A method for fault diagnosis and evaluation of electric valve performance in nuclear power plants
By obtaining the parameters of key components of electric valves online and evaluating them using a health management platform, the problem of electric valve fault diagnosis in nuclear power plants relying on manual experience is solved, and rapid fault location and efficient management are achieved.
Patent Information
- Application Number
- CN202310058866.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-01-17
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2043-01-17
AI Technical Summary
In the existing technology, fault diagnosis of electric valves in nuclear power plants relies on manual experience, which makes it difficult to quickly and accurately identify the cause and location of the fault. In addition, the maintenance strategy consumes a lot of manpower and material resources, and there is a risk of excessive maintenance.
The performance status parameters of key components of the electric valve are obtained online through the distributed control system, and fault assessment is performed using the health management platform. Combined with the abnormal information, importance weights and preset standards of key components, the health status assessment and fault location of the electric valve are achieved.
It realizes the rapid collection and analysis of electric valve data in nuclear power plants, quickly locates faulty components, improves fault diagnosis efficiency, optimizes the electric valve management mode, and reduces human misjudgment and excessive maintenance.
Smart Images
Figure CN116047207B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fault diagnosis of electric valves in nuclear power plants, and in particular to a method for diagnosing and evaluating performance faults of electric valves in nuclear power plants. Background Art
[0002] As a critical piece of equipment in nuclear power plants, valve health is directly related to the reliability of the entire production system. Currently, the mainstream maintenance strategy for valves in nuclear power plants combines corrective repairs for valve failures with preventive maintenance through regular inspections and disassembly. While this approach keeps valves in good operating condition, it also consumes significant manpower and material resources, and carries the risk of over-maintenance and human error.
[0003] With the development of intelligent instruments and various fieldbus technologies, electric valve fault diagnosis technology has gradually been put into use. Through electric valve fault diagnosis technology, it is possible to obtain information such as current, voltage, thrust, and torque during the opening and closing process of electric valves. However, it still requires diagnostic personnel with extensive field experience to identify the cause of the fault and determine the location of the valve fault.
[0004] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above content has been disclosed before the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of this application. Summary of the Invention
[0005] In order to overcome the shortcomings of the existing technology, the present invention provides a method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants. The specific technical solution is as follows: A method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants comprises the following steps:
[0006] Based on the component composition of the electric valve in the nuclear power plant, its key components and corresponding parameters are determined. The key components include torque switch, travel switch, valve disc / valve seat, motor, potentiometer, worm gear, valve stem, packing and T-head. The performance status parameters of the key components are first obtained online using the distributed control system to check whether there are any alarm conditions. If an alarm condition occurs, the position information corresponding to the electric valve causing the alarm is obtained to perform offline diagnostic tests on the corresponding electric valve performance and further determine abnormal information of the electric valve. The abnormal information includes abnormal conditions corresponding to different key components.
[0007] The abnormal information associated with the electric valve is input into the electric head health management platform for health assessment; in the health assessment, the abnormal information of the electric valve is compared with the preset standard conditions to judge the degree of parameter degradation corresponding to the key component of the electric valve failure, and different or the same importance weights are assigned to different key components according to the consequences and handling methods of the failure of the key components; according to the degree of parameter degradation and the importance weights of the key components, different or the same scores are mapped to them. If the sum of the scores of the key components of the electric valve failure is lower than the first preset value or the scores of each are lower than the second preset value, it indicates that the electric valve is in a healthy state and does not affect normal use.
[0008] Furthermore, the failure modes of abnormal key components are divided into internal leakage, refusal to open / refusal to close, and external leakage. Each failure mode corresponds to one or more failure mechanisms and corresponding analysis methods to identify different failure modes of the key components under the same failure mode. Different failure modes of the same key component correspond to different or the same importance weights.
[0009] Furthermore, different parameter standard ranges are predefined according to different failure modes of the key components, and the parameter degradation degrees are divided into different levels. If the abnormal information of the key component exceeds the corresponding parameter standard range and reaches the warning value, the parameter degradation degree corresponding to the key component is a low level. If the abnormal information of the key component exceeds the corresponding warning value and reaches the alarm value, the parameter degradation degree corresponding to the key component is a high level. Under the same importance weight, the higher the parameter degradation degree level, the higher the corresponding score of the key component.
[0010] Furthermore, the score of each critical component is the sum of its scores under all failure modes.
[0011] Furthermore, if the score of the key component of the electric valve failure is greater than a third preset value, it indicates that the electric valve is in a dangerous state and cannot support the next operation cycle and needs to be repaired or replaced, wherein the third preset value is greater than twice the second preset value.
[0012] Furthermore, if an alarm occurs during the online monitoring of the electric valve, offline monitoring is required; the objects of the online monitoring data include the torque switch, travel switch, valve disc / valve seat, and the real-time signal emitted when the valve switch is actuated is obtained through the distributed control system; the electric valve performance fault diagnosis data acquisition equipment is used to perform performance diagnostic testing on the electric valve to complete offline monitoring, and the objects of the offline monitoring data include the motor, torque switch, travel switch, potentiometer, worm gear, valve stem, packing, valve disc / valve seat, and T-head.
[0013] Furthermore, for the monitoring of the torque switch, the distributed control system is used to monitor whether there is a torque alarm in the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, according to the electric valve performance diagnostic test, it is judged in turn whether the torque switch is triggered normally during the valve switching process and whether the valve closing torque is within the normal value range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0014] Furthermore, for the monitoring of the travel switch, the distributed control system is used to monitor whether there is a travel alarm on the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, according to the electric valve performance diagnostic test, it is judged in turn whether the travel switch is triggered normally during the valve switching process and whether the valve travel time is within the normal value range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0015] Furthermore, for the monitoring of the valve disc / valve seat, the distributed control system is used to monitor whether there is an upstream and downstream pressure difference alarm in the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, based on the electric valve performance diagnostic test, it is judged whether the valve switch thrust curve is in the normal variation range, whether the valve disc seating force value is in a reasonable range, and whether the valve disc pull-out force value is in a preset range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0016] Furthermore, for monitoring the potentiometer, according to the electric valve performance diagnostic test, observe whether there is any abnormality in the valve position display during the valve opening and closing process, and whether there is any sudden change in the potentiometer resistance. If it is judged that there is, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform;
[0017] For monitoring of the worm gear, based on the electric valve performance diagnostic test, a curve of the thrust change on the valve stem during the opening and closing of the electric valve is obtained, and the curve is observed to see whether there is a periodic fluctuation signal. If it is determined to be present, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform;
[0018] For valve stem monitoring, according to the electric valve performance diagnostic test, observe whether the valve stem is bent and whether there are scratches or wear on the valve stem surface. If it is judged to be present, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform;
[0019] For packing monitoring, the electric valve performance diagnostic test is used to determine whether the packing friction during the valve opening and closing process is within the preset normal range. If not, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform;
[0020] For T-head monitoring, based on the electric valve performance diagnostic test, the thrust curve of the valve stem during the electric valve opening and closing process is obtained. The T-slot platform portion of the thrust curve is observed to see if it is within the normal standard range. If not, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform.
[0021] For the monitoring of the motor, according to the electric valve performance diagnostic test, observe whether the three imbalance coefficients of the motor are within the preset safety range and whether the operating temperature is within the safe temperature range during the operation of the motor. If it is judged as not, it means there is an abnormality, and the abnormal information is recorded to the electric head health management platform.
[0022] Compared with the existing technology, the present invention has the following advantages: it realizes the rapid collection and analysis of the electric valve data of the nuclear power plant, quickly locates the valve fault component, solves the problem of unclear and non-standardized fault identification of the existing electric valve, improves the efficiency of valve fault diagnosis, and optimizes the electric valve management mode of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 1 is a schematic diagram of a process framework of a method for diagnosing and evaluating a performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0024] Figure 2 This is a schematic diagram of the torque switch evaluation process in the method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0025] Figure 3 This is a schematic diagram of a travel switch evaluation process in a method for diagnosing and evaluating a performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0026] Figure 4 This is a schematic diagram of the valve disc / valve seat evaluation process in the method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0027] Figure 5 This is a schematic diagram of a potentiometer evaluation process in a method for diagnosing and evaluating a performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0028] Figure 6 This is a schematic diagram of a worm gear evaluation process in a method for diagnosing and evaluating a performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0029] Figure 7 This is a schematic diagram of the valve stem evaluation process in the method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention;
[0030] Figure 8 This is a schematic diagram of the packing evaluation process in the method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants provided by an embodiment of the present invention;
[0031] Figure 9 It is a schematic diagram of the T-head evaluation process in the method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.
[0033] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.
[0034] In one embodiment of the present invention, a method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants is provided, comprising the following steps: Figure 1 Based on the component structure of electric valves in nuclear power plants, the key components and corresponding parameters are identified. A fault assessment model for electric valves is established based on the possible failure modes of each component, the impact of equipment failure on the equipment itself and the unit, the failure symptoms, indicator parameters, and parameter degradation levels. The key components include torque switches, travel switches, valve discs / seats, motors, potentiometers, worm gears, valve stems, packings, and T-heads.
[0035] First, the performance status parameters of key components are obtained online using the distributed control system to check whether there are any alarm conditions. If an alarm condition occurs, the location information of the electric valve corresponding to the alarm condition is obtained to perform offline diagnostic tests on the corresponding electric valve performance to further determine abnormal information of the electric valve, including abnormal conditions corresponding to different key components.
[0036] The abnormal information associated with the electric valve is input into the electric head health management platform for health assessment. During the health assessment, the abnormal information of the electric valve is compared with preset standard conditions to determine the degree of parameter degradation corresponding to the key component of the electric valve failure. Different key components are assigned different or the same importance weights based on the consequences of the failure of the key component and the treatment method. Different or the same scores are mapped based on the parameter degradation degree and importance weight of the key components. If the sum of the scores of the key components of the electric valve failure is lower than the first preset value or the scores of each component are lower than the second preset value, it indicates that the electric valve is in a healthy state and does not affect normal use. If the score of the key component of the electric valve failure is greater than a third preset value, it indicates that the electric valve is in a dangerous state and cannot support the next operating cycle and needs to be repaired or replaced, wherein the third preset value is greater than twice the second preset value.
[0037] The failure modes of abnormal key components are divided into internal leakage, refusal to open / refusal to close, and external leakage. See Table 1. Each failure mode corresponds to one or more failure mechanisms and corresponding analysis methods to identify different failure modes of the key components under the same failure mode. Different failure modes of the same key component correspond to different or the same importance weights.
[0038] Table 1 Method for determining failure modes of key components
[0039]
[0040]
[0041] Different parameter standard ranges are predefined based on the different failure modes of the key components. The parameter degradation degree is divided into different levels. If the abnormal information of the key component exceeds the corresponding parameter standard range and reaches the warning value, the corresponding parameter degradation degree of the key component is low. If the abnormal information of the key component exceeds the corresponding warning value and reaches the alarm value, the corresponding parameter degradation degree of the key component is high. Under the same importance weight, the higher the parameter degradation degree level, the higher the corresponding score of the key component. The score of each key component is the sum of the scores under all its failure modes.
[0042] Specifically, the parameter degradation degree is divided into 4 levels: HH, H, L, LL. The parameter standard range is the normal operation interval (c, d), where a < b < c < d < e < f. The warning values are b and e, and the alarm values are a and f. HH means the parameter is higher than the warning value and reaches the alarm value, that is, greater than f; H means the parameter is higher than the normal operation interval and reaches the warning value, that is, in the range (e, f); L means the parameter is lower than the normal operation interval and reaches the warning value, that is, in the range (a, b); LL means the parameter is lower than the warning value and reaches the alarm value, that is, less than a. According to the consequences and treatment methods after component failures, the component importance weights are divided into 4 levels: I, II, III, IV. The component abnormal scoring criteria are obtained based on the component parameter degradation degree levels and the component importance weight levels. See Table 2.
[0043] Table 2 Component Abnormal Scoring Criteria
[0044] Importance weight Ⅰ Ⅱ Ⅲ Ⅳ H / L 2 4 8 16 HH / LL 4 8 16 32
[0045] Score according to the component abnormal state information: When the sum of all score values of a key component is less than 16 and a single score value is less than 10, the health state of the key component is green, indicating that the equipment state is excellent and there are no defects affecting the equipment availability; when the sum of all score values of a component is greater than 16 and a single score value is in the range (10, 16), the health state of the component is white, indicating that the performance has changed, but it can run for a long time; when a component has a single score value in the range [16, 32), the health level of the component is yellow, indicating that the equipment is significantly degraded and is stable and acceptable within a short period of 30 days, but it cannot maintain long-term (one operation cycle) operation; when a key component has a single score value greater than or equal to 32, the health level of the component is red, indicating that the equipment is severely degraded and will fail within a short period of 30 days. <00001In one embodiment of the present invention, if an alarm occurs during the online monitoring of the electric valve, offline monitoring is required; the objects of the online monitoring data include the torque switch, the travel switch, and the valve disc / valve seat, and the real-time signal emitted when the valve is switched is obtained through the distributed control system. The valve switching action will trigger the torque switch and the travel switch in the actuator to determine whether an alarm exists and obtain the status information of each component; the electric valve performance fault diagnosis data acquisition equipment is used to perform performance diagnostic testing on the electric valve to complete offline monitoring. The objects of the offline monitoring data include the motor, torque switch, travel switch, potentiometer, worm gear, valve stem, packing, valve disc / valve seat, and T-head.
[0048] Use special electric valve performance fault diagnosis data acquisition equipment to perform performance diagnosis test on electric valve. The diagnostic test should be carried out according to the following steps: setting the diagnostic characteristic parameters of the electric valve driving force; selecting test sensors, including voltage measurement sensors, current measurement sensors, thrust and torque measurement sensors, valve stroke measurement sensors, etc.; confirming that the valve is in a testable state; installing test sensors; operating the valve switch to obtain the current, voltage, switch signal circuit action timing of the electric actuator, the thrust and torque received during valve action, etc.; pre-analysis of on-site data; after the test is completed, restore the site.
[0049] According to the classification results of the key components of the electric valve, the health status of each component is evaluated:
[0050] See also Figure 2 For the monitoring of the torque switch, the distributed control system is used to monitor whether there is a torque alarm on the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, according to the electric valve performance diagnostic test, it is judged in turn whether the torque switch is triggered normally during the valve switching process and whether the valve closing torque is within the normal value range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0051] See also Figure 3 For the monitoring of the travel switch, the distributed control system is used to monitor whether there is a travel alarm on the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, according to the electric valve performance diagnostic test, it is judged in turn whether the travel switch is triggered normally during the valve switching process and whether the valve travel time is within the normal value range. If it is judged as no, it means there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0052] See also Figure 4For the monitoring of the valve disc / valve seat, the distributed control system is used to monitor whether there is an upstream and downstream pressure difference alarm in the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, according to the electric valve performance diagnostic test, it is judged whether the valve switch thrust curve is within the normal variation range, whether the valve disc seating force value is within a reasonable range, and whether the valve disc pull-out force value is within the preset range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
[0053] See also Figure 5 , for the monitoring of the potentiometer, according to the electric valve performance diagnostic test, observe whether the valve position display is abnormal during the valve switching process, and whether there is a sudden change in the potentiometer resistance. If it is judged that there is, it means there is an abnormality, and the abnormal information is recorded to the electric head health management platform;
[0054] See also Figure 6 For monitoring of the worm gear, based on the electric valve performance diagnostic test, a curve of the thrust change on the valve stem during the opening and closing of the electric valve is obtained, and the curve is observed to see whether there is a periodic fluctuation signal. If it is determined to be present, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform;
[0055] See also Figure 7 For valve stem monitoring, according to the electric valve performance diagnostic test, observe whether the valve stem is bent and whether there are scratches or wear on the valve stem surface. If it is judged to be present, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform;
[0056] See also Figure 8 For packing monitoring, according to the electric valve performance diagnostic test, it is determined whether the packing friction during the valve opening and closing process is within the preset normal range. If it is not, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform;
[0057] See also Figure 9 For T-head monitoring, based on the electric valve performance diagnostic test, the thrust change curve of the valve stem during the electric valve opening and closing process is obtained, and the T-slot platform part of the thrust curve is observed to see if it is within the normal standard range. If not, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform;
[0058] For the monitoring of the motor, according to the electric valve performance diagnostic test, observe whether the three imbalance coefficients of the motor are within the preset safety range and whether the operating temperature is within the safe temperature range during the operation of the motor. If it is judged as not, it means there is an abnormality, and the abnormal information is recorded to the electric head health management platform.
[0059] The method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants provided in this embodiment decomposes the electric valve as a whole into its main components, establishes an electric valve health assessment model based on the parameter indicators, fault modes, fault impacts, and importance of each component, obtains parameter information of each valve component through online or offline monitoring methods, and compares it with standard data to obtain health assessment results of each component. In this way, data collection and analysis of electric valves in nuclear power plants are realized, and faulty components of valves are quickly located, which solves the problems of unclear and non-standardized fault identification of existing electric valves, improves the efficiency of valve fault diagnosis, and optimizes the management mode of electric valves in nuclear power plants.
[0060] The above description is only a preferred embodiment of the present invention and does not limit the scope of the patent. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, directly or indirectly applied in other related technical fields, is also included in the scope of patent protection of the present invention.
Claims
1. A method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants, characterized in that: The following steps are involved: Based on the component composition of the electric valve in the nuclear power plant, its key components and corresponding parameters are determined. The key components include torque switch, travel switch, valve disc / valve seat, motor, potentiometer, worm gear, valve stem, packing and T-head. The performance status parameters of the key components are first obtained online using the distributed control system to check whether there are any alarm conditions. If an alarm condition occurs, the position information corresponding to the electric valve causing the alarm is obtained to perform offline diagnostic tests on the corresponding electric valve performance and further determine abnormal information of the electric valve. The abnormal information includes abnormal conditions corresponding to different key components. The abnormal information associated with the electric valve is input into the electric head health management platform for health assessment; in the health assessment, the abnormal information of the electric valve is compared with the preset standard conditions to judge the degree of parameter degradation corresponding to the key component of the electric valve failure, and different or the same importance weights are assigned to different key components according to the consequences and handling methods of the failure of the key components; according to the degree of parameter degradation and the importance weights of the key components, different or the same scores are mapped to them. If the sum of the scores of the key components of the electric valve failure is lower than the first preset value or the scores of each are lower than the second preset value, it indicates that the electric valve is in a healthy state and does not affect normal use.
2. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 1, wherein: The failure modes of abnormal key components are divided into internal leakage, refusal to open / refusal to close, and external leakage. Each failure mode corresponds to one or more failure mechanisms and corresponding analysis methods to determine the different failure modes of the key components under the same failure mode. Different failure modes of the same key component correspond to different or the same importance weights.
3. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 2, wherein: Different parameter standard ranges are predefined according to different failure modes of the key components, and the parameter degradation degrees are divided into different levels. If the abnormal information of the key component exceeds the corresponding parameter standard range and reaches the warning value, the parameter degradation degree corresponding to the key component is a low level. If the abnormal information of the key component exceeds the corresponding warning value and reaches the alarm value, the parameter degradation degree corresponding to the key component is a high level. Under the same importance weight, the higher the parameter degradation degree level, the higher the corresponding score of the key component.
4. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 3, characterized in that: The score of each critical component is the sum of its scores under all failure modes.
5. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 1, wherein: If the score of the key component of the electric valve failure is greater than a third preset value, it indicates that the electric valve is in a dangerous state and cannot support the next operation cycle and needs to be repaired or replaced, wherein the third preset value is greater than twice the second preset value.
6. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 1, wherein: If an alarm occurs during the online monitoring of the electric valve, offline monitoring is required; the objects of the online monitoring data include the torque switch, travel switch, valve disc / valve seat, and the real-time signal emitted when the valve switches is actuated is obtained through the distributed control system; the electric valve performance fault diagnosis data acquisition equipment is used to perform performance diagnostic tests on the electric valve to complete offline monitoring. The objects of the offline monitoring data include the motor, torque switch, travel switch, potentiometer, worm gear, valve stem, packing, valve disc / valve seat, and T-head.
7. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 6, characterized in that: For the monitoring of the torque switch, the distributed control system is used to monitor whether the electric head of the electric valve has a torque alarm. If there is an alarm, the alarm information is recorded in the electric head health management platform; then according to the electric valve performance diagnostic test, it is judged in turn whether the torque switch is triggered normally during the valve switching process and whether the valve closing torque is within the normal value range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
8. The method for diagnosing and evaluating the performance faults of electric valves in nuclear power plants according to claim 6, characterized in that: For the monitoring of the travel switch, the distributed control system is used to monitor whether there is a travel alarm on the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then according to the electric valve performance diagnostic test, it is judged in turn whether the travel switch is triggered normally during the valve switching process and whether the valve travel time is within the normal value range. If it is judged as no, it means there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
9. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 6, wherein: For the monitoring of the valve disc / valve seat, the distributed control system is used to monitor whether there is an upstream and downstream pressure difference alarm in the electric head of the electric valve. If there is an alarm, the alarm information is recorded in the electric head health management platform; then, based on the electric valve performance diagnostic test, it is judged whether the valve switch thrust curve is in the normal variation range, whether the valve disc seating force value is in a reasonable range, and whether the valve disc pull-out force value is in a preset range. If it is judged as no, it indicates that there is an abnormality, and the abnormal information is recorded in the electric head health management platform.
10. The method for diagnosing and evaluating the performance fault of an electric valve in a nuclear power plant according to claim 6, wherein: For monitoring the potentiometer, according to the electric valve performance diagnostic test, observe whether there is any abnormality in the valve position display during the valve opening and closing process, and whether there is any sudden change in the potentiometer resistance. If it is judged that there is, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform; For monitoring of the worm gear, based on the electric valve performance diagnostic test, a curve of the thrust change on the valve stem during the opening and closing of the electric valve is obtained, and the curve is observed to see whether there is a periodic fluctuation signal. If it is determined to be present, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform; For valve stem monitoring, according to the electric valve performance diagnostic test, observe whether the valve stem is bent and whether there are scratches or wear on the valve stem surface. If it is judged to be present, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform; For packing monitoring, the electric valve performance diagnostic test is used to determine whether the packing friction during the valve opening and closing process is within the preset normal range. If not, it indicates an abnormality and the abnormal information is recorded to the electric head health management platform; For T-head monitoring, based on the electric valve performance diagnostic test, the thrust curve of the valve stem during the electric valve opening and closing process is obtained. The T-slot platform portion of the thrust curve is observed to see if it is within the normal standard range. If not, it indicates an abnormality, and the abnormal information is recorded to the electric head health management platform. For the monitoring of the motor, according to the electric valve performance diagnostic test, observe whether the three imbalance coefficients of the motor are within the preset safety range and whether the operating temperature is within the safe temperature range during the operation of the motor. If it is judged as not, it means there is an abnormality, and the abnormal information is recorded to the electric head health management platform.