CN-120930415-B - Petrochemical equipment creep service safety evaluation method and system

CN120930415BCN 120930415 BCN120930415 BCN 120930415BCN-120930415-B

Abstract

The invention provides a method and a system for evaluating creep service safety of petrochemical equipment, which relate to the technical field of the creep service safety evaluation of the petrochemical equipment, firstly, according to the load fluctuation amplitude, material performance index and service defect type of a component, limiting conditions for evaluation of each level are set, whether the component meets corresponding conditions or not is judged, a corresponding evaluation flow is entered, the evaluation calculation pressure, service time and evaluation temperature are defined and evaluated in the evaluation process, and calculating three-dimensional main stress based on the evaluation and calculation pressure, screening a screening curve and a damage curve of a corresponding material, calculating total creep damage, comparing the total creep damage with a threshold value to judge the result through the 1-level evaluation, judging whether plastic collapse risks exist or not through one-time reference stress and plastic collapse judging criteria for the 2-level and 3-level evaluation, and then comparing the total creep damage with an allowable value to determine the result, wherein the 3-level evaluation adopts finite element calculation and directly judges crack defects to be failed.

Inventors

ZHANG MING
BAI YU
ZHANG JIANYONG
LI MENGLI
LIU LONG
Gao Menglin
LI HAOJIE
ZHAO ZIZHEN
SU YANCAI

Assignees

齐鲁工业大学(山东省科学院)

Dates

Publication Date: 20260512
Application Date: 20250728

Claims (8)

1. The creep service safety evaluation method for petrochemical equipment is characterized by comprising the following specific steps: Setting a limiting condition of 1,2 and 3 grades of evaluation according to the load fluctuation amplitude, the material performance index and the service defect type of the component, sequentially judging whether the component meets the limiting condition of the corresponding grade evaluation, and entering 1,2 or 3 grades of evaluation to evaluate the component; According to the 1,2 or 3-level evaluation selection process, the process comprises the steps of determining the correction of evaluation calculation pressure, service time and evaluation temperature, calculating three-dimensional main stress through the evaluation calculation pressure, selecting an evaluation main stress, screening a screening curve and a damage curve of a corresponding material, determining the maximum running time based on the screening curve, determining the creep damage rate based on the damage curve, and calculating the total creep damage in combination with the service time; Setting a total creep damage threshold in the 1-level evaluation, extracting an evaluation temperature and evaluating and calculating the maximum running time of the pressure acquisition component according to the step2 under a single operation condition, if the maximum running time is higher than the service time, entering a total creep damage calculation flow, if the maximum running time is lower than the service time, judging that the total creep damage passes the evaluation, and if the total creep damage is lower than the total creep damage threshold, judging that the total creep damage passes the evaluation, otherwise, judging that whether the maximum running time enters the 2-level or 3-level evaluation according to the limiting conditions of each evaluation; In the 2-level evaluation, calculating primary reference stress through an elastic mechanical classical formula, constructing a plastic collapse judging criterion based on the material types, judging whether the primary reference stress is not passed through when the primary reference stress is larger than the plastic collapse judging criterion, judging whether the primary reference stress is passed through the 3-level evaluation according to the limiting conditions of the respective evaluations, if the primary reference stress is lower than the plastic collapse judging criterion, the primary reference stress is passed through the 3-level evaluation, entering a total creep damage calculation process, and judging that the primary reference stress is passed through the 2-level evaluation when the total creep damage is lower than a preset allowable value, otherwise, the primary reference stress is passed through the 3-level evaluation; In the 3-level evaluation, finite elements are adopted to perform stress calculation, the evaluation program is the same as that of the 2-level evaluation, and the components with crack defects are directly judged and evaluated without passing; The load fluctuation amplitude comprises a pressure fluctuation amplitude and a temperature fluctuation amplitude, the material performance indexes comprise minimum Brinell hardness and carbon content, and the defects and damages of the component comprise local thinning, grooves and pitting, hydrogen swelling, hydrogen induced cracking, stress-induced hydrogen induced cracking and stress corrosion cracking, out-of-round, swelling, concave or concave grooves exceeding the standard, crack defects, microstructure anomalies such as high-temperature hydrogen corrosion or severe graphitization, obvious deformation caused by no fire or overheating of the component, and professional evaluation personnel determine whether the defects and damages exist in the component; Recording the load fluctuation amplitude in the running process, extracting the maximum pressure, the minimum pressure, the maximum temperature and the minimum temperature of the component in the running process, and calculating the pressure fluctuation amplitude: In the formula, Representing the magnitude of the pressure fluctuation, The maximum pressure is indicated and the maximum pressure is indicated, The minimum pressure is indicated as being the value of the minimum pressure, Representing the design pressure; Calculating the temperature fluctuation amplitude value: In the formula, Indicating the magnitude of the temperature fluctuation, The temperature of the liquid is indicated as the maximum temperature, Representing a minimum temperature; When (when) Or (b) And when two or more periodic changes occur in the running time, judging that the component bears cyclic load, and setting the minimum Brinell hardness specified value as the material performance index test The carbon content gauge is set as Checking the service defect type of the component, and judging whether the defect and damage exist or not; When the original design of the component meets the related specification or standard requirement, the component does not bear cyclic load, the material performance index exceeds a specified value, the service defect type does not have the defect or damage, the 1-grade evaluation limiting condition is judged to be met, when the original design of the component meets the related specification or standard requirement, the component does not bear cyclic load, the service defect type does not have the defect or damage, the operation condition history of the component is recorded, and the 2-grade evaluation limiting condition is judged to be met when the future operation condition is known, and when the component bears cyclic load and the crack defect does not contain stress corrosion cracking, the 3-grade evaluation limiting condition is judged to be met.
2. The method for evaluating creep service safety of petrochemical equipment according to claim 1, wherein the method for determining the correction of the evaluation calculation pressure, the service time and the evaluation temperature is as follows: In the 1-level evaluation, the actual operating temperature of the component under a single operating condition or the actual operating temperature of each operating condition under multiple operating conditions is used as an evaluation temperature, if a bearing welding seam exists in the component, and the welding seam direction is perpendicular to the maximum main stress direction of the calculated wall thickness, 14 ℃ is required to be increased on the basis of the actual operating temperature to be used as the evaluation temperature; In the 2-level evaluation, selecting the maximum operating temperature under each operating condition as an evaluation temperature, selecting the maximum operating pressure under each operating condition as an evaluation calculation pressure, and taking the past running time and the future planned running time as the service time; in the 3-level evaluation, the maximum operating temperature under each operating condition is selected as an evaluation temperature, the maximum operating pressure under each operating condition is selected as an evaluation calculation pressure, and the past operating time and the future planned operating time are taken as the service time.
3. The method for evaluating creep service safety of petrochemical equipment according to claim 2, wherein the method for calculating three-dimensional principal stress by evaluating and calculating pressure and selecting and evaluating the principal stress and screening the screening curve and damage curve of the corresponding material is as follows: in the 1-level evaluation, selecting and evaluating the main stress at the position with the most serious wall thickness reduction based on the three-dimensional main stress, calculating the three-dimensional main stress based on the actual structure of the component, calculating the pressure and the wall thickness based on the evaluation by adopting a corresponding mechanical formula, and selecting the maximum main stress as the main stress: In the formula, The maximum principal stress is indicated as such, Representing three-dimensional principal stress; in the 2-level evaluation, the position with the most serious wall thickness reduction is selected to evaluate the main stress based on the three-dimensional main stress, the three-dimensional main stress is calculated based on the actual structure of the component by adopting a corresponding mechanical formula, and the equivalent stress is selected as the main stress, wherein the formula on which the equivalent stress is calculated is based is as follows: In the formula, Representing equivalent stress; in the 3-level evaluation, a finite element model is established, equivalent stress is calculated according to a rule that the weakest position of each defect is consistent with the 2-level evaluation, and the maximum value is taken as evaluation main stress; According to a creep test method specified by GB/T35013-2018 standard, performing creep performance test on the material under different temperature and different stress conditions to obtain creep rupture time and creep damage rate data corresponding to each temperature-stress combination; Taking the temperature as an abscissa and the stress as an ordinate, fitting the maximum running time of the same material under different temperature-stress combinations to form a continuous curve as a screening curve; taking the temperature as an abscissa and the stress as an ordinate, fitting creep damage rates of the same material under different temperature-stress combinations to form a continuous curve as a damage curve; According to the material types of the parts, matching a screening curve and a damage curve corresponding to the material types in a material database, wherein the maximum running time is a safety threshold of creep rupture time, and the creep damage rate is the damage increment in unit time.
4. The method for evaluating creep service safety of petrochemical equipment according to claim 3, wherein the method for determining the maximum operation time based on the screening curve, determining the creep damage rate based on the damage curve and calculating the total creep damage by combining the service time is as follows: In the 1-level evaluation, extracting and evaluating main stress, evaluating temperature and material type, acquiring the maximum running time corresponding to the combination from a screening curve of the corresponding materials, acquiring the creep damage rate of the combination from a damage curve of the corresponding materials, and constructing a total creep damage formula by combining the service time: In the formula, Indicating the total creep damage that is to be achieved, Represent the first Creep damage rate for each operating condition, Represent the first The length of service for each operating condition, An index that is a positive integer greater than 0, representing an operating condition, when the component is in a single operating condition, When the component is in a multi-operating condition, , Representing a total number of operating conditions; In the 2-level evaluation, extracting and evaluating main stress, evaluating temperature and material type, acquiring creep damage rate corresponding to the combination from damage curves of corresponding materials, and calculating total creep damage according to a total creep damage formula by combining time; In the 3-level evaluation, the main stress, the evaluation temperature and the material type are extracted and evaluated, the creep damage rate corresponding to the combination is obtained from the damage curve of the corresponding material, and the total creep damage is calculated by the total creep damage formula according to the combination time.
5. The method for evaluating the creep service safety of petrochemical equipment according to claim 3, wherein in the 1-level evaluation, the total creep damage threshold is set, and the method for extracting the evaluation temperature and evaluating and calculating the maximum running time of the pressure acquisition component according to the step 2 under the single operation condition is as follows: setting a total creep damage threshold And in a single operation condition, according to the evaluation temperature, the evaluation principal stress and the material type of the component, acquiring the maximum operation time through a corresponding screening curve.
6. The method for evaluating creep service safety of petrochemical equipment according to claim 1, wherein the method for constructing plastic collapse judging criteria based on material types is as follows: In the formula, Represents the criterion of the plastic collapse determination, The yield strength corresponding to the type of material is shown.
7. The method for evaluating creep service safety of petrochemical equipment according to claim 4, wherein in the 3-level evaluation, the method for calculating stress by adopting finite elements is as follows: Establishing a finite element model containing service defects for a component, wherein the model is consistent with the actual state of the component, selecting the maximum operating temperature under each operating condition as an evaluation temperature, selecting the maximum operating pressure under each operating condition as an evaluation calculation pressure, respectively taking the evaluation temperature and the evaluation calculation pressure as a thermal boundary condition and a force boundary condition, loading the thermal boundary condition and the force boundary condition on the finite element model, obtaining three-dimensional principal stress at the weakest position of each defect, calculating primary reference stress through an elastic mechanical classical formula, calculating equivalent stress according to an equivalent stress formula, judging that the evaluation does not pass when the primary reference stress is larger than a plastic collapse judging criterion, otherwise taking the equivalent stress as the evaluation principal stress, combining the evaluation temperature and the material type, obtaining a creep damage rate corresponding to the combination from a damage curve of the corresponding material, calculating total creep damage through a total creep damage formula when the total creep damage is lower than a preset allowable value, and judging that the evaluation passes or else judging that the evaluation does not pass.
8. A petrochemical equipment creep service safety evaluation system is characterized in that the system is used for executing the petrochemical equipment creep service safety evaluation method according to any one of claims 1-7: The evaluation selection module is used for setting the limiting conditions of 1, 2 and 3 grades of evaluation according to the load fluctuation amplitude, the material performance index and the service defect type of the component, sequentially judging whether the component meets the limiting conditions of the corresponding grade evaluation, and entering 1, 2 or 3 grades of evaluation to evaluate the component; The flow construction module is used for selecting a flow according to 1, 2 or 3-level evaluation, wherein the flow comprises the steps of determining the correction of evaluation calculation pressure, service time and evaluation temperature, calculating three-dimensional main stress through the evaluation calculation pressure, selecting the evaluation main stress, screening a screening curve and a damage curve of a corresponding material, determining the maximum running time based on the screening curve, determining the creep damage rate based on the damage curve, and calculating the total creep damage in combination with the service time; The first-level evaluation module is used for setting a total creep damage threshold in the 1-level evaluation, extracting an evaluation temperature and evaluating and calculating the maximum running time of the pressure acquisition component according to the step 2 in a single operation working condition, if the maximum running time is higher than the service time, entering a total creep damage calculation flow, if the total creep damage is lower than the total creep damage threshold, judging that the total creep damage passes the evaluation, otherwise judging whether to enter the 2-level or 3-level evaluation according to the limiting conditions of each evaluation; The second-level evaluation module is used for calculating primary reference stress through an elastic mechanical classical formula in the 2-level evaluation, constructing a plastic collapse judging criterion based on the material types, judging whether the evaluation does not pass when the primary reference stress is larger than the plastic collapse judging criterion, judging whether the evaluation enters the 3-level evaluation according to the limiting conditions of each evaluation, if the evaluation passes when the primary reference stress is lower than the plastic collapse judging criterion, entering a total creep damage calculation process, judging that the evaluation passes the 2-level evaluation when the total creep damage is lower than a preset allowable value, and otherwise, entering the 3-level evaluation; And the three-level evaluation module is used for performing stress calculation by adopting finite elements in the 3-level evaluation, the evaluation program is the same as that of the 2-level evaluation, and the evaluation is directly judged to be failed for the part with the crack defects.

Description

Petrochemical equipment creep service safety evaluation method and system Technical Field The invention relates to the technical field of creep service safety evaluation of petrochemical equipment, in particular to a method and a system for evaluating the creep service safety of the petrochemical equipment. Background When pressure-bearing equipment such as pressure vessels, pressure pipelines, storage tanks and the like run for a long time in a high-temperature and high-pressure environment, creep phenomenon can occur to materials. Creep is the slow plastic deformation of a material under sustained stress and can eventually lead to degradation, crack propagation, and even failure of the material. Because the industries such as petrochemical industry, electric power, metallurgy and the like widely use pressure-bearing equipment, accurate assessment of creep damage is important for guaranteeing safe operation of the equipment. The traditional creep damage evaluation method mainly relies on manual detection, experience judgment and off-line laboratory analysis, and has the problems of low efficiency, strong subjectivity, insufficient precision and the like. Traditional methods rely on personnel experience and related criteria to make qualitative determinations, such as by visual inspection, hardness testing, or metallographic analysis to evaluate the extent of creep damage. However, the method is high in subjectivity, difficult to quantify the damage degree, high in requirements on the professional level of detection personnel and easy to misjudge due to human factors, and partial enterprises adopt sampling analysis, such as electron microscope observation, creep test and the like, to evaluate the creep damage of the material. In recent years, finite element analysis is used for simulating a creep damage process, but the method is complex in calculation, needs to rely on a high-precision material model and a large number of input parameters, takes long calculation time and is difficult to rapidly apply to an engineering site. In addition, the finite element simulation generally requires professional personnel to operate, so that popularization of the finite element simulation in daily detection of enterprises is limited, and the conventional standard GB/T35013-2018 provides an evaluation method of creep damage, but the evaluation method is complex, the evaluation process is long in time consumption, the manual calculation workload is large, and a conclusion is difficult to quickly give during the running of equipment. Thus, while the existing standards provide a theoretical basis, there are significantly shorter plates for its utility in terms of rapid, accurate, consistent, efficient assessment of creep damage and intelligent decision-making in the engineering field. The intelligent evaluation system is one of core pain points which the intelligent evaluation system aims to solve, standard logic algorithm, flow automation, decision intellectualization and operation convenience are realized through proper optimization standards, and the practical value of the evaluation process is remarkably improved. The above information disclosed in the background section is only for enhancement of understanding of the background of the disclosure and therefore it may include information that does not form the prior art that is already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide a petrochemical equipment creep service safety evaluation method and system, which are used for solving the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: A petrochemical equipment creep service safety evaluation method specifically comprises the following steps: Setting a limiting condition of 1,2 and 3 grades of evaluation according to the load fluctuation amplitude, the material performance index and the service defect type of the component, sequentially judging whether the component meets the limiting condition of the corresponding grade evaluation, and entering 1,2 or 3 grades of evaluation to evaluate the component; According to the 1,2 or 3-level evaluation selection process, the process comprises the steps of determining the correction of evaluation calculation pressure, service time and evaluation temperature, calculating three-dimensional main stress through the evaluation calculation pressure, selecting an evaluation main stress, screening a screening curve and a damage curve of a corresponding material, determining the maximum running time based on the screening curve, determining the creep damage rate based on the damage curve, and calculating the total creep damage in combination with the service time; Setting a total creep damage threshold in the 1-level evaluation, extracting an evaluation temperature and evaluating and calculating the maximum running time of the pressure acquisit