Multi-directional thermal stress compensation analysis method and system for molten salt tanks

Abstract

This invention relates to the field of data processing technology, and discloses a method and system for multi-directional thermal stress compensation analysis of molten salt tanks. The method includes determining the operating conditions of the molten salt tank, collecting comprehensive material parameters, obtaining comprehensive structural parameters of the molten salt tank, constructing a tank simulation model, constructing an inverted cone region, calculating the calibration height, dividing the molten salt tank into stress regions based on the region height, calculating the regional thermal stress of the stress regions, and generating stress compensation information. This invention achieves the effect of breaking down multi-directional thermal stress in molten salt tanks into smaller, manageable parts, reducing the significant burden of overall multi-directional thermal stress compensation analysis. It also ensures that multiple stress regions correspond one-to-one with spatial locations at different heights and temperatures within the molten salt tank, achieving independent compensation analysis of multi-directional thermal stress regions within the molten salt tank. This results in independent, accurate, and rapid compensation analysis of multi-directional thermal stress at different heights and temperature locations within the molten salt tank.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and more specifically, to a method and system for multi-directional thermal stress compensation analysis of molten salt tanks. Background Technology

[0002] Molten salt tanks, as the core equipment of molten salt energy storage systems, are widely used in fields such as solar thermal power generation and industrial waste heat storage. The high-temperature molten salt stored inside generates significant thermal stress during the charging and releasing process. The structural materials of molten salt tanks are prone to creep, fatigue damage, and even structural failure under high temperature and cyclic heat loads. In order to ensure the accuracy of subsequent thermal stress compensation operations on molten salt tanks, it is necessary to conduct accurate compensation analysis of the multi-directional thermal stress of molten salt tanks.

[0003] The patent application with publication number CN119358320A discloses a finite element analysis method, system, electronic device, and storage medium for stress on a gas tank base. It adopts an adaptive mesh generation technique, comprehensively considers stress concentration areas and stress gradient changes, and performs refined modeling of the gas tank base to obtain a high-quality finite element mesh model. In the mesh generation process, it focuses on the mesh density of stress concentration areas under load to improve the mesh quality in these areas, so as to accurately capture stress gradient changes. Furthermore, it uses a load combination method to study the stress distribution law of the gas tank base under the coupling of multiple loads.

[0004] Existing methods for multi-directional thermal stress compensation analysis of molten salt vessels employ a holistic thermal stress analysis of the vessel as a whole to achieve thermal stress compensation in different directions. However, treating the molten salt vessel as a whole for thermal stress analysis not only leads to excessive computational load but also makes it difficult to independently analyze the thermal stress in different height and temperature regions within the vessel. Consequently, the multi-directional thermal stress obtained from the compensation analysis cannot be dynamically correlated with the actual thermal stress in different height and temperature regions within the vessel, reducing the accuracy of the multi-directional thermal stress compensation analysis results and failing to meet the precise requirements of molten salt vessels for localized thermal stress compensation.

[0005] In view of this, the present invention proposes a multi-directional thermal stress compensation analysis method and system for molten salt tanks to solve the above problems. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution: a multi-directional thermal stress compensation analysis method for molten salt tanks, comprising:

[0007] S01: Based on the temperature change data within a standard time period, determine the operating conditions of the molten salt tank at the current moment, and collect the comprehensive material parameters of the molten salt tank, including elastic modulus, Poisson's ratio and linear thermal expansion coefficient.

[0008] S02: Obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model. The comprehensive structural parameters include height, diameter and wall thickness.

[0009] S03: Determine the spatial base point of the tank simulation model, construct the inverted cone region based on the spatial base point, collect the region parameters of the inverted cone region, and calculate the calibration height of the tank simulation model. The region parameters include the region hypotenuse value and the region vertical value.

[0010] S04: Based on the equidistant partitioning criterion, the calibration height is reduced to the regional height, and the molten salt tank is divided into stress regions based on the regional height. The equidistant partitioning criterion is that the heights of any two adjacent stress regions are equal.

[0011] S05: Collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information.

[0012] Furthermore, the operating conditions include startup conditions, steady-state conditions, and shutdown conditions;

[0013] The steps for determining the operating conditions are as follows:

[0014] The database is used to retrieve A historical temperature change events of the molten salt tank over a past period. The temperature change value and duration are retrieved from the A historical temperature change events. The temperature change value and duration are compared and then A unit durations are calculated.

[0015] The standard duration is calculated by averaging the maximum and minimum values ​​of the unit duration. Then, starting from the current moment, the temperature variation period is generated by counting backwards by one standard duration.

[0016] Find the temperature values ​​at B temperature change moments in the molten salt tank during the temperature change period, and analyze the changing trends of the B temperature values;

[0017] When the trend of temperature values ​​B is a continuous increase, the molten salt tank is in start-up condition.

[0018] When the trend of the B temperature values ​​is continuously flat, the molten salt tank is in steady-state operation.

[0019] When the trend of temperature value B is a continuous decrease, the molten salt tank is in a shutdown condition.

[0020] Furthermore, the steps for building the basic model are as follows:

[0021] The outline of the molten salt tank is constructed in three-dimensional space using 3D modeling technology. The outline of the molten salt tank is stretched and deformed until the height, diameter and wall thickness of the molten salt tank outline reach the height value, diameter value and wall thickness value respectively.

[0022] Scan the boundary chamfer image of the molten salt tank, and use the boundary chamfer image as a standard to chamfer the boundary of the expanded and deformed molten salt tank contour to generate the basic model;

[0023] Three attribute bits are established for two simulation units distributed vertically. The simulation unit located at the top of the three attribute bits is labeled with the text of the elastic modulus, the text of Poisson's ratio, and the text of the linear thermal expansion coefficient, respectively, so that the three attribute bits are transformed into the first simulation bit, the second simulation bit, and the third simulation bit.

[0024] Furthermore, the conversion steps for the tank simulation model are as follows:

[0025] The digital portions of the elastic modulus, Poisson's ratio, and linear thermal expansion coefficient are imported into the simulation cells located at the bottom of the first, second, and third simulation bits, respectively.

[0026] The elastic modulus, Poisson's ratio, linear thermal expansion coefficient, height, diameter, and wall thickness are fused using a data fusion algorithm to generate a set of model parameters.

[0027] A note box is created on the model parameter set, and the operating conditions of the molten salt tank are imported into the note box, which prompts the basic model to be converted into a tank simulation model.

[0028] Furthermore, the steps for constructing the inverted cone region are as follows:

[0029] The bottom sidewall of the tank simulation model is used as the reference wall, and the center point of the reference wall is marked and denoted as the spatial base point.

[0030] Starting from the spatial base point, draw an auxiliary line perpendicular to the reference wall and extending to the top side wall of the tank simulation model, and record the intersection of the auxiliary line and the top side wall of the tank simulation model as the upper base point.

[0031] Using the above base points as the center and one-third of the diameter as the radius, draw the base point circle on the top side wall of the tank simulation model;

[0032] Randomly select a point on the boundary of the base circle, connect the point to the spatial base point to generate a region line, keep the spatial base point stationary, drive the point to rotate around the base circle, and record the region enclosed by the rotated region line as the inverted cone region.

[0033] Furthermore, the calculation steps for the calibration height are as follows:

[0034] Mark the midpoint of the auxiliary line, draw an extension line through the midpoint that is perpendicular to the auxiliary line and intersects the area line, and mark the intersection of the auxiliary line and the area line as the diagonal point;

[0035] Measure the distances from the spatial base point to the midpoint and from the spatial base point to the oblique point one by one, and record them as the vertical value and the hypotenuse value of the region, respectively.

[0036] After comparing the vertical value of the region with the hypotenuse value of the region, the hypotenuse-to-vertical ratio is calculated, and the hypotenuse-to-vertical ratio is multiplied by the unit height value to calculate the calibration height.

[0037] Furthermore, the steps for dividing the stress region are as follows:

[0038] Divide the height value by the calibration height to calculate the calibration multiple;

[0039] When the calibration multiple is a positive integer, the calibration height is used as the area height, and the molten salt tank is divided into D stress areas starting from the bottom sidewall of the molten salt tank;

[0040] When the calibration multiple is not a positive integer, the calibration height is continuously reduced by 1% of the calibration height, and the calibration multiple after reduction is calculated in real time until the calibration multiple after reduction is a positive integer for the first time.

[0041] The reduced calibration height is recorded as the region height. Starting from the bottom sidewall of the molten salt vessel, the molten salt vessel is divided into D stress regions.

[0042] Furthermore, the comprehensive stress data includes regional pressure values ​​and regional temperature change values;

[0043] Regional thermal stress includes axial thermal stress, radial thermal stress, and tangential thermal stress.

[0044] Furthermore, the stress compensation information includes axial over-limit information, radial over-limit information, and tangential over-limit information;

[0045] The steps for generating regional compensation information are as follows:

[0046] Stress over-limit analysis was performed on each of the D stress regions for axial thermal stress, radial thermal stress, and tangential thermal stress.

[0047] When the axial thermal stress exceeds the axial safe stress, axial over-limit information is generated in the stress region;

[0048] When the radial thermal stress exceeds the radial safe stress, radial over-limit information is generated in the stress region;

[0049] When the tangential thermal stress exceeds the tangential safe stress, tangential over-limit information is generated in the stress region.

[0050] The molten salt tank multi-directional thermal stress compensation analysis system is used to realize the multi-directional thermal stress compensation analysis method of molten salt tank. It includes a material parameter acquisition module, a simulation model construction module, a calibration height calculation module, a stress region division module, and a stress compensation analysis module. The modules are connected to each other via wired or wireless network.

[0051] The material parameter acquisition module is used to determine the operating conditions of the molten salt tank at the current moment based on the temperature change data over a standard time period, and to collect the comprehensive material parameters of the molten salt tank.

[0052] The simulation model construction module is used to obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model.

[0053] The calibration height calculation module is used to determine the spatial base point of the tank simulation model, construct an inverted cone region based on the spatial base point, collect the regional parameters of the inverted cone region, and calculate the calibration height of the tank simulation model.

[0054] The stress zone division module is used to reduce the calibration height to a zone height based on the equidistant partitioning criterion, and divide the molten salt tank into stress zones based on the zone height.

[0055] The stress compensation analysis module is used to collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information.

[0056] The technical effects and advantages of the multi-directional thermal stress compensation analysis method and system for molten salt tanks of this invention are as follows:

[0057] (1): By collecting comprehensive material parameters and comprehensive structural parameters, and combining them with three-dimensional modeling technology, this invention can construct a tank simulation model that is consistent with and matches the molten salt tank. This provides an accurate model partitioning space basis for subsequent multi-directional thermal stress compensation analysis of the molten salt tank. By constructing an inverted cone region within the tank simulation model, it can provide a spatial range with clear boundaries for subsequent calculation and analysis of the model partitioning standard. This allows the model partitioning standard to play a dynamic role in relation to the actual operating conditions and multi-modal parameters of the molten salt tank, avoiding the phenomenon that the model partitioning standard is isolated from the actual situation of the molten salt tank and cannot be associated.

[0058] (2): This invention can reduce the calibration height to a regional height by using the equidistant partitioning criterion, so as to ensure that the integral molten salt tank can be divided into multiple stress regions of the same height. This can not only achieve the analysis effect of breaking down the multi-directional thermal stress of the molten salt tank into smaller parts, but also reduce the huge burden brought about by the overall compensation analysis of multi-directional thermal stress and improve the accuracy of subsequent multi-directional thermal stress compensation analysis results. It can also ensure that multiple stress regions can correspond one-to-one with the spatial positions of different heights and temperatures in the molten salt tank, so as to achieve the independent compensation analysis effect of multi-directional thermal stress regionalization in the molten salt tank. In this way, the independent, accurate and rapid compensation analysis of multi-directional thermal stress at different heights and temperature positions in the molten salt tank is achieved, providing accurate theoretical support for subsequent thermal stress compensation measures of the molten salt tank. Attached Figure Description

[0059] Figure 1 This is a flowchart illustrating the multi-directional thermal stress compensation analysis method for molten salt tanks provided in Embodiment 1 of the present invention.

[0060] Figure 2 This is a schematic diagram of the module of the molten salt tank multi-directional thermal stress compensation analysis system provided in Embodiment 2 of the present invention. Detailed Implementation

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0062] Example 1: Please refer to Figure 1 As shown in this embodiment, the multi-directional thermal stress compensation analysis method for molten salt tanks includes:

[0063] S01: Based on the operating condition stability criterion, determine the operating condition of the molten salt tank at the current moment and collect the comprehensive material parameters of the molten salt tank;

[0064] Operating conditions are a specific representation of the actual operating status of the molten salt tank at the current moment. Since the molten salt tank will undergo different dynamic changes under different operating conditions, and the molten salt medium in the molten salt tank will cause different amounts of thermal stress to the tank body when charging and releasing energy under different operating conditions, the thermal stress distribution of the molten salt tank will also change accordingly. Therefore, it is necessary to determine the operating conditions of the molten salt tank.

[0065] Specifically, the operating conditions include startup, steady-state, and shutdown conditions;

[0066] Start-up condition refers to the initial start-up process of the molten salt tank, shutdown condition refers to the shutdown and static process of the molten salt tank, and steady-state condition refers to the dynamic stabilization process of the molten salt tank. Among these, the thermal stress inside the molten salt tank is not stable under the start-up and shutdown conditions, while the thermal stress inside the molten salt tank is relatively stable under the steady-state condition.

[0067] In order to ensure the accuracy and authenticity of the results of the determination of operating conditions, it is necessary to limit the determination process of operating conditions in accordance with the operating condition stability criteria, so as to improve the accuracy of the determination of the operating conditions at the current moment and avoid the phenomenon of misjudgment of operating conditions.

[0068] Specifically, the operating condition stability criterion is: based on the temperature change data within a standard time period, the temperature change of the molten salt tank within a specific time period can be accurately represented, and sufficient and reasonable temperature data can be provided for the determination of subsequent actual operating conditions.

[0069] The steps for determining the operating conditions are as follows:

[0070] The database is used to retrieve A historical temperature change events of the molten salt tank over a past period. The temperature change value and duration are retrieved from these A historical temperature change events. The temperature change value and duration are compared to calculate A unit durations. Historical temperature change events are used to summarize and store the temperature change data of the molten salt tank over a past period, and provide the necessary data foundation for determining the duration of subsequent operating conditions.

[0071] The formula for calculating unit time is:

[0072] ;

[0073] In the formula, For the first The duration of a historical temperature change event per unit of time. =1, 2...A, For the first The duration of temperature changes in a historical temperature change event. For the first Temperature change values ​​of a historical temperature change event;

[0074] The standard duration is calculated by averaging the maximum and minimum values ​​of the unit duration.

[0075] The formula for calculating standard duration is:

[0076] ;

[0077] In the formula, For standard duration, The maximum value per unit duration. The minimum value per unit of time;

[0078] Starting from the current moment, a standard time period is calculated backward to generate a temperature change period; this allows the temperature change period to provide a time-dimensional basis for the determination and analysis of operating conditions.

[0079] The system retrieves the temperature values ​​at B temperature change moments within a temperature change period and analyzes the trends of these B temperature values. The trend represents the overall change in the temperature value of the molten salt tank during the temperature change period, thereby determining the magnitude of the temperature change. Specifically, the trends include continuous increase, continuous stabilization, and continuous decrease.

[0080] When the trend of the B temperature values ​​is a continuous increase, the temperature inside the molten salt tank is in a phase of gradual increase, and the molten salt tank is in the start-up condition.

[0081] When the trend of the change of B temperature values ​​is continuously flat, the temperature inside the molten salt tank is in a gradually flat phase, and the molten salt tank is in a steady state.

[0082] When the trend of temperature values ​​B is a continuous decrease, the temperature inside the molten salt tank is in a phase of gradual decrease, and the molten salt tank is in a shutdown condition.

[0083] After determining the operating conditions of the molten salt tank, the changing properties of multi-directional thermal stress during the storage and utilization of molten salt medium in the molten salt tank at the current moment are clarified, which can provide a basic constraint for the subsequent compensation analysis of multi-directional thermal stress in the molten salt tank.

[0084] To ensure the accuracy of subsequent multi-directional thermal stress compensation analysis, it is necessary to collect comprehensive material parameters of the molten salt tank. These comprehensive material parameters refer to the parameters of the molten salt tank's manufacturing material that can affect the changes in multi-directional thermal stress, so that the comprehensive material parameters can provide an analytical basis for the changes in multi-directional thermal stress of the molten salt tank in terms of material properties.

[0085] Specifically, the comprehensive material parameters include elastic modulus, Poisson's ratio, and linear thermal expansion coefficient;

[0086] The elastic modulus is the ratio of stress to strain in a material during the elastic deformation stage, used to describe the ability of a molten salt vessel material to resist elastic deformation. Poisson's ratio is the ratio of lateral strain to axial strain in a material under uniaxial force, reflecting the lateral deformation characteristics of the molten salt vessel material under force. The linear thermal expansion coefficient describes the sensitivity of the molten salt vessel material to length changes with temperature variations.

[0087] The specific values ​​of elastic modulus, Poisson's ratio, and linear thermal expansion coefficient vary depending on the materials used to manufacture the molten salt tank. When collecting the elastic modulus, Poisson's ratio, and linear thermal expansion coefficient of the molten salt tank, it is necessary to determine the material of the molten salt tank and the current temperature. The values ​​can then be obtained by consulting technical manuals, international standards, and other relevant sources.

[0088] S02: Obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model;

[0089] To ensure the accuracy of subsequent multi-directional thermal stress compensation analysis, it is also necessary to collect the comprehensive structural parameters of the molten salt tank. At this time, the comprehensive structural parameters refer to the parameters that the structural shape of the molten salt tank itself has that can affect the changes in multi-directional thermal stress, so that the comprehensive structural parameters can provide an analytical basis for the changes in multi-directional thermal stress of the molten salt tank in terms of structural shape.

[0090] Specifically, the comprehensive structural parameters include height, diameter, and wall thickness. The height value represents the overall height of the molten salt tank, the diameter value represents the diameter of the bottom and top of the molten salt tank, and the wall thickness value represents the thickness of the tank wall. In this embodiment, the height, diameter, and wall thickness values ​​are obtained by consulting the design drawings of the molten salt tank.

[0091] After obtaining the comprehensive structural parameters, a basic model matching the molten salt tank can be constructed based on the comprehensive structural parameters using three-dimensional modeling technology, thereby representing the structural features of the molten salt tank in three-dimensional space.

[0092] Specifically, the steps for building the basic model are as follows:

[0093] The outline of a molten salt tank is constructed in three-dimensional space using 3D modeling technology. The outline is then stretched and deformed until its height, diameter, and wall thickness reach their respective values. This stretching and deformation process increases the length, height, and diameter of the initially constructed molten salt tank outline to match the actual height, diameter, and wall thickness of the molten salt tank.

[0094] The boundary chamfer image of the molten salt tank is scanned, and the boundary of the expanded and deformed molten salt tank contour is chamfered based on the boundary chamfer image to generate the basic model. Boundary chamfer refers to the position of the edge contour line of the molten salt tank. By chamfering the boundary, the smoothness of the edge contour line position of the basic model can be ensured.

[0095] Three attribute bits are established for two simulation units distributed vertically. The simulation unit located at the top of the three attribute bits is labeled with the text of the elastic modulus, the text of Poisson's ratio, and the text of the linear thermal expansion coefficient, respectively, so that the three attribute bits are transformed into the first simulation bit, the second simulation bit, and the third simulation bit.

[0096] After obtaining the basic model, the basic model can only represent the structural shape of the molten salt tank, but cannot represent the changes in multi-directional thermal stress in terms of material properties. Therefore, it is necessary to integrate the comprehensive material parameters with the simulation position of the basic model to obtain the tank simulation model. This tank simulation model can provide accurate model support for the compensation analysis of multi-directional thermal stress of the molten salt tank in terms of structural morphology and material properties.

[0097] Specifically, the conversion steps for the tank simulation model are as follows:

[0098] The digital portions of the elastic modulus, Poisson's ratio, and linear thermal expansion coefficient are imported into the simulation cells located at the bottom of the first, second, and third simulation bits, respectively.

[0099] The data fusion algorithm integrates the elastic modulus, Poisson's ratio, linear thermal expansion coefficient, height, diameter, and wall thickness values ​​to generate a set of model parameters. The data fusion algorithm is an information processing technology that aims to automatically analyze and synthesize data from different sources, formats, or time points to form a more comprehensive and accurate basis for decision-making. In this embodiment, the data fusion algorithm can fuse multimodal data parameters in the molten salt tank to achieve dynamic correlation of multimodal data parameters.

[0100] A note box is created on the model parameter set, and the operating conditions of the molten salt tank are imported into the note box, which prompts the basic model to be converted into a tank simulation model.

[0101] It should be noted that the constructed tank simulation model is consistent with the actual molten salt tank in terms of structural morphology and material properties, thus providing realistic and accurate model support for subsequent compensation analysis of multi-directional thermal stress in the molten salt tank.

[0102] S03: Determine the spatial base point of the tank simulation model, construct the inverted cone region based on the spatial base point, collect the regional parameters of the inverted cone region, and calculate the calibration height of the tank simulation model;

[0103] After constructing the tank simulation model, the tank simulation model can be used as a one-to-one simulation model of the molten salt tank in three-dimensional space. This allows the tank simulation model to achieve an overall simulation effect of the multi-directional thermal stress of the molten salt tank. Since the temperature values ​​at different heights inside the molten salt tank are not the same, the thermal stress at different heights of the molten salt tank will also be different. Therefore, the overall multi-directional thermal stress analysis operation has limitations, so it is necessary to partition the tank simulation model according to specific rules.

[0104] When partitioning the tank simulation model, it is necessary to first determine the partitioning basis of the tank simulation model, that is, the specific height of the partition of the tank simulation model. When determining the specific height of the partition, the tank simulation model is used as the basis for data collection and calculation.

[0105] Specifically, when determining the specific height of the partition, it is necessary to identify the inverted cone region within the tank simulation model and use the inverted cone region as the analysis object to calculate the subsequent partition height;

[0106] In this embodiment, the inverted cone region is the region in the tank simulation model that has an inverted cone structure. Before constructing the inverted cone region, a spatial base point must be determined in the tank simulation model so that the spatial base point can be used as the initial position for constructing the inverted cone region.

[0107] Specifically, the steps for constructing the inverted cone region are as follows:

[0108] The bottom sidewall of the tank simulation model is used as the reference wall, and the center point of the reference wall is marked and denoted as the spatial base point.

[0109] Starting from the spatial base point, draw an auxiliary line perpendicular to the reference wall and extending to the top side wall of the tank simulation model, and record the intersection of the auxiliary line and the top side wall of the tank simulation model as the upper base point.

[0110] Using the above base points as the center and one-third of the diameter as the radius, draw the base point circle on the top side wall of the tank simulation model;

[0111] Randomly select a point on the boundary of the base circle, connect the point to the spatial base point to generate a region line, keep the spatial base point stationary, drive the point to rotate around the base circle, and record the region enclosed by the rotated region line as the inverted cone region.

[0112] The constructed inverted cone region is an inverted cone structure. By collecting and analyzing the regional parameters of the inverted cone region, the height calibration can be provided for the subsequent partitioning of the tank simulation model.

[0113] Region parameters are boundary parameters used for different positions and inclination amplitudes in the inverted cone region. By collecting and calculating the boundary parameters, the calibration height of the tank simulation model can be calculated.

[0114] Specifically, the region parameters include the region hypotenuse value and the region vertical value; the region hypotenuse value is used to represent the boundary length of the inverted cone region in its inclined state, and the region vertical value is used to represent the boundary length of the inverted cone region in its vertical state.

[0115] The calculation steps for the calibration height are as follows:

[0116] Mark the midpoint of the auxiliary line, draw an extension line through the midpoint that is perpendicular to the auxiliary line and intersects the area line, and mark the intersection of the auxiliary line and the area line as the diagonal point;

[0117] Measure the distances from the spatial base point to the midpoint and from the spatial base point to the oblique point one by one, and record them as the vertical value and the hypotenuse value of the region, respectively.

[0118] After comparing the vertical value of the area with the hypotenuse value of the area, the hypotenuse-to-vertical ratio is calculated. The hypotenuse-to-vertical ratio is then multiplied by the unit height value to calculate the calibration height. The unit height value refers to a pre-set height value of one unit size. The unit height value is set according to actual needs. For example, the unit height value is 1M.

[0119] The formula for calculating the calibration height is:

[0120] ;

[0121] In the formula, To calibrate the height, Values ​​per unit height. This represents the hypotenuse value of the region. This represents the vertical value for the region.

[0122] It should be noted that the calculated calibration height is only used as the initial numerical basis for partitioning the tank simulation model. In actual partitioning of the tank simulation model, the value of the calibration height can be kept unchanged or reduced to meet the partitioning requirements of the tank simulation model.

[0123] S04: Based on the equidistant zoning criterion, the calibration height is converted into the regional height, and the molten salt tank is divided into stress zones based on the regional height.

[0124] After calculating the calibration height, it is necessary to further analyze the calibration height to determine whether the calibration height can divide the molten salt tank into equal parts. The specific value that satisfies the division of the molten salt tank into equal parts is recorded as the area height, ensuring that the area height is derived from the calibration height.

[0125] When converting the calibration height to the area height, it must be done under the constraint of the equidistant zoning criterion to ensure the accuracy and rationality of the area height, and at the same time ensure that the height of the stress area obtained by the subsequent molten salt tank zoning is consistent.

[0126] Specifically, the equidistant partitioning criterion is that the height of any two adjacent stress regions is equal; this ensures that the molten salt tank can be uniformly divided into multiple stress regions of equal height.

[0127] The stress region refers to a specific height range obtained by dividing the molten salt tank according to the regional height standard, and serves as the direct object for subsequent multi-directional thermal stress compensation analysis of the molten salt tank.

[0128] The steps for dividing the stress region are as follows:

[0129] Divide the height value by the calibration height to calculate the calibration multiple;

[0130] When the calibration multiple is a positive integer, the calibration height is used as the area height, and the molten salt tank is divided into D stress areas starting from the bottom sidewall of the molten salt tank;

[0131] When the calibration multiple is not a positive integer, the calibration height is continuously reduced by 1% of the calibration height, and the calibration multiple after reduction is calculated in real time until the calibration multiple after reduction is a positive integer for the first time.

[0132] The reduced calibration height is recorded as the region height. Starting from the bottom sidewall of the molten salt vessel, the molten salt vessel is divided into D stress regions.

[0133] It should be noted that the defined stress regions are used to define the actual location of the molten salt tank in subsequent multi-directional thermal stress compensation analysis, and to ensure that the acquisition and analysis of relevant data within the molten salt tank can correspond to the stress regions.

[0134] S05: Collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information;

[0135] Comprehensive stress data refers to the comprehensive data that can affect the distribution and magnitude of multi-directional thermal stress in the molten salt tank at the spatial location corresponding to the stress area, thereby providing a comprehensive data foundation for the multi-directional thermal stress compensation analysis at different height locations in the molten salt tank;

[0136] Comprehensive stress data includes regional pressure values ​​and regional temperature change values;

[0137] The regional pressure value refers to the pressure value inside the molten salt tank at the corresponding height position of different stress areas. It can represent the magnitude of the molten salt medium and gas pressure at different height positions inside the molten salt tank. The regional pressure value is obtained by detecting pressure transmitters installed inside the molten salt tank.

[0138] Regional temperature change value refers to the temperature change value inside the molten salt tank at the corresponding height position of different stress areas. It can represent the temperature change at different height positions inside the molten salt tank. When collecting regional temperature change values ​​of stress areas, they are obtained by detecting and acquiring them through fiber optic temperature sensors installed at the corresponding positions of stress areas in the molten salt tank.

[0139] After collecting the comprehensive stress data, the comprehensive stress parameters and comprehensive material parameters can be combined to calculate the thermal stress in each direction of the stress region, and the composition of thermal stress in all directions is recorded as the regional thermal stress.

[0140] Specifically, regional thermal stress includes axial thermal stress, radial thermal stress, and tangential thermal stress;

[0141] Among them, axial thermal stress refers to the thermal stress caused by the expansion due to temperature changes at different locations in the stress area along the height of the molten salt tank.

[0142] The formula for calculating axial thermal stress is:

[0143] ;

[0144] In the formula, For axial thermal stress, For elastic modulus, It is the linear thermal expansion coefficient. This represents the temperature change value between the top and bottom of the stress region. Poisson's ratio, The pressure value within the region, This is the diameter value. This represents the wall thickness value.

[0145] Radial thermal stress refers to the thermal stress caused by uneven heating along the circumference of the molten salt vessel;

[0146] The formula for calculating radial thermal stress is:

[0147] ;

[0148] In the formula, Radial thermal stress, This represents the temperature change value between one side and the other side of the stress region.

[0149] Tangential thermal stress refers to the shear stress generated at welded joints or flange connections on molten salt tanks due to the lack of coordination in multi-directional expansion.

[0150] The formula for calculating tangential thermal stress is:

[0151] ;

[0152] In the formula, For tangential thermal stress, This represents the temperature change value of the area between one side and the other side of the weld in the stress zone. For weld thickness, This refers to the weld length.

[0153] When calculating tangential thermal stress, it is necessary to first determine whether there are welded joints or flange connections in the stress region, and then use camera vision technology to measure the length and thickness of the welds to meet the calculation requirements of tangential thermal stress.

[0154] After calculating the axial thermal stress, radial thermal stress, and tangential thermal stress, a compensation analysis can be performed on the calculation results to determine whether the magnitude of the axial thermal stress, radial thermal stress, and tangential thermal stress in each stress region exceeds the preset thermal stress. Based on the analysis and comparison results, regional stress compensation information corresponding to the stress region is generated to provide necessary data and theoretical support for the subsequent thermal stress compensation of the molten salt tank.

[0155] Specifically, stress compensation information includes axial over-limit information, radial over-limit information, and tangential over-limit information. Axial over-limit information refers to the phenomenon that the axial thermal stress in the stress region has exceeded the limit. At this time, the axial thermal stress in the stress region is too large, and the probability of the molten salt tank corresponding to the stress region being deformed or cracked is relatively high. Similarly, radial over-limit information and tangential over-limit information correspond to the radial thermal stress and tangential thermal stress in the stress region, respectively.

[0156] The steps for generating regional compensation information are as follows:

[0157] Stress over-limit analysis was performed on each of the D stress regions for axial thermal stress, radial thermal stress, and tangential thermal stress.

[0158] When the axial thermal stress is greater than the axial safe stress, it indicates that the axial thermal stress in the stress region exceeds the axial thermal stress under safe conditions, and axial over-limit information is generated for that stress region. The axial safe stress refers to the maximum value of the axial thermal stress when the stress region is in a safe state. The axial safe stress is obtained by collecting a large number of historical maximum values ​​of the axial thermal stress when the stress region is in a safe state and then calculating their average value.

[0159] When the radial thermal stress is greater than the radial safe stress, it indicates that the radial thermal stress in the stress region exceeds the radial thermal stress under safe conditions, and radial over-limit information is generated for that stress region. The radial safe stress refers to the maximum value of the radial thermal stress when the stress region is under safe conditions. The radial safe stress is obtained by collecting a large number of historical maximum values ​​of radial thermal stress when the stress region is under safe conditions and then calculating their average value.

[0160] When the tangential thermal stress exceeds the tangential safe stress, it indicates that the tangential thermal stress in the stress region exceeds the tangential thermal stress under safe conditions, and thus tangential over-limit information is generated for that stress region. The tangential safe stress refers to the maximum value of the tangential thermal stress when the stress region is under safe conditions; the tangential safe stress is obtained by averaging the maximum values ​​of the tangential thermal stress in a large number of historical stress regions under safe conditions.

[0161] It should be noted that the number of regional compensation information in each stress region is not unique; it may be 0 or 3. When the number of regional compensation information is 0, it means that the thermal stress in the axial, radial, and tangential directions of the stress region has not exceeded the maximum thermal stress under safe conditions. Therefore, the thermal stress in the stress region is in a safe state and no further thermal stress compensation operation is required for the stress region.

[0162] When the amount of regional compensation information is not zero, it is necessary to identify which of the axial thermal stress, radial thermal stress, and tangential thermal stresses in the stress region exceed the safe stress, and then perform subsequent targeted compensation analysis operations on the specific objects that exceed the safe stress.

[0163] Example 2: Please refer to Figure 2 As shown, the parts not described in detail in this embodiment are described in Embodiment 1. A multi-directional thermal stress compensation analysis system for molten salt tanks is provided to realize the multi-directional thermal stress compensation analysis system for molten salt tanks. The system includes a material parameter acquisition module, a simulation model construction module, a calibration height calculation module, a stress region division module, and a stress compensation analysis module. The modules are connected to each other via wired or wireless network.

[0164] The material parameter acquisition module is used to determine the operating conditions of the molten salt tank at the current moment based on the temperature change data over a standard time period, and to collect the comprehensive material parameters of the molten salt tank.

[0165] The simulation model construction module is used to obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model.

[0166] The calibration height calculation module is used to determine the spatial base point of the tank simulation model, construct an inverted cone region based on the spatial base point, collect the regional parameters of the inverted cone region, and calculate the calibration height of the tank simulation model.

[0167] The stress zone division module is used to reduce the calibration height to a zone height based on the equidistant partitioning criterion, and divide the molten salt tank into stress zones based on the zone height.

[0168] The stress compensation analysis module is used to collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information.

[0169] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for multi-directional thermal stress compensation analysis of molten salt vessels, characterized in that, include: S01: Based on the temperature change data within a standard time period, determine the operating conditions of the molten salt tank at the current moment, and collect the comprehensive material parameters of the molten salt tank, including elastic modulus, Poisson's ratio and linear thermal expansion coefficient. S02: Obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model. The comprehensive structural parameters include height, diameter and wall thickness. S03: Determine the spatial base point of the tank simulation model, construct the inverted cone region based on the spatial base point, collect the region parameters of the inverted cone region, and calculate the calibration height of the tank simulation model. The region parameters include the region hypotenuse value and the region vertical value. S04: Based on the equidistant partitioning criterion, the calibration height is reduced to the regional height, and the molten salt tank is divided into stress regions based on the regional height. The equidistant partitioning criterion is that the heights of any two adjacent stress regions are equal. S05: Collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information.

2. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 1, characterized in that, Operating conditions include startup, steady-state, and shutdown conditions; The steps for determining the operating conditions are as follows: The database is used to retrieve A historical temperature change events of the molten salt tank over a past period. The temperature change value and duration are retrieved from the A historical temperature change events. The temperature change value and duration are compared and then A unit durations are calculated. The standard duration is calculated by averaging the maximum and minimum values ​​of the unit duration. Then, starting from the current moment, the temperature variation period is generated by counting backwards by one standard duration. Find the temperature values ​​at B temperature change moments in the molten salt tank during the temperature change period, and analyze the changing trends of the B temperature values; When the trend of temperature values ​​B is a continuous increase, the molten salt tank is in start-up condition. When the trend of the B temperature values ​​is continuously flat, the molten salt tank is in steady-state operation. When the trend of temperature value B is a continuous decrease, the molten salt tank is in a shutdown condition.

3. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 2, characterized in that, The steps for building the basic model are as follows: The outline of the molten salt tank is constructed in three-dimensional space using 3D modeling technology. The outline of the molten salt tank is stretched and deformed until the height, diameter and wall thickness of the molten salt tank outline reach the height value, diameter value and wall thickness value respectively. Scan the boundary chamfer image of the molten salt tank, and use the boundary chamfer image as a standard to chamfer the boundary of the expanded and deformed molten salt tank contour to generate the basic model; Three attribute bits are established for two simulation units distributed vertically. The simulation unit located at the top of the three attribute bits is labeled with the text of the elastic modulus, the text of Poisson's ratio, and the text of the linear thermal expansion coefficient, respectively, so that the three attribute bits are transformed into the first simulation bit, the second simulation bit, and the third simulation bit.

4. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 3, characterized in that, The conversion steps for the tank simulation model are as follows: The digital portions of the elastic modulus, Poisson's ratio, and linear thermal expansion coefficient are imported into the simulation cells located at the bottom of the first, second, and third simulation bits, respectively. The elastic modulus, Poisson's ratio, linear thermal expansion coefficient, height, diameter, and wall thickness are fused using a data fusion algorithm to generate a set of model parameters. A note box is created on the model parameter set, and the operating conditions of the molten salt tank are imported into the note box, which prompts the basic model to be converted into a tank simulation model.

5. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 4, characterized in that, The steps for constructing the inverted cone region are as follows: The bottom sidewall of the tank simulation model is used as the reference wall, and the center point of the reference wall is marked and denoted as the spatial base point. Starting from the spatial base point, draw an auxiliary line perpendicular to the reference wall and extending to the top side wall of the tank simulation model, and record the intersection of the auxiliary line and the top side wall of the tank simulation model as the upper base point. Using the above base points as the center and one-third of the diameter as the radius, draw the base point circle on the top side wall of the tank simulation model; Randomly select a point on the boundary of the base circle, connect the point to the spatial base point to generate a region line, keep the spatial base point stationary, drive the point to rotate around the base circle, and record the region enclosed by the rotated region line as the inverted cone region.

6. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 5, characterized in that, The calculation steps for the calibration height are as follows: Mark the midpoint of the auxiliary line, draw an extension line through the midpoint that is perpendicular to the auxiliary line and intersects the area line, and mark the intersection of the auxiliary line and the area line as the diagonal point; Measure the distances from the spatial base point to the midpoint and from the spatial base point to the oblique point one by one, and record them as the vertical value and the hypotenuse value of the region, respectively. After comparing the vertical value of the region with the hypotenuse value of the region, the hypotenuse-to-vertical ratio is calculated, and the hypotenuse-to-vertical ratio is multiplied by the unit height value to calculate the calibration height.

7. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 6, characterized in that, The steps for dividing the stress region are as follows: Divide the height value by the calibration height to calculate the calibration multiple; When the calibration multiple is a positive integer, the calibration height is used as the area height, and the molten salt tank is divided into D stress areas starting from the bottom sidewall of the molten salt tank; When the calibration multiple is not a positive integer, the calibration height is continuously reduced by 1% of the calibration height, and the calibration multiple after reduction is calculated in real time until the calibration multiple after reduction is a positive integer for the first time. The reduced calibration height is recorded as the region height. Starting from the bottom sidewall of the molten salt vessel, the molten salt vessel is divided into D stress regions.

8. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 7, characterized in that, Comprehensive stress data includes regional pressure values ​​and regional temperature change values; Regional thermal stress includes axial thermal stress, radial thermal stress, and tangential thermal stress.

9. The method for multi-directional thermal stress compensation analysis of a molten salt vessel according to claim 8, characterized in that, Stress compensation information includes axial over-limit information, radial over-limit information, and tangential over-limit information; The steps for generating regional compensation information are as follows: Stress over-limit analysis was performed on each of the D stress regions for axial thermal stress, radial thermal stress, and tangential thermal stress. When the axial thermal stress exceeds the axial safe stress, axial over-limit information is generated in the stress region; When the radial thermal stress exceeds the radial safe stress, radial over-limit information is generated in the stress region; When the tangential thermal stress exceeds the tangential safe stress, tangential over-limit information is generated in the stress region.

10. A molten salt vessel multi-directional thermal stress compensation analysis system, used to implement the molten salt vessel multi-directional thermal stress compensation analysis method according to any one of claims 1-9, characterized in that, It includes a material parameter acquisition module, a simulation model construction module, a calibration height calculation module, a stress region division module, and a stress compensation analysis module. The modules are connected to each other via wired or wireless networks. The material parameter acquisition module is used to determine the operating conditions of the molten salt tank at the current moment based on the temperature change data over a standard time period, and to collect the comprehensive material parameters of the molten salt tank. The simulation model construction module is used to obtain the comprehensive structural parameters of the molten salt tank, construct a basic model with simulation positions, and integrate the comprehensive material parameters with the corresponding simulation positions to convert the basic model into a tank simulation model. The calibration height calculation module is used to determine the spatial base point of the tank simulation model, construct an inverted cone region based on the spatial base point, collect the regional parameters of the inverted cone region, and calculate the calibration height of the tank simulation model. The stress zone division module is used to reduce the calibration height to a zone height based on the equidistant partitioning criterion, and divide the molten salt tank into stress zones based on the zone height. The stress compensation analysis module is used to collect comprehensive stress data of the stress area, calculate the regional thermal stress of the stress area, perform over-limit analysis on the regional thermal stress, and generate stress compensation information.

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