Real-time prediction method, device, equipment and medium for safe service life of rotor

Abstract

The application discloses a real-time prediction method, device and equipment for safe service life of a rotor, and a medium, and relates to the field of rotor life prediction.The method comprises the following steps: simulating a first crack duration of the rotor at each temperature point based on a creep effect, wherein the temperature point and the first crack duration are in one-to-one correspondence; simulating a second crack duration of a target rotor at each temperature point based on a fatigue accumulation effect and the creep effect, wherein the temperature point and the second crack duration are also in one-to-one correspondence; constructing a difference curve according to the first crack duration and the second crack duration at each temperature point; determining an expected operation plan of a steam turbine, and determining the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.The application belongs to the field of rotor life prediction, and can improve the accuracy of rotor life prediction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rotor life prediction, and in particular to a real-time prediction method, device, equipment and medium for safe service life of a rotor. BACKGROUND

[0002] A steam turbine rotor is one of the core components of a steam turbine, responsible for converting the thermal energy of steam into mechanical energy. The steam turbine rotor is usually a rotating component made of high-strength alloy steel, designed to withstand the stress caused by high temperature, high pressure and high speed rotation.

[0003] The life prediction of a steam turbine rotor is a complex process involving multidisciplinary knowledge and technology. The purpose is to ensure the safe operation of the equipment and maximize the service life, while avoiding economic losses and safety hazards caused by unexpected failures. The current methods for life prediction of the rotor include damage analysis and multi-axial stress state analysis, etc. In order to improve the accuracy of life prediction, the present application provides a real-time prediction method for safe service life of a rotor. SUMMARY

[0004] The present application provides a real-time prediction method, device, equipment and medium for safe service life of a rotor, which solves the technical problem of insufficient accuracy of life prediction of the rotor in the prior art, and achieves the technical effect of improving the accuracy of life prediction of the rotor.

[0005] In a first aspect, the present application provides a real-time prediction method for safe service life of a rotor, comprising:

[0006] Based on the creep effect, simulate the first crack duration of the rotor at each temperature point, wherein the temperature point and the first crack duration are one-to-one corresponding;

[0007] Based on the fatigue accumulation effect and the creep effect, simulate the second crack duration of the target rotor at each temperature point, wherein the temperature point and the second crack duration are also one-to-one corresponding;

[0008] According to the first crack duration and the second crack duration at each temperature point, construct a difference curve;

[0009] Determine the expected operation plan of the steam turbine, and determine the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.

[0010] Further, based on the creep effect, simulate the first crack duration of the rotor at each temperature point, comprising:

[0011] Construct a three-dimensional finite element model of the rotor;

[0012] Based on the creep effect, for each temperature point, perform steps S111-S114, comprising:

[0013] Step S111, determine the creep stress distribution diagram of the three-dimensional finite element model at each time stage at the temperature point;

[0014] Step S112, extract the key nodes of the rotor in the three-dimensional finite element model, and determine the ultimate stress value of each key node;

[0015] Step S113, in the creep stress distribution diagram, determine the limit time stage when the simulated stress value of the key node is greater than the ultimate stress value of the key node for the first time, and the number of limit time stages corresponds to the number of key nodes one-to-one;

[0016] Step S114, take the minimum value in the limit time stage as the first cracking time of the rotor at the temperature point.

[0017] Further, according to the first cracking time and the second cracking time at each temperature point, a difference curve is constructed, including:

[0018] According to the first cracking time and the second cracking time at each temperature point, determine the cracking time difference at the temperature point;

[0019] Preprocess the cracking time difference, the preprocessing including: removing outliers in the cracking time difference, and filling in missing cracking time differences based on the difference method;

[0020] According to the preprocessed cracking time difference, construct a difference curve.

[0021] Further, according to the expected operation plan and the difference curve, determine the safe service life of the rotor of the steam turbine, including:

[0022] According to the expected operation plan, determine the expected operation temperature point of the rotor of the steam turbine;

[0023] According to the expected operation plan, divide the time ratio between the start-stop operation time length, the stable operation time length, and the temperature state start and load change time length of the rotor of the steam turbine;

[0024] According to the time ratio, the first cracking time, the second cracking time at the expected operation temperature point, and the difference curve, determine the safe service life of the rotor of the steam turbine.

[0025] Further, according to the time ratio, the first cracking time, the second cracking time at the expected operation temperature point, and the difference curve, determine the safe service life of the rotor of the steam turbine, including:

[0026] According to the time ratio and the first cracking time at the expected operation temperature point, determine the first safe service period of the rotor under the creep effect;

[0027] determine the second safe service period of the rotor under the fatigue cumulative effect and the creep effect according to the time ratio and the second fracture time under the expected operating temperature point;

[0028] determine the third safe service period of the rotor according to the time ratio and the value corresponding to the difference curve at the expected operating temperature point;

[0029] determine the safe service life of the rotor of the steam turbine according to the first safe service period, the second safe service period and the third safe service period.

[0030] Further, determine the safe service life of the rotor of the steam turbine according to the first safe service period, the second safe service period and the third safe service period, including:

[0031] take the minimum value of the first safe service period, the second safe service period and the third safe service period as the target safe service period;

[0032] determine the safe service life of the rotor of the steam turbine at the expected operating temperature point according to the target safe service period.

[0033] Further, simulate the second fracture time of the target rotor at each temperature point based on the fatigue cumulative effect and the creep effect, including:

[0034] based on the fatigue cumulative effect and the creep effect, execute steps S121-S123 for each temperature point, including:

[0035] Step S121, determine the fatigue creep stress distribution diagram of the three-dimensional finite element model at each time stage under the temperature point;

[0036] Step S122, in the fatigue creep stress distribution diagram, determine the limit time stage when the simulation stress value of the key node is greater than the limit stress value of the key node for the first time;

[0037] Step S123, take the minimum value in the limit time stage as the second fracture time of the rotor at the temperature point.

[0038] In a second aspect, the present application provides a real-time prediction device for the safe service life of a rotor, including:

[0039] a first time length module for simulating the first fracture time of the rotor at each temperature point based on the creep effect, wherein the temperature point and the first fracture time correspond one by one;

[0040] a second time length module for simulating the second fracture time of the target rotor at each temperature point based on the fatigue cumulative effect and the creep effect, wherein the temperature point and the second fracture time also correspond one by one;

[0041] a difference curve module, configured to construct a difference curve according to the first and second fission time lengths at each temperature point;

[0042] a life determination module, configured to determine an expected operation plan of the steam turbine, and determine the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.

[0043] In a third aspect, the present application provides an electronic device, comprising:

[0044] a processor;

[0045] a memory for storing processor-executable instructions;

[0046] The processor is configured to execute to implement the real-time prediction method for the safe service life of the rotor as provided in the first aspect.

[0047] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, when instructions in the non-transitory computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to implement the real-time prediction method for the safe service life of the rotor as provided in the first aspect.

[0048] The one or more technical solutions provided in the present application have at least the following technical effects or advantages:

[0049] The present application simulates the first fission time length considering only the creep effect and the second fission time length considering both fatigue and creep respectively, constructs a difference curve for error analysis and correction, makes the model closer to the actual operation condition, and improves the prediction accuracy.

[0050] The present application dynamically evaluates the influence of different stages on life loss in combination with the expected operation plan of the steam turbine (such as start-stop frequency, stable operation and load change ratio), and realizes real-time prediction of life based on the operation state. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0052] Figure 1 A flowchart of the real-time prediction method for the safe service life of the rotor provided by the present application;

[0053] Figure 2 A structural diagram of the real-time prediction device for the safe service life of the rotor provided by the present application. DETAILED DESCRIPTION

[0054] The embodiment of the present application provides a real-time prediction method for safe service life of a rotor, and solves the technical problem of insufficient accuracy of rotor life prediction in the prior art.

[0055] To solve the above technical problems, the technical solution of the present application is as follows:

[0056] The real-time prediction method for safe service life of a rotor comprises the following steps: simulating first cracking durations of the rotor at temperature points based on a creep effect, wherein the temperature points and the first cracking durations are in one-to-one correspondence; simulating second cracking durations of a target rotor at the temperature points based on a fatigue accumulation effect and the creep effect, wherein the temperature points and the second cracking durations are also in one-to-one correspondence; constructing a difference curve according to the first cracking durations and the second cracking durations at the temperature points; determining an expected operation plan of a steam turbine, and determining the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.

[0057] In order to better understand the above technical solution, the above technical solution will be described in detail in combination with the drawings of the specification and the specific embodiments.

[0058] First of all, the term "and / or" appearing in this paper is only to describe the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0059] It should be noted that the method of the present application is used in the field of rotors, but there are great differences in rotors in different application scenarios, for example:

[0060] The steam turbine rotor and the elevator hoisting machine rotor both belong to rotating machinery, but they are quite different in function, environment and design due to the huge difference in application scenarios.

[0061] The steam turbine rotor is used for high-temperature and high-pressure, high-speed and high-power energy conversion, and works in a harsh environment of more than 500°C and more than 24MPa, and needs to have excellent creep resistance and fatigue resistance. The material is mostly high-strength alloy steel, the manufacturing precision and detection standard are extremely high, the maintenance period is long and the cost is high.

[0062] While the working temperature of the elevator hoisting machine rotor is low, the rotation speed is low, the smooth start and stop, the rapid response and the quiet operation are emphasized, the cost control, the modular design and the convenience of daily maintenance are emphasized, and the rotor is mostly used in the working condition of frequent start and stop and load change.

[0063] Due to the difference of application scene, the rotor is different in design, use, detection and the like, and therefore the application scheme is limited to the rotor used in the steam turbine scene.

[0064] In the operation of frequent load adjustment of the unit, the core test encountered by the rotor is the fatigue accumulation induced by the low-frequency thermal stress fluctuation and the inevitable creep effect under high-temperature environment, both of which can significantly shorten the service life of the rotor. The service life of the rotor is affected by the double effects of fatigue and creep, the fatigue damage is mainly determined by the size of alternating thermal stress, temperature and stress duration, and each time the thermal stress is cycled, the rotor material experiences fatigue accumulation, and the fatigue damage is aggravated with the increase of temperature; on the other hand, the creep damage is also particularly significant under high temperature, which increases with the prolongation of stress duration, and is manifested as the slow deformation of the material under constant stress.

[0065] The application provides a real-time prediction method for the safe service life of a rotor, as shown in formula (I): Figure 1 The method comprises steps S11-S14.

[0066] Step S11, based on the creep effect, simulating the first crack duration of the rotor at each temperature point, wherein the temperature point is in one-to-one correspondence with the first crack duration.

[0067] Specifically, it comprises: constructing a three-dimensional finite element model of the rotor.

[0068] The three-dimensional geometric model of the rotor can be established by using a CAD model or an actual drawing; the grid is divided in the finite element software, the boundary conditions and loads (such as centrifugal force, thermal stress and the like) are set; the material properties need to include the creep model parameters (such as Norton creep constitutive equation).

[0069] Based on the creep effect (that is, the rotor does not rotate, and only the effect of high temperature on the rotor is considered), steps S111-S114 are performed for each temperature point, comprising:

[0070] Step S111, determining the creep stress distribution diagram of the three-dimensional finite element model at each time stage under the temperature point.

[0071] There are several temperature points, and the more the number of temperature points, the more accurate the prediction result. The application provides a temperature point setting: 500℃, 510℃, 520℃, 530℃, 540℃……, 700℃

[0072] Under the set temperature condition, transient creep analysis is carried out; the finite element calculation under the temperature condition is continuously calculated, and the creep stress distribution diagram inside the rotor is output, and a series of stress field data changing with time are obtained.

[0073] Step S112, extracting key nodes of the rotor in the three-dimensional finite element model, and determining the limit stress value of each key node.

[0074] The key node refers to a point in the rotor that is prone to cracking due to creep. For each key node, the limit stress value (usually the yield strength or fatigue limit of the material) at the current temperature is determined in combination with the material manual or experimental data. The limit stress value is the standard for judging whether a crack will occur.

[0075] The key node can be: a stress concentration area; a geometric mutation (such as a transition fillet, a hole, a keyway, etc.); a location with a significant temperature gradient; an area that bears alternating loads or strong constraints; a part that has historically experienced failure or failure; an interface or welding area with large changes in material properties.

[0076] Step S113, in the creep stress distribution diagram, determining the limit time stage when the simulated stress value of the key node is greater than the limit stress value of the key node for the first time, and the number of limit time stages corresponds to the number of key nodes.

[0077] It can be understood that the creep stress distribution diagram changes over time. When the stress value of a key node is greater than the limit stress value of the key node for the first time at a certain time point, the time point is recorded as the limit time stage of the key node.

[0078] In other words, one key node corresponds to one limit time stage.

[0079] Step S114, taking the minimum value in the limit time stage as the first cracking duration of the rotor at the temperature point.

[0080] Compare several limit time stages respectively, and take the minimum value as the first cracking duration of the rotor at the temperature point.

[0081] Step S12, based on the fatigue cumulative effect and the creep effect, simulating the second cracking duration of the target rotor at each temperature point, wherein the temperature points and the second cracking duration also correspond one by one.

[0082] Specifically, it includes:

[0083] Based on the fatigue cumulative effect and the creep effect (that is, the rotor is affected by the fatigue cumulative effect and the creep effect), for each temperature point, steps S121-S123 are performed, including:

[0084] Step S121, determining the fatigue creep stress distribution diagram of the three-dimensional finite element model at each time stage at the temperature point;

[0085] Step S122, in the fatigue creep stress distribution diagram, determine the limit time stage when the simulation stress value of the key node is greater than the limit stress value of the key node for the first time;

[0086] Step S123, take the minimum value in the limit time stage as the second crack time of the rotor at the temperature point.

[0087] It can be understood that, at the same temperature, the second crack time affected by the fatigue cumulative effect and the creep effect is less than the first crack time affected by the creep effect only.

[0088] Steps S121-S123 are similar to the implementation logic of steps S111-S114 described above, and therefore will not be described here.

[0089] Step S13, according to the first crack time and the second crack time at each temperature point, construct a difference curve.

[0090] Specifically, it includes:

[0091] According to the first crack time and the second crack time at each temperature point, determine the crack time difference at the temperature point.

[0092] Subtract the second crack time from the first crack time at the same temperature point, and the difference is greater than or equal to 0.

[0093] Preprocess the crack time difference, which includes: removing outliers in the crack time difference, and filling in missing crack time differences based on the difference method.

[0094] The method for removing the difference value that deviates from the normal range includes:

[0095] 3σ principle (applicable to normal distribution), IQR method (interquartile range method) or manual discrimination

[0096] The method for filling in missing values includes: linear interpolation, polynomial fitting interpolation, previous and next value filling, KNN interpolation.

[0097] According to the preprocessed crack time differences, construct a difference curve.

[0098] Connect the preprocessed crack time differences in order of temperature point size, and obtain the difference curve.

[0099] In the present application, the difference curve is regarded as the crack time curve obtained by the fatigue cumulative effect only.

[0100] Step S14, determine the expected operation plan of the steam turbine, and determine the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.

[0101] Specifically comprising:

[0102] According to the expected operation plan, an expected operation temperature point of the rotor of the steam turbine is determined.

[0103] The expected operation plan can be an operation plan of the steam turbine in the last few months, and the expected operation plan includes an expected operation temperature of the steam turbine (also including an expected operation temperature of the rotor), a start-stop number of the rotor, and a running time of the rotor in a stable stage, and a complete and repeated operation stage is divided into an operation cycle.

[0104] According to the expected operation plan, a time ratio between a start-stop running time, a stable running time, and a warm state starting and load changing time of the rotor of the steam turbine is determined.

[0105] The time ratio between the start-stop running time, the stable running time, and the warm state starting and load changing time of the rotor of the steam turbine in an operation cycle is determined.

[0106] When the steam turbine is in a long-term stable operation under its design working condition, especially under high temperature and high pressure conditions, the rotor bears relatively constant stress and temperature, and creep becomes a dominant factor; in the process of rapid starting or emergency shutdown, due to the rapid and drastic change of thermal stress, combined with the rapid increase or decrease of mechanical load, periodic stress fluctuation is generated inside the material, which is the cause of fatigue damage; in the process of warm state starting (i.e. starting from the hot standby state) or load adjustment, the rotor will experience both temperature change and alternating mechanical stress, and then is subjected to fatigue and creep effect; an operation cycle can include the above stages.

[0107] The corresponding time length can be determined in a cycle.

[0108] According to the time ratio, the first crack time, the second crack time, and the difference curve at the expected operation temperature point, the safe service life of the rotor of the steam turbine is determined.

[0109] Specifically comprising:

[0110] According to the time ratio and the first crack time at the expected operation temperature point, the first safe service cycle of the rotor under the creep effect is determined.

[0111] For example, the time ratio of a complete start-stop cycle at a certain temperature point is 20 (fatigue damage): 60 (creep): 10 (fatigue and creep), and the first crack time is 1000 minutes, then the first safe service cycle is 1000 / 60 = 16 (rounded down), that is, the number of complete cycles is 16, and the meaning of 60 is that the steam turbine is in stable operation for 60 minutes in a complete start-stop cycle in the expected operation plan.

[0112] According to the time ratio, the second safe service period of the rotor under the fatigue cumulative effect and the creep effect at the expected operating temperature point is determined. According to the above example, the second safe service period is 500 / 10=50 at the same temperature point when the second creep duration is 500 minutes.

[0113] According to the time ratio, the value corresponding to the difference curve at the expected operating temperature point, the third safe service period of the rotor is determined. According to the above example, the third safe service period is (1000-500) / 20=25 in the actual calculation process.

[0114] The purpose of determining the third safe service period is to quantify the independent influence of fatigue damage on the service life of the rotor, so as to realize the overall life assessment of the rotor under complex operating conditions. By constructing the difference curve, i.e. the first creep duration (only considering the creep effect) minus the second creep duration (considering the fatigue and creep effects), the equivalent life loss caused by fatigue alone is extracted, so that the third safe service period can specially evaluate the additional fatigue damage risk brought by frequent start-stop or load variation, and avoid the safety hidden danger caused by ignoring the fatigue damage.

[0115] According to the first safe service period, the second safe service period and the third safe service period, the safe service life of the rotor of the steam turbine is determined, including:

[0116] The minimum value among the first safe service period, the second safe service period and the third safe service period is taken as the target safe service period.

[0117] According to the target safe service period, the safe service life of the rotor of the steam turbine at the expected operating temperature point is determined.

[0118] The length of the safe service period is multiplied by the number of the safe service period, and then the safe service life of the rotor is obtained.

[0119] In summary, the present application provides a real-time prediction method for the safe service life of a rotor, comprising: simulating a first crack duration of the rotor at each temperature point based on a creep effect, wherein the temperature points correspond one-to-one to the first crack duration; simulating a second crack duration of the target rotor at each temperature point based on a fatigue accumulation effect and a creep effect, wherein the temperature points also correspond one-to-one to the second crack duration; constructing a difference curve according to the first crack duration and the second crack duration at each temperature point; determining an expected operation plan of the steam turbine, and determining the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve. The present application simulates the first crack duration considering only the creep effect and the second crack duration considering fatigue and creep at the same time, respectively, and constructs a difference curve for error analysis and correction, so that the model is closer to the actual operation condition, and the prediction accuracy is improved. Combined with the expected operation plan of the steam turbine (such as start-stop frequency, stable operation and load change ratio), the influence of different stages on life loss is dynamically evaluated, and real-time life prediction based on the operation state is realized. In addition, the present application adopts three-dimensional finite element modeling and key node analysis technology to accurately identify weak points in the structure; and through data preprocessing, the prediction stability is improved, which is suitable for various complex operating environments such as high temperature and high pressure, frequent start-stop, etc., and provides strong support for equipment condition-based maintenance, operation optimization and safety evaluation.

[0120] Based on the same inventive concept, the present application provides a real-time prediction device for the safe service life of a rotor as shown in Figure 2 The present application provides a real-time prediction device for the safe service life of a rotor as shown in

[0121] The first duration module 21 is configured to simulate a first crack duration of the rotor at each temperature point based on a creep effect, wherein the temperature points correspond one-to-one to the first crack duration.

[0122] The second duration module 22 is configured to simulate a second crack duration of the target rotor at each temperature point based on a fatigue accumulation effect and a creep effect, wherein the temperature points also correspond one-to-one to the second crack duration.

[0123] The difference curve module 23 is configured to construct a difference curve according to the first crack duration and the second crack duration at each temperature point.

[0124] The life determination module 24 is configured to determine an expected operation plan of the steam turbine, and determine the safe service life of the rotor of the steam turbine according to the expected operation plan and the difference curve.

[0125] Based on the same inventive concept, the present application further provides an electronic device, comprising:

[0126] A processor;

[0127] A memory for storing processor-executable instructions;

[0128] The processor is configured to implement the method for real-time prediction of safe service life of a rotor as provided in the foregoing.

[0129] Based on the same inventive concept, the application further provides a non-transitory computer-readable storage medium, when instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to implement the method for real-time prediction of safe service life of a rotor as provided in the foregoing.

[0130] Since the electronic device introduced in the embodiment is the electronic device used to implement the method for information processing in the embodiment of the application, the specific implementation of the electronic device and its various forms can be understood by those skilled in the art based on the method for information processing introduced in the embodiment of the application, so the implementation of the method in the embodiment of the application by the electronic device is not introduced in detail here. As long as the electronic device used to implement the method for information processing in the embodiment of the application is implemented by those skilled in the art, it belongs to the scope of the application.

[0131] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system, or a computer program product. Therefore, the application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media containing computer usable program code (including but not limited to disk storage, CD-ROM, optical storage, etc.).

[0132] The application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one flow or multiple flows and / or blocks. Figure 1 The device that implements the function specified in one block or multiple blocks.

[0133] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction devices that implement the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one flow or multiple flows and / or blocks. Figure 1the function specified in the one or more blocks.

[0134] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, thus the instructions executed on the computer or other programmable data processing devices provide a process for implementing the flowchart Figure 1 the flowchart or flowcharts and / or a block Figure 1 the steps of the function specified in the one or more blocks.

[0135] Although preferred embodiments of the application have been described, those skilled in the art will recognize that additional modifications and variations can be made thereto without departing from the spirit and scope of the application. It is therefore intended that the appended claims cover all such modifications and variations as fall within the scope of the application.

[0136] It is apparent that a person skilled in the art can make a variety of modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application fall within the scope of the claims and their equivalents, the application is also intended to include these modifications and variations.

Claims

1. A method for real-time prediction of safe service life of a rotor, characterized in that, The method comprises the following steps: simulate first cracking time of the rotor at each temperature point based on the creep effect, wherein the temperature point corresponds to the first cracking time; simulate second cracking time of the target rotor at each temperature point based on the fatigue accumulation effect and the creep effect, wherein the temperature point also corresponds to the second cracking time; construct a difference curve according to the first cracking time and the second cracking time at each temperature point; determine the safe service life of the rotor of the steam turbine according to the expected operation plan of the steam turbine and the difference curve, comprising: determining the expected operation temperature point of the rotor of the steam turbine according to the expected operation plan; dividing the time ratio between the start-stop operation time, the stable operation time and the temperature state starting and load changing time of the rotor of the steam turbine according to the expected operation plan; determining the safe service life of the rotor of the steam turbine according to the time ratio, the first cracking time, the second cracking time at the expected operation temperature point and the difference curve, wherein: determining the first safe service period of the rotor under the creep effect according to the time ratio and the first cracking time at the expected operation temperature point; determining the second safe service period of the rotor under the fatigue accumulation effect and the creep effect according to the time ratio, the second cracking time at the expected operation temperature point; determining the third safe service period of the rotor according to the value corresponding to the difference curve at the expected operation temperature point; determining the safe service life of the rotor of the steam turbine according to the first safe service period, the second safe service period and the third safe service period.

2. The method for real time prediction of safe life of rotor as claimed in claim 1 wherein, simulate first cracking time of the rotor at each temperature point based on the creep effect, comprising: construct a three-dimensional finite element model of the rotor; for each temperature point, perform steps S111-S114 based on the creep effect, comprising: step S111, determine the creep stress distribution diagram of the three-dimensional finite element model at each time stage at the temperature point; step S112, extract the key nodes of the rotor in the three-dimensional finite element model and determine the ultimate stress value of each key node; step S113, in the creep stress distribution diagram, determine the limit time stage when the simulation stress value of the key node is greater than the ultimate stress value of the key node for the first time, and the number of limit time stages corresponds to the number of key nodes; step S114, take the minimum value in the limit time stage as the first cracking time of the rotor at the temperature point.

3. The method for real time prediction of safe life of rotor as claimed in claim 1 wherein, construct a difference curve according to the first cracking time and the second cracking time at each temperature point, comprising: determine the cracking time difference at the temperature point according to the first cracking time and the second cracking time at each temperature point; preprocess the cracking time difference, which includes: eliminating outliers in the cracking time difference, and filling in missing cracking time differences based on the difference method; construct a difference curve according to the preprocessed cracking time difference.

4. The method for real time prediction of safe life of rotor as claimed in claim 1 wherein, determine the safe service life of the rotor of the steam turbine according to the first safe service period, the second safe service period and the third safe service period, comprising: taking the minimum value among the first safe service period, the second safe service period and the third safe service period as a target safe service period; determining a safe service life of a rotor of the steam turbine at an expected operating temperature point according to the target safe service period.

5. The method for real time prediction of safe life of a rotor as claimed in claim 2 wherein, simulating a second crack time of the target rotor at each temperature point based on fatigue accumulation effect and creep effect, including: for each temperature point, performing steps S121-S123 based on fatigue accumulation effect and creep effect, including: S121, determining a fatigue creep stress distribution diagram of a three-dimensional finite element model at each time stage at the temperature point; S122, determining a limit time stage at which a simulation stress value of a key node in the fatigue creep stress distribution diagram is greater than a limit stress value of the key node for the first time; S123, taking the minimum value in the limit time stage as the second crack time of the rotor at the temperature point.

6. A device for real time prediction of safe life of a rotor characterized in that, The method for real-time prediction of safe service life of a rotor according to any one of claims 1-5, comprising: a first time length module configured to simulate a first crack time of the rotor at each temperature point based on creep effect, wherein the temperature point and the first crack time correspond to each other one by one; a second time length module configured to simulate a second crack time of the target rotor at each temperature point based on fatigue accumulation effect and creep effect, wherein the temperature point and the second crack time also correspond to each other one by one; a difference curve module configured to construct a difference curve according to the first crack time and the second crack time at each temperature point; a life determination module configured to determine an expected operation plan of the steam turbine, and determine a safe service life of a rotor of the steam turbine according to the expected operation plan and the difference curve.

7. An electronic device, comprising: comprising: a processor; a memory for storing instructions executable by the processor; wherein the processor is configured to execute to implement the method for real-time prediction of safe service life of a rotor according to any one of claims 1-5.

8. A non-transitory computer-readable storage medium, comprising: When the instructions in the non-transitory computer readable storage medium are executed by the processor of the electronic device, the electronic device can perform the method for real-time prediction of safe service life of a rotor according to any one of claims 1-5.

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