A method, device, equipment and medium for calculating the residual life of a high-temperature defective component of a power plant boiler

Abstract

The application discloses a power station boiler high-temperature component with defects remaining life calculation method, device, equipment and medium, relates to the field of boiler risk analysis, and the method comprises the following steps: according to the basic information of the power station boiler component with defects, determining the initial material yield strength, the reference stress at the defect position, the load ratio, the fracture ratio, the creep damage before the defect is generated, the load ratio cutoff line and the failure evaluation curve; when the initial state of the defect is safe, the entire service cycle of the component with defects is divided into multiple time load steps, the creep crack propagation damage, the load ratio and the fracture ratio of each time load step are calculated; and when a certain time load step does not pass the safety assessment, the remaining service life of the component with defects is determined according to the cracking time corresponding to the time load step and the running time of the component with defects. The application improves the calculation accuracy and efficiency of the remaining service life of the power station boiler high-temperature component with defects.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of boiler risk analysis, in particular to a method, device, equipment and medium for calculating the residual life of a high-temperature defective component of a power plant boiler. BACKGROUND

[0002] Boilers are important energy conversion equipment, and power plant boilers, as an important part of thermal power generating units, are important infrastructure for power supply. The components of power plant boilers generally bear high temperature and high pressure during operation. These pressure-bearing components inevitably have defects of different degrees during manufacturing and installation, and new defects may occur during use due to various factors such as load and medium.

[0003] For the pressure-bearing components of power plant boilers, it is not economical to allow any defects to exist from the safety point of view, but it is also dangerous to allow them to exist without analysis. Practice shows that not all defects will lead to the failure of boiler components. It is important to distinguish between defects, perform necessary analysis and calculation, eliminate those defects with potential dangers, and retain defects with a certain range of residual service life. This has important significance for extending the service life of boiler components, reducing maintenance costs, and ensuring the safe operation of boilers.

[0004] The working temperature of components such as headers and pipes of power plant boilers often exceeds the creep temperature limit of the material, and with the increase of service time during service, there will be creep damage. For defects (pores, slag inclusions, cracks, etc.) found during non-destructive testing, the damage mode is not only creep damage, but also creep crack propagation. In order to ensure the safe operation of the boiler, it is necessary to conduct rapid safety assessment and residual life calculation for defective components according to the structural characteristics and operating conditions of the components of the power plant boiler. SUMMARY

[0005] The purpose of the present application is to provide a method, device, equipment and medium for calculating the residual life of a high-temperature defective component of a power plant boiler, which can improve the calculation accuracy and efficiency of the residual service life of the defective component.

[0006] To achieve the above-mentioned purpose, the present application provides the following solutions:

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

[0008] According to the basic information of the defective component of the power plant boiler, the initial material yield strength, the reference stress at the defect position, 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;

[0009] According to the load ratio under the initial state of the defect, the fracture ratio under the initial state of the defect, the creep damage before the defect is generated, the load ratio cutoff line and the failure evaluation curve, it is judged whether the initial state of the defect passes the safety evaluation, if not, the calculation is stopped, if yes, the entire service cycle of the component containing the defect is divided into multiple time load steps, and the initial cracking time and the initial creep crack propagation 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 propagation damage of the i-1-th time load step, the creep crack propagation cumulative damage, the load ratio and the fracture ratio of the component containing the defect 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 propagation damage of the first time load step is the initial creep crack propagation damage;

[0011] According to the creep damage before the defect is generated, the load ratio cutoff line, the failure evaluation curve, the creep crack propagation cumulative damage, the load ratio and the fracture ratio of the component containing the defect corresponding to the i-th time load step, it is judged whether the i-th time load step passes the safety evaluation, if yes, 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 residual service life of the component containing the defect is determined according to the cracking time corresponding to the i-th time load step and the running time of the component containing the defect.

[0012] In a second aspect, the present application provides a residual life calculation device for a high-temperature component containing a defect of a power station boiler, comprising:

[0013] An initial data acquisition module is configured to determine the initial material yield strength, the reference stress at the defect position, the load ratio under the initial state of the defect, the fracture ratio under the initial state of the defect, the creep damage before the defect is generated, the load ratio cutoff line and the failure evaluation curve according to the basic information of the component containing the defect of the power station boiler;

[0014] An initial state judgment module is configured to judge whether the initial state of the defect passes the safety evaluation according to the load ratio under the initial state of the defect, the fracture ratio under the initial state of the defect, the creep damage before the defect is generated, the load ratio cutoff line and the failure evaluation curve, if not, the calculation is stopped, if yes, the entire service cycle of the component containing the defect is divided into multiple time load steps, and the initial cracking time and the initial creep crack propagation damage are set;

[0015] a time load step calculation module, configured to calculate, for the i-th time load step, a creep crack growth cumulative damage, a load ratio and a fracture ratio of the component with the defect corresponding to the i-th time load step according to the initial material yield strength, the reference stress at the defect position, defect size information of the i-th time load step, a crack time of the i-th time load step, a crack time of the i-1-th time load step, and a creep crack growth damage of the i-1-th time load step; i>1; the crack time of the 1st time load step is an initial crack time, and the creep crack growth damage of the 1st time load step is an initial creep crack growth damage;

[0016] a residual life calculation module, configured to determine whether the i-th time load step passes the safety assessment according to the creep damage before the defect is generated, the load ratio cutoff line, the failure assessment curve, the creep crack growth cumulative damage, the load ratio and the fracture ratio of the component with the defect corresponding to the i-th time load step, if yes, update the defect size information and the crack time, and perform calculation of the i+1-th time load step, and if no, determine the residual service life of the component with the defect according to the crack time corresponding to the i-th time load step and the running time of the component with the defect.

[0017] In a third aspect, the present application provides a computer device, comprising: a memory, a processor to store a computer program on the memory and executable on the processor, and the processor executes the computer program to implement the power station boiler high-temperature component with defect residual life calculation method.

[0018] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the power station boiler high-temperature component with defect residual life calculation method.

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

[0020] The present application provides a power station boiler high-temperature component with defect residual life calculation method, device, equipment and medium, when the initial state of the defect passes the safety assessment, the entire service period of the component with the defect is divided into multiple time load steps, the service time is included in the research range in each time load step, and the material yield strength varying with the service time is used to calculate the load ratio of each time load step, so that the calculation result of the load ratio is more accurate, the creep crack growth damage calculation is combined with the defect safety assessment, the residual life of the boiler high-temperature component with the defect is calculated, the complex calculation process for a specific problem is greatly simplified, the residual life calculation for the power station boiler component with the defect is more convenient and efficient, and the calculation efficiency of the residual service life of the component with the defect is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described below only constitute some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0022] Figure 1 An application environment diagram of a residual life calculation method for a high-temperature defective component of a power station boiler in an embodiment of the present application;

[0023] Figure 2 A whole flowchart of the residual life calculation method for the high-temperature defective component of the power station boiler provided in an embodiment of the present application;

[0024] Figure 3 A detailed flowchart of the residual life calculation method for the high-temperature defective component of the power station boiler provided in an embodiment of the present application;

[0025] Figure 4 A functional module schematic diagram of a residual life calculation device for the high-temperature defective component of the power station boiler provided in an embodiment of the present application;

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

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application.

[0028] In order to make the above purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0029] The residual life calculation method for the high-temperature defective component of the power station boiler provided in the embodiments of the present application can be applied to, for example Figure 1The application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data required by the server 104 to process. The data storage system can be set up separately, or integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the basic information of the power station boiler defective component to the server 104, and the server 104 calculates the remaining service life of the defective component based on the received basic information of the power station boiler defective component. The server 104 can feed back the remaining service life of the defective component to the terminal 102. In addition, in some embodiments, the power station boiler defective component remaining life calculation method can also be implemented by the server 104 or the terminal 102 alone.

[0030] Among them, the terminal 102 can be, but not limited to, various desktop computers, notebook computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices, and the Internet of Things devices can be smart speakers, smart televisions, smart air conditioners, smart vehicle devices, etc. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, etc. The server 104 can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0031] In an exemplary embodiment, as shown in Figure 2 and Figure 3 A power station boiler high-temperature defective component remaining life calculation method is provided, which is executed by a computer device, specifically by a terminal or a server computer device alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to the server 104 in Figure 1 The following steps 201 to 204 are described.

[0032] Step 201, according to the basic information of the power station boiler defective component, the initial material yield strength, the reference stress at the defect position, 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.

[0033] In an exemplary embodiment, the basic information of the power station boiler defective component includes the diameter D of the defective component, the wall thickness B of the defective component, the defect depth d, the defect length L, the defect height h, the defect characterization height a and the defect characterization length c. Among them, the above basic information is determined by data query and on-site nondestructive testing.

[0034] In an exemplary embodiment, the basic information of the defective component of the power plant boiler further comprises: the calculated temperature T and the 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 of the defective component, the pressure history monitoring data) and the future operation condition (the preset future operation load curve of the boiler).

[0035] In an exemplary embodiment, the basic information of the defective component of the power plant boiler further comprises: the temperature difference △T between the inner wall and the outer wall of the defective component of the power plant boiler, the elastic modulus E at the calculated temperature, the allowable stress σ and the material yield strength σ s at the initial calculated temperature. The above basic information is obtained by querying the wall temperature monitoring data of the power plant boiler and the relevant material standard data.

[0036] Step 201 comprises steps 11 to 17.

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

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

[0039] Specifically, the hoop principal stress σ1, the axial principal stress σ2 and the radial principal stress σ3 of the defective component are calculated by using the finite element method, and the primary membrane stress P m , the primary bending stress P b , the secondary membrane stress Q m (for the butt weld embedded defect, the influence of residual stress after a certain period of time can be ignored) and the secondary bending stress Q b at the location of the defect are determined according to the defect location, the component structure characteristics, the stress action area and the nature according to the membrane stress theory.

[0040] P m = f2×P m1 ;

[0041] P b = f2×P b1 ;

[0042] Q m = 0;

[0043] Q b = f4×σ t ;

[0044] In the formula:

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

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

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

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

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

[0050] σ m is the membrane 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 stress linearization inner wall hoop stress, σ 1n = R i (σ 1qy - σ 1qn ) / h + σ 1qn -(σ 1qy - σ 1qn )R n / h.

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

[0054] σ1qn The circumferential stress is located inside the defect.

[0055] σ 1qy This refers to the circumferential stress located on the outer side of the defect.

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

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

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

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

[0060] Step 13: Calculate the reference stress at the defect location based on 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] Where ζ and γ are intermediate quantities. d1 is the distance from the defect to the nearest point on the surface, d1=Min(Bda,d+a).

[0064] Step 14: Calculate the load ratio L in the initial state of the defect based on the initial material yield strength and the reference stress. r :

[0065] Step 15: Calculate the fracture ratio in the initial state of the defect based on the basic information of the defective components 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) According to the basic information of the power plant boiler component containing defects, the primary membrane stress, the primary bending stress, the secondary membrane stress and the secondary bending stress, the stress intensity factor is calculated.

[0068] Specifically, the fracture toughness K IC of the material is determined according to the material properties of the power plant boiler component containing defects.

[0069]

[0070] wherein, 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 an intermediate quantity:

[0071]

[0072]

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

[0074] (2) According to the basic information of the power plant boiler component containing defects, the stress intensity factor, the initial material yield strength and the load ratio in the initial state of the defect, the plastic correction factor is calculated:

[0075]

[0076] wherein, a is the plastic correction factor in the defect depth direction, ρ c is the plastic correction factor in the defect length direction, Ψ a and Ψ c are intermediate quantities,

[0077] (3) If the component containing defects has one defect, then according to the stress intensity factor and the plastic correction factor, the fracture ratio in the initial state of the defect is calculated.

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

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

[0080]

[0081] in, The maximum allowable load ratio is represented by G1, N1, M, L1, and 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 determining whether two coplanar defects should be merged. Relevant data are obtained by consulting relevant material standards and non-destructive testing results. r2 This represents the initial load ratio for other defects.

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

[0089]

[0090] in, This represents the fracture ratio along the defect depth direction. K is the fracture ratio along the defect length direction. P To assess the fracture toughness of the material, K p =K IC / f3,K IC f3 is the fracture toughness of the material (data obtained by consulting 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 L on the failure assessment curve r Corresponding function value

[0092] Step 16: Calculate the creep damage D before the defect occurs, based on the component's operating time and creep fracture life before the defect occurs. bc : t0 is the working time of the component before the defect occurs, L bc is the creep rupture life of the component before the defect occurs:

[0093]

[0094]

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

[0096]

[0097] S l_bc = lg (0.145 x n σ e );

[0098] wherein A0, A1, A2, A3, A4 are material creep strain parameters, B0, B1, B2, B3, B4 are material uniaxial damage parameters, and the relevant data are obtained by consulting relevant standards. α Ω , β Ω , are constants, the value of α Ω is 2, the value of β Ω 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 are all intermediate quantities.

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

[0100] Step 202, judging 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, stopping the calculation, if yes, dividing the entire service period of the component containing the defect into multiple time load steps, and setting the initial cracking time and the initial creep crack propagation damage.

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

[0102] Step 21, judging whether the creep damage D bcwhether the creep damage D before the defect is generated is greater than the allowable creep damage D c allow .

[0103] Step 22, if the creep damage D before the defect is generated is greater than the allowable creep damage D bc c allow then it is determined that the initial state of the defect fails the safety assessment.

[0104] Step 23, if the creep damage D before the defect is generated is less than or equal to the allowable creep damage D bc c allow then it is determined whether a coordinate point determined by the load ratio at the initial state of the defect and the fracture ratio at the initial state of the defect is located in an area surrounded by the failure assessment curve, the load ratio cutoff line and the horizontal and vertical coordinate axes, if yes, 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] Further, it is provided that i＝1 a = a, i＝1 c = c, i＝1 t = 0, i＝1 D ac = 0. Wherein, 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 growth 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, the creep crack growth cumulative damage, the load ratio and the fracture ratio of the component containing the defect 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.

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

[0108] Step 31, the creep fracture life L i ac :

[0109] ​​​

[0110] Ω n = max{ (Ω - n BN , 3.0} ;

[0111]

[0112] S l = lg(0.145 x i σ ref ) ;

[0113] wherein, Ω m , Ω n , Ω, δ Ω , n BN , S l are intermediate quantities.

[0114] Step 32, 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, the creep crack growth cumulative damage of the i-th time load step is calculated i D ac :

[0115] Step 33, according to the yield strength of the initial material, the yield strength of the material under the corresponding calculation temperature at the i-th time load step is calculated i σ ys :

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

[0117] Step 35, according to the basic information of the power plant boiler component containing defects, the yield strength of the material under 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. The process of calculating the fracture ratio here is the same as the process of calculating the fracture ratio under the initial state of the defect in step 15 above, and further calculates the corresponding function value on the failure assessment curve i L r : i K r max .

[0118] Step 204, judging whether the ith time load step passes the safety assessment according to the creep damage before the defect is generated, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the component with defect corresponding to the ith time load step, the load ratio and the fracture ratio, if yes, updating the defect size information and the cracking time, and performing the calculation of the i+1th time load step, if no, determining the remaining service life of the component with defect according to the cracking time corresponding to the ith time load step and the running time of the component with defect.

[0119] In an exemplary embodiment, the judging whether the ith time load step passes the safety assessment according to the creep damage before the defect is generated, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the component with defect corresponding to the ith time load step, the load ratio and the fracture ratio in step 204 comprises the following steps 41 to 43.

[0120] Step 41, judging whether the coordinate point determined by the load ratio corresponding to the ith time load step and the fracture ratio corresponding to the ith time load step is located in the region 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 is generated and the creep crack propagation cumulative damage of the component with defect corresponding to the ith time load step is less than a set threshold value (such as 0.8), that is, whether the cumulative damage satisfies D bc + i D ac ≤0.8.

[0121] Step 42, if yes, determining that the initial state of the defect passes the safety assessment.

[0122] Step 43, if no, determining that the initial state of the defect does not pass the safety assessment.

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

[0124] Step 44, calculating the creep crack propagation driving force according to the defect size information of the ith time load step:

[0125]

[0126]

[0127] wherein, is the creep crack propagation driving force in the defect depth direction, is the creep crack propagation driving force in the defect length direction, C *a ( i a, i c)、 C*c i a, i c)、 are intermediate quantities, is the creep strain rate of the i th time load step, and the correlation calculation is performed with reference to step 31.

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

[0129]

[0130] wherein, 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, according to the crack growth rate, the time increment Δt is calculated: wherein, C intg is a constant value, and the recommended value is 0.0005.

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

[0133]

[0134] i t= i t+Δt.

[0135] At the end of the calculation, the cracking time corresponding to the last time load step is subtracted from the running time of the defect-containing component to obtain the remaining service life of the defect-containing component.

[0136] Further according to the calculation results, the remaining life calculation report of the high-temperature defect-containing component of the power station boiler is arranged, and the safe use of the high-temperature defect-containing component of the power station boiler is suggested.

[0137] Based on the material, specification, structural characteristics, defect size, past operation history of the power station boiler high-temperature defect-containing component and the preset future operation condition, the related working parameters of the boiler defect-containing component are determined, the remaining life of the boiler component with defects is calculated, and the remaining life of the boiler defect-containing component is calculated based on the component material, structural basic information, defect basic information and real-time running parameters., prolong the service life of the boiler component, reduce the maintenance cost, and provide a scientific basis for ensuring the safe operation of the boiler.

[0138] The present application has the characteristics of more accurate, convenient and efficient calculation of the remaining life of the high-temperature defect-containing component of the power station boiler, and the specific description is as follows: ​

[0139] (1) GB / T 19624-2019 "Safety Assessment of Defective Pressure Vessels in Use" provides a method for calculating the load ratio. However, the material yield strength used in the calculation is only the material yield strength at the calculation temperature, and the influence of service time on the material yield strength is not considered. Ignoring the influence of service time on the material yield strength will have a significant impact on the accuracy of the calculation results. In fact, when a material is used beyond its creep temperature range, its 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 pipes, is generally higher than the material creep temperature. Ignoring the influence of service time on the material yield strength will have a significant impact on the calculation of the life damage of boiler components.

[0140] This application addresses this major problem by improving the calculation of material yield strength. i σ ys Add to the formula This study incorporates service time into its scope and uses the material yield strength as a function of service time. i σ ys Calculate the load ratio for each time load step. i L r This makes the assessment results, which change over time, more closely reflect physical reality and are more accurate.

[0141] (2) GB / T 35013-2018 "Evaluation of the Compliance of Pressure Equipment with Use" provides the calculation method for creep fracture life and creep crack propagation damage of pressure equipment operating within the creep temperature range, but does not provide the calculation method for the safety assessment of pressure components with defects under high temperature service conditions. Therefore, it is not possible to directly calculate the remaining life of pressure components with defects under high temperature service conditions according to GB / T35013-2018 "Evaluation of the Compliance of Pressure Equipment with Use".

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

[0143] Based on the same inventive concept, the application further provides a power station boiler high-temperature component with defects remaining life calculation device for implementing the power station boiler high-temperature component with defects remaining life calculation method. The implementation scheme of the device for solving the problem is similar to the implementation scheme described in the above method, so the specific limitations in one or more power station boiler high-temperature component with defects remaining life calculation device embodiments provided below can refer to the limitations of the power station boiler high-temperature component with defects remaining life calculation method described above, which will not be repeated here.

[0144] In one exemplary embodiment, as shown in Figure 4 A power station boiler high-temperature component with defects remaining life calculation device is provided, comprising:

[0145] An initial data acquisition module 401 is configured to determine the initial material yield strength, the reference stress at the defect position, 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 is generated, the load ratio cutoff line, and the failure assessment curve according to the basic information of the power station boiler component with defects.

[0146] An initial state judgment module 402 is configured 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 is generated, the load ratio cutoff line, and the failure assessment curve. If not, stop calculating; if yes, divide the entire service period of the component with defects into a plurality of time load steps, and set the initial cracking time and the initial creep crack propagation damage.

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

[0148] The remaining life calculation module 404 is configured to determine whether the i th time load step passes the safety assessment according to the creep damage before the defect is generated, the load ratio cutoff line, the failure assessment curve, the creep crack propagation cumulative damage of the component with defects corresponding to the i th time load step, the load ratio and the fracture ratio, if yes, update the defect size information and the cracking time, and perform the calculation of the i+1 th time load step, and if not, determine the remaining service life of the component with defects according to the cracking time corresponding to the i th time load step and the running time of the component with defects.

[0149] In an exemplary embodiment, a computer device is provided, which can be a server or a terminal, and an internal structure diagram thereof can be as shown in Figure 5 The computer device includes a processor, a memory, an input / output interface (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 configured 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 operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store basic information of the component with defects of the power plant boiler. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement a remaining life calculation method for a high-temperature component with defects of a power plant boiler.

[0150] Those skilled in the art can understand that Figure 5 The structure shown in the above

[0151] In an exemplary embodiment, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[0152] In an exemplary embodiment, a computer program product is provided, which includes a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[0153] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0154] In the present application, all actions of obtaining signals, information or data are carried out in compliance with the data protection regulations and policies of the country where the device is located, and with the authorization of the owner of the corresponding device.

[0155] A person 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 a computer program instructing related hardware. 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 above-mentioned embodiments. Any reference to memory, database or other medium used in the embodiments provided by 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 storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0156] The database involved in the embodiments provided by the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on blockchain, etc., without being limited thereto. The processor involved in the embodiments provided by the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0157] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, it should be understood that the application encompasses all possible combinations of the technical features described above.

[0158] The principles and implementation manners of the present application are described herein by using specific examples, and the above embodiments are only used to help understand the method of the present application and its core idea; meanwhile, according to the idea of the present application, the specific implementation manners and application scopes will be changed by those skilled in the art. In conclusion, the content of the present specification should not be understood as a limitation of the present application.

Claims

1. A method of calculating the residual life of a high-temperature defective component of a power plant boiler, characterized by, The method for calculating the residual life of a high-temperature defective component of a power plant boiler comprises the following steps: According to the basic information of the defective component of the power plant boiler, the initial material yield strength, the reference stress at the defect position, the load ratio under the initial state of the defect, the fracture ratio under 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. According to the load ratio under the initial state of the defect, the fracture ratio under 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 determined 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 propagation damage are set. Regarding the first i The time load step is based on the initial material yield strength, the reference stress at the defect location, and the... i Defect size information at each time load step, the first i Cracking time of the first time load step, the first i -1 time load step cracking time and the first i The creep crack propagation damage at time-1 load step is calculated. i Cumulative damage, load ratio, and fracture ratio of creep crack propagation in defective components corresponding to each time load step; i >1; The cracking time of the first time load step is the initial cracking time, and the creep crack propagation damage of the first time load step is the initial creep crack propagation damage. wherein the yield strength of the material at the temperature corresponding to the calculation of the time load step is calculated from the yield strength of the initial material i :​ ； ； ； ； According to the first i , the yield strength of the material at the calculated temperature and the reference stress at the defect location are calculated for the first i , the load ratio : ; wherein According to the basic information of the defective component of the power plant boiler, the initial material yield strength, the reference stress at the defect position, the load ratio under the initial state of the defect, the fracture ratio under 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. s is the yield strength of the material at the initial calculation temperature, E is the elastic modulus at the calculation temperature, , and are intermediate quantities, A 0, A 1, A 2, A 3, A 4 is a material creep strain parameter, B 0, B 1, B 2, B 3, B 4 is a material uniaxial damage parameter, , are constants, T is the calculation temperature of the component of the power plant boiler containing the defect, is the reference stress at the location of the defect; Based on the creep damage before the defect occurred, the load ratio cutoff line, the failure assessment curve, and the first i The cumulative damage, load ratio, and fracture ratio of the creep crack propagation of the defective component corresponding to each time load step are used to determine the first... i If the time load step passes the safety assessment, then update the defect size information and cracking time, and proceed to the next step. i +1 time load step calculation, if not, then according to the first time load step. i The remaining service life of the defective component is determined by the cracking time corresponding to each time load step and the operating time of the defective component.

2. The method of claim 1, wherein the method is characterized by: The material yield strength of the defective component at the initial calculation temperature is determined to obtain the initial material yield strength. The primary membrane stress, the primary bending stress, the secondary membrane stress, and the secondary bending stress at the position of the defect are determined. According to the basic information of the defective component of the power plant boiler, the primary membrane stress, and the primary bending stress, the reference stress at the position of the defect is calculated. According to the initial material yield strength and the reference stress, the load ratio under the initial state of the defect is calculated. 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 under the initial state of the defect, the fracture ratio under the initial state of the defect is calculated. According to the working time of the component before the defect occurs and the creep fracture life, the creep damage before the defect occurs is calculated. According to the material quality of the defective component, the load ratio cutoff line and the failure assessment curve are determined. 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 under the initial state of the defect, the fracture ratio under the initial state of the defect is calculated, which specifically comprises the following steps:

3. The method of claim 2, wherein the method is characterized by: 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, and the secondary bending stress, the stress intensity factor is calculated. 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, the plastic correction factor is calculated. If there is one defect in the defective component, the fracture ratio under the initial state of the defect is calculated according to the stress intensity factor and the plastic correction factor. If there are multiple defects in the defective component, the elastic-plastic interference effect coefficient is determined according to the initial load ratios of the multiple defects, and the fracture ratio under the initial state of the defect is calculated according to the stress intensity factor, the plastic correction factor, and the elastic-plastic interference effect coefficient. ​ 4. The method of claim 1, wherein the method is characterized by: If yes, it is determined that the defect initial state passes the safety assessment. If no, it is determined that the defect initial state fails the safety assessment. If yes, it is determined that the defect initial state passes the safety assessment. If no, it is determined that the defect initial state fails the safety assessment.

5. The method of claim 1, wherein According to the initial material yield strength, the reference stress at the defect position, the defect size information of the first i time load step, the cracking time of the first i time load step, the cracking time of the first i -1 time load step, and the creep crack growth damage of the first i -1 time load step, the creep crack growth cumulative damage of the component containing defects corresponding to the first i time load step, the load ratio and the fracture ratio are calculated, specifically including: Computing the creep rupture life at the i corresponding state of the time load step; According to the i Cracking time of the first time load step, the first i -1 time load step cracking time, the first i The creep fracture life under the corresponding state at the first time load step and the first i The creep crack propagation damage at time-1 load step is calculated. i Cumulative damage from creep crack propagation over a time load step; According to the yield strength of the initial material, the yield strength of the material at the calculated temperature corresponding to the time load step is calculated. i the yield strength of the material at the calculated temperature corresponding to the time load step is calculated. According to the first i The yield strength of the material at the calculated temperature and the reference stress at the defect location are calculated for the first i The load ratio at the first time load step is calculated. Based on the basic information of the defective components of the power plant boiler, the first i The material yield strength at the calculated temperature corresponding to the first time load step and the second time load step i Calculate the load at the load step of the first time, and calculate the load at the first time step. i The fracture ratio at each time load step.

6. The method of claim 1, wherein Based on the creep damage before the defect occurred, the load ratio cutoff line, the failure assessment curve, and the first i The cumulative damage, load ratio, and fracture ratio of the creep crack propagation of the defective component corresponding to each time load step are used to determine the first time load step. i Whether each time load step passes the safety assessment, specifically including: Judge the first i The load ratio corresponding to the first time load step is the same as the first time load step. i Whether the coordinate point determined by the fracture ratio corresponding to the first time load step is located within the area enclosed by the failure assessment curve, the load ratio cutoff line, and the horizontal and vertical coordinate axes, and whether the creep damage before the defect occurs is related to the first time load step. i Whether the sum of the cumulative damage from creep crack propagation in the defective component corresponding to each time load step is less than a set threshold; If yes, it is determined that the defect initial state passes the safety assessment. If no, it is determined that the defect initial state fails the safety assessment.

7. The method of claim 1, wherein the method is characterized by: The updating of the defect size information and the cracking time specifically includes: According to the defect size information of the first i time load step, a creep crack growth driving force is calculated; calculating a crack propagation rate according to the creep crack propagation driving force; calculating a time increment according to the crack propagation rate; updating the defect size information and the cracking time according to the crack propagation rate and the time increment.

8. A device for calculating the residual life of a high-temperature component having a defect of a power plant boiler, which is applied to the method for calculating the residual life of a high-temperature component having a defect of a power plant boiler according to any one of claims 1 to 7, characterized by, The power station boiler high-temperature defect-containing component residual life calculation device includes: an initial data acquisition module configured to determine, according to basic information of a power station boiler defect-containing component, an initial material yield strength, a reference stress at a defect position, a load ratio at a defect initial state, a fracture ratio at the defect initial state, a creep damage before the defect is generated, a load ratio cutoff line, and a failure assessment curve; an initial state judgment module configured to judge, according to the load ratio at the defect initial state, the fracture ratio at the defect initial state, the creep damage before the defect is generated, the load ratio cutoff line, and the failure assessment curve, whether the defect initial state passes the safety assessment, and if no, stop the calculation, and if yes, divide a whole service period of the defect-containing component into a plurality of time load steps, and set an initial cracking time and an initial creep crack propagation damage; a time load step calculation module, configured to calculate, for a first time load step, a creep crack growth cumulative damage of a component with a defect corresponding to the first time load step, a load ratio and a fracture ratio according to the initial material yield strength, a reference stress at the defect position, defect size information of the first time load step, a crack initiation time of the first time load step, a crack initiation time of the -1th time load step and a creep crack growth damage of the -1th time load step; i i i i i i i >1; the crack initiation time of the first time load step is an initial crack initiation time, and the creep crack growth damage of the first time load step is an initial creep crack growth damage.​​​​​​ a remaining life calculation module for calculating the remaining life of the component with defect according to the creep damage before the defect, the load ratio cut-off line, the failure assessment curve, the cumulative damage of the component with defect corresponding to the first time load step, the load ratio and the fracture ratio, judging whether the first time load step passes the safety assessment, if yes, updating the defect size information and the cracking time, and calculating the first +1 time load step, if not, determining the remaining life of the component with defect according to the cracking time corresponding to the first time load step and the running time of the component with defect. i i i i ​​​​ 9. A computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the power station boiler high-temperature defect-containing component residual life calculation method in any one of claims 1-7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the power station boiler high-temperature defect-containing component residual life calculation method in any one of claims 1-7.

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