Creep fatigue state evaluation method and system for high-temperature nuclear power station equipment

Abstract

The invention discloses a creep fatigue state evaluation method and system for high-temperature nuclear power station equipment. The method comprises the following steps: acquiring operation state parameter data of the high-temperature nuclear power station equipment; determining a total strain range of the equipment based on the operation state parameter data; according to the total strain range, the allowable cycle index and the creep initial stress of the equipment are determined; determining the fatigue damage and the creep damage of the equipment by using the allowable cycle index and the creep initial stress respectively; and based on the fatigue damage and the creep damage, evaluating the creep fatigue state of the equipment. Creep-fatigue comprehensive damage full-period safety and service life analysis management of key components of the high-temperature power station can be realized, when equipment has risks, an evaluation result is fed back to a main control room in time to remind a user of focusing on attention and monitoring, and a corresponding technical scheme is provided for a health monitoring and service life prediction system of a digital nuclear power station and an in-service power station.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment life monitoring in nuclear power plants, and particularly to a method and system for evaluating the creep-fatigue state of high-temperature nuclear power plant equipment. Background Art

[0002] High-temperature nuclear power plant units operate under the combination of high temperature and cyclic loads to achieve faster start-up and shutdown response times. Real-time monitoring of cyclic data caused by load changes or operations is of great significance for evaluating the creep-fatigue behavior of operating power plants and predicting the life of power plants. The efficient operation of high-temperature components in nuclear power plants requires monitoring several key operating characteristics, such as fluid pressure, temperature, and flow rate. Measuring these characteristic data requires providing a sufficient number of accurate values over a relatively long period of time. The main degradation mechanisms affecting the long-term reliability of high-temperature components are creep and fatigue. During the operation of the power plant, the accumulation of material damage ultimately leads to the initiation and propagation of cracks. In many components, the question is not whether cracks occur, but when they occur. In extreme cases, the growth of these cracks can lead to leakage or rupture. Therefore, the monitoring and analysis of creep-fatigue damage accumulation are essential for formulating effective life assessment strategies for high-temperature components and systems.

[0003] The existing patent CN104464851B discloses a prototype monitoring device and its monitoring method for thermal fatigue of high-temperature pipelines in the primary loop of a nuclear power plant. The background server of the monitoring device is electrically connected to one or several external data storage servers. Each external data storage server is electrically connected to one or more data acquisition modules. Each data acquisition module is electrically connected to multiple data acquisition sensors, and the transmission cables are reinforced and shielded. This solution only describes the method for fatigue monitoring and does not comprehensively evaluate fatigue and creep conditions.

[0004] The existing patent CN110993132B discloses a transient monitoring method for supporting fatigue monitoring functions in a nuclear power plant. By using the real-time measurement data of the original instruments in the nuclear power plant's instrument control system, the start and end of the transient occurring on the monitoring object are automatically identified, and the characteristic parameters of the identified transient are summarized. At the same time, based on the database, the following are achieved: ① By comparing the characteristic parameters, it is determined whether the identified transient belongs to the expected transient category of the monitoring object or its affiliated process system, and the transient category, occurrence times, and occurrence time are recorded. The stress change time history of the corresponding monitoring object is directly obtained from the database through the recorded transient category. ② If the identified transient does not belong to any existing transient category in the database, a new transient category is established in the database according to the characteristic parameters of the identified transient. The stress change time history of the monitoring object under the action of this transient category is obtained through analysis and calculation and stored in the new transient category in the database to support the subsequent completion of the fatigue damage assessment of the monitoring object.

[0005] In summary, neither of the above two existing patents has proposed a creep-fatigue monitoring and evaluation method for high-temperature power station operating equipment. Summary of the Invention

[0006] Based on the above technical problems, the present invention proposes a creep-fatigue state evaluation method and system for high-temperature nuclear power plant equipment.

[0007] A creep-fatigue state evaluation method for high-temperature nuclear power plant equipment, the method comprising:

[0008] Collecting operation state parameter data of high-temperature nuclear power plant equipment;

[0009] Based on the operation state parameter data, determining the total strain range of the equipment;

[0010] Respectively determining the allowable number of cycles and the initial creep stress of the equipment according to the total strain range;

[0011] Respectively determining the fatigue damage and creep damage of the equipment by using the allowable number of cycles and the initial creep stress;

[0012] Based on the fatigue damage and creep damage, evaluating the creep-fatigue state of the equipment.

[0013] Further, the operation state parameter data includes: temperature data, pressure data, and flow rate data during the start-up and shutdown of the nuclear power plant and when the equipment is abnormal.

[0014] Further, before determining the total strain range of the equipment based on the operation state parameter data, it further includes:

[0015] Setting corresponding change thresholds for the operation state parameters;

[0016] Removing the data exceeding the change threshold from the operation state parameter data.

[0017] Further, determining the total strain range of the equipment based on the operation state parameter data includes:

[0018] Determining the corresponding stress components of the equipment based on the operation state parameter data, and extracting the maximum strain range according to the stress components;

[0019] Determining the maximum equivalent strain range according to the maximum strain range;

[0020] Correcting the maximum equivalent strain range to determine the corrected maximum equivalent strain range;

[0021] Determining the creep strain increment;

[0022] Based on the corrected maximum equivalent strain range and the creep strain increment, determining the total strain range of the equipment.

[0023] Further, determining the maximum equivalent strain range based on the maximum strain range includes:

[0024] Based on the maximum strain range, determining the maximum equivalent strain range through Equation (1), Equation (1):

[0025] Δε mod = K e KΔε max

[0026] where Δε mod is the maximum equivalent strain range. When , K e = 1. When , K is the equivalent stress concentration factor determined by tests or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration. is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, and Δε max is the maximum strain range.

[0027] Further, correcting the maximum equivalent strain range to determine the corrected maximum equivalent strain range includes:

[0028] Determining the plastic Poisson's ratio correction coefficient;

[0029] Using the plastic Poisson's ratio correction coefficient to correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range.

[0030] Further, determining the creep strain increment includes:

[0031] Determining the effective creep stress through Equation (2), Equation (2): σ c = ZS y , where σ c is the effective creep stress, S y is the yield strength, and Z is determined by parameters X and Y. X = (P L + P b / K t ) max / S y , Y = (Q R ) max / S y , where (P L + P b / K t ) max is the maximum value of the primary stress intensity adjusted by K t for the bending stress in the evaluated cycle, and (Q R ) max is the maximum range of the secondary stress intensity in the considered cycle;

[0032] Based on the effective creep stress, the creep strain increment is determined according to Equation 3, Equation 3, Δε c = 1.25σ c where Δε c is the creep strain increment.

[0033] Furthermore, based on the corrected maximum equivalent strain range and the creep strain increment, the total strain range of the device is determined, including:

[0034] Based on the corrected maximum equivalent strain range and the creep strain increment, the total strain range of the device is determined through Equation 4, Equation 4,

[0035] ε t = K v Δε mod + KΔε c

[0036] where ε t is the total strain range, K v = 1 + f(K′ v - 1), K′ v is the plastic Poisson's ratio correction factor, f is determined according to the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by tests or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration, Δε c is the creep strain increment.

[0037] Furthermore, the creep initial stress of the device is determined based on the total strain range, including:

[0038] Obtain the isochronous stress-strain curve;

[0039] Correspond the total strain range to the isochronous stress-strain curve to determine the creep initial stress of the device.

[0040] Furthermore, the creep damage of the device is determined using the creep initial stress, including:

[0041] Based on the creep initial stress, the calibrated relaxation stress of the device is determined through Equation 5, Equation 5, where S r is the calibrated relaxation stress of the device under the multiaxial stress state at time t, S j is the creep initial stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, represents the relaxation stress under the uniaxial model at time t;

[0042] Obtain the creep fracture life curve;

[0043] Determine the allowable creep rupture life of the equipment according to the calibrated relaxation stress and creep rupture life curve of the equipment;

[0044] Determine the creep damage of the equipment based on the allowable creep rupture life.

[0045] Furthermore, based on the fatigue damage and creep damage, evaluate the creep-fatigue state of the equipment, including:

[0046] Judge whether the fatigue damage and creep damage satisfy Formula Six, Formula Six,

[0047]

[0048] where D is the total creep-fatigue damage, (N d ) j is the design allowable number of cycles of the j-th type of cycle, (T d ) k is the allowable duration within the time interval k, (n) j is the number of cycles of the j-th type of cycle, p is the number of stress / temperature time history, q is the high-temperature service time for calculating the creep damage at the monitoring point; (Δt) k is the duration of the time interval k;

[0049] If the fatigue damage and creep damage satisfy Formula Six, it is determined that there is no risk for the high-temperature nuclear power plant equipment;

[0050] If the fatigue damage and creep damage do not satisfy Formula Six, it is determined that there is a risk for the high-temperature nuclear power plant equipment, and the fatigue damage and creep damage are transmitted to the main control room of the high-temperature nuclear power plant for alarm.

[0051] To achieve the above object, the present invention also proposes a creep-fatigue state evaluation system for high-temperature nuclear power plant equipment.

[0052] A creep-fatigue state evaluation system for high-temperature nuclear power plant equipment, comprising:

[0053] An acquisition module for acquiring the operation state parameter data of the high-temperature nuclear power plant equipment;

[0054] A first determination module for determining the total strain range of the equipment based on the operation state parameter data;

[0055] A second determination module for respectively determining the allowable number of cycles and the initial creep stress of the equipment according to the total strain range;

[0056] A third determination module for respectively determining the fatigue damage and creep damage of the equipment by using the allowable number of cycles and the initial creep stress;

[0057] An evaluation module for evaluating the creep-fatigue state of a device based on fatigue damage and creep damage.

[0058] Furthermore, the operating state parameter data includes: temperature data, pressure data, and flow rate data during the start-up and shutdown of a nuclear power plant and when the device is abnormal.

[0059] Furthermore, before determining the total strain range of the device based on the operating state parameter data, it also includes:

[0060] Setting a corresponding change threshold for the operating state parameters;

[0061] Excluding the data that exceeds the change threshold from the operating state parameter data.

[0062] Furthermore, a first determination module is used for:

[0063] Determining the stress components corresponding to the device based on the operating state parameter data, and extracting the maximum strain range according to the stress components;

[0064] Determining the maximum equivalent strain range based on the maximum strain range;

[0065] Correcting the maximum equivalent strain range to determine the corrected maximum equivalent strain range;

[0066] Determining the creep strain increment;

[0067] Determining the total strain range of the device based on the corrected maximum equivalent strain range and the creep strain increment.

[0068] Furthermore, determining the maximum equivalent strain range based on the maximum strain range includes:

[0069] Based on the maximum strain range, determining the maximum equivalent strain range through Formula 1. Formula 1,

[0070] Δε mod =K e KΔε max

[0071] where Δε mod is the maximum equivalent strain range. When is the case, K e =1. When is the case, K is the equivalent stress concentration factor determined by experiment or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the considered local area, is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, and Δε max is the maximum strain range.

[0072] Further, correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range, including:

[0073] Determine the plastic Poisson's ratio correction coefficient;

[0074] Use the plastic Poisson's ratio correction coefficient to correct the maximum equivalent strain range and determine the corrected maximum equivalent strain range.

[0075] Further, determine the creep strain increment, including:

[0076] Determine the effective creep stress through Formula 2. Formula 2: σ c =ZS y where σ c is the effective creep stress, S y is the yield strength, and Z is determined by parameters X and Y. X = (P L +P b / K t ) max / S y , Y = (Q R ) max / S y where (P L +P b / K t ) max is the maximum value of the primary stress intensity adjusted by K t for the bending stress in the evaluated cycle, and (Q R ) max is the maximum range of the secondary stress intensity in the considered cycle;

[0077] Based on the effective creep stress, determine the creep strain increment according to Formula 3. Formula 3: Δε c =1.25σ c where Δε c is the creep strain increment.

[0078] Further, based on the corrected maximum equivalent strain range and the creep strain increment, determine the total strain range of the equipment, including:

[0079] Based on the corrected maximum equivalent strain range and the creep strain increment, determine the total strain range of the equipment through Formula 4. Formula 4:

[0080] ε t =K v Δε mod +KΔε c

[0081] where ε t is the total strain range, and K v =1+f(K′v -1), K' v is the plastic Poisson's ratio correction coefficient, f is determined according to the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by experiment or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration, Δε c is the creep strain increment.

[0082] Furthermore, the second determination module is used for:

[0083] Obtain the isochronous stress-strain curve;

[0084] Correspond the total strain range to the isochronous stress-strain curve to determine the initial creep stress of the equipment.

[0085] Furthermore, determining the creep damage of the equipment using the initial creep stress includes:

[0086] Based on the initial creep stress, determine the calibrated relaxation stress of the equipment through Equation Five, Equation Five, where S r is the calibrated relaxation stress of the equipment under the multiaxial stress state at time t, S j is the initial creep stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, represents the relaxation stress under the uniaxial model at time t;

[0087] Obtain the creep fracture life curve;

[0088] Determine the allowable creep fracture life of the equipment according to the calibrated relaxation stress of the equipment and the creep fracture life curve;

[0089] Determine the creep damage of the equipment based on the allowable creep fracture life.

[0090] Furthermore, the evaluation module is used for:

[0091] Judge whether the fatigue damage and creep damage satisfy Equation Six, Equation Six,

[0092]

[0093] where D is the total creep-fatigue damage, (N d ) j is the design allowable number of cycles for the j-th type of cycle, (T d ) k is the allowable duration within the time interval k, (n) j is the number of cycles of the j-th type of cycle, p is the number of stress / temperature time history, q is the high-temperature service time for calculating the creep damage at the monitoring point; (Δt)k is the duration of the time interval k;

[0094] If the fatigue damage and creep damage satisfy Equation VI, it is determined that there is no risk for the high-temperature nuclear power plant equipment;

[0095] If the fatigue damage and creep damage do not satisfy Equation VI, it is determined that there is a risk for the high-temperature nuclear power plant equipment, and the fatigue damage and creep damage are transmitted to the main control room of the high-temperature nuclear power plant for alarm.

[0096] Based on the above technical solutions, the present invention has at least the following beneficial effects:

[0097] 1. The present invention determines the total strain range of the equipment based on the operating state parameter data of the high-temperature nuclear power plant equipment, determines the allowable number of cycles and the initial creep stress of the equipment respectively according to the total strain range, and then determines the fatigue damage and creep damage of the equipment respectively, realizing the assessment of the creep-fatigue state of the equipment. The present invention can realize the full-cycle safety and life analysis management of the creep-fatigue comprehensive damage of the key components of the high-temperature power station. When there is a risk for the equipment, the evaluation result is timely fed back to the main control room to remind key attention and monitoring, providing corresponding technical solutions for digital nuclear power and the health monitoring and life prediction system of the in-service power station.

[0098] 2. The present invention determines the maximum equivalent strain range based on the maximum strain range, corrects the maximum equivalent strain range considering factors such as multiaxial and plasticity, and then determines the total strain range. The total strain range determined in this way is more accurate, can more truly reflect the actual strain state of the material under complex load conditions, and further makes the creep-fatigue damage state calculated based on this parameter more accurate, improving the accuracy and reliability of the damage assessment.

[0099] 3. A method and device for evaluating the creep-fatigue state of high-temperature nuclear power plant equipment proposed by the present invention are more efficient and reliable for the monitoring and life assessment of the flow rate, pressure, and temperature change data of high-temperature pressure components or pipeline systems under high-temperature creep conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0101] Figure 1 is a flowchart of a method for evaluating the creep-fatigue state of high-temperature nuclear power plant equipment according to an embodiment of the present invention;

[0102] Figure 2 is a flowchart for determining the total strain range of the equipment based on the operating state parameter data in an embodiment of the present invention;

[0103] Figure 3 For ASME Code Figure HBB-T-1332-1 (for Test B-1);

[0104] Figure 4 For ASME Code Figure HBB-T-1332-2 (for Test B-2);

[0105] Figure 5 It is a schematic diagram of the principle for determining parameter f based on the multiaxial coefficient;

[0106] Figure 6 It is a schematic diagram of the creep-fatigue damage envelope corresponding to the high-temperature nuclear power plant equipment in an embodiment of the present invention;

[0107] Figure 7 It is a schematic diagram of a creep-fatigue state evaluation system for high-temperature nuclear power plant equipment in an embodiment of the present invention. Detailed implementation manners

[0108] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0109] The following further describes the present invention in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present invention.

[0110] Embodiment

[0111] The present invention provides a creep-fatigue state evaluation method and system for high-temperature nuclear power plant equipment.

[0112] To achieve the above object, the present invention provides a creep-fatigue state evaluation method for high-temperature nuclear power plant equipment.

[0113] As Figure 1 shows a flowchart of a creep-fatigue state evaluation method for high-temperature nuclear power plant equipment in an embodiment of the present invention, and the method includes the following steps:

[0114] S1, collect the operation state parameter data of the high-temperature nuclear power plant equipment.

[0115] This embodiment pre-arranges thermocouples that can measure temperature changes, pressure sensors that measure pressure changes, and flow meters that measure flow changes. In addition to the installation points arranged in the conventional design, the local locations that are prone to creep-fatigue damage identified in the design stage are numbered, such as: CF01, CF02, CF03, CF04, ..., and a measuring device is installed at each numbered position. Data is collected by numbered groups, and the collected data includes operating parameter data and sensor monitoring data. By reasonably arranging monitoring instruments and meters (according to system design and process requirements, or special requirements for equipment and pipeline design and monitoring, instruments and meters are arranged on pipelines and equipment inlets and outlets, etc.), temperature data, pressure data, and flow data are collected when the nuclear power plant is started and stopped and when the equipment is abnormal under complex on-site environments, and the data are classified and stored.

[0116] Furthermore, before determining the total strain range of the equipment based on the operating status parameter data, the operating status parameter data is also preprocessed. Compared with the process design curve used to calculate creep-fatigue damage in the design stage, the regularity of the change of operating transients over time is not strong, and it is necessary to filter and screen according to certain rules, and to demonstrate the reliability and rationality of the filtering and screening criteria, and finally determine the actual operating transient data that needs to be analyzed and calculated in each stage (such as a material replacement or maintenance cycle of a power station). The specific process is as follows: First, set the corresponding change threshold for the operating status parameter; then, remove the data that exceeds the change threshold from the operating status parameter data.

[0117] S2, based on the operating status parameter data, determine the total strain range of the equipment.

[0118] like Figure 2 As shown, based on the operating status parameter data, determining the total strain range of the equipment includes the following steps:

[0119] S201, determining stress components corresponding to the equipment based on the operating status parameter data, and extracting a maximum strain range according to the stress components.

[0120] The operating state parameters collected in step S1 are imported into the calculation model stored in the design phase, and the calculation model is used to calculate the stress components of the key point positions of the equipment under each working condition under the operating state parameters. Subsequently, based on the stress components, the maximum strain range is extracted using finite element analysis software.

[0121] S202, determining a maximum equivalent strain range according to the maximum strain range.

[0122] Based on the maximum strain range, the maximum equivalent strain range is determined by formula 1:

[0123] Δε mod =K e KΔε max

[0124] wherein, Δε mod is the maximum equivalent strain range. When is the case, K e = 1. When is the case, K is the equivalent stress concentration factor determined by tests or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration. is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, and Δε max is the maximum strain range.

[0125] S203, correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range.

[0126] Furthermore, correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range. The process is as follows: First, determine the plastic Poisson's ratio correction coefficient; then use the plastic Poisson's ratio correction coefficient to correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range.

[0127] S204, determine the creep strain increment.

[0128] The main process of this step is as follows: First, determine the effective creep stress through Equation 2.

[0129] Equation 2, σ c = ZS y , wherein, σ c is the effective creep stress, S y is the yield strength, Z is determined by parameters X and Y, X = (P L + P b / K t ) max / S y , Y = (Q R ) max / S y , wherein, (P L + P b / K t ) max is the maximum value of the primary stress intensity adjusted by K t for the bending stress in the evaluated cycle, and (Q R ) max is the maximum range of the secondary stress intensity in the considered cycle. According to the calculated values of X and Y, it can be found in ASME Code Figure HBB-T-1332-1 (for Test B-1, such as Figure 3 ) or Figure HBB-T-1332-2 (for Test B-2, such as Figure 4)Find the dimensionless effective creep stress parameter Z for any load combination in the [reference], and then calculate the corresponding effective creep stress. Among them, Figure 3 and Figure 4 The abscissa in both is the primary stress parameter X, and the ordinate in both is the secondary stress parameter Y.

[0130] Subsequently, based on the effective creep stress, determine the creep strain increment according to Formula Three. Formula Three: Δε c = 1.25σ c , where Δε c is the creep strain increment. The above Formula Three can be understood as using a stress intensity equal to 1.25 times the effective creep stress σ c to determine the sum of the creep strain increments Δε c accumulated during the stress cycle time caused by the load-controlled stress.

[0131] S205, based on the corrected maximum equivalent strain range and creep strain increment, determine the total strain range of the equipment.

[0132] Furthermore, based on the corrected maximum equivalent strain range and creep strain increment, determine the total strain range of the equipment through Formula Four. Formula Four:

[0133] ε t = K v Δε mod + KΔε c

[0134] where ε t is the total strain range, K v = 1 + f(K′ v - 1), K v is greater than or equal to 1, K′ v is the plastic Poisson's ratio correction coefficient, f is determined according to the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by experiment or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area considered, and Δε c is the creep strain increment.

[0135] Specifically, in this embodiment, the f is determined according to the corresponding multiaxial coefficient (T.F.). T.F. represents the stress states at the two extreme values of the stress cycle, and the f should take the larger value of the two extreme values of the stress cycle. The plastic Poisson's ratio correction coefficient K′ v is determined according to Figure 5 the KK at the corresponding ratio e Δε max E / 3Sˉm The value is determined.

[0136] S3. Determine the allowable cyclic number and the initial creep stress of the equipment respectively according to the total strain range.

[0137] Further, determining the initial creep stress of the equipment according to the total strain range includes:

[0138] S301. Obtain the isochronous stress-strain curve.

[0139] Specifically, the isochronous stress-strain curve corresponds to FIGS. HBB-T-1800-A-1 to HBB-T-1800-E-11 in the ASME code diagram.

[0140] S302. Correlate the total strain range to the isochronous stress-strain curve to determine the initial creep stress of the equipment.

[0141] S4. Determine the fatigue damage and creep damage of the equipment respectively by using the allowable cyclic number and the initial creep stress.

[0142] The fatigue damage of the equipment can be determined according to the allowable cyclic number where (N d ) j is the design allowable cyclic number of the j-th type of cycle, and (n) j is the cyclic number of the j-th type of cycle.

[0143] Further, determining the creep damage of the equipment by using the initial creep stress includes:

[0144] S401. Based on the initial creep stress, determine the calibrated relaxation stress of the equipment through Formula Five.

[0145] Formula Five where S r is the calibrated relaxation stress of the equipment under the multiaxial stress state at time t, S j is the initial creep stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, represents the relaxation stress under the uniaxial model at time t.

[0146] S402. Obtain the creep rupture life curve.

[0147] S403. Determine the allowable creep rupture life of the equipment according to the calibrated relaxation stress of the equipment and the creep rupture life curve.

[0148] The creep rupture life curve is a curve of stress versus rupture life. Correlating the calibrated relaxation stress of the equipment to the creep rupture life curve can determine the allowable creep rupture life of the equipment.

[0149] S404. Determine the creep damage of the equipment based on the allowable creep rupture life.

[0150] Determine the creep damage of the equipment based on the allowable creep rupture life where (T d ) k is the allowable duration within the time interval k, and (Δt) k is the duration of the time interval k.

[0151] S5. Evaluate the creep-fatigue state of the equipment based on the fatigue damage and creep damage.

[0152] Furthermore, evaluate the creep-fatigue state of the equipment based on the fatigue damage and creep damage, including:

[0153] S501. Determine whether the fatigue damage and creep damage satisfy Equation 6.

[0154] Equation 6 where D is the total creep-fatigue damage, (N d ) j is the design allowable number of cycles for the j-th type of cycle, (T d ) k is the allowable duration within the time interval k, (n) j is the number of cycles of the j-th type of cycle, p is the number of stress / temperature time histories, q is the high-temperature service time for calculating the creep damage at the point to be monitored. (Δt) k is the duration of the time interval k.

[0155] S502. If the fatigue damage and creep damage satisfy Equation 6, determine that there is no risk for the high-temperature nuclear power plant equipment.

[0156] S503. If the fatigue damage and creep damage do not satisfy Equation 6, determine that there is a risk for the high-temperature nuclear power plant equipment, and transmit the fatigue damage and creep damage to the main control room of the high-temperature nuclear power plant for alarm.

[0157] Specifically, the above steps S501 to S503 can be understood as follows: based on the fatigue damage and the creep damage, a creep-fatigue comprehensive damage assessment landing point diagram is drawn; it is determined whether the landing point data in the creep-fatigue comprehensive damage assessment landing point diagram is located below the creep-fatigue damage envelope corresponding to the high-temperature nuclear power plant equipment (i.e., the creep-fatigue synthesis is less than the total creep-fatigue damage D); if the landing point data is located below the creep-fatigue damage envelope corresponding to the high-temperature nuclear power plant equipment, it is determined that there is no risk for the high-temperature nuclear power plant equipment; if the landing point data is located above the creep-fatigue damage envelope corresponding to the high-temperature nuclear power plant equipment, it is determined that there is a risk for the high-temperature nuclear power plant equipment, and the landing point data is transmitted to the main control room of the high-temperature nuclear power plant for alarm. As Figure 6 shows the creep-fatigue damage envelope corresponding to the high-temperature nuclear power plant equipment in this embodiment, Figure 6 where the abscissa represents the fatigue comprehensive damage and the ordinate represents the creep comprehensive damage.

[0158] Through the present invention, a steady-state analysis of the envelopes of the operation transient data received within a certain time period can be performed, and it can be quickly analyzed and judged whether the equipment is safe initially. If it is safe, the landing position of the creep-fatigue comprehensive damage result in the two-dimensional safety envelope diagram at this stage is recorded, and the detailed evaluation results of the transient conditions will be fed back to the main control later; if it is initially judged that there is a risk for the equipment, the evaluation results will be fed back to the main control room to remind to pay key attention and monitor, and a detailed evaluation and analysis of the transient conditions will be carried out synchronously.

[0159] To achieve the above object, the present invention also proposes a creep-fatigue state evaluation system for high-temperature nuclear power plant equipment.

[0160] As Figure 7 shows a schematic diagram of a creep-fatigue state evaluation system for high-temperature nuclear power plant equipment according to an embodiment of the present invention, including: a collection module 51, a first determination module 52, a second determination module 53, a third determination module 54, and an evaluation module 55.

[0161] The collection module 51 is used to collect the operation state parameter data of the high-temperature nuclear power plant equipment.

[0162] Monitoring points are arranged at the key sensitive parts found in the design stage calculation to monitor the changes in temperature, pressure, and flow rate, such as the inlets and outlets of the tube side and the shell side of the steam generator. For example, the monitoring points of the tube orifice temperature are arranged at an angle of 30 degrees, and 12 monitoring points are arranged at the tube orifice to measure the temperature of the metal wall surface. The collection module collects the monitoring instrument data and stores it in the server, and the monitoring data can be displayed in the form of a real-time change curve in the server interface viewer.

[0163] Furthermore, the acquisition module 51 has the function of continuous data acquisition, and can realize the real-time, accurate entry, storage and reading of the acquired data. The acquisition module includes a data storage sub-module, a data information transmission sub-module and a server, where the data information transmission sub-module is used to digitally classify and process the acquired data, and transmit the data to the preprocessing module through the server.

[0164] Furthermore, before determining the total strain range of the equipment based on the operating state parameter data, a corresponding change threshold is also set for the operating state parameters through the preprocessing module 56; the data exceeding the change threshold is removed from the operating state parameter data.

[0165] The monitoring data is transmitted to the preprocessing module 56, and the preprocessing module 56 identifies, classifies and statistically analyzes the operating transient data, analyzes the actual operating conditions, screens the actual operating transient data, and compares and analyzes the screened data with the designed transient curve in the design analysis stage to obtain the real operating transient data, which is transmitted to the calculation data call ports of the first determination module 52, the second determination module 53, the third determination module 54 and the evaluation module 55 as the calculation input conditions.

[0166] The first determination module 52 is used to determine the total strain range of the equipment based on the operating state parameter data.

[0167] Furthermore, the operating state parameter data includes: temperature data, pressure data and flow data during the start-up and shutdown of the nuclear power plant and when the equipment is abnormal.

[0168] Furthermore, the first determination module 52 is used for:

[0169] Determine the stress components corresponding to the equipment based on the operating state parameter data, and extract the maximum strain range according to the stress components.

[0170] Determine the maximum equivalent strain range based on the maximum strain range.

[0171] Correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range.

[0172] Determine the creep strain increment.

[0173] Determine the total strain range of the equipment based on the corrected maximum equivalent strain range and the creep strain increment.

[0174] Furthermore, determining the maximum equivalent strain range based on the maximum strain range includes:

[0175] Based on the maximum strain range, determine the maximum equivalent strain range through Formula 1. Formula 1,

[0176] Δε mod =Ke KΔε max

[0177] wherein, Δε mod is the maximum equivalent strain range, when then, K e = 1, when then K is the equivalent stress concentration factor determined by tests or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration, is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, Δε max is the maximum strain range.

[0178] Furthermore, the maximum equivalent strain range is corrected to determine the corrected maximum equivalent strain range, including:

[0179] Determine the plastic Poisson's ratio correction factor.

[0180] Use the plastic Poisson's ratio correction factor to correct the maximum equivalent strain range to determine the corrected maximum equivalent strain range.

[0181] Furthermore, determine the creep strain increment, including:

[0182] Determine the effective creep stress through Formula Two. Formula Two: σ c = ZS y , wherein, σ c is the effective creep stress, S y is the yield strength, Z is determined by parameters X and Y, X = (P L + P b / K t ) max / S y , Y = (Q R ) max / S y , wherein, (P L + P b / K t ) max is the maximum value of the primary stress intensity adjusted by K t for the bending stress in the evaluated cycle, and (Q R ) max is the maximum range of the secondary stress intensity in the considered cycle.

[0183] Based on the effective creep stress, determine the creep strain increment according to Formula Three. Formula Three: Δε c = 1.25σ c , wherein, Δε c is the creep strain increment.

[0184] Further, based on the corrected maximum equivalent strain range and the creep strain increment, determine the total strain range of the device, including:

[0185] Based on the corrected maximum equivalent strain range and the creep strain increment, determine the total strain range of the device through Formula Four. Formula Four,

[0186] ε t =K v Δε mod +KΔε c

[0187] where ε t is the total strain range, K v =1 + f(K' v - 1), K' v is the plastic Poisson's ratio correction factor, f is determined based on the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by experiment or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the considered local area, Δε c is the creep strain increment.

[0188] The second determination module 53 is used to determine the allowable number of cycles and the initial creep stress of the device respectively according to the total strain range.

[0189] Further, the second determination module 53 is used to:

[0190] Obtain the isochronous stress-strain curve.

[0191] Correspond the total strain range to the isochronous stress-strain curve to determine the initial creep stress of the device.

[0192] The third determination module 54 is used to determine the fatigue damage and creep damage of the device by using the allowable number of cycles and the initial creep stress respectively.

[0193] Further, determining the creep damage of the device by using the initial creep stress includes:

[0194] Based on the initial creep stress, determine the calibrated relaxation stress of the device through Formula Five. Formula Five, S r =S j - 0.8G(S j -ˉS r ), where S r is the calibrated relaxation stress of the device under the multiaxial stress state at time t, S j is the initial creep stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, ˉS rDenotes the relaxation stress under the uniaxial model at time t.

[0195] Obtain the creep rupture life curve.

[0196] Determine the allowable creep rupture life of the equipment based on the calibrated relaxation stress and the creep rupture life curve of the equipment.

[0197] Determine the creep damage of the equipment based on the allowable creep rupture life.

[0198] An evaluation module 55 for evaluating the creep-fatigue state of the equipment based on fatigue damage and creep damage.

[0199] Furthermore, the evaluation module 55 is used for:

[0200] Judge whether the fatigue damage and the creep damage satisfy Formula Six, Formula Six,

[0201]

[0202] where D is the total creep-fatigue damage, (N d ) j is the design allowable number of cycles for the j-th type of cycle, (T d ) k is the allowable duration within the time interval k, (n) j is the number of cycles of the j-th type of cycle, p is the number of stress / temperature time histories, q is the high-temperature service time for calculating the creep damage at the point to be monitored. (Δt) k is the duration of the time interval k.

[0203] If the fatigue damage and the creep damage satisfy Formula Six, it is determined that there is no risk for the high-temperature nuclear power plant equipment.

[0204] If the fatigue damage and the creep damage do not satisfy Formula Six, it is determined that there is a risk for the high-temperature nuclear power plant equipment, and the fatigue damage and the creep damage are transmitted to the main control room of the high-temperature nuclear power plant for alarm.

[0205] It should be understood that the creep-fatigue state evaluation system for high-temperature nuclear power plant equipment of the present invention is described consistently with its corresponding creep-fatigue state evaluation method embodiment for high-temperature nuclear power plant equipment, so this embodiment will not be elaborated herein.

[0206] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0207] 1. The present invention determines the total strain range of equipment based on the operating state parameter data of high-temperature nuclear power plant equipment, determines the allowable number of cycles and the initial creep stress of the equipment respectively according to the total strain range, and then determines the fatigue damage and creep damage of the equipment respectively, so as to realize the evaluation of the creep-fatigue state of the equipment. The present invention can realize the full-cycle safety and life analysis management of the creep-fatigue comprehensive damage of key components in high-temperature power plants. When there are risks in the equipment, the evaluation results are timely fed back to the main control room to remind key attention and monitoring, and provide corresponding technical solutions for digital nuclear power and the health monitoring and life prediction system of in-service power plants.

[0208] 2. The present invention determines the maximum equivalent strain range based on the maximum strain range, corrects the maximum equivalent strain range considering factors such as multi-axial and plasticity, and then determines the total strain range. The total strain range determined in this way is more accurate, can more truly reflect the actual strain state of the material under complex loads, and further makes the creep-fatigue damage state calculated based on this parameter more accurate, improving the accuracy and reliability of damage evaluation.

[0209] 3. A creep-fatigue state evaluation method and system for high-temperature nuclear power plant equipment proposed by the present invention is more efficient and reliable for the monitoring and life evaluation of the flow rate, pressure, and temperature change data of high-temperature pressure components or pipeline systems under high-temperature creep conditions.

[0210] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0211] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0212] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definite ordered listing of executable instructions for implementing logical functions, and can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device.

[0213] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0214] It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

Claims

1. A creep fatigue state assessment method for high temperature nuclear power plant equipment, characterized in that: include: Collect operating status parameter data of high-temperature nuclear power plant equipment; Determining a total strain range of the device based on the operating status parameter data; Determining the allowable number of cycles and the creep initial stress of the equipment according to the total strain range; Determine fatigue damage and creep damage of the equipment by using the allowable number of cycles and the creep initial stress respectively; Based on the fatigue damage and the creep damage, the creep fatigue state of the equipment is evaluated.

2. The method according to claim 1, characterized in that The operating status parameter data include: temperature data, pressure data and flow data when the nuclear power plant is started and stopped and when equipment is abnormal.

3. The method according to claim 2, characterized in that Before determining the total strain range of the equipment based on the operating status parameter data, the method further includes: Setting a corresponding change threshold for the operating status parameter; Data exceeding the change threshold is eliminated from the operating status parameter data.

4. The method according to claim 1, characterized in that: Determining a total strain range of the device based on the operating status parameter data includes: Determine the stress component corresponding to the device based on the operating status parameter data, and extract the maximum strain range according to the stress component; Determining a maximum equivalent strain range according to the maximum strain range; Correcting the maximum equivalent strain range to determine a corrected maximum equivalent strain range; Determine creep strain increment; The total strain range of the device is determined based on the corrected maximum equivalent strain range and the creep strain increment.

5. The method according to claim 4, characterized in that Determining a maximum equivalent strain range according to the maximum strain range includes: Based on the maximum strain range, the maximum equivalent strain range is determined by formula 1, wherein: No mod =K e No max Among them, Δε mod is the maximum equivalent strain range, when When K e =1, when hour, K is the equivalent stress concentration factor determined by test or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration. is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, Δε max is the maximum strain range.

6. The method according to claim 4, characterized in that Correcting the maximum equivalent strain range to determine the corrected maximum equivalent strain range includes: Determine the plastic Poisson's ratio correction factor; The maximum equivalent strain range is corrected using the plastic Poisson's ratio correction coefficient to determine the corrected maximum equivalent strain range.

7. The method according to claim 4, characterized in that Determine the creep strain increment, including: The effective creep stress is determined by formula 2, where σ c =ZS y , where σ c is the effective creep stress, S y is the yield strength, Z is determined by parameters X and Y, X = (P L +P b / K t ) max / S y ,Y=(Q R ) max / S y , where (P L +P b / K t ) max The bending stress is K in the evaluated cycle. t The maximum value of the adjusted primary stress intensity, (Q R ) max is the maximum range of secondary stress intensity in the considered cycle; Based on the effective creep stress, the creep strain increment is determined according to Formula 3, where Δε c =1.25σ c , where Δε c is the creep strain increment.

8. The method according to any one of claims 4 to 7, characterized in that: Determining a total strain range of the device based on the corrected maximum equivalent strain range and the creep strain increment includes: Based on the corrected maximum equivalent strain range and the creep strain increment, the total strain range of the device is determined by formula 4, wherein: e t =K v No mod +KNo c Among them, ε t is the total strain range, K v =1+f(K′ v -1), K′ v is the plastic Poisson's ratio correction factor, f is determined based on the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by test or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration, Δε c is the creep strain increment.

9. The method according to claim 1, characterized in that: Determining the creep initial stress of the device according to the total strain range includes: Obtain isochronous stress-strain curves; The total strain range is mapped to the isochronous stress-strain curve to determine the creep initial stress of the device.

10. The method according to claim 1, characterized in that Determining the creep damage of the device by using the creep initial stress comprises: Based on the creep initial stress, the calibration relaxation stress of the device is determined by formula 5, wherein: Among them, S r is the calibrated relaxation stress of the device under multiaxial stress state at time t, S j is the creep initial stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, represents the relaxation stress under the uniaxial model at time t; Obtain creep rupture life curve; determining the allowable creep rupture life of the device according to the calibrated relaxation stress of the device and the creep rupture life curve; The creep damage of the equipment is determined according to the allowable creep rupture life.

11. The method according to claim 1, characterized in that: Based on the fatigue damage and the creep damage, the creep fatigue state of the equipment is evaluated, including: Determine whether the fatigue damage and the creep damage satisfy Formula 6, wherein: Where D is the total creep-fatigue damage, (N d )j is the design allowable number of cycles for the jth type of cycle, (T d )k is the allowable duration in time interval k, (n)j is the number of cycles of the jth type of cycle, p is the number of stress / temperature time histories, q is the high temperature service time for creep damage calculation of the monitored point; (Δt)k is the duration of time interval k; If the fatigue damage and the creep damage satisfy Formula 6, it is determined that there is no risk to the high-temperature nuclear power plant equipment; If the fatigue damage and the creep damage do not satisfy Formula 6, it is determined that the high-temperature nuclear power plant equipment is at risk, and the fatigue damage and the creep damage are transmitted to the main control room of the high-temperature nuclear power plant for alarm.

12. A creep fatigue state assessment system for high temperature nuclear power plant equipment, characterized in that: include: The acquisition module is used to collect the operating status parameter data of the high-temperature nuclear power plant equipment; A first determination module, configured to determine a total strain range of the device based on the operating status parameter data; A second determination module is used to determine the allowable number of cycles and the creep initial stress of the equipment according to the total strain range; A third determination module is used to determine fatigue damage and creep damage of the equipment using the allowable number of cycles and the creep initial stress respectively; An evaluation module is used to evaluate the creep fatigue state of the equipment based on the fatigue damage and the creep damage.

13. The system according to claim 12, characterized in that The operating status parameter data include: temperature data, pressure data and flow data when the nuclear power plant is started and stopped and when equipment is abnormal.

14. The system according to claim 13, characterized in that Before determining the total strain range of the equipment based on the operating status parameter data, the method further includes: Setting a corresponding change threshold for the operating status parameter; Data exceeding the change threshold is eliminated from the operating status parameter data.

15. The system according to claim 12, characterized in that The first determining module is used to: Determine the stress component corresponding to the device based on the operating status parameter data, and extract the maximum strain range according to the stress component; Determining a maximum equivalent strain range according to the maximum strain range; Correcting the maximum equivalent strain range to determine a corrected maximum equivalent strain range; Determine creep strain increment; The total strain range of the device is determined based on the corrected maximum equivalent strain range and the creep strain increment.

16. The system according to claim 15, characterized in that Determining a maximum equivalent strain range according to the maximum strain range includes: Based on the maximum strain range, the maximum equivalent strain range is determined by formula 1, wherein: No mod =K e No max Among them, Δε mod is the maximum equivalent strain range, when When K e =1, when hour, K is the equivalent stress concentration factor determined by test or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration. is the stress intensity based on the combined stress-strain curve, E is the elastic modulus, Δε max is the maximum strain range.

17. The system according to claim 15, characterized in that Correcting the maximum equivalent strain range to determine the corrected maximum equivalent strain range includes: Determine the plastic Poisson's ratio correction factor; The maximum equivalent strain range is corrected using the plastic Poisson's ratio correction coefficient to determine the corrected maximum equivalent strain range.

18. The system according to claim 15, characterized in that Determine the creep strain increment, including: The effective creep stress is determined by formula 2, where σ c =ZS y , where σ c is the effective creep stress, S y is the yield strength, Z is determined by parameters X and Y, X=(P L +P b / K t ) max / S y ,Y=(Q R ) max / S y , where (P L +P b / K t ) max The bending stress is K in the evaluated cycle. t The maximum value of the adjusted primary stress intensity is (Q R ) max is the maximum range of secondary stress intensity in the considered cycle; Based on the effective creep stress, the creep strain increment is determined according to Formula 3, where Δε c =1.25σ c , where Δε c is the creep strain increment.

19. The system according to any one of claims 15 to 18, characterized in that Determining a total strain range of the device based on the corrected maximum equivalent strain range and the creep strain increment includes: Based on the corrected maximum equivalent strain range and the creep strain increment, the total strain range of the device is determined by formula 4, wherein: e t =K v No mod +KNo c Among them, ε t is the total strain range, K v =1+f(K′ v -1), K′ v is the plastic Poisson's ratio correction factor, f is determined based on the multiaxial coefficient, Δε mod is the maximum equivalent strain range, K is the equivalent stress concentration factor determined by test or analysis, or the maximum value of the theoretical elastic stress concentration factor in any direction of the local area under consideration, Δε c is the creep strain increment.

20. The system according to claim 12, characterized in that The second determining module is used to: Obtain isochronous stress-strain curves; The total strain range is mapped to the isochronous stress-strain curve to determine the creep initial stress of the device.

21. The system according to claim 12, characterized in that Determining the creep damage of the device by using the creep initial stress comprises: Based on the creep initial stress, the calibration relaxation stress of the device is determined by formula 5, wherein: Among them, S r is the calibrated relaxation stress of the device under multiaxial stress state at time t, S j is the creep initial stress, G represents the minimum value of the multiaxial factor of the maximum and minimum stress states in the stress cycle, represents the relaxation stress under the uniaxial model at time t; Obtain creep rupture life curve; determining the allowable creep rupture life of the device according to the calibrated relaxation stress of the device and the creep rupture life curve; The creep damage of the equipment is determined according to the allowable creep rupture life.

22. The system according to claim 12, characterized in that The evaluation module is used to: Determine whether the fatigue damage and the creep damage satisfy Formula 6, wherein: Where D is the total creep-fatigue damage, (N d )j is the design allowable number of cycles for the jth type of cycle, (T d )k is the allowable duration in time interval k, (n)j is the number of cycles of the jth type of cycle, p is the number of stress / temperature time histories, q is the high temperature service time for creep damage calculation of the monitored point; (Δt)k is the duration of time interval k; If the fatigue damage and the creep damage satisfy Formula 6, it is determined that there is no risk to the high-temperature nuclear power plant equipment; If the fatigue damage and the creep damage do not satisfy Formula 6, it is determined that the high-temperature nuclear power plant equipment is at risk, and the fatigue damage and the creep damage are transmitted to the main control room of the high-temperature nuclear power plant for alarm.

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