A method and system for the operation and maintenance of a shielded pump in a nuclear reactor experimental device.

Abstract

This invention discloses a method and system for the operation and maintenance of a shielded pump in a nuclear reactor experimental setup. By monitoring the stress of devices related to the shielded pump within the experimental setup and utilizing a stress assessment model for the shielded pump, the invention enables a clear, comprehensive, and real-time diagnosis of the pump's operating status. This allows for more rational intervention in preventative partial and full disassembly inspections of the shielded pump, enhancing the targeted nature of maintenance interventions, saving manpower and time costs, and increasing the safety and economy of shielded pump operation and maintenance.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power technology, and specifically relates to a method and system for the operation and maintenance of a shielded pump in a nuclear reactor experimental device. Background Technology

[0002] Nuclear reactor experimental devices can be used to conduct experimental research on the thermal, hydraulic, and safety aspects of nuclear reactor systems and equipment. The shielded pump, serving as the circulating power source for these devices, differs from ordinary industrial shielded pumps. Nuclear reactor experimental pumps must operate under high temperatures, high pressures, multiple transient conditions, and intense thermal stress, posing significant safety and technical risks. Improper operation and maintenance can lead to excessive stress and torque on the pump nozzles and internal components. When primary and secondary stresses exceed the pump's allowable stress, it not only affects the pump's normal operation but also introduces safety risks.

[0003] Currently, the main methods for maintaining and operating shielded pumps in nuclear reactor experimental devices are as follows: 1. Disassemble and repair the shielded pump, replacing damaged components. This method can repair faulty components, but it lacks effective monitoring and assessment of stress, is a reactive measure, cannot be predicted in advance, poses safety risks, and can adversely affect the progress and data validity of nuclear reactor experimental research.

[0004] 2. By monitoring the vibration of the canned motor pump, it is possible to determine whether the pump is malfunctioning. This method can detect potential component damage to some extent through vibration monitoring. However, it cannot measure or represent the true level of stress, nor can it accurately determine the matching relationship between vibration and stress.

[0005] 3. Measuring the surface stress level of a very small number of individual parts of the canned motor pump using strain gauges. This method directly measures the surface stress value of a very small number of individual parts of the equipment, providing a direct feedback on the stress level of the measured surface of the canned motor pump. However, it has the following two shortcomings: high-temperature and high-pressure strain gauges are expensive, and they can only monitor the surface stress level of a very small number of individual parts of the canned motor pump, failing to reflect the stress level inside the canned motor pump and other unmeasured points, thus failing to provide an overall stress assessment of the canned motor pump; and for the cases where the surface stress exceeds the standard in a very small number of individual parts of the canned motor pump, the lack of systematic analysis makes it impossible to effectively handle the situation. Summary of the Invention

[0006] In view of the technical problems existing in the prior art, the purpose of this invention is to provide a method for the operation and maintenance of a shielded pump in a nuclear reactor experimental device.

[0007] Another objective of this invention is to provide an operation and maintenance system for a shielded pump of a nuclear reactor experimental apparatus used in the above-described control method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A method for maintaining and operating a shielded pump in a nuclear reactor experimental setup includes the following steps: S1 conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains stress-related values; S2 calculates the reliability coefficient based on the value obtained in step S1 and the stress evaluation model of the shielded pump; the stress evaluation model is: R = 1 - X1Y1 - ... - X n Y n ; In the formula, R is the reliability coefficient of the shielded pump of the nuclear reactor experimental device; Y1~Y n These are the ratios of the influencing factors corresponding to the stress-related values ​​described in step S1; X1~X n They are Y1~Y n The influence coefficient on the stress level of the shielded pump is independently set to 0~1; S3 compares the reliability coefficient obtained in step S2 with the safety threshold to determine and execute the operation of shutdown maintenance, non-shutdown intervention maintenance, or no intervention.

[0009] Further, the stress assessment model described in step S2 is R=1-X1Y1-…-X n Y n for: R=1-A1M1-A2M2-A3M3-B1P1-B2P2-B3P3-B4P4-B5P5-B6P6-B7P7-B8P8; In the formula, Y1~Y n Including M1~M3 and P1~P8; X1~X n Including A1~A3 and B1~B8; M1~M2 are the stress ratios of the outlet and inlet pipes of the shielded pump, respectively; M3 is the stress ratio of the experimental body of the nuclear reactor experimental device; P1~P2 are the expansion ratio and load ratio of the piping system of the nuclear reactor experimental device, respectively; P3~P8 are the tilt ratio, vibration ratio, vibration frequency ratio, bearing temperature ratio, bearing radial wear ratio, and axial displacement ratio of the shielded pump, respectively; A1~A3 and B1~B8 are the influence coefficients of M1~M3 and P1~P8 on the stress level of the shielded pump, respectively.

[0010] Further, the security threshold mentioned in step S3 includes R1 and R2; step S3 is as follows: If R < R1, then perform a shutdown maintenance. If R1≤R<R2, then perform maintenance without shutting down the machine. If R ≥ R2, no intervention is needed, and the experiment can proceed normally. Wherein, R1 is the reliability coefficient corresponding to stresses that seriously affect industrial safety and equipment safety; R2 is the reliability coefficient corresponding to stresses that potentially affect industrial safety and equipment safety.

[0011] Furthermore, when the sum of A1~A3 and B1~B8 is 1, the value of R1 is 0.5 and the value of R2 is 0.8.

[0012] Furthermore, the stress assessment model is as follows: R=1-0.1M1-0.1M2-0.1M3-0.1P1-0.05P2-0.1P3-0.1P4-0.1P5-0.05P6-0.1P7-0.1P8.

[0013] Further, the stress monitoring in step S1 includes directly measuring the stress of the relevant device and / or indirectly measuring the stress of the relevant device to obtain the stress-related value; The direct stress measurement includes measuring stress values ​​using high-temperature strain gauges; the indirect stress measurement includes measuring values ​​of other factors related to the stress of the shielded pump using sensors or monitoring instruments; the related devices include the experimental body, the shielded pump, and the piping system of the nuclear reactor experimental device.

[0014] Further, step S1, which involves measuring stress values ​​using high-temperature strain gauges, includes measuring the stress values ​​of the outlet pipe and inlet pipe of the shielded pump and the experimental body of the nuclear reactor experimental device using high-temperature strain gauges.

[0015] Furthermore, step S1, which involves measuring the values ​​of other factors related to the stress of the canned pump using sensors or monitoring instruments, includes: The expansion value of the piping system of the nuclear reactor experimental device was measured using a single-point displacement sensor; The load values ​​of the piping system of the nuclear reactor experimental device were measured using a tensile sensor; The tilt value of the shielded pump was measured using a multi-point displacement sensor; The vibration values ​​of the shielded pump were measured using a vibration velocity sensor; The vibration frequency of the shielded pump was measured using a vibration acceleration sensor; The bearing temperature of the canned pump is measured using a temperature sensor; The radial wear value of the bearings of the canned pump was measured using a bearing radial wear monitor; The axial displacement of the canned pump is measured using an axial displacement monitor.

[0016] Further, the stress ratio mentioned in step S2 is the ratio of the stress value at the measurement location of the shielded pump to the allowable stress value of the material at the measurement location in the stress-related values ​​measured in step S1.

[0017] Further, the expansion ratio mentioned in step S2 is the ratio of the stress value corresponding to the expansion value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location.

[0018] Further, the load ratio in step S2 is the ratio of the stress value corresponding to the load value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location.

[0019] Further, the tilt ratio in step S2 is the ratio of the tilt value in the stress-related values ​​measured in step S1 to the upper limit value of the corresponding installation specification of the shielded pump.

[0020] Further, the vibration ratio mentioned in step S2 is the ratio of the vibration value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the shielded pump.

[0021] Further, the vibration frequency ratio mentioned in step S2 is the ratio of the vibration frequency in the stress-related value measured in step S1 to the power grid supply frequency.

[0022] Further, the bearing temperature ratio in step S2 is the ratio of the bearing temperature in the stress-related value measured in step S1 to the upper limit of the corresponding design shutdown value of the canned pump.

[0023] Further, the bearing radial wear ratio in step S2 is the ratio of the bearing radial wear value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the canned pump.

[0024] Further, the axial displacement ratio in step S2 is the ratio of the axial displacement value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the shielded pump.

[0025] Furthermore, the shutdown maintenance described in step S3 includes: Replace the bearings of the shielded pump in the nuclear reactor experimental setup; And / or, check other components of the shielded pump of the nuclear reactor experimental apparatus for damage, and if so, repair or replace them; And / or, disassemble the inlet and outlet flanges of the shielded pump of the nuclear reactor experimental device, the heater flange of the nuclear reactor experimental device, and the flange of the experimental body, and reconnect the inlet and outlet flanges of the shielded pump, the heater flange and the experimental body flange in sequence. And / or, slide the base of the shielded pump of the nuclear reactor experimental device to eliminate the stress effects caused by the deformation of the piping system online; And / or, lubricate the support contact surfaces of the nuclear reactor experimental apparatus; And / or, adjust the load-bearing capacity of the shielded pump of the nuclear reactor experimental device to the design value range, and adjust the piping load of the nuclear reactor experimental device to the design value range.

[0026] Furthermore, the non-stop intervention maintenance described in step S3 includes: Control the heating power of the nuclear reactor experimental apparatus; And / or, increase the cooling water flow rate of the shielded pump of the nuclear reactor experimental apparatus; And / or, control the operating frequency of the shielded pump of the nuclear reactor experimental apparatus; And / or, check the bearing condition of the shielded pump of the nuclear reactor experimental apparatus.

[0027] An operation and maintenance system for a shielded pump of a nuclear reactor experimental device, applying the aforementioned shielded pump operation and maintenance method, includes: The monitoring module monitors the devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains the stress-related values ​​of the shielded pump in the nuclear reactor experimental device. The processing module processes the data collected by the monitoring module and calculates the reliability coefficient based on the stress assessment model of the shielded pump. The feedback module outputs suggestions on whether to perform maintenance without stopping the machine or to conduct normal experiments based on the reliability coefficient obtained from the processing module.

[0028] The implementation of this invention has the following beneficial effects: This invention monitors the stress of devices related to the shielded pump in a nuclear reactor experimental setup and evaluates the stress level of the shielded pump using a stress assessment model. This allows for a clear, comprehensive, and real-time diagnosis of the shielded pump's operating status, enabling more rational intervention in preventative partial and full disassembly inspections. This enhances the targeted nature of shielded pump maintenance interventions, saves manpower and time costs, and increases the safety and economy of shielded pump operation and maintenance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the stress monitoring of the shielded pump in the nuclear reactor experimental device of the present invention.

[0030] Figure 2 This is a schematic diagram of the stress assessment process for the shielded pump of the nuclear reactor test device of the present invention.

[0031] Among them, M1~M3 and P1~P8 correspond to the positions of the measuring devices in M1~M3 and P1~P8, respectively; 1-Shielded pump; 2-Outlet pipe of shielded pump; 3-First heater; 4-First regulating valve; 5-Experimental body; 6-Second regulating valve; 7-Second regulating valve; 8-Inlet pipe of shielded pump. Detailed Implementation

[0032] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the present invention and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0033] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are used only for the convenience of describing the present invention and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0034] In the following embodiments, the nuclear reactor experimental apparatus includes a shielded pump, an experimental body, a first regulating valve, a second regulating valve, a first heater, a second heater, and related piping systems.

[0035] This embodiment provides a method for the operation and maintenance of a shielded pump in a nuclear reactor experimental device, including the following steps: S1 conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains stress-related values; S2 calculates the reliability coefficient based on the values ​​obtained in step S1 and the stress assessment model of the shielded pump; the stress assessment model is: R = 1 - X1Y1 - ... - X n Y n ; In the formula, R is the reliability coefficient of the shielded pump of the nuclear reactor experimental device; Y1~Y n These represent the ratios of influencing factors corresponding to the stress-related values ​​in step S1, respectively; X1~X n They are Y1~Y n The influence coefficient on the stress level of the canned motor pump is independently set to 0~1; S3 compares the reliability coefficient obtained in step S2 with the safety threshold to determine and execute the operation of shutdown maintenance, non-shutdown intervention maintenance, or no intervention.

[0036] like Figure 1 As shown in the figure, this embodiment provides a method for the operation and maintenance of a shielded pump in a nuclear reactor experimental device, including the following steps: S1 Data Acquisition: Stress monitoring is conducted on devices related to the stress of the shielded pump in the nuclear reactor experimental setup to obtain stress-related values.

[0037] Specifically, stress monitoring includes directly measuring the stress of relevant devices and / or indirectly measuring the stress of relevant devices to obtain stress-related values. Direct stress measurement includes measuring stress values ​​using high-temperature strain gauges; indirect stress measurement includes measuring values ​​of other factors related to the stress of the shielded pump using sensors or monitoring instruments; relevant devices include the experimental body, the shielded pump, and the piping system of the nuclear reactor experimental apparatus.

[0038] The use of high-temperature strain gauges to measure stress values ​​includes: measuring the stress values ​​of the outlet and inlet pipes of a shielded pump, as well as the experimental body of a nuclear reactor experimental device.

[0039] The following parameters are measured using sensors or monitoring instruments: expansion of the piping system of the nuclear reactor experimental setup using a single-point displacement sensor; load on the piping system of the nuclear reactor experimental setup using a tensile sensor; tilt of the shielded pump using a multi-point displacement sensor; vibration of the shielded pump using a vibration velocity sensor; vibration frequency of the shielded pump using a vibration acceleration sensor; bearing temperature of the shielded pump using a temperature sensor; radial wear of the bearings of the shielded pump using a bearing radial wear monitor; and axial displacement of the shielded pump using an axial displacement monitor.

[0040] S2 Calculation of Reliability Coefficient: The reliability coefficient is calculated based on the stress assessment model of the canned pump; the stress assessment model is R = 1 - X1Y1 - ... - X n Y n for: R=1-A1M1-A2M2-A3M3-B1P1-B2P2-B3P3-B4P4-B5P5-B6P6-B7P7-B8P8; In the formula, Y1~Y n Including M1~M3 and P1~P8; X1~X n Including A1~A3 and B1~B8; R is the reliability coefficient of the shielded pump of the nuclear reactor experimental device; M1~M2 are the stress ratios of the outlet and inlet pipes of the shielded pump, respectively; M3 is the stress ratio of the experimental body of the nuclear reactor experimental device; P1~P2 are the expansion ratio and load ratio of the piping system of the nuclear reactor experimental device, respectively; P3~P8 are the tilt ratio, vibration ratio, vibration frequency ratio, bearing temperature ratio, bearing radial wear ratio, and axial displacement ratio of the shielded pump, respectively; A1~A3 and B1~B8 are the influence coefficients of M1~M3 and P1~P8 on the stress level of the shielded pump, respectively. The measurement locations of M1~M3 and P1~P8 are as follows: Figure 1 As shown.

[0041] In some embodiments, the stress assessment model is: R=1-0.1M1-0.1M2-0.1M3-0.1P1-0.05P2-0.1P3-0.1P4-0.1P5-0.05P6-0.1P7-0.1P8; Specifically, the stress ratio is the ratio of the stress value at the measurement location of the canned motor pump to the allowable stress value of the material at the measurement location among the stress-related values ​​measured in step S1. The expansion ratio is the ratio of the stress value corresponding to the expansion value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location. The load ratio is the ratio of the stress value corresponding to the load value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location. The tilt ratio is the ratio of the tilt value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding installation specification for the canned motor pump. The vibration ratio is the ratio of the vibration value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value for the canned motor pump. The vibration frequency ratio is the ratio of the vibration frequency in the stress-related values ​​measured in step S1 to the power grid frequency (50Hz). The bearing temperature ratio is the ratio of the bearing temperature in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value for the canned motor pump. The bearing radial wear ratio is the ratio of the bearing radial wear value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the canned motor pump. The axial displacement ratio is the ratio of the axial displacement value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the canned motor pump.

[0042] Furthermore, the allowable stress value of the material is obtained based on the material grade or the manufacturer's usage information.

[0043] Furthermore, the expansion value and stress value are converted using the following formula: σ1 = E (-α ΔT) = -E α ΔT; where σ1 is thermal stress, E is elastic modulus, α is coefficient of thermal expansion, and ΔT is temperature change.

[0044] Furthermore, the load values ​​and stress values ​​are converted using the following formula: σ2=F / A; where σ2 is the compressive stress, F is the compressive load, and A is the bearing area.

[0045] Furthermore, the upper limit of the installation specification is the upper limit of the inclination range specified by the manufacturer when the canned pump leaves the factory.

[0046] Furthermore, the design shutdown value refers to the upper limit value corresponding to the safe operation of the canned pump under specified operating conditions. The specific value can be obtained from international standards, national standards, industry specifications or equipment manufacturer's instructions.

[0047] Furthermore, the bearing temperature is measured by a temperature sensor installed at the front flange of the canned pump motor, and it is consistent with the cooling water temperature.

[0048] S3 performs intervention operations based on the reliability factor: assesses the stress level of the canned pump based on the reliability factor. If R < R1, then there is already stress that seriously affects industrial safety and equipment safety, and the machine needs to be shut down for maintenance; If R1≤R<R2, there is stress that may affect industrial safety and equipment safety, and maintenance intervention without shutting down the machine is required. If R ≥ R2, no intervention is needed, and the experiment can proceed normally.

[0049] In some embodiments, the sum of A1~A3 and B1~B8 is 1, R1 is 0.5, and R2 is 0.8.

[0050] Specifically, the shutdown maintenance includes: replacing the bearings of the shielded pump of the nuclear reactor experimental device; checking other components of the shielded pump of the nuclear reactor experimental device for damage, and repairing or replacing them if necessary; disassembling the inlet and outlet flanges of the shielded pump of the nuclear reactor experimental device, as well as the flanges of the heater and the experimental body of the nuclear reactor experimental device, and reconnecting them in sequence; sliding the base of the shielded pump of the nuclear reactor experimental device to eliminate the stress caused by the deformation of the piping system online; lubricating the contact surfaces of the support of the nuclear reactor experimental device; adjusting the load-bearing capacity of the shielded pump of the nuclear reactor experimental device to the design range, and adjusting the piping load of the nuclear reactor experimental device to the design range.

[0051] Specifically, non-stop intervention maintenance includes: controlling the heating power of the nuclear reactor experimental device; increasing the cooling water flow rate of the shielded pump of the nuclear reactor experimental device; controlling the operating frequency of the shielded pump of the nuclear reactor experimental device; and checking the bearing condition of the shielded pump of the nuclear reactor experimental device.

[0052] In some embodiments, such as Figure 2 As shown, a maintenance system for a shielded pump in a nuclear reactor experimental setup is provided. The system utilizes the aforementioned shielded pump maintenance method and includes: The monitoring module monitors the devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains the stress-related values ​​of the shielded pump in the nuclear reactor experimental device. The processing module processes the data collected by the monitoring module and calculates the reliability coefficient based on the stress assessment model of the canned pump. The feedback module outputs suggestions on whether to perform maintenance without stopping the machine or to conduct normal experiments based on the reliability coefficient obtained from the processing module.

[0053] Specifically, before the monitoring module outputs the collected data to the processing module for processing, it also removes interference signals and invalid data, and transmits the data to the processing module to prevent signal distortion, while automatically storing the stress monitoring values.

[0054] Example 1 S1. Monitoring Module: Conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device to obtain stress-related values.

[0055] S2. Processing module: Calculates the reliability coefficient based on the stress assessment model of the canned pump.

[0056] The collected data was processed to obtain: The stress value of the outlet pipe of the canned motor pump is 60% of the allowable stress of the material, and M1 is 0.6; The stress value of the inlet pipe of the canned motor pump is 50% of the allowable stress of the material, and M2 is 0.5; The stress value of the experimental body of the nuclear reactor experimental device is 20% of the allowable stress of the material, and M3 is 0.2; The stress value corresponding to the expansion value of the shielded pump piping system of the nuclear reactor experimental device is 50% of the allowable stress of the material, and P1 is 0.5; The stress value corresponding to the load value of the shielded pump piping system of the nuclear reactor experimental device is 60% of the allowable stress of the material, and P2 is 0.6; The tilt value of the shielded pump of the nuclear reactor experimental device is 80% of the installation specification, and P3 is 0.8. The vibration value of the shielded pump of the nuclear reactor experimental device is 60% of the design shutdown value, and P4 is 0.6; The vibration spectrum of the shielded pump of the nuclear reactor experimental device differs from the power grid frequency (50Hz) by 30%, with P5 being 0.7. The temperature of the shielded pump bearing in the nuclear reactor experimental device is 40% of the design shutdown value, and P6 is 0.4. The radial wear value of the shielded pump bearing of the nuclear reactor experimental device is 75% of the design shutdown value, and P7 is 0.75; The axial displacement of the shielded pump of the nuclear reactor experimental device is 70% of the design shutdown value, and P8 is 0.7.

[0057] Substitute the above data into the stress assessment model for the canned pump: R = 1 - 0.1M1 - 0.1M2 - 0.1M3 - 0.1P1 - 0.05P2 - 0.1P3 - 0.1P4 - 0.1P5 - 0.05P6 - 0.1P7 - 0.1P8, resulting in R = 0.415.

[0058] S3. Feedback Module: Based on R=0.415 and R<0.5, provide downtime maintenance suggestions.

[0059] Perform the following actions based on the maintenance recommendations: Replace the shielded pump thrust bearing, radial bearing, and throttling bearing of the nuclear reactor experimental device.

[0060] Inspect other components of the shielded pump in the nuclear reactor experimental setup for damage. Damage was found to the shielding sleeve and impeller wear ring; repair the shielding sleeve and replace the impeller wear ring.

[0061] The inlet and outlet flanges of the shielded pump, the heater flange, and the flange of the experimental body of the nuclear reactor experimental device were disassembled, and the stress on the shielded pump and pipelines was completely released. The shielded pump inlet and outlet flanges were reinstalled first, followed by the heater flange, and finally the experimental body flange.

[0062] Along the direction of the shielded pump outlet of the nuclear reactor experimental device, slide the shielded pump base 2.1cm to eliminate the stress effect caused by the 2.1cm deformation of the piping system online.

[0063] The contact surfaces of each support structure of the nuclear reactor experimental device were re-lubricated by injecting a special lubricant.

[0064] Based on the initial design values, the load-bearing capacity of the shielded pump of the nuclear reactor experimental device was reset to within the design value range, and the load of the piping system of the nuclear reactor experimental device was adjusted to within the design value range.

[0065] Example 2 S1. Monitoring Module: Conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device to obtain stress-related values.

[0066] S2. Processing module: Calculates the reliability coefficient based on the stress assessment model of the canned pump.

[0067] The collected data were processed to obtain the following values: M1 = 0.4, M2 = 0.3, M3 = 0.15, P1 = 0.3, P2 = 0.3, P3 = 0.4, P4 = 0.4, P5 = 0.4, P6 = 0.3, P7 = 0.5, and P8 = 0.3.

[0068] Substituting into the stress evaluation model of the canned motor pump, we get R=0.655.

[0069] S3. Feedback Module: Based on R=0.655, 0.5≤R<0.8, provide suggestions for non-stop intervention and maintenance.

[0070] Perform the following actions based on the maintenance recommendations: By adjusting the power of the heater in the nuclear reactor experimental device, the temperature of the nuclear reactor experimental device can be controlled to prevent it from rising further.

[0071] The flow rate of the shielded pump cooling water was increased by adjusting the opening of the shielded pump cooling water valve of the nuclear reactor experimental device.

[0072] By adjusting the frequency converter of the shielded pump in the nuclear reactor experimental device, the operating frequency of the shielded pump was prevented from increasing.

[0073] Preventive partial disassembly and inspection of the shielded pump inverter bearings of the nuclear reactor experimental device revealed no obvious abnormalities.

[0074] Example 3 S1. Monitoring Module: Conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device to obtain stress-related values.

[0075] S2. Processing module: Calculates the reliability coefficient based on the stress assessment model of the canned pump.

[0076] The collected data were processed to obtain the following values: M1 = 0.2, M2 = 0.1, M3 = 0.1, P1 = 0.2, P2 = 0.2, P3 = 0.2, P4 = 0.2, P5 = 0.1, P6 = 0.2, P7 = 0.2, and P8 = 0.1.

[0077] Substituting into the stress evaluation model of the canned pump, we get R=0.84.

[0078] S3. Feedback Module: Based on R=0.84 and R≥0.8, provide normal experimental suggestions.

[0079] In summary, the stress state of the shielded pump is comprehensively monitored in this invention, and the operating status of the shielded pump can be clearly, comprehensively, and in real time diagnosed. Based on the suggestions generated by the shielded pump control system of the nuclear reactor experimental device, the experimental control team can more reasonably intervene in the preventive partial disassembly inspection and comprehensive disassembly inspection of the shielded pump, which enhances the pertinence of maintenance intervention, saves manpower and time costs, and increases the safety and economy of shielded pump control.

[0080] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for operating and maintaining a shielded pump in a nuclear reactor experimental setup, characterized in that, Includes the following steps: S1 conducts stress monitoring on devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains stress-related values; S2 calculates the reliability coefficient based on the value obtained in step S1 and the stress evaluation model of the shielded pump; the stress evaluation model is: R = 1 - X1Y1 - ... - X n Y n ; In the formula, R is the reliability coefficient of the shielded pump of the nuclear reactor experimental device; Y1~Y n These are the ratios of the influencing factors corresponding to the stress-related values ​​described in step S1; X1~X n They are Y1~Y n The influence coefficient on the stress level of the shielded pump is independently set to 0~1; S3 compares the reliability coefficient obtained in step S2 with the safety threshold to determine and execute the operation of shutdown maintenance, non-shutdown intervention maintenance, or no intervention.

2. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 1, characterized in that: The stress assessment model described in step S2 is R = 1 - X1Y1 - ... - X n Y n for: R=1-A1M1-A2M2-A3M3-B1P1-B2P2-B3P3-B4P4-B5P5-B6P6-B7P7-B8P8; In the formula, Y1~Y n Including M1~M3 and P1~P8; X1~X n Including A1~A3 and B1~B8; M1~M2 are the stress ratios of the outlet and inlet pipes of the shielded pump, respectively; M3 is the stress ratio of the experimental body of the nuclear reactor experimental device; P1~P2 are the expansion ratio and load ratio of the piping system of the nuclear reactor experimental device, respectively; P3~P8 are the tilt ratio, vibration ratio, vibration frequency ratio, bearing temperature ratio, bearing radial wear ratio, and axial displacement ratio of the shielded pump, respectively; A1~A3 and B1~B8 are the influence coefficients of M1~M3 and P1~P8 on the stress level of the shielded pump, respectively. And / or, the security threshold in step S3 includes R1 and R2; step S3 is: If R < R1, then perform a shutdown maintenance. If R1≤R<R2, then perform maintenance without shutting down the machine. If R ≥ R2, no intervention is needed, and the experiment can proceed normally. Wherein, R1 is the reliability coefficient corresponding to stresses that seriously affect industrial safety and equipment safety; R2 is the reliability coefficient corresponding to stresses that potentially affect industrial safety and equipment safety.

3. The operation and maintenance method of the shielded pump of the nuclear reactor experimental device according to claim 2, characterized in that: When the sum of A1~A3 and B1~B8 is 1, the value of R1 is 0.5 and the value of R2 is 0.

8.

4. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 2 or 3, characterized in that, The stress assessment model is as follows: R=1-0.1M1-0.1M2-0.1M3-0.1P1-0.05P2-0.1P3-0.1P4-0.1P5-0.05P6-0.1P7-0.1P8.

5. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 1, characterized in that: The stress monitoring in step S1 includes directly measuring the stress of the relevant device and / or indirectly measuring the stress of the relevant device to obtain the stress-related value; Direct stress measurement includes measuring stress values ​​using high-temperature strain gauges; indirect stress measurement includes measuring values ​​of other factors related to the stress of the shielded pump using sensors or monitoring instruments; related devices include the experimental body, the shielded pump, and the piping system of the nuclear reactor experimental apparatus.

6. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 5, characterized in that: Step S1, which involves measuring stress values ​​using high-temperature strain gauges, includes measuring the stress values ​​of the outlet pipe and inlet pipe of the shielded pump and the experimental body of the nuclear reactor experimental device using high-temperature strain gauges. And / or, step S1, which involves measuring values ​​of other factors related to the stress of the canned pump using sensors or monitoring instruments, includes: The expansion value of the piping system of the nuclear reactor experimental device was measured using a single-point displacement sensor; The load values ​​of the piping system of the nuclear reactor experimental device were measured using a tensile sensor; The tilt value of the shielded pump was measured using a multi-point displacement sensor; The vibration values ​​of the shielded pump were measured using a vibration velocity sensor; The vibration frequency of the shielded pump was measured using a vibration acceleration sensor; The bearing temperature of the canned pump is measured using a temperature sensor; The radial wear value of the bearings of the canned pump was measured using a bearing radial wear monitor; The axial displacement of the canned pump is measured using an axial displacement monitor.

7. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 2, characterized in that: The stress ratio mentioned in step S2 is the ratio of the stress value at the measurement location of the shielded pump to the allowable stress value of the material at the measurement location in the stress-related values ​​measured in step S1. And / or, the expansion ratio in step S2 is the ratio of the stress value corresponding to the expansion value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location. And / or, the load ratio in step S2 is the ratio of the stress value corresponding to the load value in the stress-related values ​​measured in step S1 to the allowable stress value of the material at the measurement location. And / or, the tilt ratio in step S2 is the ratio of the tilt value in the stress-related values ​​measured in step S1 to the upper limit value of the corresponding installation specification of the shielded pump. And / or, the vibration ratio in step S2 is the ratio of the vibration value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the shielded pump. And / or, the vibration frequency ratio in step S2 is the ratio of the vibration frequency in the stress-related value measured in step S1 to the power grid frequency. And / or, the bearing temperature ratio in step S2 is the ratio of the bearing temperature in the stress-related value measured in step S1 to the upper limit of the corresponding design shutdown value of the canned pump. And / or, the bearing radial wear ratio in step S2 is the ratio of the bearing radial wear value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the canned pump. And / or, the axial displacement ratio in step S2 is the ratio of the axial displacement value in the stress-related values ​​measured in step S1 to the upper limit of the corresponding design shutdown value of the canned pump.

8. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 1, characterized in that, The shutdown maintenance described in step S3 includes: Replace the bearings of the shielded pump in the nuclear reactor experimental setup; And / or, check other components of the shielded pump of the nuclear reactor experimental apparatus for damage, and if so, repair or replace them; And / or, disassemble the inlet and outlet flanges of the shielded pump of the nuclear reactor experimental device, the heater flange of the nuclear reactor experimental device, and the flange of the experimental body, and reconnect the inlet and outlet flanges of the shielded pump, the heater flange and the experimental body flange in sequence. And / or, slide the base of the shielded pump of the nuclear reactor experimental device to eliminate the stress effects caused by the deformation of the piping system online; And / or, lubricate the support contact surfaces of the nuclear reactor experimental apparatus; And / or, adjust the load-bearing capacity of the shielded pump of the nuclear reactor experimental device to the design value range, and adjust the piping load of the nuclear reactor experimental device to the design value range.

9. The method for maintaining and operating the shielded pump of the nuclear reactor experimental apparatus according to claim 1, characterized in that, Step S3, the non-stop intervention maintenance, includes: Control the heating power of the nuclear reactor experimental apparatus; And / or, increase the cooling water flow rate of the shielded pump of the nuclear reactor experimental apparatus; And / or, control the operating frequency of the shielded pump of the nuclear reactor experimental apparatus; And / or, check the bearing condition of the shielded pump of the nuclear reactor experimental apparatus.

10. A maintenance system for a shielded pump of a nuclear reactor experimental device, using the maintenance method for the shielded pump according to any one of claims 1-9, comprising: The monitoring module monitors the devices related to the stress of the shielded pump in the nuclear reactor experimental device and obtains the stress-related values ​​of the shielded pump in the nuclear reactor experimental device. The processing module processes the data collected by the monitoring module and calculates the reliability coefficient based on the stress assessment model of the shielded pump. The feedback module outputs suggestions on whether to perform maintenance without stopping the machine or to conduct normal experiments based on the reliability coefficient obtained from the processing module.

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