Safety evaluation method, equipment, medium and product for steel welded vertical atmospheric storage tank

Abstract

The invention discloses a safety evaluation method and equipment for a steel welded vertical atmospheric storage tank, a medium and a product, and relates to the technical field of safety evaluation of atmospheric storage tanks. Determining the stress state of the defect according to the defect of the atmospheric storage tank; according to the stress state of the defect and the material performance data of the atmospheric storage tank, a load ratio is obtained through calculation; calculating a stress intensity factor according to the stress state of the defect; calculating to obtain a fracture ratio according to the stress intensity factor; and generating an evaluation result according to the load ratio, the stress intensity factor and the fracture ratio. According to the method, the safety of the vertical atmospheric storage tank under the condition that weld defects exist can be scientifically evaluated, the situation that the thin-wall cylindrical structure deforms due to local stress caused by weld repair is avoided, and reliable guarantee is provided for safe operation of the vertical atmospheric storage tank.

Description

Technical Field

[0001] The invention relates to the technical field of safety assessment of atmospheric pressure storage tanks, and in particular to a safety assessment method, equipment, medium and product of a steel welded vertical atmospheric pressure storage tank. Background Art

[0002] Vertical atmospheric pressure storage tanks are widely used in the petroleum, chemical, grain storage and other industries to store liquids or gases. With the development of industry, the scale of storage tanks is getting larger and larger, and the structure tends to be thinner, which puts higher requirements on the safety of storage tanks. During the use of storage tanks, due to material aging, corrosion, manufacturing defects and other reasons, cracks, lack of fusion, incomplete penetration, slag inclusions, pores and other defects may occur, and the existence of these defects may affect the structural integrity and safety performance of the storage tank.

[0003] In the prior art, there are relatively mature standards and methods for the safety assessment of pressure vessels, such as the API579 standard of the American Petroleum Engineering Society and the GB / T 19624-2019 "Safety Assessment of Defective Pressure Vessels in Use" standard of my country. However, these standards are mainly aimed at pressure vessels that withstand a certain internal pressure, and there are no special safety assessment standards for atmospheric pressure storage tanks, especially vertical atmospheric pressure storage tanks. Existing assessment methods cannot be directly applied to atmospheric pressure storage tanks because they are significantly different from pressure vessels in terms of structure, operating status and the impact of defect types.

[0004] Specific limitations of existing technologies include:

[0005] 1. The lack of safety assessment standards for vertical atmospheric pressure storage tanks results in a lack of pertinence and accuracy in the assessment results.

[0006] 2. The existing assessment method fails to fully consider the thin-wall and variable-section structural characteristics of atmospheric pressure storage tanks, which may lead to the assessment results being too conservative or unsafe.

[0007] 3. The defect assessment of in-use storage tanks mostly relies on experience and judgment, lacks the support of scientific calculation methods, and it is difficult to accurately evaluate the impact of defects on the safety of storage tanks.

[0008] Previous solutions and their shortcomings:

[0009] The assessment standards for pressure vessels are directly applied, but since the working pressure and structural characteristics of atmospheric pressure storage tanks are different from those of pressure vessels, this method cannot accurately reflect the actual safety status of atmospheric pressure storage tanks.

[0010] Adopting an overly conservative design and assessment approach, such as repairing or replacing all detected defects, not only increases operating costs but can also result in a waste of resources. Summary of the invention

[0011] The purpose of the present invention is to provide a safety assessment method, equipment, medium and product for a steel welded vertical atmospheric pressure storage tank, which can scientifically evaluate the safety of a vertical atmospheric pressure storage tank in the presence of weld defects and provide reliable guarantee for the safe operation of the vertical atmospheric pressure storage tank.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] In a first aspect, the present invention provides a safety assessment method for a steel welded vertical atmospheric pressure storage tank, the safety assessment method for a steel welded vertical atmospheric pressure storage tank comprising:

[0014] Obtain the defects of the atmospheric pressure storage tank; the defects of the atmospheric pressure storage tank include: type, location and size of the defects.

[0015] According to the defects of the atmospheric pressure storage tank, the stress state at the defect is determined; the stress state at the defect includes: film stress and bending stress. Bending stress is caused by the bending moment borne by the tank body and is inversely proportional to the square of the wall thickness. When the wall thickness decreases, the bending stress will increase significantly. When calculating the stress state, the difference in material properties between the weld and the base material is taken into account, and the stress state is calculated separately based on the material property data of the weld area and the base material area.

[0016] The load ratio is calculated based on the stress state at the defect and the material performance data of the atmospheric pressure storage tank; the material performance data of the atmospheric pressure storage tank include: the elastic modulus of the material, the yield strength of the weld and the base material at the evaluation temperature, the tensile strength and the Poisson's ratio.

[0017] According to the stress state at the defect, the stress intensity factor is calculated; the stress intensity factor includes: the stress intensity factor caused by the primary stress and the stress intensity factor caused by the secondary stress. During the calculation process, the influence of the plastic area at the crack tip on the stress field is considered and the plastic correction method is used for correction.

[0018] According to the stress intensity factor, the fracture ratio is calculated.

[0019] According to the load ratio, the stress intensity factor and the fracture ratio, an assessment result is generated; the assessment result includes: a safe assessment result, a relatively safe assessment result, a relatively unsafe assessment result and an unsafe assessment result, so as to more finely reflect the safety status of the storage tank. The assessment result is more in line with the actual situation, which helps engineers to formulate more reasonable maintenance and repair plans according to the specific safety status of the storage tank.

[0020] Optionally, determining the stress state at the defect according to the defect of the atmospheric pressure storage tank specifically includes:

[0021] According to the defect characterization principle, the defects of the atmospheric pressure storage tank are characterized in a regular manner to obtain the defects after regular characterization.

[0022] According to the defect after regularization characterization, the stress state at the defect is determined.

[0023] Optionally, the method for determining the primary stress specifically includes:

[0024] For girth welds, the axial stress caused by the liquid column pressure is mainly considered in the assessment; the axial stress is composed of membrane stress and bending stress; the bending stress on the tank wall is 0, and the calculation formula of the membrane stress is:

[0025]

[0026] M = 1-α(C / B);

[0027] For longitudinal welds, the hoop stress caused by the liquid column pressure is mainly considered in the assessment; the hoop stress only includes the film stress, and the calculation formula of the film stress is:

[0028]

[0029] M = 1-α(C / B);

[0030] Among them, P m is the film stress obtained by primary stress decomposition, 1 / M is the safety correction factor, α is the undetermined coefficient, C is the corrosion depth at the defect, B is the original thickness of the wall, P is the design pressure of the tank, and D i is the inner diameter of the tank, B s To evaluate the calculated shell thickness, the minimum measured thickness at the defect is deducted from the corrosion allowance for one cycle, mm.

[0031] The method for determining secondary stress includes:

[0032] When evaluating defects in the weld area, welding residual stress must be considered. The calculation formula for the residual stress of defects parallel to the weld is:

[0033]

[0034] Among them, Q m is the defect residual stress parallel to the weld obtained by secondary stress decomposition, σ s is the yield strength of the parent material, is the maximum yield strength, is the yield strength of the weld.

[0035] For the secondary stress caused by misalignment during the evaluation of circumferential weld defects, the calculation formula for the bending stress caused by misalignment is:

[0036]

[0037] Among them, Q b is the bending stress caused by the misalignment obtained by secondary stress decomposition, e is the amount of misalignment, b is a constant, t1 and t2 are the wall thicknesses on both sides of the weld, t1>t2.

[0038] Optionally, the calculation formula of the load ratio is:

[0039]

[0040] Among them, L r is the load ratio, P b is the bending stress obtained from the primary stress decomposition, P m is the film stress obtained by primary stress decomposition, ζ is the intermediate parameter, σ S is the yield strength of the material at the evaluation temperature, a is the defect depth, c is the half length of the defect, B S To evaluate the calculated shell thickness, the minimum measured thickness at the defect is deducted from the corrosion allowance for one cycle, mm.

[0041] Optionally, the calculation formula of the stress intensity factor is:

[0042]

[0043] Among them, K I is the stress intensity factor, σ m is the film stress, σ b is the bending stress, and σ obtained by primary stress decomposition m , σ b , respectively P m , P b ;σ obtained by secondary stress decomposition m , σ b , respectively Q m , Q b , a is the defect depth, c is the defect half length, B S To evaluate the calculated shell thickness, the minimum measured thickness at the defect minus the corrosion allowance for one cycle, mm, superscript A is the coefficient used to calculate the depth of the defect, and superscript B is the coefficient used to calculate the two end points of the defect length direction. The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by the film stress is: The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by the film stress is: The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by bending stress is is the crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by bending stress, f m The crack configuration factor used to calculate the stress intensity factor at the defect depth or defect tip in the length direction caused by film stress, f b The crack configuration factor used to calculate the defect depth caused by bending stress or the stress intensity factor at the tip of the defect in the length direction.

[0044] Optionally, the calculation formula of the fracture ratio is:

[0045]

[0046] Among them, K r is the fracture ratio, G is the elastic-plastic interference effect coefficient between two adjacent cracks, is the stress intensity factor caused by the primary stress, is the stress intensity factor caused by secondary stress, K IC is the plane strain fracture toughness, n K is the safety factor and ρ is the plasticity correction factor.

[0047] Optionally, generating an evaluation result according to the load ratio, the stress intensity factor and the fracture ratio specifically includes:

[0048] It is determined whether the stress intensity factor is lower than the fracture toughness of the material, and whether the fracture ratio and the load ratio are within a preset threshold range, to obtain a determination result; the fracture toughness of the material is the ability of the material to prevent crack propagation.

[0049] According to the specific values ​​of the fracture ratio and load ratio, the assessment results are broken down into safe assessment results, relatively safe assessment results, relatively unsafe assessment results and unsafe assessment results, making it easier for engineering personnel to formulate corresponding maintenance and overhaul plans based on the assessment results.

[0050] In a second aspect, the present invention provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described methods for safety assessment of steel welded vertical atmospheric pressure storage tanks.

[0051] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for safety assessment of steel welded vertical atmospheric pressure storage tanks.

[0052] In a fourth aspect, the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned methods for safety assessment of steel welded vertical atmospheric pressure storage tanks.

[0053] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0054] The present invention provides a safety assessment method, equipment, medium and product for a steel welded vertical atmospheric pressure storage tank. First, by obtaining the defects of the atmospheric pressure storage tank, the stress state at the defect is determined according to the defects of the atmospheric pressure storage tank; secondly, the load ratio is calculated according to the stress state at the defect and the material performance data of the atmospheric pressure storage tank; the influence of the load on the fracture of the material can be determined by the load ratio; furthermore, the stress intensity factor is calculated according to the stress state at the defect; the fracture ratio is calculated according to the stress intensity factor; the fracture toughness of the material can be determined by the fracture ratio; finally, the assessment result can be generated according to the load ratio, the stress intensity factor and the fracture ratio; the assessment result includes: safety assessment result, relatively safe assessment result, relatively unsafe assessment result and unsafe assessment result. The present invention scientifically assesses the weld defects in the vertical atmospheric pressure storage tank by combining the principles of fracture mechanics and plastic mechanics. Compared with the traditional experience-based assessment method, the method of the present invention can more accurately calculate the stress state at the defect and the fracture risk of the material. The accuracy of this assessment helps avoid overly conservative or overly aggressive maintenance decisions caused by inaccurate assessments, ensuring the safe operation of the tank. At the same time, the method of the present invention can accurately determine whether the defects in the tank will affect its safe use, thereby avoiding unnecessary replacement or excessive maintenance of the tank. This not only extends the service life of the tank, but also reduces the economic costs caused by frequent replacement or maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 This is an application environment diagram of a safety assessment method for a steel welded vertical atmospheric pressure storage tank in one embodiment of the present invention.

[0057] Figure 2 A schematic flow chart of a safety assessment method for a steel welded vertical atmospheric pressure storage tank provided in one embodiment of the present invention.

[0058] Figure 3 A schematic diagram of the structure of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0060] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] The steel welded vertical atmospheric pressure storage tank safety assessment method provided by the embodiment of the present invention can be applied to Figure 1 In the application environment shown, the terminal 102 communicates with the server 104 through a network. The data storage system can store data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the acquired defects of the atmospheric pressure storage tank to the server 104. After receiving the defects of the atmospheric pressure storage tank, the server 104 determines the stress state at the defect according to the defects of the atmospheric pressure storage tank; the stress state at the defect includes: film stress and bending stress; the load ratio is calculated according to the stress state at the defect and the material performance data of the atmospheric pressure storage tank; the material performance data of the atmospheric pressure storage tank includes: elastic modulus of the material, yield strength, tensile strength and Poisson's ratio of the weld and the parent material at the assessment temperature; the stress intensity factor is calculated according to the stress state at the defect; the stress intensity factor includes: stress intensity factor caused by primary stress and stress intensity factor caused by secondary stress; the fracture ratio is calculated according to the stress intensity factor; the evaluation result is generated according to the load ratio, the stress intensity factor and the fracture ratio; the evaluation result includes: safety evaluation result, relatively safe evaluation result, relatively unsafe evaluation result and unsafe evaluation result. The server 104 can feedback the obtained evaluation result to the terminal 102. In addition, in some embodiments, the safety assessment method for steel welded vertical atmospheric pressure storage tanks can also be implemented independently by the server 104 or the terminal 102. For example, the terminal 102 can directly perform a safety assessment on the defects of the atmospheric pressure storage tank, or the server 104 can obtain the defects of the atmospheric pressure storage tank from the data storage system and perform a safety assessment on the defects of the atmospheric pressure storage tank.

[0062] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones and tablet computers, IoT devices and portable wearable devices. IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0063] In an exemplary embodiment, Figure 2 As shown, a method for safety assessment of a steel welded vertical atmospheric storage tank is provided. The method is executed by a computer device, and specifically can be executed by a computer device such as a terminal or a server alone, or can be executed by a terminal and a server together. In an embodiment of the present invention, the method is applied to Figure 1 The server 104 in the example is used as an example to illustrate the method, which includes the following steps S1 to S6. Among them:

[0064] S1: Obtain defects of an atmospheric pressure storage tank; the defects of the atmospheric pressure storage tank include: type, location and size of the defects.

[0065] S2: According to the defects of the atmospheric pressure storage tank, the stress state at the defect is determined; the stress state at the defect includes: film stress and bending stress. Bending stress is caused by the bending moment borne by the tank body and is inversely proportional to the square of the wall thickness. When the wall thickness decreases, the bending stress will increase significantly. When calculating the stress state, the difference in material properties between the weld and the base material is taken into account, and the stress state is calculated separately based on the material property data of the weld area and the base material area.

[0066] S3: Calculate the load ratio according to the stress state at the defect and the material performance data of the atmospheric pressure storage tank; the material performance data of the atmospheric pressure storage tank include: elastic modulus of the material, yield strength of the weld and the base material at the evaluation temperature, tensile strength and Poisson's ratio.

[0067] S4: Calculate the stress intensity factor according to the stress state at the defect; the stress intensity factor includes: the stress intensity factor caused by the primary stress and the stress intensity factor caused by the secondary stress. In the calculation process, the influence of the plastic area at the crack tip on the stress field is considered and the plastic correction method is used for correction.

[0068] S5: Calculate the fracture ratio according to the stress intensity factor.

[0069] S6: Generate an assessment result based on the load ratio, the stress intensity factor and the fracture ratio; the assessment result includes: a safety assessment result, a relatively safe assessment result, a relatively unsafe assessment result and an unsafe assessment result, so as to more precisely reflect the safety status of the storage tank. This makes the assessment result more in line with the actual situation, which helps engineers to formulate a more reasonable maintenance and repair plan based on the specific safety status of the storage tank.

[0070] The implementation of the above steps S1 to S6 can scientifically evaluate the safety of the vertical atmospheric pressure storage tank in the presence of weld defects, providing a reliable guarantee for the safe operation of the storage tank.

[0071] In another exemplary embodiment of the present invention, in step S1, advanced non-destructive testing techniques such as ultrasonic testing (UT) and radiographic testing (RT) are used to comprehensively test the welds and other key parts of the atmospheric pressure storage tank. The test results will be used to identify the type of defects (such as cracks, lack of fusion, lack of penetration, slag inclusions, pores, etc.), location, size, activity and morphology. Defect characterization will be carried out according to its geometric characteristics. For example, cracks can be characterized as semi-elliptical or elliptical buried cracks, while volume defects such as slag inclusions are characterized according to their volume and location.

[0072] In another exemplary embodiment of the present invention, in step S2, specifically including:

[0073] S21: performing regular characterization on the defects of the atmospheric pressure storage tank according to defect characterization principles to obtain defects after regular characterization.

[0074] Based on the inspection results of the inspectors, the type, location, size, activity and morphology of the atmospheric pressure storage tank defects are determined, and the defects are characterized in a regular manner according to the defect characterization principle, and the actual defects are simplified into a defect with a simple geometric shape to determine the defect size a and c for calculation. a is the defect depth and c is the defect half length.

[0075] S22: Determine the stress state at the defect according to the defect after regularization characterization.

[0076] After determining the specific situation of the defect, stress analysis is performed to determine the stress state at the defect. The film stress and bending stress at the defect are calculated for the calculation of the stress intensity factor. Considering the impact of corrosion on atmospheric pressure storage tanks, a safety correction factor is introduced to correct its film stress to ensure safety.

[0077] The method for determining the primary stress specifically includes:

[0078] For girth welds, the axial stress caused by the liquid column pressure is mainly considered in the assessment; the axial stress is composed of membrane stress and bending stress; the bending stress on the tank wall is 0, and the calculation formula of the membrane stress is:

[0079]

[0080] M = 1-α(C / B);

[0081] For longitudinal welds, the hoop stress caused by the liquid column pressure is mainly considered in the assessment; the hoop stress only includes the film stress, and the calculation formula of the film stress is:

[0082]

[0083] M = 1-α(C / B);

[0084] Among them, P m is the film stress obtained by primary stress decomposition, 1 / M is the safety correction factor, α is the undetermined coefficient, which can be determined by theoretical deduction or experimental data fitting. According to the residual strength data after corrosion, the relationship between α and corrosion depth, material properties and other factors is fitted; C is the corrosion depth of the defect, B is the original thickness of the wall plate, P is the design pressure of the tank, D i is the inner diameter of the tank, B s To evaluate the calculated thickness of the shell, the measured minimum thickness at the defect is deducted from the corrosion allowance for one cycle, mm. The bending stress is calculated based on the loading conditions and geometric characteristics of the atmospheric pressure storage tank.

[0085] The method for determining secondary stress includes:

[0086] When evaluating defects in the weld area, welding residual stress must be considered. The calculation formula for the residual stress of defects parallel to the weld is:

[0087]

[0088] Among them, Q m is the defect residual stress parallel to the weld obtained by secondary stress decomposition, σ s is the yield strength of the parent material, is the maximum yield strength, is the yield strength of the weld;

[0089] For the secondary stress caused by misalignment during the evaluation of circumferential weld defects, the calculation formula for the bending stress caused by misalignment is:

[0090]

[0091] Among them, Q bis the bending stress caused by the misalignment obtained by secondary stress decomposition, e is the misalignment amount, b is a constant, in this embodiment b is 1.5, t1 and t2 are the wall thicknesses on both sides of the weld, t1>t2.

[0092] In another exemplary embodiment of the present invention, in step S3, according to the operating condition of the atmospheric pressure storage tank, the material performance data of the atmospheric pressure storage tank under the evaluation condition is determined, and the material performance data of the atmospheric pressure storage tank includes: the elastic modulus E of the material, the yield strength σ of the material at the evaluation temperature S , tensile strength σ u and Poisson's ratio v.

[0093] The calculation formula of the load ratio is:

[0094]

[0095] Among them, L r is the load ratio, which indicates the effect of load on material fracture, P b is the bending stress obtained from the primary stress decomposition, P m is the film stress obtained by primary stress decomposition, ζ is the intermediate parameter, σ S is the yield strength of the material at the evaluation temperature, MPa, a is the defect depth, c is the half length of the defect, B S To evaluate the calculated shell thickness, the minimum measured thickness at the defect is deducted from the corrosion allowance for one cycle, mm.

[0096] In another exemplary embodiment of the present invention, in step S4, the calculation formula of the stress intensity factor is:

[0097]

[0098]

[0099] Among them, K I is the stress intensity factor, σ m is the film stress, σ b is the bending stress, and σ obtained by primary stress decomposition m , σ b , respectively P m , P b ;σ obtained by secondary stress decomposition m , σ b , respectively Q m , Q b , a is the defect depth, c is the defect half length, B STo evaluate the calculated shell thickness, the minimum measured thickness at the defect minus the corrosion allowance for one cycle, mm, superscript A is the coefficient used to calculate the depth of the defect, superscript B is the coefficient used to calculate the two end points of the defect length direction, applicable range: a / B S ≤0.8, a / c≤1.0, c / L≤0.15, c / W≤0.15, L is half of the length of the defective laminate, W is half of the width of the defective laminate, It is the crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by the film stress. It is the crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by the film stress. The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by bending stress is is the crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by bending stress, f m The crack configuration factor used to calculate the stress intensity factor at the defect depth or defect tip in the length direction caused by film stress, f b It is the crack configuration factor used to calculate the defect depth caused by bending stress or the stress intensity factor at the tip of the defect in the length direction. m for and The general term for b for and A general term for .

[0100] In another exemplary embodiment of the present invention, in step S5, the calculation formula of the fracture ratio is:

[0101]

[0102] Among them, K r is the fracture ratio, which indicates the fracture toughness of the material; G is the elastic-plastic interference effect coefficient between two adjacent cracks, which is determined by referring to Appendix E of GB / T 19624-2019; is the stress intensity factor caused by the primary stress, is the stress intensity factor caused by secondary stress, K IC is the plane strain fracture toughness, which can be measured directly; n K is the safety factor, refer to Table 1 of GB / T19624-2019; ρ is the plasticity correction factor, refer to 5.7.5 and Appendix C of GB / T 19624-2019.

[0103] In another exemplary embodiment of the present invention, in step S6, specifically including:

[0104] S61: Determine whether the stress intensity factor is lower than the fracture toughness of the material, and whether the fracture ratio and the load ratio are within a preset threshold range, and obtain a determination result; the fracture toughness of the material is the ability of the material to prevent crack propagation;

[0105] S62: Based on the specific values ​​of the fracture ratio and the load ratio, the assessment results are broken down into safe assessment results, relatively safe assessment results, relatively unsafe assessment results and unsafe assessment results, so that engineering personnel can formulate corresponding maintenance and overhaul plans based on the assessment results.

[0106] Through the above steps, the technical effects of the present invention are embodied in the following aspects:

[0107] Improve the accuracy of safety assessment:

[0108] The present invention combines the principles of fracture mechanics and plastic mechanics to scientifically evaluate weld defects in vertical atmospheric pressure storage tanks. Compared with the traditional experience-based evaluation method, the method of the present invention can more accurately calculate the stress state at the defect and the fracture risk of the material. The accuracy of this evaluation helps to avoid overly conservative or overly radical maintenance decisions caused by inaccurate evaluation, and ensure the safe operation of the storage tank.

[0109] Reduce economic costs:

[0110] The method of the present invention can accurately determine whether the defects in the storage tank will affect its safe use, thereby avoiding unnecessary replacement or excessive maintenance of the storage tank. This not only prolongs the service life of the storage tank, but also reduces the economic costs caused by frequent replacement or maintenance, which has a positive impact on the economic benefits of the enterprise.

[0111] Improve the safety level of storage tanks:

[0112] Through the method of the present invention, potential risks in the storage tank can be discovered and evaluated in a timely manner, providing a higher level of protection for the safe operation of the storage tank. This improved level of safety protection is of great significance for preventing accidents, protecting the environment and personnel safety.

[0113] Optimize maintenance and inspection processes:

[0114] The method of the present invention provides a clear assessment process and calculation method for equipment management personnel and safety assessment personnel, making the maintenance and inspection process of storage tanks more scientific and standardized. This optimized process helps to improve work efficiency, reduce human errors, and ensure the consistency and reliability of assessment results.

[0115] Promote the improvement of industry standards:

[0116] Since there is a lack of safety assessment standards for vertical atmospheric pressure storage tanks in the prior art, the method of the present invention can be used as a reference and basis for the formulation of industry standards, thereby promoting the improvement and development of relevant industry standards.

[0117] Enhance corporate social responsibility:

[0118] By ensuring the safe operation of the storage tank, the present invention helps enterprises to fulfill their social responsibilities and reduce the negative impacts that may be caused to the environment and society. This enhanced sense of social responsibility has a positive effect on improving corporate image and public trust.

[0119] To sum up, the technical effect of the present invention is not only reflected in improving the scientificity and accuracy of tank safety assessment, but also in reducing operating costs, improving safety assurance levels, optimizing maintenance and inspection processes, promoting the improvement of industry standards, and enhancing corporate social responsibility.

[0120] The present invention also provides an application scenario, which applies the above-mentioned steel welded vertical atmospheric pressure storage tank safety assessment method. Specifically: The steel welded vertical atmospheric pressure storage tank safety assessment method provided in this embodiment can be applied in the vertical atmospheric pressure storage tank safety assessment scenario. The vertical atmospheric pressure storage tank safety assessment scenario includes the atmospheric pressure storage tank defect acquisition link, stress state determination link, safety assessment parameter calculation link and assessment link; the acquired atmospheric pressure storage tank defects, after regularized characterization, enter the stress state determination link, and then according to the stress state and the material performance data of the atmospheric pressure storage tank, the load ratio can be calculated, according to the stress state, the stress intensity factor can be calculated, according to the stress intensity factor, the fracture ratio can be calculated, and finally, enter the assessment link, according to the load ratio, stress intensity factor and fracture ratio, the assessment result can be generated.

[0121] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 3As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store defect data of atmospheric pressure storage tanks. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a safety assessment method for a steel welded vertical atmospheric pressure storage tank is implemented.

[0122] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0123] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the above-mentioned method embodiments are implemented when the processor executes the computer program.

[0124] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0125] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0126] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0127] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0128] The database involved in each embodiment provided by the present invention may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided by the present invention may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0129] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A safety assessment method for a steel welded vertical atmospheric pressure storage tank, characterized in that: The safety assessment method for the steel welded vertical atmospheric pressure storage tank includes: Obtaining defects of the atmospheric pressure storage tank; the defects of the atmospheric pressure storage tank include: type, location and size of the defects; According to the defect of the atmospheric pressure storage tank, the stress state at the defect is determined; the stress state at the defect includes: film stress and bending stress; The load ratio is calculated based on the stress state of the defect and the material performance data of the atmospheric pressure storage tank; the material performance data of the atmospheric pressure storage tank includes: elastic modulus of the material, yield strength of the weld and the parent material at the evaluation temperature, tensile strength and Poisson's ratio; Calculating a stress intensity factor according to the stress state at the defect; the stress intensity factor includes: a stress intensity factor caused by primary stress and a stress intensity factor caused by secondary stress; According to the stress intensity factor, a fracture ratio is calculated; An assessment result is generated according to the load ratio, the stress intensity factor and the fracture ratio; the assessment result includes: a safe assessment result, a relatively safe assessment result, a relatively unsafe assessment result and an unsafe assessment result.

2. The safety assessment method for steel welded vertical atmospheric pressure storage tank according to claim 1 is characterized in that: According to the defects of the atmospheric pressure storage tank, the stress state at the defect is determined, specifically including: Regularly characterizing the defects of the atmospheric pressure storage tank according to the defect characterization principle to obtain the defects after regular characterization; According to the defect after regularization characterization, the stress state at the defect is determined.

3. The safety assessment method for steel welded vertical atmospheric pressure storage tanks according to claim 1 is characterized in that: The method for determining the primary stress includes: For girth welds, the axial stress caused by the liquid column pressure is mainly considered in the assessment; the axial stress is composed of membrane stress and bending stress; the bending stress on the tank wall is 0, and the calculation formula of the membrane stress is: M = 1-α(C / B); For longitudinal welds, the hoop stress caused by the liquid column pressure is mainly considered in the assessment; the hoop stress only includes the film stress, and the calculation formula of the film stress is: M = 1-α(C / B); Among them, P m is the film stress obtained by primary stress decomposition, 1 / M is the safety correction factor, α is the undetermined coefficient, C is the corrosion depth at the defect, B is the original thickness of the wall, P is the design pressure of the tank, and D i is the inner diameter of the tank, B s To evaluate the calculated shell thickness, the minimum measured thickness at the defect minus the corrosion allowance for one cycle, mm; The method for determining secondary stress includes: When evaluating defects in the weld area, welding residual stress must be considered. The calculation formula for the residual stress of defects parallel to the weld is: Among them, Q m is the defect residual stress parallel to the weld obtained by secondary stress decomposition, σ s is the yield strength of the parent material, is the maximum yield strength, is the yield strength of the weld; For the secondary stress caused by misalignment during the evaluation of circumferential weld defects, the calculation formula for the bending stress caused by misalignment is: Among them, Q b is the bending stress caused by the misalignment obtained by secondary stress decomposition, e is the amount of misalignment, b is a constant, t1 and t2 are the wall thicknesses on both sides of the weld, t1>t2.

4. The safety assessment method for steel welded vertical atmospheric pressure storage tank according to claim 1 is characterized in that: The calculation formula of the load ratio is: Among them, L r is the load ratio, P b is the bending stress obtained from the primary stress decomposition, P m is the film stress obtained by primary stress decomposition, ζ is the intermediate parameter, σ S is the yield strength of the material at the evaluation temperature, a is the defect depth, c is the half length of the defect, B S To evaluate the calculated shell thickness, the minimum measured thickness at the defect is deducted from the corrosion allowance for one cycle, mm.

5. The safety assessment method for steel welded vertical atmospheric pressure storage tank according to claim 1 is characterized in that: The calculation formula of the stress intensity factor is: Among them, K I is the stress intensity factor, σ m is the film stress, σ b is the bending stress, a is the defect depth, c is the defect half length, B S To evaluate the calculated shell thickness, the minimum measured thickness at the defect minus the corrosion allowance for one cycle, mm, superscript A is the coefficient used to calculate the depth of the defect, and superscript B is the coefficient used to calculate the two end points of the defect length direction. The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by the film stress is: The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by the film stress is: The crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the depth direction caused by bending stress is is the crack configuration factor used to calculate the stress intensity factor at the tip of the defect in the length direction caused by bending stress, f m The crack configuration factor used to calculate the stress intensity factor at the defect depth or defect tip in the length direction caused by film stress, f b The crack configuration factor used to calculate the defect depth caused by bending stress or the stress intensity factor at the tip of the defect in the length direction.

6. The safety assessment method for steel welded vertical atmospheric pressure storage tanks according to claim 1 is characterized in that: The calculation formula of the fracture ratio is: Among them, K r is the fracture ratio, G is the elastic-plastic interference effect coefficient between two adjacent cracks, is the stress intensity factor caused by the primary stress, is the stress intensity factor caused by secondary stress, K IC is the plane strain fracture toughness, n K is the safety factor and ρ is the plasticity correction factor.

7. The safety assessment method for steel welded vertical atmospheric pressure storage tanks according to claim 1 is characterized in that: Generating an evaluation result according to the load ratio, the stress intensity factor and the fracture ratio, specifically including: Determine whether the stress intensity factor is lower than the fracture toughness of the material, and whether the fracture ratio and the load ratio are within a preset threshold range, and obtain a determination result; the fracture toughness of the material is the ability of the material to prevent crack propagation; According to the specific values ​​of the fracture ratio and the load ratio, the assessment results are refined into safe assessment results, relatively safe assessment results, relatively unsafe assessment results and unsafe assessment results.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the safety assessment method for a steel welded vertical atmospheric pressure storage tank as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the safety assessment method for a steel welded vertical atmospheric pressure storage tank described in any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the safety assessment method for a steel welded vertical atmospheric pressure storage tank described in any one of claims 1 to 7 is implemented.

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