A method and system for determining a creep stage of a nuclear power plant component based on acoustic emission

Abstract

The application discloses a kind of based on acoustic emission's nuclear power plant component creep stage determination method and system.The method comprises: first, from nuclear power plant component meets the preconditions of selected to-be-measured component;Second, the acoustic emission signal of to-be-measured component is collected;Then, the acoustic emission signal is preprocessed to obtain corresponding acoustic emission data;Next, the characteristic parameters in acoustic emission data are identified, and corresponding characteristic curve is generated according to characteristic parameter;Finally, the characteristic curve is compared with the pre-set material creep and acoustic emission relationship curve, and the creep stage of to-be-measured component is determined according to the comparison result.The determination method and system of the nuclear power plant component creep stage based on acoustic emission of the embodiment of the application carry out real-time, continuous, non-destructive on-line monitoring to the nuclear power plant component in high temperature and high pressure environment, to quickly and accurately determine the creep stage of nuclear power plant component, thereby preventing nuclear power plant component from creep damage rupture, guarantee the safety and reliability of nuclear power station operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear power, and in particular to a method and system for determining a creep stage of a nuclear power plant component based on acoustic emission. BACKGROUND

[0002] Nuclear power structure materials and their components serve in harsh environments such as high temperature, high pressure, and irradiation. The reliability and stability of their long-term service are important factors affecting the safety and reliability of nuclear power plants. Creep is one of the main forms of high-temperature structural damage. Under high-temperature conditions in nuclear power plants, creep deformation and damage are one of the most critical life-limiting factors for nuclear power components. Specifically, nuclear power plant components are in a high-temperature and high-pressure environment for a long time in the running state. Since the stress state of some nuclear power plant components is high but has not reached the yield limit, these nuclear power plant components in the high-temperature environment will produce creep deformation with the length of service, thereby affecting the safety of the nuclear power plant components. Therefore, it is necessary to monitor the creep of nuclear power plant components to effectively prevent creep damage and rupture of nuclear power plant components. However, creep damage monitoring of nuclear power plant components is a long-term and continuous safety service monitoring method. Due to the complexity of creep expansion measurement, the influence of the environment, poor precision, and the inability to monitor online, it cannot meet the requirements of online real-time creep monitoring of nuclear power plant components.

[0003] Patent CN110274836 discloses a creep strength test method based on acoustic emission activity analysis, which includes continuously applying a constant load to a solid material test piece and collecting acoustic emission waves, setting an acoustic emission threshold value, recording the acoustic emission event rate, judging the change rule of the acoustic emission event rate, and directly obtaining the creep strength of the solid material test piece. However, this method is applied in the field of petrology, which is different from the nuclear power plant components that are easily affected by high-temperature and high-pressure environments in the nuclear power field. This method collects acoustic emission waves by applying a constant load to test the creep strength of solid materials, which is not suitable for long-term and continuous creep damage monitoring of nuclear power plant components under high temperature and high pressure. Patent CN111238940 discloses a method and system for quantitatively identifying the accelerated creep stage of rock based on acoustic emission signals, which includes collecting acoustic emission information of the rock creep process using an acoustic emission device and performing real-time identification processing of the acoustic emission signals collected by the acoustic emission device based on a Matlab calculation platform. However, the above method also does not consider the influence of high-temperature and high-pressure environments, and is not suitable for long-term and continuous creep damage monitoring of nuclear power plant components under high temperature and high pressure. SUMMARY

[0004] The present application aims to at least partially solve one of the above technical problems.

[0005] To this end, a first object of the present application is to provide a method for determining the creep stage of a nuclear power plant component based on acoustic emission, which can realize real-time, continuous and non-destructive online monitoring of the nuclear power plant component in a high-temperature and high-pressure environment, and quickly and accurately determine the creep stage of the nuclear power plant component, thereby preventing the nuclear power plant component from being damaged and broken due to creep, and ensuring the safety and reliability of the nuclear power plant.

[0006] A second object of the present application is to provide a system for determining the creep stage of a nuclear power plant component based on acoustic emission.

[0007] To achieve the above object, the first aspect of the present application provides a method for determining the creep stage of a nuclear power plant component based on acoustic emission, comprising:

[0008] selecting a to-be-tested component from the nuclear power plant component that meets a preset condition, wherein the preset condition is that the temperature of the nuclear power plant component is greater than or equal to a preset temperature, the stress state is a dangerous state, and the time length of the dangerous state is greater than a preset time length;

[0009] acquiring an acoustic emission signal of the to-be-tested component;

[0010] preprocessing the acoustic emission signal to obtain corresponding acoustic emission data;

[0011] identifying a characteristic parameter in the acoustic emission data, and generating a corresponding characteristic curve according to the characteristic parameter;

[0012] comparing the characteristic curve with a preset material creep and acoustic emission relationship curve, and determining the creep stage of the to-be-tested component according to the comparison result.

[0013] Optionally, the stress state is calculated by a stress simulation model of the nuclear power plant component.

[0014] Optionally, before acquiring the acoustic emission signal of the to-be-tested component, the method further comprises:

[0015] setting a waveguide rod and a nuclear radiation resistant probe according to the structure of the to-be-tested component.

[0016] Optionally, acquiring the acoustic emission signal of the to-be-tested component comprises:

[0017] acquiring the acoustic emission signal within a preset filtering range and triggering an acoustic emission event.

[0018] Optionally, the characteristic parameter comprises a cumulative event number and a cumulative energy, the creep stage comprises an initial stage, a steady stage and an acceleration stage, the comparison of the characteristic curve with the preset material creep and acoustic emission relationship curve, and the determination of the creep stage of the to-be-tested component according to the comparison result, comprise:

[0019] determine the creep stage corresponding to the cumulative energy from the creep stage with the highest degree of coincidence with the characteristic curve of the cumulative energy among the three creep stages of the preset material creep and acoustic emission relationship curve;

[0020] determine the creep stage corresponding to the cumulative energy from the creep stage with the highest degree of coincidence with the characteristic curve of the cumulative energy among the three creep stages of the preset material creep and acoustic emission relationship curve;

[0021] determine the creep stage of the component to be tested according to the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy.

[0022] Optionally, the method further comprises:

[0023] determine the creep damage location according to the acoustic emission data;

[0024] safety assess the component to be tested according to the creep stage of the component to be tested and the creep damage location.

[0025] The technical solutions in the above embodiments of the present application achieve the following technical effects:

[0026] 1. The method can monitor the components of the nuclear power plant in real time, continuously and non-destructively, and can quickly and accurately determine the creep stage of the components of the nuclear power plant, thereby effectively preventing the components of the nuclear power plant from being damaged and cracked due to creep, and ensuring the safety and reliability of the operation of the nuclear power plant.

[0027] 2. The method takes into account the influence of the high temperature, high pressure and radiation environment in the nuclear power plant on the creep of the components of the nuclear power plant, as well as the stress changes of the components of the nuclear power plant due to the high temperature, high pressure and radiation environment, and the influence of the vibration noise source on the collection of acoustic emission signals, and accurately selects the component to be tested by preset conditions.

[0028] 3. When collecting the acoustic emission signals of the component to be tested, the acoustic emission signals of the acoustic emission events are quickly and accurately collected according to the determined threshold after the acoustic emission signals emitted by the component to be tested are filtered by bandwidth.

[0029] 4. The method determines the creep stage of the component to be tested in real time and dynamically by at least two characteristic curves, thereby improving the accuracy of creep stage determination in creep monitoring.

[0030] To achieve the above-mentioned purpose, the second aspect of the present application proposes a system for determining the creep stage of the components of the nuclear power plant based on acoustic emission, which comprises: a component to be tested, a waveguide rod, a nuclear radiation resistant probe and a data acquisition system;

[0031] The waveguide rod is fixedly connected to one end of the component to be tested;

[0032] The nuclear radiation resistant probe is arranged on the other end of the waveguide rod.

[0033] The data acquisition system is arranged outside the containment of the nuclear power plant, and the data acquisition system is connected with the nuclear radiation resistant probe;

[0034] The system for determining the creep stage of the nuclear power plant component based on acoustic emission is used to execute the method for determining the creep stage of the nuclear power plant component based on acoustic emission.

[0035] Optionally, the data acquisition system comprises an acoustic emission signal processing device and an analysis system;

[0036] The acoustic emission signal processing device is connected with the nuclear radiation resistant probe;

[0037] The analysis system is connected with the acoustic emission signal processing device.

[0038] Optionally, the waveguide rod is welded with the component to be measured.

[0039] Optionally, the system further comprises a main control room monitoring system connected with the analysis system.

[0040] The technical solutions in the above embodiments of the present application achieve the following technical effects:

[0041] 1. The system can control the nuclear radiation resistant probe to accurately acquire the acoustic emission signal of the component to be measured through the acoustic emission signal processing device.

[0042] 2. The system can guide and transmit the acoustic emission signal in the component to be measured to the nuclear radiation resistant probe through the waveguide rod, and the waveguide rod can effectively reduce the influence of high temperature on the nuclear radiation resistant probe.

[0043] 3. The system executes the method for determining the creep stage of the nuclear power plant component based on acoustic emission, can determine the creep stage of the component to be measured in real time, dynamically and comprehensively, and further improves the accuracy of the creep stage determination in the creep monitoring, thereby effectively preventing the creep damage and rupture of the nuclear power plant component, and ensuring the operation safety and reliability of the nuclear power plant.

[0044] 4. The system can receive the creep stage and the creep damage position of the component to be measured determined by the analysis system, so as to comprehensively analyze and evaluate the safety of the component to be measured.

[0045] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in conjunction with the description of the application. The embodiments of the present application, illustrated in the drawings and described below, serve to explain the present application and do not constitute an undue limitation on the present application. In the drawings:

[0047] Figure 1 A flow chart of a method for determining a creep stage of a nuclear power plant component based on acoustic emission is shown in one embodiment;

[0048] Figure 2 A schematic diagram of a predetermined material creep stage is shown in one embodiment;

[0049] Figure 3 A flow chart of a method for determining a creep stage of a nuclear power plant component based on acoustic emission is shown in another embodiment;

[0050] Figure 4 A schematic diagram of a waveguide rod and spatial distribution of anti-nuclear radiation probes is shown in one embodiment Figure 1 ;

[0051] Figure 5 A schematic diagram of a waveguide rod and spatial distribution of anti-nuclear radiation probes is shown in one embodiment Figure 2 ;

[0052] Figure 6 A schematic diagram of a waveguide rod and spatial distribution of anti-nuclear radiation probes is shown in one embodiment Figure 3 ;

[0053] Figure 7 A flow chart of a method for determining a creep stage of a nuclear power plant component based on acoustic emission is shown in yet another embodiment;

[0054] Figure 8 A schematic diagram of a structure of a system for determining a creep stage of a nuclear power plant component based on acoustic emission is shown in one embodiment;

[0055] Figure 9 A schematic diagram of a structure of a system for determining a creep stage of a nuclear power plant component based on acoustic emission is shown in another embodiment.

[0056] Reference signs: 100, component to be tested; 200, waveguide rod; 300, anti-nuclear radiation probe; 400, data acquisition system; 410, acoustic emission signal processing device; 420, analysis system; 500, nuclear power plant containment; 600, main control room monitoring system. DETAILED DESCRIPTION

[0057] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0058] The present application will be further described in detail below in combination with specific embodiments, which cannot be understood as limiting the scope of the present application.

[0059] A method and system for determining a creep stage of a nuclear power plant component based on acoustic emission are described below with reference to the accompanying drawings.

[0060] Figure 1 is a flowchart of a method for determining a creep stage of a nuclear power plant component based on acoustic emission according to an embodiment of the present application, and specifically includes the following steps:

[0061] S1, selecting a to-be-tested component from the nuclear power plant components that meets a preset condition.

[0062] The preset condition is that the temperature of the nuclear power plant component is greater than or equal to a preset temperature, the stress state is a dangerous state, and the duration of the dangerous state is greater than a preset time length.

[0063] In an embodiment of the present application, a temperature sensor is used to measure the temperature of the nuclear power plant component. When the temperature of the nuclear power plant component is greater than or equal to a preset temperature and continues to operate in a state of greater than or equal to the preset temperature, it indicates that the nuclear power plant component needs to consider the effect of creep. It should be noted that the preset temperature corresponding to different nuclear power plant components is determined according to the creep initiation temperature and the actual application environment. For example, the temperature of a ferrite component in a nuclear power plant exceeding 371℃ needs to consider the effect of creep, so 371℃ is taken as the preset temperature of the ferrite component; the temperature of an austenitic component in a nuclear power plant exceeding 427℃ considers the effect of creep, so 427℃ is taken as the preset temperature of the austenitic component; the temperature of a nickel-based alloy component in a nuclear power plant exceeding 427℃ considers the effect of creep, so 427℃ is taken as the preset temperature of the nickel-based alloy component.

[0064] The stress state is calculated by a stress simulation model of the nuclear power plant component. Specifically, a stress simulation calculation model is used to perform mechanical analysis and calculation on the nuclear power plant component under the corresponding actual operating condition to obtain the position of the nuclear power plant component in the stress concentration section, and the stress state of the nuclear power plant component in the stress concentration section is determined as a dangerous state. In a specific embodiment, based on a simulation analysis software, a mechanical analysis is performed on the simulation model under the actual operating condition. According to the calculation result, when the creep evaluation item reaches 80% or more of the corresponding limit value, it is determined that the corresponding position is in a dangerous state.

[0065] Further, the nuclear power plant component with a dangerous stress state is further subjected to mechanical analysis and calculation, and if the duration of the dangerous stress state of the nuclear power plant component is greater than a preset duration, the nuclear power plant component is determined as a to-be-tested component.

[0066] It should be noted that by determining the stress state of the nuclear power plant component, the to-be-tested component can be effectively located, so that subsequent acoustic emission data can be collected under constant load or approximately constant load conditions, ensuring the pertinence and reliability of the damage monitoring of the nuclear power plant component during the creep process.

[0067] Thus, the nuclear power plant component with a temperature greater than or equal to the preset temperature, a stress state in the dangerous state, and a time length of the dangerous state greater than the preset time length is determined as the to-be-tested component according to the above conditions.

[0068] The above process considers the influence of the high temperature, high pressure, and radiation environment in the nuclear power plant on the creep of the nuclear power plant component and the stress change of the nuclear power plant component due to the high temperature, high pressure, and radiation environment, and realizes accurate selection of the to-be-tested component and corresponding position determination based on preset conditions, which provides a guarantee for obtaining accurate acoustic emission signals when the creep of the nuclear power plant component is monitored subsequently.

[0069] S2, collecting an acoustic emission signal of the to-be-tested component.

[0070] Specifically, the acoustic emission signal triggering the acoustic emission event in the preset filtering range is collected.

[0071] In an embodiment of the present application, since the to-be-tested component selected in S1 will be damaged by creep under long-term stress state, stress wave signals, i.e., acoustic emission signals, emitted from the inside of the to-be-tested component due to the creep damage can be used to realize passive, dynamic, and real-time nondestructive detection, so as to achieve the purpose of long-term and continuous online monitoring of the nuclear power plant component.

[0072] Specifically, considering that the background noise intensity is different under different temperature and stress states when the nuclear power plant component is continuously monitored, and since the background noise intensity may exceed the acoustic emission signal intensity, background filtering is performed to eliminate noise interference, and an appropriate threshold is selected to collect the acoustic emission signal triggering the acoustic emission event.

[0073] It should be understood that the collection of the acoustic emission signal is performed in a fixed unit time length (such as day or hour) when the nuclear power plant component is continuously monitored.

[0074] On the one hand, the short-time signal emitted by the to-be-tested component is picked up in the actual running environment, and the frequency composition of the short-time signal is analyzed, and the inherent frequency of the structure of the to-be-tested component is obtained by simulating the to-be-tested component through finite element software, and then the filtering range is preset according to the frequency analysis result and the inherent frequency of the to-be-tested component, so that the bandwidth filtering can be quickly and accurately realized when the acoustic emission signal is collected based on the filtering range, and then the noise interference is effectively filtered out, and the quality and clarity of the acoustic emission signal are improved. On the other hand, the threshold triggering the acoustic emission event under different temperature and stress states is determined through the uniaxial tension creep test, so that the corresponding threshold can be determined according to the temperature and stress state of the to-be-tested component in the actual running process of the nuclear power plant.

[0075] Therefore, when collecting the acoustic emission signals of the to-be-tested component, the acoustic emission signals of the acoustic emission events are quickly and accurately collected according to the threshold value determined according to the uniaxial tension creep test after the acoustic emission signals emitted by the to-be-tested component are filtered in a bandwidth.

[0076] S3, pre-processing the acoustic emission signals to obtain corresponding acoustic emission data.

[0077] In an embodiment of the present application, the acoustic emission data corresponding to the acoustic emission signals collected in S2 are obtained by pre-processing the acoustic emission signals, to provide support for subsequent identification and analysis.

[0078] S4, identifying the characteristic parameters in the acoustic emission data, and generating corresponding characteristic curves according to the characteristic parameters.

[0079] Specifically, the characteristic parameters in the acoustic emission data pre-processed in S3 are identified, and corresponding characteristic curves are generated according to the characteristic parameters. For example, the number of events and the cumulative number of events, the energy and the cumulative energy, which have different activity performances in different creep stages, can generate corresponding distribution curves; the event rate and the energy rate, which reflect the current creep damage degree and damage rate, can generate corresponding trend curves.

[0080] Therefore, the qualitative analysis of the creep stage in the creep monitoring of the components of the nuclear power plant can be quickly and accurately performed according to the characteristic curves.

[0081] S5, comparing the characteristic curves with the preset material creep and acoustic emission relationship curves, and determining the creep stage of the to-be-tested component according to the comparison result.

[0082] The creep stage includes an initial stage, a steady stage and an acceleration stage.

[0083] It should be noted that the indoor creep and acoustic emission relationship test of the to-be-tested component under different working conditions is performed under the same or similar temperature and stress state as the actual creep monitoring, to obtain the preset material creep stage curve as shown in Figure 2 , wherein I represents the initial stage, II represents the steady stage, III represents the acceleration stage, t represents time, and ε represents strain.

[0084] In an embodiment of the present application, the characteristic parameters include the cumulative number of events and the cumulative energy. The stress wave signals, i.e. the acoustic emission signals, are emitted inside the to-be-tested component due to the creep damage. At the same time, the cumulative number of events and the cumulative energy are significantly increased due to the large amount of internal damage in the initial stage and the acceleration stage. Therefore, the preset material creep stage curve (as shown in Figure 2The characteristic curves of the cumulative event count generated by S4 and the curves shown in the figure are compared to determine the creep stage with the highest degree of agreement between the three creep stages of the preset material creep and acoustic emission relationship curve and the characteristic curve of the cumulative event count. This creep stage is then used as the creep stage corresponding to the cumulative event count. Among these, the creep stage with the highest degree of agreement between the three creep stages of the preset material creep and acoustic emission relationship curve and the characteristic curve of the cumulative event count shows the best trend of agreement.

[0085] In addition, a preset material creep stage curve (such as...) can be used. Figure 2 By comparing the characteristic curve of the cumulative energy generated by S4 with that of the three creep stages of the preset material creep and acoustic emission relationship curve, the creep stage with the highest degree of agreement with the characteristic curve of the cumulative energy is determined as the creep stage corresponding to the cumulative energy.

[0086] Then, the creep stage of the component under test can be determined by combining the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy. Specifically, if the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy are the same, the same creep stage is determined as the creep stage of the component under test; if the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy are different, the sampling unit length and the threshold for triggering acoustic emission events are adjusted according to the temperature and pressure deviation between the actual creep monitoring environment and the test, so as to re-acquire acoustic emission signals and re-determine the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy, until the creep stage corresponding to the cumulative number of events and the creep stage corresponding to the cumulative energy are the same.

[0087] In one specific embodiment, if the creep stage cannot be determined, the sampling time interval is first adjusted by ±10%, and the determination is repeated; if it still cannot be determined, the signal threshold is adjusted by ±10%, and creep determination is performed; if it still cannot be determined, the operator shall check and determine according to the actual situation.

[0088] Therefore, the creep stage of the component under test can be determined in real time and dynamically by using the cumulative event distribution curve and the cumulative energy distribution curve, which improves the accuracy of creep stage judgment in creep monitoring.

[0089] In another embodiment, such as Figure 3 As shown, before acquiring the acoustic emission signal of the component under test, the following steps are also included:

[0090] S6, set up waveguide rods and nuclear radiation resistant probes according to the structure of the component under test.

[0091] In one embodiment of the present invention, the waveguide rods 200 and probes are arranged according to the arrangement structure of the component under test 100, and a certain spatial distribution configuration is adopted to facilitate subsequent determination of the creep damage location. For example...Figures 4-6 As shown, for different arrangements or structures of the to-be-tested components, such as containers, straight pipes, elbow pipes, or to-be-tested components containing tees, supports, valves, etc., different waveguide rods 200 or numbers and arrangements of probes are used to improve the precision of the collected acoustic emission data and meet the positioning requirements of the subsequent creep damage areas.

[0092] In yet another embodiment, as shown, it further comprises: Figure 7

[0093] S7, determining the creep damage position according to the acoustic emission data.

[0094] In one embodiment of the present application, the active position of the creep damage is quickly and accurately determined according to the acoustic emission data of the to-be-tested component after the preprocessing of S3 and the position of the waveguide rod or probe.

[0095] S8, performing safety assessment on the to-be-tested component according to the creep stage and the creep damage position of the to-be-tested component.

[0096] In one embodiment of the present application, the safety assessment on the to-be-tested component is comprehensive and accurate according to the creep stage of the to-be-tested component determined in S5 and the creep damage position determined in S7, and the safety of the to-be-tested component is analyzed as a whole, so that the creep damage condition of the to-be-tested component can be determined in time, and the safety of the operation of the nuclear power plant component due to creep deformation of the to-be-tested component is avoided, thereby ensuring the stability and reliability of the operation of the nuclear power plant.

[0097] By applying the technical solutions in the above embodiments of the present application, the following technical effects are achieved:

[0098] 1. The method can perform real-time, continuous, and non-destructive online monitoring on the nuclear power plant components in a high-temperature and high-pressure environment, quickly and accurately determine the creep stage of the nuclear power plant components, effectively prevent the nuclear power plant components from being damaged and cracked due to creep, and ensure the safety and reliability of the operation of the nuclear power plant.

[0099] 2. The method considers the influence of the high-temperature, high-pressure, and radiation environment in the nuclear power plant on the creep of the nuclear power plant components, the stress changes of the nuclear power plant components due to the high-temperature, high-pressure, and radiation environment, and the influence of the vibration noise source on the collection of acoustic emission signals, and accurately selects the to-be-tested component through preset conditions.

[0100] 3. When collecting the acoustic emission signals of the to-be-tested component, the acoustic emission signals of the triggered acoustic emission events are quickly and accurately collected after the bandwidth filtering of the acoustic emission signals emitted by the to-be-tested component.

[0101] 4. The method determines the creep stage of the to-be-tested component in real time and dynamically through at least two characteristic curves, thereby improving the accuracy of the creep stage determination in the creep monitoring. ​

[0102] To achieve the above-mentioned embodiments, the application further provides a system for determining the creep stage of a nuclear power plant component based on acoustic emission.

[0103] Figure 8 is a structural schematic diagram of the system for determining the creep stage of a nuclear power plant component based on acoustic emission according to an embodiment of the application.

[0104] As shown in Figure 8 , the system for determining the creep stage of a nuclear power plant component based on acoustic emission comprises a component to be tested 100, a waveguide rod 200, a nuclear radiation resistant probe 300, and a data acquisition system 400.

[0105] The waveguide rod 200 is fixedly connected to one end of the component to be tested 100, and the nuclear radiation resistant probe 300 is arranged on the other end of the waveguide rod 200.

[0106] In a specific embodiment of the application, the waveguide rod 200 is welded to the component to be tested 100. Further, a coupling agent such as vaseline is applied at the welding position. In this way, the acoustic emission signals in the component to be tested 100 can be transmitted through the waveguide rod 200 in real time and stably. In addition, the component to be tested is a high-temperature component, and the waveguide rod can effectively reduce the influence of high temperature on the nuclear radiation resistant probe.

[0107] In this embodiment, the data acquisition system 400 is arranged outside the containment 500 of the nuclear power plant, and the data acquisition system is connected to the nuclear radiation resistant probe 300.

[0108] In a specific embodiment of the application, the data acquisition system comprises an acoustic emission signal processing device 410 and an analysis system 420. The acoustic emission signal processing device 410 is connected to the nuclear radiation resistant probe 300, and can control the nuclear radiation resistant probe 300 to collect acoustic emission signals in a preset filter range and trigger acoustic emission events, and pre-process the collected acoustic emission signals. In addition, the analysis system 420 is connected to the acoustic emission signal processing device 410, and is used to analyze the pre-processed acoustic emission data to determine the creep stage and the creep damage position of the component to be tested.

[0109] In this embodiment, the system for determining the creep stage of a nuclear power plant component based on acoustic emission is used to execute the method for determining the creep stage of a nuclear power plant component based on acoustic emission in the previous embodiment, and can determine the creep stage of the component to be tested in real time, dynamically, and comprehensively, further improving the accuracy of the creep stage determination in the creep monitoring, thereby effectively preventing the creep damage and destruction of the nuclear power plant component, and ensuring the operation safety and reliability of the nuclear power plant.

[0110] In another embodiment, as shown in Figure 9As shown, the system for determining the creep stage of a nuclear power plant component based on acoustic emission further comprises a main control room monitoring system 600.

[0111] In particular, the main control room monitoring system 600 is connected with the analysis system 420, for receiving the creep stage and the creep damage position of the component to be tested determined by the analysis system 420, so as to comprehensively analyze and evaluate the safety of the component to be tested. In one specific embodiment, the analysis system 420 is embedded in the main control room monitoring system 600.

[0112] By applying the technical solutions in the above embodiments of the present application, the following technical effects are achieved:

[0113] 1. The system can control the anti-nuclear radiation probe to accurately collect the acoustic emission signal of the component to be tested through the acoustic emission signal processing device.

[0114] 2. The system can guide and transmit the acoustic emission signal in the component to be tested to the anti-nuclear radiation probe through the waveguide rod, and the waveguide rod can effectively reduce the influence of high temperature on the anti-nuclear radiation probe.

[0115] 3. The system executes the method for determining the creep stage of a nuclear power plant component based on acoustic emission, can determine the creep stage of the component to be tested in real time, dynamically and comprehensively, and further improves the accuracy of the creep stage determination in the creep monitoring, thereby effectively preventing the creep damage and destruction of the nuclear power plant component, and ensuring the operation safety and reliability of the nuclear power plant.

[0116] 4. The system can receive the creep stage and the creep damage position of the component to be tested determined by the analysis system, so as to comprehensively analyze and evaluate the safety of the component to be tested.

[0117] It should be noted that, in this document, the terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of another identical element in the process, method, article or equipment including the element.

[0118] It should be noted that in the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. The illustrative representation of the above terms in the present specification does not necessarily refer to the same embodiment or example. Moreover, the specific feature, structure, material or characteristic described can be combined in any suitable manner in one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

Claims

1. A method for determining the creep stage of a component of a nuclear power plant based on acoustic emission, characterized in that, The method comprises the following steps: selecting a to-be-tested component from nuclear power plant components, wherein the to-be-tested component meets preset conditions, the preset conditions being that the temperature of the nuclear power plant component is greater than or equal to a preset temperature, the stress state is a dangerous state, and the time length of the dangerous state is greater than a preset time length; acquiring an acoustic emission signal of the to-be-tested component; preprocessing the acoustic emission signal to obtain corresponding acoustic emission data; identifying a characteristic parameter in the acoustic emission data, and generating a corresponding characteristic curve according to the characteristic parameter; comparing the characteristic curve with a preset material creep and acoustic emission relationship curve, and determining a creep stage of the to-be-tested component according to a comparison result; the characteristic parameter comprises a cumulative event number and a cumulative energy, the creep stage comprises an initial stage, a steady stage and an acceleration stage, the characteristic curve is compared with the preset material creep and acoustic emission relationship curve, and the creep stage of the to-be-tested component is determined according to the comparison result, which comprises the following steps: determining a creep stage with the highest fitting degree with the characteristic curve of the cumulative event number in three creep stages of the preset material creep and acoustic emission relationship curve as the creep stage corresponding to the cumulative event number; determining a creep stage with the highest fitting degree with the characteristic curve of the cumulative energy in three creep stages of the preset material creep and acoustic emission relationship curve as the creep stage corresponding to the cumulative energy; determining the creep stage of the to-be-tested component according to the creep stage corresponding to the cumulative event number and the creep stage corresponding to the cumulative energy.

2. The method of claim 1, wherein, The stress state is calculated by a nuclear power plant component stress simulation model.

3. The method of claim 1, wherein, Before acquiring the acoustic emission signal of the to-be-tested component, the method further comprises the following steps: setting a waveguide rod and a nuclear radiation resistant probe according to the structure of the to-be-tested component.

4. The method of claim 1, wherein, Acquiring the acoustic emission signal of the to-be-tested component comprises the following step: acquiring an acoustic emission signal within a preset filtering range and triggering an acoustic emission event.

5. The method of claim 1, wherein, The method further comprises the following steps: determining a creep damage position according to the acoustic emission data; safety rating the to-be-tested component according to the creep stage of the to-be-tested component and the creep damage position.

6. A system for determining a creep stage of a component of a nuclear power plant based on acoustic emission, characterized in that, The system comprises the following components: a to-be-tested component, a waveguide rod, a nuclear radiation resistant probe and a data acquisition system, one end of the waveguide rod is fixedly connected with the to-be-tested component; the nuclear radiation resistant probe is arranged on the other end of the waveguide rod; the data acquisition system is arranged outside a nuclear power plant containment, and the data acquisition system is connected with the nuclear radiation resistant probe; the system for determining a creep stage of a nuclear power plant component based on acoustic emission is used to perform the method for determining a creep stage of a nuclear power plant component based on acoustic emission according to any one of claims 1-5.

7. The system of claim 6, wherein, The data acquisition system comprises an acoustic emission signal processing device and an analysis system, the acoustic emission signal processing device is connected with the nuclear radiation resistant probe; the analysis system is connected with the acoustic emission signal processing device.

8. The system of claim 6, wherein, The waveguide rod is welded with the to-be-tested component.

9. The system of claim 7, wherein, The system further comprises the following component: a main control room monitoring system connected with the analysis system.

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