and based on the temperature boundary condition and a preset constraint condition, performing static structure analysis on the electric heater model to obtain stress distribution of the electric heater model. The method can effectively improve the accuracy of electric heater stress analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of electric heaters, and in particular to a method, device, electronic equipment and storage medium for analyzing stress of an electric heater. Background Art

[0002] With the advancement of science and technology and industrial development, electric heaters are increasingly used in various industrial production as an efficient, fast and environmentally friendly heating method. The widespread use of electric heaters not only improves production efficiency, but also improves product quality and reduces energy consumption. It has significant economic and environmental benefits and is widely used in petrochemical, food processing, plastic molding and other fields.

[0003] In order to ensure that the electric heater can withstand mechanical and thermal loads during use, force analysis is usually required during the design and manufacturing process of the electric heater. However, due to the complex structure of the electric heater, which contains multiple components with complex connections and interactions between the components, and is affected by multiple loads and heat transfer processes, the results of the force analysis may differ from the actual force conditions during use. Summary of the invention

[0004] The problem solved by the invention is how to improve the accuracy of stress analysis of electric heaters.

[0005] In order to solve the above problems, the present invention provides an electric heater stress analysis method, device, electronic equipment and storage medium.

[0006] In a first aspect, the present invention provides a method for analyzing stress of an electric heater, comprising:

[0007] Determine the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship;

[0008] Mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model;

[0009] Based on the temperature boundary conditions and preset constraint conditions, a static structural analysis is performed on the electric heater model to obtain the stress distribution of the electric heater model.

[0010] Optionally, the method further comprises:

[0011] Constructing a simplified three-dimensional model of the electric heater according to the acquired parameter information of the electric heater, wherein the simplified three-dimensional model includes a fluid domain and a solid domain;

[0012] According to the relationship between the solid domain and the fluid domain in the simplified three-dimensional model, the simplified three-dimensional model is split into the first local model and the second local model, wherein the first local model includes the fluid domain and the solid domain, and the second local model includes the solid domain.

[0013] Optionally, determining the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship includes:

[0014] Performing mesh division according to the structural features of the first local model to obtain a meshed first local model;

[0015] According to the preset thermal boundary conditions, the temperature field is obtained by performing fluid analysis on the first local model of the grid.

[0016] Optionally, performing fluid analysis on the first local model of the grid to obtain the temperature field according to a preset thermal boundary condition includes:

[0017] Obtaining material parameters of the first local model of the grid;

[0018] The first local model of the grid is imported into a preset fluid analysis software, and the material parameters, the thermal boundary conditions and the preset linear temperature relationship are used as boundary conditions. The fluid analysis software is used to perform fluid analysis on the first local model of the grid to obtain the temperature field.

[0019] Optionally, the linear temperature relationship satisfies:

[0020]

[0021] Among them, T a is the temperature at position a on the wall of the electric heater in the first local model of the grid, T min is the minimum temperature of the wall of the electric heater, T max is the maximum temperature of the wall of the electric heater, and L is the length of the wall of the electric heater.

[0022] Optionally, mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model includes:

[0023] determining a difference region according to structural characteristics of the electric heater model;

[0024] The temperature field is mapped to the difference region by an interpolation method to obtain the temperature boundary condition of the electric heater model.

[0025] Optionally, the constraint conditions include load constraints and displacement constraints; and the static structural analysis of the electric heater model based on the temperature boundary conditions and preset constraint conditions to obtain the stress distribution of the electric heater model includes:

[0026] Based on the temperature boundary adjustment, the load constraint and the displacement constraint, a static structural analysis is performed on the electric heater model through a solver to obtain the stress distribution of the electric heater model.

[0027] In a second aspect, the present invention provides an electric heater stress analysis device, comprising:

[0028] A processing module, used for determining a temperature field of a first local model of the electric heater based on a fluid-solid conjugate heat transfer relationship;

[0029] an integration module, used for mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model;

[0030] The analysis module is used to perform static structural analysis on the electric heater model based on the temperature boundary conditions and preset constraint conditions to obtain the stress distribution of the electric heater model.

[0031] In a third aspect, the present invention provides an electronic device, including a memory and a processor;

[0032] The memory is used to store computer programs;

[0033] The processor is used to implement the electric heater stress analysis method as described in the first aspect when executing the computer program.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the electric heater stress analysis method as described in the first aspect is implemented.

[0035] The electric heater stress analysis method, device, electronic device and storage medium of the present invention have the following beneficial effects: by determining the temperature field of the first local model based on the fluid-solid conjugate heat transfer relationship, the heat exchange process between the fluid domain and the solid domain can be accurately considered, and the heat transfer mechanism inside the electric heater can be more realistically reflected. At the same time, the flow of the fluid and the thermal conduction of the solid are considered, avoiding the errors that may be caused by simple heat conduction calculations. Factors such as the flow of the fluid and the thermal conductivity of the solid in the electric heater will affect the temperature distribution. Based on the fluid-solid conjugate heat transfer relationship, the interaction of these factors can be fully captured to obtain a more accurate temperature field distribution. The temperature field of the first local model is mapped to the electric heater model, so that the entire electric heater model can obtain temperature boundary conditions based on accurate temperature field data, thereby constructing a calculation model that is more consistent with the actual physical scene, avoiding complex thermal analysis calculations on the overall electric heater model, and improving calculation efficiency and accuracy. Based on accurate temperature boundary conditions and preset constraints, static structural analysis is performed to obtain accurate stress distribution of the electric heater under the above conditions. Accurate stress distribution can comprehensively evaluate the structural strength and stress changes of the electric heater under actual working conditions. Taking into account the combined effects of temperature and different constraints, potential structural weaknesses can be discovered, and measures can be taken in advance to optimize the design to avoid structural failure caused by stress concentration caused by temperature changes and structural constraints. In addition, through accurate stress distribution analysis of electric heaters, the deformation and stress of the electric heater model under temperature and constraints can be deeply understood, thereby providing a basis for the optimal design of the structure. According to the stress distribution results, the geometric shape and material distribution of the structure can be adjusted to achieve a more uniform stress distribution and improve the bearing capacity and stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of a process of analyzing stress of an electric heater according to an embodiment of the present invention;

[0037] Figure 2 It is a structural schematic diagram of an electric heater model according to an embodiment of the present invention;

[0038] Figure 3 The structural intention of the electric heating pipe model of the embodiment of the present invention;

[0039] Figure 4 The structural intention of the first partial model of the embodiment of the present invention;

[0040] Figure 5 is a schematic structural diagram of a second partial model according to an embodiment of the present invention;

[0041] Figure 6 is a schematic structural diagram of a cross section of an electric heater according to an embodiment of the present invention;

[0042] Figure 7 It is a structural schematic diagram of an electric heater stress analysis device according to an embodiment of the present invention;

[0043] Figure 8 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention.

[0044] Description of reference numerals:

[0045] 1-flange; 2-pipe connection; 3-cylinder; 4-saddle; 5-connection structure; 6-electric heating tube; 7-support plate; 8-electric heater cavity. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0047] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0048] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0049] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0050] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0051] like Figure 1 As shown, an electric heater stress analysis method provided by an embodiment of the present invention includes:

[0052] S100, determining a temperature field of a first local model of the electric heater based on a fluid-solid conjugate heat transfer relationship;

[0053] Specifically, the fluid-solid conjugate heat transfer relationship refers to the process of heat exchange between the fluid domain and the solid domain in the electric heater. When calculating the fluid-solid conjugate heat transfer relationship, the fluid and solid interfaces will automatically apply the coupled thermal boundary conditions, that is, Tw = Twf = Tws, where Tw is the wall temperature, Twf is the fluid side wall temperature, and Tws is the solid side wall temperature. The heat flux through each side of the wall is automatically balanced. The fluid domain of the electric heater refers to the space occupied by the fluid in the electric heater system, and the solid domain refers to the space occupied by the solid part of the electric heater except the fluid medium. The flow and heat transfer characteristics of the fluid and the thermal conductivity characteristics of the solid interact with each other. In this case, heat is transferred from the solid to the fluid or from the fluid to the solid, and the temperature field and heat flow distribution of the two are interrelated. According to the relationship between the electric heater structure and the fluid domain, the electric heater is divided into a first local model and a second local model. The two local models differ in terms of geometric structure, material properties or heat load distribution. The first local model includes the fluid domain and the solid domain, and the second local model includes the solid domain.

[0054] Furthermore, if Figure 2 and Figure 3 As shown, the electric heater includes a flange 1, a connecting pipe 2, a cylinder 3, a saddle 4 and a connecting structure 5, as well as an electric heating tube 6 and a supporting plate 7 inside the electric heater, wherein Figure 4 and Figure 5 As shown, the electric heater is divided into a first local model and a second local model according to whether it is related to the fluid and the connection relationship. The first local model includes a cylinder 3 related to the fluid, and an internal electric heating pipe 6 and a support plate 7. The second local model includes a flange 1, a pipe 2, a saddle 4 and a connection structure 5 that are not related to the fluid. Figure 6The electric heating tube 6 is placed inside the cylinder 3 through a through hole arranged on the flange 1 connected to the cylinder 3, and is used to heat the heating medium (i.e., fluid) in the electric heater cavity 8 (fluid domain) inside the cylinder 3. The connection terminal of the electric heating tube is left outside the cylinder 3 for connection to a power source. The saddle 4 is used to fix the electric heater cylinder 3. The connecting pipe 2 includes an inlet connecting pipe and an outlet connecting pipe, which are used to allow the heating medium to flow into and out of the electric heater cavity 8 inside the electric heater, and heat the heating medium in the electric heater cavity 8 by the heat generated by the power supply of the electric heating tube 6. The electric heating medium flows in the electric heater cavity 8 in the form of a fluid. The electric heater cavity 8 is the fluid domain of the electric heater, and the remaining solid structure of the electric heater is the solid domain of the electric heater.

[0055] Exemplarily, based on the fluid analysis software, the first local model is firstly meshed reasonably, and the relationship between the fluid domain and the solid domain is set to a shared topology during model processing to ensure the consistency of the mesh at the coupled wall of the fluid domain and the solid domain. The mesh near the wall of the electric heating tube needs to be refined, because the temperature variation near the wall is large, and the refined mesh can more accurately capture the change in temperature gradient. The mesh away from the wall is gradually coarsened to reduce the amount of calculation while ensuring the calculation accuracy. Special attention should also be paid to the division and transition of the mesh boundary layer near the support plate hole, because the temperature field in these areas may be more complex, and reasonable mesh division helps to accurately simulate the temperature distribution in these areas. After the mesh division is completed, the boundaries and region sets required in the conjugate heat transfer analysis are named to facilitate subsequent calculations and result analysis.

[0056] Furthermore, the first local model with mesh division is imported into the fluid analysis software to define the material parameters in the first local model, including thermal conductivity, specific heat capacity, density and other related thermophysical property parameters of solids and fluids. Boundary condition setting: inlet and outlet conditions of the first local model: the inlet boundary is set as the velocity inlet, and the velocity magnitude and direction of the fluid at the inlet are given; the outlet boundary is set as the pressure outlet, and the outflow of the fluid is simulated by giving the pressure condition at the outlet. Fluid-solid interface heat transfer mode: On the fluid-solid interface, the heat transfer mode is set to coupled, so that the heat transfer between the fluid and the solid is realized through coupled calculation to ensure the continuity of heat transfer. Definition of the wall temperature of the electric heating tube in the first local model: Since the temperature of the wall of the electric heating tube is linearly distributed along the length direction, the wall temperature is defined as a function of the position coordinate by customizing the linear temperature relationship, so as to more accurately simulate the influence of the wall temperature distribution on the temperature field. Thermal radiation considerations: When setting thermal boundary conditions, the influence of radiation needs to be considered because the temperature of the electric heating tube is high, usually up to 495°C. After verification by multiple examples, the emissivity coefficient of the wall in the calculation model is conservatively determined to be 0.9, and the radiation absorption coefficient of the internal fluid is 0, which simplifies the calculation while considering the influence of radiation on the temperature field. Through the processing and settings of the above stages, calculations are performed in the fluid analysis software based on the corresponding physical laws and mathematical models to obtain the temperature field of the first local model.

[0057] S200, mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model.

[0058] Specifically, the first local model includes the fluid domain and part of the solid domain, and the second local model includes the remaining solid domain structure. The first local model and the second local model are combined together in the finite element software to form a complete electric heater model. This process requires ensuring that the two local models are spliced ​​in geometric structure according to the connection relationship between different structures. For example, in the actual electric heater structure, the saddle and the cylinder are welded together. Through the corresponding connection relationship, the combined electric heater model can be consistent with the actual electric heater structure and connection relationship, so that the force distribution of the electric heater when it is working can be accurately simulated according to the electric heater model.

[0059] Furthermore, according to the temperature field of the first local model and the corresponding positions of the nodes or units in the first local model and the electric heater model, the temperature value of each point in the first local model is transferred to the corresponding position of the electric heater model. When the geometric shapes of the two are different, for areas without direct corresponding points in the electric heater model, the temperature value is determined according to the temperatures of the surrounding mapped points using an interpolation algorithm (such as linear interpolation, quadratic difference or Newton interpolation, etc.). In the electric heater model, select areas where temperature boundary conditions need to be defined, such as the outer surface, contact interface, etc. Assign the mapped temperature values ​​to these boundary areas to obtain the temperature boundary conditions of the entire electric heater model.

[0060] S300: Based on the temperature boundary conditions and preset constraint conditions, a static structural analysis is performed on the electric heater model to obtain a stress distribution of the electric heater model.

[0061] Specifically, through finite element software, according to the set dimensional boundary conditions and constraints, the electric heater model is subjected to static structural analysis to determine the stress changes of the unit structure caused by the electric heater model under the above constraints, thereby obtaining the overall stress distribution of the electric heater model. Among them, the temperature boundary conditions can be used to simulate the stress caused by uneven deformation in different temperature zones, and the geometric constraints and load constraints can be used to simulate the stress distribution of different mechanism connection relationships under the action of external forces.

[0062] In this embodiment, by determining the temperature field of the first local model based on the fluid-solid conjugate heat transfer relationship, the heat exchange process between the fluid domain and the solid domain can be accurately considered, and the heat transfer mechanism inside the electric heater can be more realistically reflected. At the same time, the flow of the fluid and the heat conduction of the solid are considered, avoiding the errors that may be caused by simple heat conduction calculations. Factors such as the flow of the fluid and the thermal conductivity of the solid in the electric heater will affect the temperature distribution. Based on the fluid-solid conjugate heat transfer relationship, the interaction of these factors can be fully captured to obtain a more accurate temperature field distribution. The temperature field of the first local model is mapped to the electric heater model, so that the entire electric heater model can obtain temperature boundary conditions based on accurate temperature field data, thereby constructing a calculation model that is more consistent with the actual physical scene, avoiding complex thermal analysis calculations on the overall electric heater model, and improving calculation efficiency and accuracy. Based on accurate temperature boundary conditions and preset constraints, static structural analysis is performed to obtain accurate stress distribution of the electric heater under the above conditions. Accurate stress distribution can comprehensively evaluate the structural strength and stress changes of the electric heater under actual working conditions. Taking into account the combined effects of temperature and different constraints, potential structural weaknesses can be discovered, and measures can be taken in advance to optimize the design to avoid structural failure caused by stress concentration caused by temperature changes and structural constraints. In addition, through accurate stress distribution analysis of electric heaters, the deformation and stress of the electric heater model under temperature and constraints can be deeply understood, thereby providing a basis for the optimal design of the structure. According to the stress distribution results, the geometric shape and material distribution of the structure can be adjusted to achieve a more uniform stress distribution and improve the bearing capacity and stability of the structure.

[0063] Optionally, the method further comprises:

[0064] Constructing a simplified three-dimensional model of the electric heater according to the acquired parameter information of the electric heater, wherein the simplified three-dimensional model includes a fluid domain and a solid domain;

[0065] According to the relationship between the solid domain and the fluid domain in the simplified three-dimensional model, the simplified three-dimensional model is split into the first local model and the second local model, wherein the first local model includes the fluid domain and the solid domain, and the second local model includes the solid domain.

[0066] Specifically, first collect various parameter information of the electric heater, which may include the shape and size of the electric heater, material properties, flow rate of the fluid, temperature and other related data. Since the temperature of the outer wall of the electric heating tube remains constant, only the outer wall of the electric heating tube is established in the simulation analysis model, and the specific internal heating elements are not considered. Since the support plate is a thin plate structure, the original support plate entity structure is simplified to a surface, and then a simplified three-dimensional model of the electric heater is constructed using the above parameters. This model will simultaneously present the distribution of fluids and solids in the electric heater, that is, it includes the fluid domain (the area where the heating medium flows) and the solid domain (solid structural parts such as the shell of the heater and the heating tube). By simplifying the three-dimensional model, the complexity of the model calculation can be reduced while ensuring that the main physical structure characteristics can be reflected.

[0067] Furthermore, according to the structure of the electric heater and the distribution of the fluid domain therein, the electric heater model is split into a first local model and a second local model, wherein the first local model includes the fluid domain and the solid domain related thereto, so that it is convenient to study the fluid-solid conjugate heat transfer relationship between the fluid and part of the solid separately; and the second local model only includes the remaining solid domain that is unrelated to the fluid domain.

[0068] In this optional embodiment, a simplified electric heater model is constructed based on the electric heater parameters, which can highlight the key features of the fluid domain and the solid domain, filter minor details, avoid interference, and reduce the computational complexity, reduce the amount of computation, and save resources and time. After splitting the simplified three-dimensional model into a first local model containing a fluid domain and a solid domain, and a second local model containing only a solid domain, a temperature analysis can be performed on the first local model containing the fluid domain and the associated solid domain, thereby effectively improving the analysis efficiency and accuracy.

[0069] Optionally, determining the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship includes:

[0070] Performing mesh division according to the structural features of the first local model to obtain a meshed first local model;

[0071] According to the preset thermal boundary conditions, the temperature field is obtained by performing fluid analysis on the first local model of the grid.

[0072] Specifically, the first local model is processed with a geometric model, and the model is reasonably divided according to the mesh division requirements to obtain the first local model of the mesh, wherein, in order to ensure the consistency of the mesh at the coupled wall in the first local model, that is, to ensure the consistency of the wall mesh at the junction of the fluid domain and the solid domain. During model processing, the relationship between the fluid domain and the solid domain is set to a shared topology. The mesh near the wall is refined, and the mesh away from the wall is gradually coarsened. Special attention should be paid to the division and transition of the mesh boundary layer near the support plate hole. According to the preset thermal boundary conditions, the first local model of the mesh is subjected to fluid analysis to obtain the temperature field, and the divided first local model of the mesh is imported into the fluid analysis software, the material parameters in the model are defined, and the boundary conditions of the calculation model are set at the same time, wherein the model inlet boundary is set to the velocity inlet, the outlet boundary is set to the pressure outlet, and the heat transfer mode on the fluid-solid interface is set to coupled. Since the temperature of the wall of the electric heating tube is linearly distributed along the length direction, the wall temperature is defined as a function of the position coordinates by a custom expression. When setting the thermal boundary conditions, since the temperature of the electric heating tube in the calculation model is as high as 495°C, the influence of radiation needs to be considered to determine the radiation absorption coefficient of the internal fluid and the emission coefficient of the heating wall. After verification by multiple examples, the emission coefficient of the wall in the calculation model is conservatively determined to be 0.9, and the radiation absorption coefficient of the internal fluid is 0. After setting the solution parameters, the solution can be performed to calculate the temperature field of the first local model of the grid related to the fluid.

[0073] In this optional embodiment, by reasonable meshing, refining the meshes at different positions in the first local model, and dividing and transitioning the mesh boundary layer, the flow and heat transfer of the fluid in the first local model can be simulated more accurately, thereby improving the calculation accuracy. According to the set thermal boundary conditions, the fluid analysis of the first local model of the mesh is performed to obtain an accurate temperature field. The accurate temperature field data helps to accurately obtain the overall stress distribution, providing strong support for the design and optimization of the electric heater.

[0074] Optionally, performing fluid analysis on the first local model of the grid to obtain the temperature field according to a preset thermal boundary condition includes:

[0075] Obtaining material parameters of the first local model of the grid;

[0076] The first local model of the grid is imported into a preset fluid analysis software, and the material parameters, the thermal boundary conditions and the preset linear temperature relationship are used as boundary conditions. The fluid analysis software is used to perform fluid analysis on the first local model of the grid to obtain the temperature field.

[0077] Optionally, the linear temperature relationship satisfies:

[0078]

[0079] Among them, T min is the minimum temperature of the wall of the electric heater, T max is the maximum temperature of the wall of the electric heater, L is the length of the wall of the electric heater, T a is the temperature at position a on the wall of the electric heater in the first local model of the grid, that is, in the electric heater, the value of a is between 0 and L. It should be noted that since the electric heater has a uniform heating source and stable heat conduction, the temperature increases linearly along the fluid flow direction in a stable working state.

[0080] Specifically, the material parameters involved in the first local model of the grid are obtained. The material parameters may include the density, specific heat capacity, thermal conductivity, etc. of the fluid and solid. The above material parameters can be used to accurately perform fluid analysis and calculate the temperature field of the first local model of the grid. The first local model of the grid is imported into a special fluid analysis software, usually a finite element analysis software, which can handle the relevant calculations of fluid flow and heat transfer. At the same time, the first material parameters obtained previously, the preset thermal boundary conditions (such as the temperature and pressure of the inlet and outlet of the first local model of the grid) and the preset linear temperature relationship are input into the fluid analysis software as boundary conditions. The fluid analysis software performs calculations based on the input first local model of the grid, material parameters and boundary conditions, etc., to simulate the flow, heat transfer and other processes of the fluid in the model. Through the analysis of the fluid, the temperature field of the first local model is finally obtained, that is, the distribution of temperature in the first local model.

[0081] For example, the material parameters of the solid structure in the first partial model include 304 stainless steel, density: set to 7930 kg / m 3 Specific heat capacity: 502.48 J / (kg·℃), which indicates the amount of heat absorbed (or released) when the temperature of 304 stainless steel per kilogram increases (or decreases) by 1℃; Thermal conductivity: 16.27 W / (m·℃), which describes the heat conduction capacity of 304 stainless steel per unit length and per unit temperature gradient. The fluid material (superheated steam) in the first local model includes parameters at different temperatures: At 175℃, density: 4.65 kg / m 3 Specific heat capacity: 2773.03 J / (kg·℃), thermal conductivity: 0.0356 W / (m·℃), viscosity: 14.865 μPa.s; at 380℃, density: 3 kg / m 3, specific heat capacity: 3234.25J / (kg·℃), thermal conductivity: 0.0538W / (m·℃), viscosity: 23.796μPa.s. Inlet boundary: Temperature: fixed at 175℃, which is the initial temperature when the superheated steam enters the calculation area; mass flow rate: set to 2100kg / h, which specifies the mass of superheated steam passing through the inlet section per unit time; pressure: the pressure at the inlet is 0.8MPa. Outlet boundary: Temperature: set to 380℃, which is the expected temperature when the superheated steam flows out of the calculation area; pressure: the outlet pressure is 0.79MPa. Fluid-solid interface heat transfer setting: Set the heat transfer mode on the fluid-solid interface to coupled, which means that the heat transfer between the solid and the fluid on the interface is interrelated. The software will consider the heat transfer processes such as heat conduction and convection on both sides during calculation to ensure the continuity of heat flow on the interface. Electric heating tube wall temperature setting: Since the temperature of the electric heating tube wall is linearly distributed along the length direction, ranging from 233℃-445℃, and the temperature increases linearly along the fluid flow direction, the wall temperature is defined as a function of the position coordinates through a custom expression, so that the wall temperature can be accurately calculated according to the position coordinates during the calculation process, thereby more accurately simulating the heat transfer process. This setting can reflect the changes in wall temperature at different positions, which is very critical for calculation models involving heat transfer and fluid flow, and can make the simulation results closer to the actual physical situation. When performing fluid analysis calculations on the first local model, by accurately setting the boundary conditions as mentioned above, the simulation accuracy of the first local model can be effectively improved, close to the actual working conditions, so that the temperature field of the first local model obtained is closer to the actual temperature field, and the accuracy of the temperature field simulation is improved.

[0082] In this optional embodiment, material parameters, thermal boundary conditions and linear temperature relationships are used as boundary conditions for fluid analysis, which can comprehensively consider the impact of various factors on the temperature field and improve the accuracy of the analysis. The accurate temperature field obtained provides a reliable basis for subsequent structural simulation analysis and stress calculation of the overall model, which helps to optimize the design of the electric heater.

[0083] Optionally, mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model includes:

[0084] determining a difference region according to structural characteristics of the electric heater model;

[0085] The temperature field is mapped to the difference region by an interpolation method to obtain the temperature boundary condition of the electric heater model.

[0086] Specifically, Figure 2 and Figure 3As shown, the electric heater model has a specific structure, including components such as the electric heating tube 6, the support plate 7, the cylinder 3, and the flange 1. When determining the difference area, it is necessary to consider the shape, position, and relationship of these components. For example, for components in direct contact with the fluid, such as the outer wall of the electric heating tube and the inner wall of the cylinder 3, it may be necessary to determine the difference area more accurately to accurately map the temperature field. In addition, it is also necessary to consider the connection parts between the components, such as the connection between the flange 1 and the cylinder 3. These areas may have an important influence on the transfer and distribution of temperature. Through a detailed analysis of the structure of the electric heater model, the specific area where the difference calculation needs to be performed, namely the difference area, is determined.

[0087] Furthermore, interpolation is a mathematical method used to estimate the data value of an unknown location based on known data points. When mapping the temperature field to the difference area, a suitable interpolation algorithm is selected according to the geometry and position of the difference area. Common interpolation algorithms include linear interpolation, polynomial interpolation, spline interpolation, etc. Taking linear interpolation as an example, assuming that there are two known points (x 1 ,y 1 ) and (x 2 ,y 2 ), to estimate the temperature y at point x, the following formula can be used: y = y 1 +(y 2 -y 1 )*(xx 1 ) / (x 2 -x 1 ). By applying the interpolation algorithm, the data points in the temperature field are matched with the positions of the difference area, and the temperature values ​​of each position in the difference area are calculated, so that the obtained temperature distribution is determined as the temperature boundary condition of the electric heater model for subsequent structural analysis and stress calculation.

[0088] In this optional embodiment, by determining the difference area according to the structural characteristics of the electric heater model and mapping the temperature field by interpolation, the temperature distribution of different parts inside the electric heater can be more accurately reflected, thereby improving the accuracy of the temperature distribution. Compared with directly using the overall model for calculation, this regional interpolation method can better handle the complex structure and boundary conditions in the model, reduce calculation errors, and improve the accuracy of the calculation results. At the same time, by reasonably determining the difference area and adopting an efficient interpolation algorithm, the calculation efficiency can be improved and the calculation time and resource consumption can be reduced while ensuring the calculation accuracy.

[0089] Optionally, the constraint conditions include load constraints and displacement constraints; and the static structural analysis of the electric heater model based on the temperature boundary conditions and preset constraint conditions to obtain the stress distribution of the electric heater model includes:

[0090] Based on the temperature boundary adjustment, the load constraint and the displacement constraint, a static structural analysis is performed on the electric heater model through a solver to obtain the stress distribution of the electric heater model.

[0091] Specifically, load constraints refer to the restrictions on various external forces or load conditions applied to the electric heater model. For example, pipe loads, gravity loads, pressure loads, etc., these loads will affect the structure of the electric heater. Displacement constraints refer to the conditions that limit the displacement of each part of the electric heater model. By setting displacement constraints, it can be ensured that the electric heater will not be excessively displaced or deformed during operation. Temperature boundary adjustment: The temperature boundary conditions of the electric heater model previously obtained by interpolation are applied to the static structural analysis. This temperature boundary condition reflects the temperature distribution of the electric heater during operation and is an important basis for stress analysis. Application of load constraints and displacement constraints: The determined load constraints and displacement constraints are also input into the analysis to simulate the various constraints and restrictions that the electric heater is subject to in actual operation. According to the above constraints, a special solver is used to perform static structural analysis on the electric heater model. The solver will perform complex calculations and analyses based on the input temperature boundary conditions, load constraints and displacement constraints, as well as the geometric shape, material properties and other information of the electric heater model. Through the calculation of the solver, the stress distribution of the electric heater model under the given temperature boundary conditions and constraints is finally obtained. The solver may be a solver in finite element software or a solver used for nonlinear dynamics analysis.

[0092] In this optional embodiment, by performing static structural analysis with comprehensive consideration of temperature boundary conditions, load constraints, and displacement constraints, the stress distribution of the electric heater model can be accurately obtained, thereby being able to more accurately evaluate the structural performance of the electric heater and ensure its safety and reliability during operation. Furthermore, based on the accurate stress distribution, the design of the electric heater can also be optimized, such as adjusting the structural shape, selecting suitable materials, etc., to improve the performance and service life of the electric heater.

[0093] like Figure 7 As shown, an electric heater stress analysis device 700 provided in an embodiment of the present invention includes:

[0094] A processing module 710 is used to determine a temperature field of a first local model of the electric heater based on a fluid-solid conjugate heat transfer relationship;

[0095] an integration module 720, configured to map the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model;

[0096] The analysis module 730 is used to perform a static structural analysis on the electric heater model based on the temperature boundary conditions and preset constraint conditions to obtain the stress distribution of the electric heater model.

[0097] The electric heater stress analysis device of this embodiment is used to implement the electric heater stress analysis method described above. Its advantages over the prior art are the same as the advantages of the above electric heater stress analysis method over the prior art, and will not be repeated here.

[0098] like Figure 8 As shown, an electronic device 800 provided by an embodiment of the present invention includes a memory 810 and a processor 820; the memory 810 is used to store a computer program; the processor 820 is used to implement the electric heater stress analysis method as described above when executing the computer program.

[0099] In other words, an electronic device 800 includes a memory 810 and a processor 820 coupled to the memory 810; the memory 810 is configured to store a computer program; and the processor 820 is configured to perform the following operations when executing the computer program:

[0100] Determine the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship;

[0101] Mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model;

[0102] Based on the temperature boundary conditions and preset constraint conditions, a static structural analysis is performed on the electric heater model to obtain the stress distribution of the electric heater model.

[0103] An embodiment of the present invention provides a computer-readable storage medium, wherein a computer program is stored on the storage medium. When the computer program is executed by a processor, the electric heater stress analysis method as described above is implemented.

[0104] In other words, a non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following operations:

[0105] Determine the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship;

[0106] Mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model;

[0107] Based on the temperature boundary conditions and preset constraint conditions, a static structural analysis is performed on the electric heater model to obtain the stress distribution of the electric heater model.

[0108] An electronic device 800 that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device 800 is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device 800 can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present invention described herein and / or required.

[0109] The electronic device 800 includes a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for the operation of the device can also be stored. The computing unit, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0110] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. In the present application, the unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present invention. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0111] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for analyzing stress of an electric heater, characterized in that: include: Determine the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship; Mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model; Based on the temperature boundary conditions and preset constraint conditions, a static structural analysis is performed on the electric heater model to obtain the stress distribution of the electric heater model.

2. The electric heater stress analysis method according to claim 1, characterized in that: Also includes: Constructing a simplified three-dimensional model of the electric heater according to the acquired parameter information of the electric heater, wherein the simplified three-dimensional model includes a fluid domain and a solid domain; According to the relationship between the solid domain and the fluid domain in the simplified three-dimensional model, the simplified three-dimensional model is split into the first local model and the second local model, wherein the first local model includes the fluid domain and the solid domain, and the second local model includes the solid domain.

3. The electric heater stress analysis method according to claim 1, characterized in that: The method of determining the temperature field of the first local model of the electric heater based on the fluid-solid conjugate heat transfer relationship comprises: Performing mesh division according to the structural features of the first local model to obtain a meshed first local model; According to the preset thermal boundary conditions, the temperature field is obtained by performing fluid analysis on the first local model of the grid.

4. The electric heater stress analysis method according to claim 3, characterized in that: The step of performing fluid analysis on the first local model of the grid to obtain the temperature field according to the preset thermal boundary condition includes: Obtaining material parameters of the first local model of the grid; The first local model of the grid is imported into a preset fluid analysis software, and the material parameters, the thermal boundary conditions and the preset linear temperature relationship are used as boundary conditions. The fluid analysis software is used to perform fluid analysis on the first local model of the grid to obtain the temperature field.

5. The electric heater stress analysis method according to claim 4, characterized in that: The linear temperature relationship satisfies: Among them, T a is the temperature at position a on the wall of the electric heater in the first local model of the grid, T min is the minimum temperature of the wall of the electric heater, T max is the maximum temperature of the wall of the electric heater, and L is the length of the wall of the electric heater.

6. The electric heater stress analysis method according to claim 1, characterized in that: Mapping the temperature field to the electric heater model to obtain the temperature boundary condition of the electric heater model includes: determining a difference region according to structural characteristics of the electric heater model; The temperature field is mapped to the difference region by an interpolation method to obtain the temperature boundary condition of the electric heater model.

7. The electric heater stress analysis method according to claim 1, characterized in that: The constraint conditions include load constraints and displacement constraints; the static structural analysis of the electric heater model based on the temperature boundary conditions and the preset constraint conditions to obtain the stress distribution of the electric heater model includes: Based on the temperature boundary adjustment, the load constraint and the displacement constraint, a static structural analysis is performed on the electric heater model through a solver to obtain the stress distribution of the electric heater model.

8. An electric heater stress analysis device, characterized in that: include: A processing module, used for determining a temperature field of a first local model of the electric heater based on a fluid-solid conjugate heat transfer relationship; an integration module, used for mapping the temperature field to an electric heater model to obtain a temperature boundary condition of the electric heater model, wherein the electric heater model is obtained by combining the first local model and the second local model; The analysis module is used to perform static structural analysis on the electric heater model based on the temperature boundary conditions and preset constraint conditions to obtain the stress distribution of the electric heater model.

9. An electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the electric heater stress analysis method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the electric heater stress analysis method according to any one of claims 1 to 7 is implemented.

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