Safety assessment method and system for main steam pipeline of power station boiler

Abstract

The invention discloses a safety assessment method and system for a main steam pipeline of a power station boiler, and the method comprises the steps: obtaining the material information of the main steam pipeline of the power station boiler, and the material information comprises the crack length of a material and the number of cyclic loads; a nonlinear creep damage model used for describing material creep is set, a material creep rate index of the main steam pipeline of the power station boiler is calculated according to the material information, a creep rate threshold value is set, and when the material creep rate index exceeds the creep rate threshold value, warning information is sent out; or setting a non-linear crack growth model for describing the crack growth of the material, simulating the crack growth condition of the material according to the material information, and sending out alarm information when the crack growth exceeds a preset crack growth threshold value; or setting a material failure probability calculation model for describing the material failure, calculating the material failure probability according to the material information, and sending out alarm information when the material failure probability exceeds a preset material failure probability threshold value.

Description

Technical Field

[0001] The present invention belongs to the technical field of material safety assessment of a main steam pipeline of a power station boiler, and more specifically, relates to a method and system for safety assessment of a main steam pipeline of a power station boiler. Background Art

[0002] The main steam pipeline of a power plant boiler is one of the most important pressure-bearing components in the boiler system. It operates under high temperature and high pressure for a long time, and the safety risk is extremely high. At present, the DCS system of domestic thermal power units mainly focuses on the parameters and operation of the medium in the steam pipeline, and monitors the steam temperature, pressure, flow, etc. in real time, which mainly stays at the system level. There is no monitoring and safety assessment method for the material status of the equipment body, especially the main steam pipeline during operation, and the intrinsic safety of the pipeline equipment. It mainly relies on professionals and inspection agencies to detect the material status in the shutdown state to find out whether there is a problem, which results in untimely and incomplete feedback on the material status. At the same time, with the increase of the service time of the unit, under the long-term high temperature and high pressure operation environment, the stress concentration parts such as the welds of the steam pipeline are very likely to produce crack defects, the wall thickness of the elbow is thinned under the scouring of high-pressure steam, the pipeline as a whole will have creep damage, and the microstructure will cause material degradation as the operation time increases.

[0003] Therefore, there is an urgent need for a technical solution that can conduct a safety assessment of the materials of the main steam pipeline of the power plant boiler to avoid safety risks. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a safety assessment method for a main steam pipeline of a power plant boiler, comprising:

[0005] Obtaining material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length, and number of cyclic loads on the main steam pipeline of the power plant boiler;

[0006] A nonlinear creep damage model for describing material creep is set, and based on the material information, a material creep rate index of a main steam pipe of a power plant boiler is calculated, and a creep rate threshold is set, and when the material creep rate index exceeds the creep rate threshold, an alarm message is issued;

[0007] or setting a nonlinear crack growth model for describing the crack growth of the material, and simulating the crack growth of the material according to the material information, and issuing an alarm message when the crack growth exceeds a preset crack growth threshold;

[0008] Or a material failure probability calculation model for describing material failure is set, and the material failure probability is calculated based on the material information, and when the material failure probability exceeds a preset material failure probability threshold, an alarm message is issued.

[0009] Furthermore, the nonlinear creep damage model includes:

[0010]

[0011] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time T, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0012] Furthermore, the nonlinear crack growth model includes:

[0013]

[0014] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0015] Furthermore, the material failure probability calculation model includes:

[0016]

[0017] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function ofinhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0018] Furthermore, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0019]

[0020] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0021] The present invention also proposes a power plant boiler main steam pipeline safety assessment system, comprising:

[0022] An information acquisition module is used to acquire material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads of the main steam pipeline of the power plant boiler;

[0023] A creep analysis module, which is used to set a nonlinear creep damage model for describing material creep, and calculate the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and set a creep rate threshold, and issue an alarm message when the material creep rate index exceeds the creep rate threshold;

[0024] Or a crack growth analysis module is set to simulate the crack growth of the material according to a nonlinear crack growth model that describes the crack growth of the material and the material information, and issue an alarm message when the crack growth exceeds a preset crack growth threshold;

[0025] Or a material failure analysis module is set up to calculate the material failure probability according to a set material failure probability calculation model describing material failure and the material information, and an alarm message is issued when the material failure probability exceeds a preset material failure probability threshold.

[0026] Furthermore, the nonlinear creep damage model includes:

[0027]

[0028] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time t, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0029] Furthermore, the nonlinear crack growth model includes:

[0030]

[0031] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0032] Furthermore, the material failure probability calculation model includes:

[0033]

[0034] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, ν is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0035] Furthermore, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0036]

[0037] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0038] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art:

[0039] Through the above technical scheme, the present invention can accurately perform safety assessment on the main steam pipeline of the power station boiler, thereby effectively avoiding the probability of safety accidents and ensuring production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of the method of embodiment 1 of the present invention;

[0041] Figure 2 It is a structural diagram of the system of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0042] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] The method provided by the present invention can be implemented in the following terminal environment, and the terminal may include one or more of the following components: a processor, a storage medium, and a display screen. The storage medium stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method described in the following embodiment.

[0044] The processor may include one or more processing cores. The processor uses various interfaces and lines to connect various parts in the entire terminal, and executes various functions of the terminal and processes data by running or executing instructions, programs, code sets or instruction sets stored in the storage medium, and calling data stored in the storage medium.

[0045] The storage medium may include a random access memory (RAM) or a read-only memory (ROM). The storage medium may be used to store instructions, programs, codes, code sets or instructions.

[0046] The display screen is used to display the user interface of each application.

[0047] In addition, those skilled in the art can understand that the structure of the above terminal does not constitute a limitation on the terminal, and the terminal may include more or fewer components, or combine certain components, or arrange the components differently. For example, the terminal also includes components such as a radio frequency circuit, an input unit, a sensor, an audio circuit, and a power supply, which will not be described in detail here.

[0048] Example 1

[0049] like Figure 1 As shown, an embodiment of the present invention provides a method for safety assessment of a main steam pipeline of a power plant boiler, comprising:

[0050] Step 101, obtaining material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads of the main steam pipeline of the power plant boiler;

[0051] Step 102, setting a nonlinear creep damage model for describing material creep, and calculating the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and setting a creep rate threshold, and issuing an alarm message when the material creep rate index exceeds the creep rate threshold;

[0052] Specifically, the nonlinear creep damage model includes:

[0053]

[0054] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time t, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0055] Step 103, or setting a nonlinear crack growth model for describing the crack growth of the material, and simulating the crack growth of the material according to the material information, and issuing an alarm message when the crack growth exceeds a preset crack growth threshold;

[0056] Specifically, the nonlinear crack growth model includes:

[0057]

[0058] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0059] Step 104, or setting a material failure probability calculation model for describing material failure, and calculating the material failure probability based on the material information, and issuing an alarm message when the material failure probability exceeds a preset material failure probability threshold.

[0060] Specifically, the material failure probability calculation model includes:

[0061]

[0062] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0063] Specifically, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0064]

[0065] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0066] Specifically, all the above adjustment factors are fitted by gradient descent method or ant colony algorithm.

[0067] Example 2

[0068] like Figure 2As shown, the embodiment of the present invention also provides a power station boiler main steam pipeline safety assessment system, including:

[0069] An information acquisition module is used to acquire material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads of the main steam pipeline of the power plant boiler;

[0070] A creep analysis module, which is used to set a nonlinear creep damage model for describing material creep, and calculate the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and set a creep rate threshold, and issue an alarm message when the material creep rate index exceeds the creep rate threshold;

[0071] Specifically, the nonlinear creep damage model includes:

[0072]

[0073] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time T, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0074] Or a crack growth analysis module is set to simulate the crack growth of the material according to a nonlinear crack growth model that describes the crack growth of the material and the material information, and issue an alarm message when the crack growth exceeds a preset crack growth threshold;

[0075] Specifically, the nonlinear crack growth model includes:

[0076]

[0077] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0078] Or a material failure analysis module is set up to calculate the material failure probability according to a set material failure probability calculation model describing material failure and the material information, and an alarm message is issued when the material failure probability exceeds a preset material failure probability threshold.

[0079] Specifically, the material failure probability calculation model includes:

[0080]

[0081] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, ν is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0082] Specifically, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0083]

[0084] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0085] Example 3

[0086] The embodiment of the present invention further provides a storage medium storing a plurality of instructions, wherein the instructions are used to implement the method for safety assessment of a main steam pipeline of a power station boiler.

[0087] Optionally, in this embodiment, the above storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0088] Optionally, in this embodiment, the storage medium is configured to store program codes for executing the following steps: Step 101, obtaining material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length, and number of cyclic loads of the main steam pipeline of the power plant boiler;

[0089] Step 102, setting a nonlinear creep damage model for describing material creep, and calculating the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and setting a creep rate threshold, and issuing an alarm message when the material creep rate index exceeds the creep rate threshold;

[0090] Specifically, the nonlinear creep damage model includes:

[0091]

[0092] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time t, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0093] Step 103, or setting a nonlinear crack growth model for describing the crack growth of the material, and simulating the crack growth of the material according to the material information, and issuing an alarm message when the crack growth exceeds a preset crack growth threshold;

[0094] Specifically, the nonlinear crack growth model includes:

[0095]

[0096] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0097] Step 104, or setting a material failure probability calculation model for describing material failure, and calculating the material failure probability based on the material information, and issuing an alarm message when the material failure probability exceeds a preset material failure probability threshold.

[0098] Specifically, the material failure probability calculation model includes:

[0099]

[0100] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0101] Specifically, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0102]

[0103] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0104] Example 4

[0105] An embodiment of the present invention also proposes an electronic device, including a processor and a storage medium connected to the processor, wherein the storage medium stores multiple instructions, and the instructions can be loaded and executed by the processor so that the processor can execute the method for safety assessment of the main steam pipeline of a power plant boiler.

[0106] Specifically, the electronic device of this embodiment may be a computer terminal, and the computer terminal may include: one or more processors, and a storage medium.

[0107] Among them, the storage medium can be used to store software programs and modules, such as a power plant boiler main steam pipeline safety assessment method in an embodiment of the present invention, and the corresponding program instructions / modules. The processor executes various functional applications and data processing by running the software programs and modules stored in the storage medium, that is, realizing the above-mentioned power plant boiler main steam pipeline safety assessment method. The storage medium may include a high-speed random storage medium, and may also include a non-volatile storage medium, such as one or more magnetic storage systems, flash memory, or other non-volatile solid-state storage media. In some instances, the storage medium may further include a storage medium remotely arranged relative to the processor, and these remote storage media can be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0108] The processor may call the information and application program stored in the storage medium through the transmission system to execute the following steps: Step 101, obtaining material information of the main steam pipeline of the power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads of the main steam pipeline of the power plant boiler;

[0109] Step 102, setting a nonlinear creep damage model for describing material creep, and calculating the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and setting a creep rate threshold, and issuing an alarm message when the material creep rate index exceeds the creep rate threshold;

[0110] Specifically, the nonlinear creep damage model includes:

[0111]

[0112] in, is the material creep rate index of the main steam pipeline of the power plant boiler at time t, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

[0113] Step 103, or setting a nonlinear crack growth model for describing the crack growth of the material, and simulating the crack growth of the material according to the material information, and issuing an alarm message when the crack growth exceeds a preset crack growth threshold;

[0114] Specifically, the nonlinear crack growth model includes:

[0115]

[0116] Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

[0117] Step 104, or setting a material failure probability calculation model for describing material failure, and calculating the material failure probability based on the material information, and issuing an alarm message when the material failure probability exceeds a preset material failure probability threshold.

[0118] Specifically, the material failure probability calculation model includes:

[0119]

[0120] Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

[0121] Specifically, the material inhomogeneous strain ∈ inhom The influence function h(∈ inhom )include:

[0122]

[0123] Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

[0124] Example 5

[0125] Embodiment 5 is a supplement to Embodiments 1-4, and specifically includes: the main steam pipeline safety assessment evaluates the safety status of the main steam pipeline from 6 dimensions, 19 indicators, and 5 levels. The 6 dimensions and 19 indicators are shown in Table 1 below.

[0126] Table 1 Comprehensive safety status evaluation table

[0127]

[0128] Different weight factors are assigned to the influencing factors of the six dimensions according to their importance as shown in Table 2. The average comprehensive evaluation level is calculated using the formula 1.

[0129] Table 2 Weight factors of influencing factors in 6 different dimensions

[0130] Influencing factors Base Maintenance manage run monitor test Weight Factor 0.05 0.05 0.1 0.35 0.1 0.35

[0131] Average comprehensive evaluation level:

[0132] M=ΣL i ×n i (1)

[0133] M—Comprehensive safety evaluation level of main steam pipeline

[0134] L—Influencing factor level score

[0135] n—weight factor

[0136] The i-th influencing factor

[0137] Different weight factors are assigned to the influencing factors of the 19 indicators according to their importance as shown in Table 3. The average comprehensive evaluation level is calculated by formula 1

[0138] Table 3 Weight factors of 19 index influencing factors

[0139]

[0140]

[0141] Each of the 19 indicators is scored on a 5-level scale, and the final comprehensive score is obtained through the weight factor. Finally, the safety status of the pipeline is analyzed through a comprehensive evaluation radar chart.

[0142] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0143] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0144] In the several embodiments provided by the present invention, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0145] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0146] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0147] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only storage medium (ROM, Read-Only Memory), random access storage medium (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0148] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for safety assessment of main steam pipeline of power plant boiler, characterized in that: include: Obtaining material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads on the main steam pipeline of the power plant boiler; A nonlinear creep damage model for describing material creep is set, and based on the material information, a material creep rate index of a main steam pipe of a power plant boiler is calculated, and a creep rate threshold is set, and when the material creep rate index exceeds the creep rate threshold, an alarm message is issued; or setting a nonlinear crack growth model for describing the crack growth of the material, and simulating the crack growth of the material according to the material information, and issuing an alarm message when the crack growth exceeds a preset crack growth threshold; Or a material failure probability calculation model for describing material failure is set, and the material failure probability is calculated based on the material information, and when the material failure probability exceeds a preset material failure probability threshold, an alarm message is issued.

2. A method for safety assessment of a main steam pipeline of a power plant boiler according to claim 1, characterized in that: The nonlinear creep damage model includes: in, is the material creep rate index of the main steam pipeline of the power plant boiler at time T, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, Q c is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipe of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

3. A method for safety assessment of a main steam pipeline of a power plant boiler according to claim 1, characterized in that: The nonlinear crack growth model includes: Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

4. A method for safety assessment of a main steam pipeline of a power plant boiler according to claim 1, characterized in that: The material failure probability calculation model includes: Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, σ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

5. A method for safety assessment of a main steam pipeline of a power plant boiler according to claim 4, characterized in that: Material inhomogeneity strain ∈ inhom The influence function h(∈ inhom )include: Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

6. A power station boiler main steam pipeline safety assessment system, characterized in that: include: An information acquisition module is used to acquire material information of a main steam pipeline of a power plant boiler, wherein the material information includes: stress, material temperature, microstructure degradation degree, material crack length and number of cyclic loads of the main steam pipeline of the power plant boiler; A creep analysis module, used to set a nonlinear creep damage model for describing material creep, and calculate the material creep rate index of the main steam pipe of the power plant boiler according to the material information, and set a creep rate threshold, and issue an alarm message when the material creep rate index exceeds the creep rate threshold; Or a crack growth analysis module is set to simulate the crack growth of the material according to a nonlinear crack growth model that describes the crack growth of the material and the material information, and issue an alarm message when the crack growth exceeds a preset crack growth threshold; Or a material failure analysis module is set up to calculate the material failure probability according to a set material failure probability calculation model describing material failure and the material information, and an alarm message is issued when the material failure probability exceeds a preset material failure probability threshold.

7. A power plant boiler main steam pipeline safety assessment system as claimed in claim 6, characterized in that: The nonlinear creep damage model includes: in, is the material creep rate index of the main steam pipeline of the power plant boiler at time t, A is the material constant of the creep rate of the main steam pipeline of the power plant boiler, σ(t) is the stress on the main steam pipeline of the power plant boiler at time t, n is the first creep adjustment factor, T is the creep activation energy, R is the gas constant, T(t) is the material temperature at time t, ξ is the second creep adjustment factor, φ(t) is the microstructure degradation degree of the material at time t, k is the third creep adjustment factor, ρ is the fourth creep adjustment factor, σ(t′) is the stress on the main steam pipeline of the power plant boiler at time t′, and κ(tt′) is the decay rate of the material memory effect within time tt′.

8. A power plant boiler main steam pipeline safety assessment system as claimed in claim 6, characterized in that: The nonlinear crack growth model includes: Where a is the crack length of the material, N is the number of cyclic loadings, C1 is the material constant of the crack growth rate, ΔK(t) is the change in stress intensity at the crack tip at time t, ζ is the first adjustment factor for crack growth, T is the temperature of the material, x is the position of the material, m is the second adjustment factor for crack growth, γ is the third adjustment factor for crack growth, η is the fourth adjustment factor for crack growth, and ω is the loading frequency.

9. A power plant boiler main steam pipeline safety assessment system as claimed in claim 6, characterized in that: The material failure probability calculation model includes: Among them, P fail (t) is the probability of material failure at time t, σ(t) is the stress on the main steam pipe of the power plant boiler at time t, ∈ avg is the average stress on the material, γ is the first adjustment factor of the failure probability, T(t) is the material temperature at time t, δ is the second adjustment factor of the failure probability, is the material temperature gradient at the material position x at time t, v is the third adjustment factor of the failure probability, h(∈ inhom ) is the material inhomogeneous strain ∈ inhom The influence function of inhom It is the inhomogeneous strain of the material, which indicates the local strain distribution of the material under a complex stress field.

10. A power plant boiler main steam pipeline safety assessment system as claimed in claim 9, characterized in that: Material inhomogeneity strain ∈ inhom The influence function h(∈ inhom )include: Among them, α1 is the first adjustment factor of material inhomogeneous strain, β1 is the second adjustment factor of material inhomogeneous strain, α2 is the third adjustment factor of material inhomogeneous strain, γ′ is the fourth adjustment factor of material inhomogeneous strain, α3 is the fifth adjustment factor of material inhomogeneous strain, and δ′ is the sixth adjustment factor of material inhomogeneous strain.

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