A method and system for simulating the mechanical properties of energy storage lining under stress-temperature field

Abstract

The present invention provides a method and system for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field, and relates to the technical field of numerical simulation of tunnel engineering. The method and system are used to systematically collect and analyze characteristic state parameters of an adaptive material under different stress-temperature fields, respectively determine stress reference values ​​and temperature reference values, and generate evaluation indexes for evaluating the changing trends of mechanical performance parameters under different stress and temperature changes, thereby more comprehensively simulating the mechanical properties of the material under a complex environment. The method and system are used to analyze thermal performance parameters in a temperature increasing sequence, generate temperature change influence coefficients, and combine different evaluation indexes to form a comprehensive performance evaluation model. The model provides a scientific basis for the structural design and material selection of the energy storage cavern lining, has important engineering application value, and can more accurately guide the optimal design of the energy storage cavern lining, thereby improving its safety and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering numerical simulation, in particular to a method and system for simulating the mechanical characteristics of an energy storage cavern lining under a stress-temperature field. Background Art

[0002] In the development of energy storage technology, energy storage caverns, as an important energy storage method, convert excess electrical energy into other forms of energy for storage and release it when needed to achieve energy balance and efficient utilization. One of the core components of energy storage caverns is its lining structure, whose main function is to ensure the safety and stability of energy storage caverns. Therefore, it is of great research and application value to study and simulate the mechanical properties of energy storage cavern linings, especially the mechanical behavior under complex stress-temperature fields.

[0003] In the prior art, the publication number is CN118171377B, and the name is a method for numerical simulation of soil tunnel lining stress based on multi-solver coupling, which includes the following steps: establishing a groundwater model in the CFD solver; obtaining soil geological information of the soil tunnel; obtaining basic mechanical parameters of different soil layers; establishing a soil model in the DEM solver; establishing a tunnel structure model in the FEM solver; setting a coupling method between any two of the three solvers; running the program to solve and output the result data. By integrating the three solvers of CFD, DEM, and FEM and applying them to the numerical simulation of soil tunnel lining stress, not only the influence of soil solid media, but also the influence of fluid media such as groundwater are considered. The comprehensive application of fluid dynamics, discrete element and finite element methods can more accurately and realistically simulate the stress of soil tunnel lining under complex geological and groundwater conditions, and better meet the actual application needs.

[0004] In the existing technology, most studies focus on analyzing the mechanical and thermal properties of energy storage cavern lining materials under constant conditions, while ignoring the performance changes of materials under complex stress-temperature fields. However, during the actual operation of the energy storage cavern, the stress and temperature fields of the internal environment are usually dynamically changing, which will significantly affect the mechanical and thermal properties of the materials. However, the current research methods and simulation means have certain limitations in dealing with these complex changes and cannot fully and accurately reflect the comprehensive performance of materials under multi-field coupling conditions. Especially for adaptive materials, their response characteristics in different stress and temperature fields are significantly different. It is difficult for existing technologies to fully analyze and evaluate this change trend, which affects the optimal design and material selection of energy storage cavern linings;

[0005] The above information disclosed in the above Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for simulating the mechanical properties of energy storage cavern lining under stress-temperature field, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field, the specific steps comprising:

[0009] Step S1: collecting characteristic state parameters of the adaptive material in the energy storage cave lining under different stress-temperature fields, wherein the characteristic state parameters include thermal performance parameters and mechanical performance parameters, so as to establish a basic physical property database of the adaptive material under different stress-temperature fields;

[0010] Step S2: Obtain a basic physical property database, and determine the stress reference value and the temperature reference value respectively; perform the following analysis on the characteristic state parameters of the adaptive material under different stress-temperature fields:

[0011] On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence;

[0012] On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence;

[0013] Step S3: collecting thermal performance parameters of the adaptive material at different temperature values ​​in the temperature increasing sequence, and analyzing these data to generate a temperature change influence coefficient;

[0014] Step S4: Calculate the first evaluation index and the second evaluation index of the adaptive material at the current temperature and stress value respectively, combine and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient, and comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

[0015] Furthermore, the construction of the performance evaluation model specifically includes:

[0016] Determine the temperature and stress values ​​of the adaptive material at the current time, from the temperature increment sequence { , ,…, , …, } and stress increasing sequence { , ,…, , …, } respectively match the temperature value closest to the current time and stress values ; are the indexes of the increasing times when the temperature value and the stress value are closest to each other at the current time, and ; Further calculate the first evaluation index and the second evaluation index of the adaptive material at the current time;

[0017] The calculation formula of the performance evaluation model is defined as follows:

[0018] ;

[0019] Where P is the output value of the performance evaluation model; Perform standardization in the range of (0,1) to obtain the output value ; e1, e2, e3 correspond to The weight coefficient of ;

[0020] Set the effective value range of P to (0,1); determine the thermal expansion coefficient, thermal conductivity, specific heat capacity and mechanical performance parameters under temperature changes. or stress increment Previous standard value;

[0021] when , , and the first evaluation index and the second evaluation index are respectively in the low temperature section and the low stress section; the adaptive material is used for the lining layer to provide stable thermal performance parameters and mechanical properties;

[0022] Changes in temperature or stress increment Under the following conditions, the thermal performance parameters including thermal expansion coefficient, thermal conductivity and specific heat capacity shall be within 10% of the corresponding standard values; the mechanical properties shall be within 1% of the corresponding standard values;

[0023] when , , and when the first evaluation index and the second evaluation index are in the medium temperature section and the medium stress section respectively, the adaptive material is used for stress concentration areas and structural joints, which are medium-level thermal performance parameters and stress changes;

[0024] The thermal expansion coefficient, thermal conductivity and specific heat capacity change between 10% and 28% of the corresponding standard values; the mechanical performance parameters change between 2% and 12% of the corresponding standard values;

[0025] when , , and when the first evaluation index and the second evaluation index are in the high temperature section and the high stress section respectively, the adaptive material is used in a high temperature stress environment;

[0026] The changes in thermal expansion coefficient, thermal conductivity coefficient and specific heat capacity are above 28% of the corresponding standard values; the changes in mechanical properties are above 12% of the corresponding standard values.

[0027] A mechanical property simulation system for energy storage cavern lining under stress-temperature field, the system is used to execute the mechanical property simulation method for energy storage cavern lining under stress-temperature field, comprising:

[0028] Basic physical property database establishment module: used to collect characteristic state parameters of adaptive materials in energy storage cavern lining under different stress-temperature fields. The characteristic state parameters include thermal performance parameters and mechanical performance parameters, so as to establish the basic physical property database of the adaptive materials under different stress-temperature fields.

[0029] Index generation module: used to obtain the basic physical property database and determine the stress reference value and temperature reference value respectively; the following analysis is performed on the characteristic state parameters of the adaptive material under different stress-temperature fields:

[0030] On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence;

[0031] On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence;

[0032] Influence coefficient generation module: used to collect thermal performance parameters of adaptive materials at different temperature values ​​in the temperature increasing sequence, analyze these data, and generate temperature change influence coefficients;

[0033] Optimization and adjustment module: It is used to calculate the first evaluation index and the second evaluation index of the adaptive material under the current temperature and stress value respectively, and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient together to comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: a comprehensive physical property database is established by systematically collecting and analyzing the characteristic state parameters of adaptive materials under different stress-temperature fields; by respectively determining the stress reference value and the temperature reference value, an evaluation index is generated for evaluating the change trend of mechanical performance parameters under different stress and temperature changes, thereby more comprehensively simulating the mechanical properties of materials in complex environments; by analyzing the thermal performance parameters in the temperature increasing sequence, the temperature change influence coefficient is generated, and a comprehensive performance evaluation model is formed by combining different evaluation indexes; the model provides a scientific basis for the structural design and material selection of the energy storage cavern lining, has important engineering application value, and can more accurately guide the optimization design of the energy storage cavern lining and improve its safety and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall method flow of the present invention;

[0036] Figure 2 This is a block diagram of the system modules of the present invention. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0038] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] Embodiment 1:

[0040] See also Figure 1 , the present invention provides a technical solution:

[0041] A method for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field, the specific steps comprising:

[0042] Step S1: collecting characteristic state parameters of the adaptive material in the energy storage cave lining under different stress-temperature fields, the characteristic state parameters including thermal expansion coefficient, thermal conductivity coefficient, specific heat capacity and mechanical performance parameters, so as to establish a basic physical property database of the adaptive material under different stress-temperature fields;

[0043] Step S2: Obtain a basic physical property database, and determine the stress reference value and the temperature reference value respectively; perform the following analysis on the characteristic state parameters of the adaptive material under different stress-temperature fields:

[0044] On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence;

[0045] On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence;

[0046] Step S3: collecting thermal performance parameters of the adaptive material at different temperature values ​​in the temperature increasing sequence, and analyzing these data to generate a temperature change influence coefficient;

[0047] Step S4: Calculate the first evaluation index and the second evaluation index of the adaptive material at the current temperature and stress value respectively, combine and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient, and comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

[0048] It is further explained that the different stress-temperature fields are the temperature and stress states inside the adaptive material;

[0049] The thermal performance parameters include thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity. The adaptive material is a composite material with high temperature stability. The adaptive material can cause changes in thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity according to temperature changes; at the same time, it can cause changes in mechanical performance parameters according to stress changes;

[0050] The construction of the basic physical properties database includes:

[0051] Select samples of adaptive materials used in energy storage cavern linings; the adaptive materials are respectively set in the inner lining layer, stress concentration area, structural joints and joints of the lining structure;

[0052] Adaptive material samples are used in the following locations:

[0053] Lining layer: Adaptive materials are used for the lining layer of the lining structure to cope with temperature changes and stress changes inside the energy storage chamber. The lining layer is in direct contact with the energy storage device, so it needs to have excellent thermal expansion characteristics and thermal conductivity to effectively conduct heat and reduce thermal stress accumulation.

[0054] Stress concentration area: In structural design, some parts will form stress concentration areas, including corners, connection points, etc. Adaptive materials have excellent mechanical properties and self-healing properties, which can effectively alleviate stress concentration problems and extend the service life of lining structures;

[0055] Structural joints and connectors: There are joints and connectors in the lining structure of the energy storage chamber, which are prone to generate large stresses. The use of adaptive materials can improve the stress resistance of joints and connectors, while reducing cracking and deformation when the temperature changes.

[0056] Prepare the experimental equipment as follows:

[0057] Constant temperature box or temperature control room: used to control the temperature field of the material;

[0058] Stress loading device: electronic universal testing machine, used to control and apply the stress field of the material;

[0059] Thermal expansion coefficient measuring instrument: thermal expansion meter (TMA);

[0060] Thermal conductivity measuring instrument: laser flash thermal conductivity meter;

[0061] Specific heat capacity measurement device: differential scanning calorimeter (DSC);

[0062] Mechanical properties testing equipment: tensile testing machine, compression testing machine, etc.;

[0063] Establishing experimental conditions of temperature-stress field, including the combination of temperature variation range and stress variation range, so as to form different temperature-stress combination points;

[0064] Determine the temperature range: Determine the temperature range from -20°C to 60°C, with an interval of 5°C between adjacent temperature changes;

[0065] Determine the stress range: Determine the stress variation range, from 0MPa to 200MPa, with the adjacent stress variation interval being 10MPa;

[0066] Through these different temperature-stress combination points, mechanical property simulation experiments under different stress-temperature fields were carried out for the energy storage cavern lining;

[0067] The experimental measurement steps are as follows:

[0068] The thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity obtained from the mechanical properties simulation experiment are marked as , , ; and the mechanical performance parameters are comprehensively expressed as CMt, and the CMt calculation formula is as follows:

[0069] ;

[0070] Among them, Eq, Qf and are the standardized output values ​​of Young's modulus, yield strength and ultimate strength respectively; a1, a2, a3 are the positive weight coefficients of the corresponding parameters respectively, and a1+a2+a3=1; in this embodiment, a1, a2, a3 are 0.2, 0.3, 0.5 respectively; the application scenarios are as follows:

[0071] Underground environmental factors:

[0072] Energy storage caverns are affected by geological conditions (such as soil type, groundwater level, and seismic activity) and temperature changes. In this environment, the lining material needs to effectively cope with external pressure and temperature fluctuations to ensure the safety and durability of the structure.

[0073] Importance of Mechanical Properties:

[0074] Young's modulus, yield strength and ultimate strength of the material are key parameters affecting the performance of the lining; in this scenario, the high weight of 0.5 for the ultimate strength indicates that the load-bearing capacity of the lining under long-term loads is the top priority in the design;

[0075] The weight of 0.3 for yield strength means that, in extreme cases, the material cannot exceed its yield point to avoid structural failure;

[0076] Safety and economic considerations:

[0077] During the design process, safety and economy must be balanced; a lining that is too strong, while safe, will result in high material and construction costs; therefore, the lower weight of 0.2 for the Young's modulus reflects that in the current case, the stiffness of the material is not the only design limitation;

[0078] For the measurement of the coefficient of thermal expansion:

[0079] Place the adaptive material sample in a thermal dilatometer (TMA);

[0080] The adaptive material sample is gradually heated to a predetermined temperature point in an incremental manner, and a predetermined stress value is applied at each temperature point; the thermal expansion change of the adaptive material sample is recorded, and the thermal expansion coefficient is calculated:

[0081] ;

[0082] in, is the coefficient of thermal expansion, is the length change, is the original length, is each incremental temperature change;

[0083] For thermal conductivity measurements:

[0084] The adaptive material sample is placed in a laser flash method thermal conductivity instrument;

[0085] gradually heating the adaptive material sample to predetermined temperature points and applying a predetermined stress value at each temperature point;

[0086] Record the heat transfer rate of the adaptive material sample and calculate the thermal conductivity:

[0087] ;

[0088] in, is the thermal conductivity, Q is the heat flow, As is the cross-sectional area, is each incremental temperature change;

[0089] For the measurement of specific heat capacity:

[0090] The adaptive material sample was placed in a differential scanning calorimeter (DSC);

[0091] Incrementally heating the adaptive material sample to predetermined temperature points and applying a predetermined stress value at each temperature point;

[0092] Record the heat flow change of the adaptive material sample and calculate the specific heat capacity:

[0093] ;

[0094] in, is the specific heat capacity, is the absorbed heat, m is the mass of the adaptive material sample, is each incremental temperature change;

[0095] For the measurement of mechanical properties:

[0096] Place the adaptive material sample in a tensile testing machine or a compression testing machine;

[0097] gradually heating the adaptive material sample to predetermined temperature points and applying a predetermined stress value at each temperature point;

[0098] Record stress-strain curves of adaptive material samples; calculate mechanical property parameters;

[0099] Record the thermal expansion coefficient, thermal conductivity, specific heat capacity and mechanical performance parameters corresponding to each temperature-stress combination point;

[0100] All experimental data are entered into a database to establish a database of basic physical properties of adaptive materials under different stress-temperature fields.

[0101] Further explanation: Determine the temperature reference value: select the lowest ambient temperature value of the adaptive material in the stress-free state as the temperature reference value; and record the temperature reference value as ;

[0102] Determine the stress reference value: select the lowest stress value corresponding to the lowest ambient temperature value of the adaptive material as the stress reference value; and record the stress reference value as ;

[0103] The construction of the first evaluation index specifically includes:

[0104] Based on stress reference value , gradually increase the temperature value to form a temperature increasing sequence { , ,…, , …, };in, represents the i-th increasing temperature value; Indicates the nth increasing temperature value; The calculation formula is as follows;

[0105] ;

[0106] in, is the temperature change amount for each increment, and i is the index of the temperature increment sequence; in this embodiment, 5°C;

[0107] Will The first evaluation index under the temperature value is recorded as , the calculation formula is as follows:

[0108] ;

[0109] in, Indicates the stress reference value On the basis of The comprehensive mechanical properties parameters corresponding to the temperature value, It is the comprehensive mechanical performance parameter under the reference state; the evaluation index reflects the relative change rate of the comprehensive mechanical performance parameter with temperature change.

[0110] Set temperature increment sequence { , ,…, , …, The critical temperature values ​​in} are , where i−b1 refers to the position where the index value i is shifted forward by b1 in the temperature increasing sequence; i+b1 refers to the position where the index value i is shifted backward by b1 in the temperature increasing sequence; and In this embodiment, 25°C and 45°C respectively;

[0111] The low temperature section is ; Medium temperature section is ; High temperature section is ;

[0112] For the variation trend of mechanical performance parameters in the low temperature section; the low temperature section of this embodiment is -20°C to 25°C: Based on the experimental data table, it is demonstrated that: if the temperature increases , The value range is between -1% and 1%, indicating that in the low temperature section, the change trend of mechanical properties parameters is low level;

[0113] For the variation trend of mechanical performance parameters in the medium temperature section, the medium temperature section in this embodiment is 25°C to 45°C: Based on the experimental data table, it is demonstrated that: if the temperature increases , The value decreased by 2%;

[0114] From 25°C to 40°C, The value changes were -2%, -4%, and -6%;

[0115] It means that the mechanical properties of the adaptive material gradually decrease with the increase of temperature, and the adaptive material exhibits thermal expansion effect;

[0116] Regarding the change trend of the high temperature section, the high temperature section of this embodiment is 45°C to 60°C; based on the experimental data table, it is demonstrated that: if the temperature increases by , The value decreased by 5%;

[0117] From 45°C to 55°C, The value changes were -15%, -20%;

[0118] It indicates that the mechanical performance parameters of the adaptive material decrease rapidly, and the mechanical stability of the adaptive material shows a decreasing trend.

[0119] Further explanation: the construction of the second evaluation index specifically includes:

[0120] Based on temperature reference , gradually increase the stress value to form a stress increasing sequence { , ,…, , …, };in, represents the jth increasing stress value; represents the kth increasing stress value; The calculation formula is as follows;

[0121] ;

[0122] Where j is the index of the stress increasing sequence, is the stress increment for each increment;

[0123] Will The second evaluation index under stress value is recorded as , the calculation formula is as follows:

[0124] ;

[0125] in, Indicates the temperature reference value On the basis of The comprehensive mechanical properties parameters corresponding to the stress value, is the comprehensive mechanical performance parameter under the reference state; this evaluation index reflects the relative change rate of the comprehensive mechanical performance parameter with stress change;

[0126] Set the stress increment sequence { , ,…, , …, The critical stress values ​​in} are ,and In this embodiment, 50MPa and 150MPa respectively;

[0127] The low stress section is The medium stress section is The high stress section is ;

[0128] For the variation trend of mechanical properties parameters in the low stress section, if the stress increases , The value range is between -1% and 1%, which indicates that in the low stress section, the change trend of the comprehensive mechanical properties parameters of the adaptive material is low level;

[0129] For the variation trend of mechanical properties parameters in the medium stress section, if the stress increases , The value increased by 2%. The following contents were obtained through experimental analysis:

[0130] From 50MPa to 80MPa, The value changes are 2%, 4%, and 6%;

[0131] From 80MPa to 150MPa, The value changes are 8%, 10%, and 12%;

[0132] This shows that in the medium stress section, the mechanical properties parameters of the adaptive material gradually increase with the increase of stress, and the adaptive material shows an enhancement effect;

[0133] For the variation trend of mechanical properties parameters in the high stress section, if the stress increases , The value increased by 5%. The following contents were obtained through experimental analysis:

[0134] From 150MPa to 180MPa, The value changes are 15%, 20%;

[0135] From 180MPa to 200MPa, The value changes are 25%, 30%;

[0136] This indicates that in the high stress section, the change trend of the mechanical property parameters of the adaptive material is high level, and the adaptive material yields or fails.

[0137] Further explanation: the construction of the temperature change influence coefficient includes:

[0138] The temperature change influence coefficient is recorded as ; The calculation formula is as follows:

[0139] ;

[0140] in, is the stress reference value Down, The coefficient of thermal expansion corresponding to the temperature value;

[0141] is the stress reference value Down, Thermal conductivity corresponding to the temperature value; is the stress reference value Down, Specific heat capacity corresponding to the temperature value; is the temperature change at each increment; e is the base of the natural logarithm;

[0142] set up The valid value range of is (0,1);

[0143] when When the temperature is 0.5000 °C, the performance of the adaptive material is relatively stable within this temperature range, and the change range of the thermal expansion coefficient, thermal conductivity coefficient and specific heat capacity are all within 10%, and the change range is low.

[0144] when When the temperature changes, the thermal performance parameters of the adaptive material are moderately affected by the temperature change, and the change range of the thermal performance parameters including the thermal expansion coefficient, thermal conductivity and specific heat capacity are all within 10% to 28%;

[0145] when When the temperature is increased, the thermal performance parameters of the adaptive material are highly affected by the temperature change, and the change range of the thermal performance parameters including the thermal expansion coefficient, thermal conductivity and specific heat capacity are all above 28%.

[0146] Further explanation: The construction of the performance evaluation model specifically includes:

[0147] Determine the temperature and stress values ​​of the adaptive material at the current time, from the temperature increment sequence { , ,…, , …, } and stress increasing sequence { , ,…, , …, } respectively match the temperature value closest to the current time and stress values ; are the indexes of the increasing times when the temperature value and the stress value are closest to each other at the current time, and ; Further calculate the corresponding first evaluation index and second evaluation index;

[0148] The calculation formula of the performance evaluation model is defined as follows:

[0149] ;

[0150] Where P is the output value of the performance evaluation model; Perform standardization in the range of (0,1) to obtain the output value ; e1, e2, e3 correspond to The weight coefficient of ;

[0151] The specific values ​​of e1, e2, and e3 are determined by the expert group through experimental data;

[0152] Set the effective range of P to (0,1); based on experimental data or referring to technical manuals, determine the thermal expansion coefficient, thermal conductivity, specific heat capacity and mechanical performance parameters under temperature changes. or stress increment Previous standard value;

[0153] when , , and the first evaluation index and the second evaluation index are respectively in the low temperature section and the low stress section; the adaptive material is used for the lining layer to provide stable thermal performance parameters and mechanical properties;

[0154] Changes in temperature or stress increment Under the following conditions, the thermal performance parameters including thermal expansion coefficient, thermal conductivity and specific heat capacity shall be within 10% of the corresponding standard values; the mechanical properties shall be within 1% of the corresponding standard values;

[0155] when , , and when the first evaluation index and the second evaluation index are in the medium temperature section and the medium stress section respectively, the adaptive material is used for stress concentration areas and structural joints, which are medium-level thermal performance parameters and stress changes;

[0156] The thermal expansion coefficient, thermal conductivity and specific heat capacity change between 10% and 28% of the corresponding standard values; the mechanical performance parameters change between 2% and 12% of the corresponding standard values;

[0157] when , , and when the first evaluation index and the second evaluation index are in the high temperature section and the high stress section respectively, the adaptive material is used in a high temperature stress environment;

[0158] The changes in thermal expansion coefficient, thermal conductivity coefficient and specific heat capacity are above 28% of the corresponding standard values; the changes in mechanical properties are above 12% of the corresponding standard values.

[0159] Embodiment 2:

[0160] See also Figure 2 A mechanical property simulation system for energy storage cavern lining under stress-temperature field, the system is used to execute the mechanical property simulation method for energy storage cavern lining under stress-temperature field, including:

[0161] Basic physical property database establishment module: used to collect characteristic state parameters of adaptive materials in energy storage cavern lining under different stress-temperature fields. The characteristic state parameters include thermal performance parameters and mechanical performance parameters, so as to establish the basic physical property database of the adaptive materials under different stress-temperature fields.

[0162] Index generation module: used to obtain the basic physical property database and determine the stress reference value and temperature reference value respectively; the following analysis is performed on the characteristic state parameters of the adaptive material under different stress-temperature fields:

[0163] On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence;

[0164] On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence;

[0165] Influence coefficient generation module: used to collect thermal performance parameters of adaptive materials at different temperature values ​​in the temperature increasing sequence, analyze these data, and generate temperature change influence coefficients;

[0166] Optimization and adjustment module: It is used to calculate the first evaluation index and the second evaluation index of the adaptive material under the current temperature and stress value respectively, and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient together to comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

[0167] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0168] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0169] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0170] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for simulating the mechanical properties of energy storage lining under stress-temperature field, characterized in that: The specific steps include: Step S1: collecting characteristic state parameters of the adaptive material in the energy storage cave lining under different stress-temperature fields, wherein the characteristic state parameters include thermal performance parameters and mechanical performance parameters, so as to establish a basic physical property database of the adaptive material under different stress-temperature fields; Step S2: Obtain a basic physical property database, and determine the stress reference value and the temperature reference value respectively; perform the following analysis on the characteristic state parameters of the adaptive material under different stress-temperature fields: On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence; On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence; Step S3: collecting thermal performance parameters of the adaptive material at different temperature values ​​in the temperature increasing sequence, and analyzing these data to generate a temperature change influence coefficient; Step S4: Calculate the first evaluation index and the second evaluation index of the adaptive material at the current temperature and stress value respectively, combine and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient, and comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

2. According to claim 1, a method for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field is characterized in that: The different stress-temperature fields are the temperature and stress states inside the adaptive material; The thermal performance parameters include thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity. The adaptive material is a composite material with high temperature stability. The adaptive material causes changes in thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity according to temperature changes; at the same time, changes in mechanical performance parameters are caused according to stress changes; Mechanical properties parameters include Young's modulus, yield strength, and ultimate strength; The construction of the basic physical properties database includes: Select samples of adaptive materials used in energy storage cavern linings; the adaptive materials are respectively set in the inner lining layer, stress concentration area, structural joints and joints of the lining structure; Establishing experimental conditions of temperature-stress field, including the combination of temperature variation range and stress variation range, so as to form different temperature-stress combination points; Through these different temperature-stress combination points, mechanical property simulation experiments under different stress-temperature fields were carried out for the energy storage cavern lining; The thermal expansion coefficient, thermal conductivity coefficient, and specific heat capacity obtained from the mechanical properties simulation experiment are marked as , , ; and the mechanical performance parameters are comprehensively expressed as CMt, and the CMt calculation formula is as follows: ； Among them, Eq, Qf and are the standardized output values ​​of Young's modulus, yield strength and ultimate strength respectively; a1, a2, a3 are the positive weight coefficients of the corresponding parameters respectively, and the value ranges of a1, a2, a3 are all (0,1), and a1+a2+a3=1, a1<a2<a3; Record the thermal expansion coefficient, thermal conductivity, specific heat capacity and mechanical performance parameters corresponding to each temperature-stress combination point; All experimental data are entered into a database to establish a database of basic physical properties of adaptive materials under different stress-temperature fields.

3. According to claim 2, a method for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field is characterized in that: Determine the temperature reference value: select the lowest ambient temperature value of the adaptive material in the stress-free state as the temperature reference value; and record the temperature reference value as ; Determine the stress reference value: select the lowest stress value corresponding to the lowest ambient temperature value of the adaptive material as the stress reference value; The stress reference value is recorded as ; The construction of the first evaluation index specifically includes: Based on stress reference value , gradually increase the temperature value to form a temperature increasing sequence { , ,…, , …, };in, represents the i-th increasing temperature value; Indicates the nth increasing temperature value; The calculation formula is as follows; ； in, is the temperature change amount for each increment, and i is the index of the temperature increment sequence; Will The first evaluation index under the temperature value is recorded as , the calculation formula is as follows: ； in, Indicates the stress reference value On the basis of The comprehensive mechanical properties parameters corresponding to the temperature value, is the comprehensive mechanical performance parameter under the reference state; Set temperature increment sequence { , ,…, , …, The critical temperature values ​​in} are , where i−b1 refers to the position where the index value i is shifted forward by b1 in the temperature increasing sequence; i+b1 refers to the position where the index value i is shifted backward by b1 in the temperature increasing sequence; and ; Set the low temperature range to ; Medium temperature section is ; High temperature section is ; For the variation trend of mechanical properties parameters in the low temperature section, if the temperature increases , The value range is between -1% and 1%, indicating that in the low temperature section, the change trend of mechanical properties parameters is low level; For the variation trend of mechanical properties parameters in the medium temperature section, if the temperature increases , The value decreased by 2%; It means that the mechanical properties of the adaptive material gradually decrease with the increase of temperature, and the adaptive material exhibits thermal expansion effect; For the high temperature section change trend, if the temperature increases , The value decreased by 5%; It indicates that the mechanical performance parameters of the adaptive material decrease rapidly, and the mechanical stability of the adaptive material shows a decreasing trend.

4. According to claim 3, a method for simulating the mechanical properties of an energy storage cavern lining under a stress-temperature field is characterized in that: The construction of the second evaluation index specifically includes: Based on temperature reference , gradually increase the stress value to form a stress increasing sequence { , ,…, , …, };in, represents the jth increasing stress value; represents the kth increasing stress value; The calculation formula is as follows; ； Where j is the index of the stress increasing sequence, is the stress increment for each increment; Will The second evaluation index under stress value is recorded as , the calculation formula is as follows: ； in, Indicates the temperature reference value On the basis of The comprehensive mechanical properties parameters corresponding to the stress value, is the comprehensive mechanical performance parameter under the reference state; Set the stress increment sequence { , ,…, , …, The critical stress values ​​in} are ,and ; The low stress section is The medium stress section is The high stress section is ; For the variation trend of mechanical properties parameters in the low stress section, if the stress increases , The value range is between -1% and 1%, which indicates that in the low stress section, the change trend of the comprehensive mechanical properties parameters of the adaptive material is low level; For the variation trend of mechanical properties parameters in the medium stress section, if the stress increases , The value increased by 2%; This shows that in the medium stress section, the mechanical properties parameters of the adaptive material gradually increase with the increase of stress, and the adaptive material shows an enhancement effect; For the variation trend of mechanical properties parameters in the high stress section, if the stress increases , The value increased by 5%; This indicates that in the high stress section, the change trend of the mechanical property parameters of the adaptive material is high level, and the adaptive material yields or fails.

5. According to claim 4, a method for simulating the mechanical properties of energy storage lining under stress-temperature field is characterized by: The construction of the temperature change influence coefficient includes: The temperature change influence coefficient is recorded as ; The calculation formula is as follows: ； in, is the stress reference value Down, The coefficient of thermal expansion corresponding to the temperature value; is the stress reference value Down, Thermal conductivity corresponding to the temperature value; is the stress reference value Down, Specific heat capacity corresponding to the temperature value; is the temperature change at each increment; e is the base of the natural logarithm; set up The valid value range of is (0,1); when When the thermal expansion coefficient, thermal conductivity and specific heat capacity of the adaptive material change within 10%, the change range is stable and low; when When the temperature changes, the thermal performance parameters of the adaptive material are moderately affected by the temperature change, and the change range of the thermal performance parameters including the thermal expansion coefficient, thermal conductivity and specific heat capacity are all within 10% to 28%; when When the temperature is increased, the thermal performance parameters of the adaptive material are highly affected by the temperature change, and the change range of the thermal performance parameters including the thermal expansion coefficient, thermal conductivity and specific heat capacity are all above 28%.

6. The method for simulating the mechanical properties of the energy storage lining under the stress-temperature field according to claim 5 is characterized by: The construction of the performance evaluation model includes: Determine the temperature and stress values ​​of the adaptive material at the current time, from the temperature increment sequence { , ,…, , …, } and stress increasing sequence { , ,…, , …, } respectively match the temperature value closest to the current time and stress values ; are the indexes of the increasing times when the temperature value and the stress value are closest to each other at the current time, and ; Further calculate the first evaluation index and the second evaluation index of the adaptive material at the current time; The calculation formula of the performance evaluation model is defined as follows: ； Where P is the output value of the performance evaluation model; Perform standardization in the range of (0,1) to obtain the output value ; e1, e2, e3 correspond to The weight coefficient of ; Set the effective value range of P to (0,1); determine the thermal expansion coefficient, thermal conductivity, specific heat capacity and mechanical performance parameters under temperature changes. or stress increment Previous standard value; when , , and the first evaluation index and the second evaluation index are respectively in the low temperature section and the low stress section; the adaptive material is used for the lining layer to provide stable thermal performance parameters and mechanical properties; Changes in temperature or stress increment Under the following conditions, the thermal performance parameters including thermal expansion coefficient, thermal conductivity and specific heat capacity shall be within 10% of the corresponding standard values; the mechanical properties shall be within 1% of the corresponding standard values; when , , and when the first evaluation index and the second evaluation index are in the medium temperature section and the medium stress section respectively, the adaptive material is used for stress concentration areas and structural joints, which are medium-degree thermal performance parameters and stress changes; The thermal expansion coefficient, thermal conductivity and specific heat capacity change between 10% and 28% of the corresponding standard values; the mechanical performance parameters change between 2% and 12% of the corresponding standard values; when , , and when the first evaluation index and the second evaluation index are in the high temperature section and the high stress section respectively, the adaptive material is used in a high temperature stress environment; The changes in thermal expansion coefficient, thermal conductivity coefficient and specific heat capacity are above 28% of the corresponding standard values; the changes in mechanical properties are above 12% of the corresponding standard values.

7. A mechanical property simulation system for energy storage lining under stress-temperature field, characterized by: The system is used to execute the method for simulating the mechanical properties of the energy storage cavern lining under the stress-temperature field as described in any one of claims 1 to 6, comprising: Basic physical property database establishment module: used to collect characteristic state parameters of adaptive materials in energy storage cavern lining under different stress-temperature fields. The characteristic state parameters include thermal performance parameters and mechanical performance parameters, so as to establish the basic physical property database of the adaptive materials under different stress-temperature fields. Index generation module: used to obtain the basic physical property database and determine the stress reference value and temperature reference value respectively; the following analysis is performed on the characteristic state parameters of the adaptive material under different stress-temperature fields: On the basis of the stress value being the stress reference value, a temperature increasing sequence is determined by gradually increasing the temperature value, and a first evaluation index is generated for evaluating the change trend of the mechanical property parameter under different temperature changes in the temperature increasing sequence; On the basis of the temperature value being the temperature reference value, a stress increasing sequence is determined by gradually increasing the stress value, and a second evaluation index is generated for evaluating the change trend of the mechanical property parameters under different stress changes in the stress increasing sequence; Influence coefficient generation module: used to collect the thermal performance parameters of the adaptive material at different temperature values ​​in the temperature increasing sequence, analyze these data, and generate the temperature change influence coefficient; Optimization and adjustment module: It is used to calculate the first evaluation index and the second evaluation index of the adaptive material under the current temperature and stress value respectively, and analyze the first evaluation index, the second evaluation index and the temperature change influence coefficient together to comprehensively generate a performance evaluation model for constructing a design optimization strategy, which includes optimizing and adjusting the structural design and material use selection of the energy storage cavern lining.

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