Method, device and equipment for calculating residual life of high-temperature defective part of power station boiler and medium

Abstract

The invention discloses a method, a device and equipment for calculating the residual life of a high-temperature defective part of a power station boiler and a medium, and relates to the field of boiler risk analysis. Determining the yield strength of the initial material, the reference stress at the defect position, the load ratio, the fracture ratio, the creep damage before the defect is generated, the load ratio cut-off line and the failure evaluation curve; when the initial state of the defect passes the safety evaluation, dividing the whole service cycle of the defect-containing part into a plurality of time load steps, and calculating the creep crack propagation damage, the load ratio and the fracture ratio of each time load step; and when the load step does not pass the safety evaluation at a certain time, determining the residual service life of the defective part according to the cracking time corresponding to the load step at the time and the run time of the defective part. The calculation precision and efficiency of the remaining service life of the high-temperature defective part of the power station boiler are improved.

Description

Technical Field

[0001] The present application relates to the field of boiler risk analysis, and in particular to a method, device, equipment and medium for calculating the remaining life of high-temperature defective parts of a power station boiler. Background Art

[0002] Boilers are important energy conversion equipment, especially power plant boilers, as an important part of thermal power generating units, are important infrastructure for power supply. During operation, the various components of power plant boilers are generally subjected to high temperature and high pressure. These pressure-bearing components inevitably have defects of varying degrees during the manufacturing and installation process. During use, new defects may also arise due to the influence of various factors such as load and medium.

[0003] For the pressure-bearing parts of power station boilers, it is uneconomical to not allow any defects to exist only from the perspective of safety, but it is also dangerous to allow them to exist without analysis. Practice has shown that not all defects will lead to the failure of boiler parts. It is important to distinguish defects, conduct necessary analysis and calculation, eliminate those with potential dangers, and retain those with a remaining service life within a certain range. This is of great significance to extending the service life of boiler parts, reducing maintenance costs, and ensuring the safe operation of boilers.

[0004] The operating temperature of power station boiler headers, pipelines and other components often exceeds the creep temperature limit of the material. Creep damage will occur as the service time increases during service. For defects (pores, slag inclusions, cracks, etc.) found during non-destructive testing, their damage mode is not only creep damage, but also creep crack extension. In order to ensure the safe operation of the boiler, it is necessary to conduct rapid safety assessment and remaining life calculation of defective components based on the structural characteristics and operating conditions of power station boiler components. Summary of the invention

[0005] The purpose of this application is to provide a method, device, equipment and medium for calculating the remaining service life of high-temperature defective parts of power station boilers, which can improve the calculation accuracy and efficiency of the remaining service life of defective parts.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a method for calculating the remaining life of a high-temperature defective component of a power plant boiler, comprising:

[0008] According to the basic information of the defective parts of the power plant boiler, determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve;

[0009] According to the load ratio in the initial state of the defect, the fracture ratio in the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve, it is judged whether the initial state of the defect passes the safety assessment, if not, the calculation is stopped, if yes, the entire service life of the defective component is divided into multiple time load steps, and the initial cracking time and the initial creep crack extension damage are set;

[0010] For the i-th time load step, according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack growth damage of the i-1-th time load step, the creep crack growth cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step are calculated; i>1; the cracking time of the first time load step is the initial cracking time, and the creep crack growth damage of the first time load step is the initial creep crack growth damage;

[0011] According to the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step, it is judged whether the i-th time load step passes the safety assessment. If so, the defect size information and cracking time are updated, and the i+1-th time load step is calculated. If not, the remaining service life of the defective component is determined according to the cracking time corresponding to the i-th time load step and the running time of the defective component.

[0012] In a second aspect, the present application provides a device for calculating the remaining life of a high-temperature defective component of a power station boiler, comprising:

[0013] The initial data acquisition module is used to determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve based on the basic information of the defective parts of the power station boiler;

[0014] An initial state judgment module is used to judge whether the initial state of the defect passes the safety assessment according to the load ratio in the initial state of the defect, the fracture ratio in the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve. If not, the calculation is stopped. If yes, the entire service life of the defective component is divided into multiple time load steps, and the initial cracking time and the initial creep crack extension damage are set;

[0015] A time load step calculation module, for calculating the creep crack extension cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack extension damage of the i-1-th time load step for the i-th time load step; i>1; the cracking time of the first time load step is the initial cracking time, and the creep crack extension damage of the first time load step is the initial creep crack extension damage;

[0016] The remaining life calculation module is used to determine whether the i-th time load step passes the safety assessment based on the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack extension cumulative damage of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio. If so, the defect size information and the cracking time are updated, and the calculation of the i+1-th time load step is performed. If not, the remaining service life of the defective component is determined based on the cracking time corresponding to the i-th time load step and the running time of the defective component.

[0017] In a third aspect, the present application 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 the above-mentioned method for calculating the remaining life of a high-temperature defective component of a power plant boiler.

[0018] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for calculating the remaining life of a high-temperature defective component of a power plant boiler.

[0019] According to the specific embodiments provided in this application, this application has the following technical effects:

[0020] The present application provides a method, device, equipment and medium for calculating the remaining life of a high-temperature defective component of a power plant boiler. When the initial state of the defect passes the safety assessment, the entire service cycle of the defective component is divided into multiple time load steps. In each time load step, the service time is included in the research scope, and the load ratio of each time load step is calculated using the material yield strength that changes with the service time, so that the calculation result of the load ratio is more accurate, and the creep crack extension damage calculation is combined with the defect safety assessment to calculate the remaining life of the high-temperature defective component of the boiler, which greatly simplifies the complex calculation process for specific problems, makes the calculation of the remaining life of the defective component of the power plant boiler more convenient and efficient, and improves the calculation efficiency of the remaining service life of the defective component. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is an application environment diagram of a method for calculating the remaining life of a high-temperature defective component of a power station boiler in one embodiment of the present application;

[0023] Figure 2 An overall flow chart of a method for calculating the remaining life of a high-temperature defective component of a power plant boiler provided in one embodiment of the present application;

[0024] Figure 3 A detailed flow chart of a method for calculating the remaining life of a high-temperature defective component of a power plant boiler provided in one embodiment of the present application;

[0025] Figure 4 A schematic diagram of functional modules of a device for calculating the remaining life of a high-temperature defective component of a power station boiler provided in one embodiment of the present application;

[0026] Figure 5 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] The method for calculating the remaining life of a high-temperature defective component of a power plant boiler provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the 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 basic information about defective parts of the power plant boiler to the server 104, and the server 104 calculates the remaining service life of the defective parts based on the basic information about the defective parts of the power plant boiler received. The server 104 can feedback the remaining service life of the defective parts to the terminal 102. In addition, in some embodiments, the method for calculating the remaining life of defective parts of the power plant boiler can also be implemented separately by the server 104 or the terminal 102.

[0030] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The 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.

[0031] In an exemplary embodiment, Figure 2 and Figure 3 As shown, a method for calculating the remaining life of a high-temperature defective component of a power plant boiler is provided. The method is executed by a computer device, and 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 the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used for explanation, and the steps include the following steps 201 to 204.

[0032] Step 201, based on the basic information of the defective parts of the power plant boiler, determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve.

[0033] In an exemplary embodiment, the basic information of the defective component of the power plant boiler includes: the diameter D of the defective component, the wall thickness B of the defective component, the defect burial depth d, the defect length L, the defect height h, the defect characterization height a, and the defect characterization length c. The above basic information is determined through data query and on-site non-destructive testing.

[0034] In an exemplary embodiment, the basic information of the defective component of the power plant boiler also includes: the calculated temperature T and calculated pressure P of the defective component of the power plant boiler. The above basic information is obtained based on the past operation history of the boiler (including the boiler operation load curve, the temperature and pressure history monitoring data of the defective component) and the future operation conditions (the preset future operation load curve of the boiler).

[0035] In an exemplary embodiment, the basic information of the defective part of the power plant boiler also includes: the temperature difference ΔT between the inner and outer walls of the defective part of the power plant boiler, the elastic modulus E at the calculation temperature, the allowable stress σ, and the material yield strength σ at the initial calculation temperature s The above basic information is obtained by querying the power station boiler wall temperature monitoring data and related material standard data.

[0036] Step 201 includes the following steps 11 to 17.

[0037] Step 11, determining the material yield strength of the defective component at the initial calculation temperature to obtain the initial material yield strength.

[0038] Step 12, determining the primary film stress, primary bending stress, secondary film stress and secondary bending stress at the defect location.

[0039] Specifically, the finite element method is used to calculate the hoop principal stress σ1, axial principal stress σ2 and radial principal stress σ3 of the defective component, and the primary membrane stress P at the defect location is determined according to the defect location, component structural characteristics, stress action area and properties based on the membrane stress theory. m , primary bending stress P b , secondary film stress Q m (For buried defects in butt welds, the influence of residual stress can be ignored after a certain period of time) and secondary bending stress Q b :

[0040] P m =f2×P m1 ;

[0041] P b =f2×P b1 ;

[0042] Q m =0;

[0043] Q b =f4×σ t ;

[0044] Where:

[0045] f2 is the primary stress safety factor, which is determined according to the severity of the consequences of component failure: 1.1 is generally taken for failure consequences, and 1.25 is taken for severe failure consequences.

[0046] P m1 is the initial film stress. If the defect is located on the girth weld, P m1 =σ2, if the defect is located in the longitudinal weld, then P m1 =σ m .

[0047] P b1 is the initial bending stress. If the defect is located on the girth weld, P b1 = 0, if the defect is located on the longitudinal weld, then P b1 =σ B .

[0048] f4 is the secondary stress safety factor, generally f4=1.

[0049] σ t is the temperature difference stress, for ferritic steel, take σ t =1.6△T, for austenitic steel, take σ t =1.8△T.

[0050] σ m is the film stress component, σ m =(σ 1n +σ 1y ) / 2.

[0051] σ B is the bending stress component, σ B =(σ 1n -σ 1y ) / 2.

[0052] σ 1n is the inner wall hoop stress after stress linearization, σ 1n =R i (σ 1qy -σ 1qn ) / h+σ 1qn -(σ 1qy -σ 1qn )R n / h.

[0053] σ 1y is the hoop stress of the outer wall after stress linearization, σ 1y =R0(σ 1qy -σ 1qn ) / h+σ 1qn -(σ 1qy -σ 1qn )R n / h.

[0054] σ1qn is the hoop stress at the inner side of the defect,

[0055] σ 1qy is the hoop stress outside the defect,

[0056] R0 is the outer radius of the component, R0=D / 2.

[0057] R i is the inner radius of the component, R i =D / 2-B.

[0058] R n is the distance from the inner side of the defect to the center of the circle, R n =R0-dh.

[0059] R y is the distance from the outside of the defect to the center of the circle, R y =R0-d.

[0060] Step 13, calculating the reference stress at the defect position according to the basic information of the defective component of the power plant boiler, the primary membrane stress and the primary bending stress.

[0061] The equivalent stress is calculated using the following formula: n σ e and the reference stress σ at the defect location ref :

[0062]

[0063] Among them, ζ and γ are intermediate quantities d1 is the distance between the defect and the surface at its closest point, d1 = Min (Bda, d + a).

[0064] Step 14, calculating the load ratio L under the initial state of the defect according to the initial material yield strength and the reference stress r :

[0065] Step 15, calculating the fracture ratio in the initial state of the defect according to the basic information of the defective component of the power plant boiler, the primary membrane stress, the primary bending stress, the secondary membrane stress, the secondary bending stress, the initial material yield strength and the load ratio in the initial state of the defect.

[0066] Specifically, step 15 includes the following (1) to (4).

[0067] (1) Calculating a stress intensity factor based on basic information of a defective component of a power plant boiler, the primary membrane stress, the primary bending stress, the secondary membrane stress, and the secondary bending stress.

[0068] Specifically, the fracture toughness K of the material is determined according to the material properties of the defective parts of the power station boiler. IC . Calculate the stress intensity factors caused by primary stress and secondary stress in the defect depth and length direction respectively:

[0069]

[0070] in, is the stress intensity factor caused by the primary stress in the defect depth direction, is the stress intensity factor caused by the secondary stress in the defect depth direction, is the stress intensity factor caused by the primary stress in the defect length direction, is the stress intensity factor caused by the secondary stress in the defect length direction, e is the intermediate quantity:

[0071]

[0072]

[0073] e=|d1-B / 2|.

[0074] (2) According to the basic information of the defective parts of the power plant boiler, the stress intensity factor, the initial material yield strength and the load ratio under the initial state of the defect, the plasticity correction factor is calculated:

[0075]

[0076] Among them, ρ a is the plasticity correction factor in the defect depth direction, ρ c is the plasticity correction factor in the defect length direction, Ψ a and c is the intermediate quantity,

[0077] (3) If there is one defect in the defective component, the fracture ratio in the initial state of the defect is calculated based on the stress intensity factor and the plasticity correction factor.

[0078] (4) If there are multiple defects in the defective component, the elastic-plastic interference effect coefficient is determined according to the initial load ratio of the multiple defects, and the fracture ratio in the initial state of the defect is calculated according to the stress intensity factor, the plasticity correction factor and the elastic-plastic interference effect coefficient.

[0079] Specifically, the elastic-plastic interference effect coefficient G is calculated using the following formula:

[0080]

[0081] in, is the maximum allowable load ratio, G1, N1, M, L1, L max All are intermediate quantities:

[0082] G1=M+N1(0.076n-0.190)(1-L1);

[0083]

[0084]

[0085] L1 = 0.24 + 0.04 (n - 5);

[0086] L max =max(L r ,L r2 );

[0087] Where n is the material hardening index, s is the distance between two coplanar defects, and s0 is the critical distance for judging whether two coplanar defects should be merged. Relevant data are obtained by querying relevant material standards and nondestructive testing results. r2 is the initial load ratio of other defects.

[0088] The defect fracture ratio K is calculated using the following formula: r :

[0089]

[0090] in, is the fracture ratio in the defect depth direction, is the fracture ratio in the defect length direction, K P To evaluate the fracture toughness of the material, K p =K IC / f3,K IC is the fracture toughness of the material (data is obtained by querying relevant standards), and f3 is the safety factor of the fracture toughness of the material (determined according to the consequences of component failure: f3=1.1 in general and f3=1.2 in severe cases).

[0091] Further calculation of the failure assessment curve L r The corresponding function value

[0092] Step 16, based on the working time and creep rupture life of the component before the defect occurs, calculate the creep damage D before the defect occurs bc : t0 is the working time of the component before the defect occurs, L bc Creep rupture life of the component before defects occur:

[0093]

[0094]

[0095] Ω n_bc =max{(Ω bc -n BN_bc ),3.0};

[0096]

[0097] S l_bc =lg(0.145× n σ e );

[0098] Among them, A0, A1, A2, A3, A4 are material creep strain parameters, B0, B1, B2, B3, B4 are material uniaxial damage parameters, and relevant data can be obtained by querying relevant standards. Ω , β Ω , is a constant, α Ω The value of is 2, β Ω The value of is 0.33, The value of is -0.5, The value of is -0.3. Ω m_bc ,Ω n_bc ,Ω bc , δ Ω_bc 、n BN_bc , S l_bc All are intermediate amounts.

[0099] Step 17, determining the load ratio cutoff line and the failure assessment curve according to the material of the defective component.

[0100] Step 202, based on the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve, determine whether the initial state of the defect passes the safety assessment. If not, stop the calculation. If so, divide the entire service life of the defective component into multiple time load steps, and set the initial cracking time and the initial creep crack extension damage.

[0101] In an exemplary embodiment, step 202 includes steps 21 to 23 below.

[0102] Step 21, determining the creep damage D before the defect occurs bcIs it greater than the allowable creep damage D? c allow .

[0103] Step 22, if the creep damage D before the defect occurs bc Greater than the allowable creep damage D c allow , it is determined that the initial state of the defect has not passed the safety assessment.

[0104] Step 23, if the creep damage D before the defect occurs bc Less than or equal to the allowable creep damage D c allow , then determine whether the coordinate point determined by the load ratio in the initial state of the defect and the fracture ratio in the initial state of the defect is located in the area enclosed by the failure assessment curve, the load ratio cutoff line and the horizontal and vertical coordinate axes. If so, it is determined that the initial state of the defect passes the safety assessment, otherwise, it is determined that the initial state of the defect fails the safety assessment.

[0105] Furthermore, setting i＝1 a=a, i＝1 c=c, i＝1 t = 0, i＝1 D ac =0. Among them, i＝1 a is the initial defect characterization height a, i＝1 c is the initial defect characterization length c, i＝1 t=0 is the initial cracking time, i＝1 D ac = 0 is the initial creep crack extension damage.

[0106] Step 203, for the i-th time load step, according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack growth damage of the i-1-th time load step, calculate the creep crack growth cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step. i>1. The cracking time of the first time load step is the initial cracking time, and the creep crack growth damage of the first time load step is the initial creep crack growth damage.

[0107] In an exemplary embodiment, step 203 includes the following steps 31 to 35 .

[0108] Step 31, calculate the creep rupture life under the corresponding state of the i-th time load step i L ac :

[0109]

[0110] Ω n =max{(Ω-n BN ),3.0};

[0111]

[0112] S l =lg(0.145× i σ ref );

[0113] in, Ω m ,Ω n ,Ω,δ Ω 、n BN , S l All are intermediate amounts.

[0114] Step 32, calculating the creep crack growth cumulative damage of the i-th time load step according to the cracking time of the i-th time load step, the cracking time of the i-1-th time load step, the creep rupture life under the corresponding state of the i-th time load step, and the creep crack growth damage of the i-1-th time load step i D ac :

[0115] Step 33, based on the initial material yield strength, calculate the material yield strength at the corresponding calculation temperature at the i-th time load step i σ ys :

[0116] Step 34, calculating the load ratio at the i-th time load step according to the material yield strength at the corresponding calculation temperature at the i-th time load step and the reference stress at the defect position i L r :

[0117] Step 35, calculate the fracture ratio at the i-th time load step according to the basic information of the defective parts of the power plant boiler, the material yield strength at the corresponding calculation temperature at the i-th time load step, and the load at the i-th time load step. The process of calculating the fracture ratio here is the same as the process of calculating the fracture ratio at the initial state of the defect in the above step 15, and further calculate the fracture ratio on the failure assessment curve i L r The corresponding function value i K r max .

[0118] Step 204, based on the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio, determine whether the i-th time load step passes the safety assessment. If so, update the defect size information and the cracking time, and calculate the i+1-th time load step. If not, determine the remaining service life of the defective component based on the cracking time corresponding to the i-th time load step and the running time of the defective component.

[0119] In an exemplary embodiment, in step 204, based on the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the cumulative damage of creep crack propagation of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio, it is determined whether the i-th time load step passes the safety assessment, including the following steps 41 to 43.

[0120] Step 41, judging whether the coordinate point determined by the load ratio corresponding to the i-th time load step and the fracture ratio corresponding to the i-th time load step is located in the area surrounded by the failure assessment curve, the load ratio cutoff line and the horizontal and vertical coordinate axes, and whether the sum of the creep damage before the defect occurs and the cumulative damage of the creep crack propagation of the defective component corresponding to the i-th time load step is less than a set threshold (such as 0.8), that is, whether the cumulative damage satisfies D bc + i D ac ≤0.8.

[0121] Step 42: If yes, it is determined that the initial state of the defect passes the safety assessment.

[0122] Step 43: If not, it is determined that the defect initial state has not passed the safety assessment.

[0123] In an exemplary embodiment, updating the defect size information and the cracking time in step 204 includes the following steps 44 to 47 .

[0124] Step 44, calculate the creep crack growth driving force based on the defect size information of the i-th time load step:

[0125]

[0126]

[0127] in, is the driving force for creep crack extension in the defect depth direction, is the creep crack growth driving force in the defect length direction, C *a ( i a, i c) C*c ( i a, i c) All are intermediate quantities. is the creep strain rate of the i-th time load step, and the calculation is performed by referring to step 31.

[0128] Step 45, calculating the crack growth rate according to the creep crack growth driving force:

[0129]

[0130] in, is the crack growth rate in the depth direction, is the crack growth rate in the length direction, H c and μ are intermediate quantities,

[0131] Step 46, calculating the time increment Δt according to the crack growth rate: In the formula, C intg It is a constant value, and the recommended value is 0.0005.

[0132] Step 47, updating defect size information and cracking time according to the crack growth rate and the time increment:

[0133]

[0134] i t= i t+Δt.

[0135] At the end of the calculation, the remaining service life of the defective component is obtained by subtracting the operating time of the defective component from the cracking time corresponding to the last time load step.

[0136] Further, based on the calculation results, a remaining life calculation report for high-temperature defective components of power plant boilers is compiled, and safe use recommendations for high-temperature defective components of power plant boilers are given.

[0137] This application determines the relevant working parameters of the defective components of the power station boiler based on the material, specification, structural characteristics, defect size, past operation history of the boiler and preset future operating conditions of the high-temperature defective components of the power station boiler, calculates the remaining life of the defective boiler components, and realizes the calculation of the remaining life of the defective components of the boiler based on the basic information of the component material and structure, the basic information of the defect and the real-time operating parameters, providing a scientific basis for extending the service life of the boiler components, reducing maintenance costs and ensuring the safe operation of the boiler.

[0138] This application has the characteristics of more accurate, convenient and efficient calculation of the remaining life of high-temperature defective parts of power station boilers, as described below:

[0139] (1) GB / T 19624-2019 "Safety Assessment of Defective Pressure Vessels in Use" provides a method for calculating the load ratio, but the material yield strength used in the calculation is only the material yield strength at the calculation temperature, and does not consider the effect of service time on the material yield strength. Ignoring the effect of service time on the material yield strength will have an important impact on the accuracy of the calculation results. In fact, when the material is in service beyond the creep temperature range, the material yield strength will gradually decrease with the increase of service time. The operating temperature of various components of power plant boilers, especially high-temperature components such as headers and pipelines, is generally higher than the material creep temperature. Ignoring the effect of service time on the material yield strength will have an important impact on the life damage calculation of boiler components.

[0140] This application aims to solve this major problem by calculating the yield strength of the material. i σ ys Add to the formula The service time is included in the research scope, and the material yield strength that varies with service time is used i σ ys Calculate the load ratio for each time load step i L r , making the assessment results that change with service time closer to physical reality and more accurate.

[0141] (2) GB / T 35013-2018 “Evaluation of the fitness for use of pressure equipment” provides a calculation method for the creep rupture life and creep crack propagation damage of pressure equipment operating within the creep temperature range, but does not provide a calculation method for the safety assessment of pressure-bearing components with defects under high-temperature service conditions. As a result, it is impossible to directly calculate the remaining life of pressure-bearing components with defects under high-temperature service conditions based on GB / T35013-2018 “Evaluation of the fitness for use of pressure-bearing equipment”.

[0142] This application provides a reference stress σ for the defect location of power station boiler components based on the structural characteristics of power station boiler headers and pipelines. ref The calculation formula for stress intensity factor applicable to power plant boiler components is provided. At the same time, the creep crack extension damage calculation is combined with defect safety assessment to calculate the remaining life of boiler defective components, which greatly simplifies the complex calculation process for specific problems and makes the calculation of remaining life of high-temperature defective components of power plant boilers more convenient and efficient.

[0143] Based on the same inventive concept, the embodiment of the present application also provides a power plant boiler high temperature defective component remaining life calculation device for implementing the above-mentioned power plant boiler high temperature defective component remaining life calculation method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more power plant boiler high temperature defective component remaining life calculation device embodiments provided below can refer to the above-mentioned limitations on the power plant boiler high temperature defective component remaining life calculation method, and will not be repeated here.

[0144] In an exemplary embodiment, Figure 4 As shown, a device for calculating the remaining life of a high-temperature defective component of a power station boiler is provided, comprising:

[0145] The initial data acquisition module 401 is used to determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve based on the basic information of the defective parts of the power station boiler.

[0146] The initial state judgment module 402 is used to judge whether the initial state of the defect passes the safety assessment based on the load ratio in the initial state of the defect, the fracture ratio in the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve. If not, the calculation is stopped. If so, the entire service life of the defective component is divided into multiple time load steps, and the initial cracking time and initial creep crack extension damage are set.

[0147] The time load step calculation module 403 is used to calculate the creep crack growth cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack growth damage of the i-1-th time load step for the i-th time load step; i>1. The cracking time of the first time load step is the initial cracking time, and the creep crack growth damage of the first time load step is the initial creep crack growth damage.

[0148] The remaining service life calculation module 404 is used to determine whether the i-th time load step passes the safety assessment based on the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio. If so, the defect size information and the cracking time are updated, and the calculation of the i+1-th time load step is performed. If not, the remaining service life of the defective component is determined based on the cracking time corresponding to the i-th time load step and the running time of the defective component.

[0149] 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 5 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, 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 basic information of defective parts of a power plant boiler. 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 method for calculating the remaining life of a high-temperature defective part of a power plant boiler is implemented.

[0150] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application 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.

[0151] 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 steps in the above method embodiments are implemented.

[0152] 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 steps in the above method embodiments are implemented.

[0153] 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 this application 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.

[0154] In this application, all actions to obtain signals, information or data are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization given by the owner of the corresponding device.

[0155] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods 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 in the present application 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), magnetic 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).

[0156] The database involved in each embodiment provided in this application 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 in this application 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.

[0157] The technical features of the above embodiments may be arbitrarily combined. 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.

[0158] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, 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 this application.

Claims

1. A method for calculating the remaining life of high-temperature defective parts of a power plant boiler, characterized in that: The method for calculating the remaining life of high-temperature defective parts of a power station boiler includes: According to the basic information of the defective parts of the power plant boiler, determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve; According to the load ratio in the initial state of the defect, the fracture ratio in the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve, it is judged whether the initial state of the defect passes the safety assessment, if not, the calculation is stopped, if yes, the entire service life of the defective component is divided into multiple time load steps, and the initial cracking time and the initial creep crack extension damage are set; For the i-th time load step, according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack growth damage of the i-1-th time load step, the creep crack growth cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step are calculated; i>1; the cracking time of the first time load step is the initial cracking time, and the creep crack growth damage of the first time load step is the initial creep crack growth damage; According to the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step, it is judged whether the i-th time load step passes the safety assessment. If so, the defect size information and cracking time are updated, and the i+1-th time load step is calculated. If not, the remaining service life of the defective component is determined according to the cracking time corresponding to the i-th time load step and the running time of the defective component.

2. The method for calculating the remaining life of high-temperature defective parts of power plant boilers according to claim 1 is characterized in that: According to the basic information of the defective parts of the power plant boiler, the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve are determined, including: Determine the material yield strength of the defective component at the initial calculation temperature to obtain the initial material yield strength; Determine the primary film stress, primary bending stress, secondary film stress, and secondary bending stress at the defect location; Calculate the reference stress at the defect location according to the basic information of the defective component of the power plant boiler, the primary membrane stress and the primary bending stress; Calculating a load ratio at an initial state of a defect according to the initial material yield strength and the reference stress; Calculate the fracture ratio under the initial state of the defect according to the basic information of the defective part of the power plant boiler, the primary membrane stress, the primary bending stress, the secondary membrane stress, the secondary bending stress, the initial material yield strength and the load ratio under the initial state of the defect; Calculate the creep damage before the defect occurs based on the working time and creep rupture life of the component before the defect occurs; The load ratio cutoff line and failure assessment curve are determined according to the material of the defective component.

3. The method for calculating the remaining life of high-temperature defective parts of power plant boilers according to claim 2 is characterized in that: According to the basic information of the defective part of the power plant boiler, the primary membrane stress, the primary bending stress, the secondary membrane stress, the secondary bending stress, the initial material yield strength and the load ratio under the initial state of the defect, the fracture ratio under the initial state of the defect is calculated, specifically including: Calculating a stress intensity factor according to basic information of a defective component of a power plant boiler, the primary membrane stress, the primary bending stress, the secondary membrane stress and the secondary bending stress; Calculating the plasticity correction factor according to the basic information of the defective component of the power plant boiler, the stress intensity factor, the initial material yield strength and the load ratio under the initial state of the defect; If there is one defect in the defective component, the fracture ratio in the initial state of the defect is calculated according to the stress intensity factor and the plasticity correction factor; If the defective component has multiple defects, the elastic-plastic interference effect coefficient is determined according to the initial load ratio of the multiple defects, and the fracture ratio in the initial state of the defect is calculated according to the stress intensity factor, the plasticity correction factor and the elastic-plastic interference effect coefficient.

4. The method for calculating the remaining life of a high-temperature defective component of a power plant boiler according to claim 1, characterized in that: According to the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve, it is judged whether the initial state of the defect passes the safety assessment, specifically including: Determining whether the creep damage before the defect occurs is greater than the allowable creep damage; If the creep damage before the defect occurs is greater than the allowable creep damage, it is determined that the initial state of the defect fails the safety assessment; If the creep damage before the defect occurs is less than or equal to the allowable creep damage, then determine whether the coordinate point determined by the load ratio in the initial state of the defect and the fracture ratio in the initial state of the defect is located in the area enclosed by the failure assessment curve, the load ratio cutoff line and the horizontal and vertical coordinate axes. If so, it is determined that the initial state of the defect passes the safety assessment; otherwise, it is determined that the initial state of the defect fails the safety assessment.

5. The method for calculating the remaining life of a high-temperature defective component of a power plant boiler according to claim 1, characterized in that: According to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack extension damage of the i-1-th time load step, the creep crack extension cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step are calculated, specifically including: Calculate the creep rupture life under the state corresponding to the i-th time load step; Calculate the creep crack growth cumulative damage of the i-th time load step according to the cracking time of the i-th time load step, the cracking time of the i-1-th time load step, the creep rupture life under the corresponding state of the i-th time load step and the creep crack growth damage of the i-1-th time load step; Calculate the material yield strength at the corresponding calculation temperature at the i-th time load step according to the initial material yield strength; Calculate the load ratio at the i-th time load step according to the material yield strength at the corresponding calculation temperature at the i-th time load step and the reference stress at the defect position; According to the basic information of the defective parts of the power plant boiler, the material yield strength at the corresponding calculation temperature at the i-th time load step and the load at the i-th time load step, the fracture ratio at the i-th time load step is calculated.

6. The method for calculating the remaining life of high-temperature defective parts of power plant boilers according to claim 1 is characterized in that: According to the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio, judging whether the i-th time load step passes the safety assessment, specifically including: Determine whether the coordinate point determined by the load ratio corresponding to the i-th time load step and the fracture ratio corresponding to the i-th time load step is located in the area enclosed by the failure assessment curve, the load ratio cutoff line and the horizontal and vertical coordinate axes, and whether the sum of the creep damage before the defect occurs and the cumulative damage of the creep crack propagation of the defective component corresponding to the i-th time load step is less than a set threshold; If so, the initial state of the defect is determined to pass the safety assessment; If not, it is determined that the defect initial state has failed the safety assessment.

7. The method for calculating the remaining life of high-temperature defective parts of power plant boilers according to claim 1 is characterized in that: Update defect size information and cracking time, including: According to the defect size information of the i-th time load step, the creep crack growth driving force is calculated; Calculating the crack growth rate according to the creep crack growth driving force; calculating a time increment based on the crack growth rate; The defect size information and the cracking time are updated according to the crack growth rate and the time increment.

8. A device for calculating the remaining life of a high-temperature defective component of a power plant boiler, applied to the method for calculating the remaining life of a high-temperature defective component of a power plant boiler according to any one of claims 1 to 7, characterized in that: The remaining life calculation device of the high-temperature defective parts of the power station boiler comprises: The initial data acquisition module is used to determine the initial material yield strength, the reference stress at the defect location, the load ratio at the initial state of the defect, the fracture ratio at the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve based on the basic information of the defective parts of the power station boiler; An initial state judgment module is used to judge whether the initial state of the defect passes the safety assessment according to the load ratio in the initial state of the defect, the fracture ratio in the initial state of the defect, the creep damage before the defect occurs, the load ratio cutoff line and the failure assessment curve. If not, the calculation is stopped. If yes, the entire service life of the defective component is divided into multiple time load steps, and the initial cracking time and the initial creep crack extension damage are set; A time load step calculation module, for calculating the creep crack extension cumulative damage, load ratio and fracture ratio of the defective component corresponding to the i-th time load step according to the initial material yield strength, the reference stress at the defect position, the defect size information of the i-th time load step, the cracking time of the i-th time load step, the cracking time of the i-1-th time load step and the creep crack extension damage of the i-1-th time load step for the i-th time load step; i>1; the cracking time of the first time load step is the initial cracking time, and the creep crack extension damage of the first time load step is the initial creep crack extension damage; The remaining life calculation module is used to determine whether the i-th time load step passes the safety assessment based on the creep damage before the defect occurs, the load ratio cutoff line, the failure assessment curve, the creep crack extension cumulative damage of the defective component corresponding to the i-th time load step, the load ratio and the fracture ratio. If so, the defect size information and the cracking time are updated, and the calculation of the i+1-th time load step is performed. If not, the remaining service life of the defective component is determined based on the cracking time corresponding to the i-th time load step and the running time of the defective component.

9. 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 method for calculating the remaining life of a high-temperature defective component of a power plant boiler according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for calculating the remaining life of a high-temperature defective component of a power plant boiler according to any one of claims 1 to 7 is implemented.

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