Method and device for measuring rod falling time and impact force of control rod drive wire

Abstract

The invention relates to the technical field of nuclear safety, and provides a method and device for measuring rod falling time and impact force of a control rod drive wire, and the device comprises a drive wire, a test container, a displacement sensor probe, a displacement sensor receiver, a stress measurement unit, a vibration measurement unit and a processing unit. Displacement data L, vibration data A, stress data sigma and collection time T corresponding to the data in the falling process of the driving line are collected in real time, a displacement time sequence relation graph, a vibration time sequence relation graph and a stress time sequence relation graph are generated respectively, a rod falling starting point and a rod falling ending point are judged through coupling analysis, and rod falling impact force and rod falling time are determined; and the accuracy and the reliability of an experimental result are improved.

Description

Technical Field

[0001] The present invention relates to the field of nuclear safety technology, and in particular to a method and device for measuring the rod drop time and impact force of a control rod drive line. Background Art

[0002] The control rod drive line is an important executive unit of the reactor control and nuclear safety protection system. Its main function is to drive the control rod assembly to move up and down in the core to adjust the reactivity. After the emergency shutdown signal is triggered, the control rod assembly should be able to fall quickly under the action of gravity and acceleration springs to achieve safe shutdown. Therefore, the rationality of the drive line design directly affects the inherent safety and operational stability of the nuclear reactor.

[0003] In the event of an accident or emergency, if the rod drop process of the drive line is not smooth or the rod drop time exceeds the specified time, it may not be possible to quickly shut down the reactor, or even cause the core reactivity to be out of control, bringing serious safety risks. To ensure that the control rod drive line can drop rods normally in actual operation, after completing the preliminary design, it is necessary to test the drive line under open conditions, measure its rod drop time and impact force in air and water, and verify the rationality of the design, thereby consolidating the structural design of the control rod drive line. Summary of the invention

[0004] The object of the present invention is to provide a method and device for measuring the rod drop time and impact force of a control rod drive line, so as to solve the above technical problems and improve the accuracy and reliability of the experimental results.

[0005] The embodiment of the present invention is achieved through the following technical solution: A method and device for measuring the rod drop time and impact force of a control rod drive line, comprising the following steps:

[0006] S1. Drop the driving wire into the bottom of the test container and keep it still, and calibrate the reference position and the reference position stress value σ0;

[0007] S2, lift the driving line to the designed height and calibrate the initial rod position L0;

[0008] S3, releasing the driving line, and collecting in real time the displacement data L of the free-falling rod of the driving line, the vibration data A of the test container, the stress data σ on the bottom of the test container, and the collection time T corresponding to each data;

[0009] S4, generating a displacement time series, a vibration time series and a stress time series respectively according to the displacement data L, the vibration data A, the stress data σ and the acquisition time T corresponding to each data;

[0010] S5. According to the displacement time series, the point where the displacement data L begins to change is taken as the starting point of the rod drop, and the starting time T0 corresponding to the starting point of the rod drop is recorded. The displacement time series, vibration time series and stress time series are coupled to determine the end point of the rod drop, and the difference between the stress value σ1 at the end point of the rod drop and the stress value σ0 at the reference position is recorded as the rod drop impact force, and the difference between the end point time T1 corresponding to the end point of the rod drop and the starting time T0 is the rod drop time.

[0011] Furthermore, the rod drop end point is the point where the vibration data A value is the largest, the stress data σ value is the largest, and the change value of the displacement data L and the initial rod position L0 meets the design height value.

[0012] A device for measuring the rod drop time and impact force of a control rod drive line comprises a drive line, a test container and a processing unit. A displacement sensor probe is arranged at the top of the drive line, a displacement sensor receiver is arranged above the displacement sensor probe and cooperates with the displacement sensor probe to detect the displacement of the drive line, a stress measurement unit is arranged at the bottom of the test container to detect the impact stress of the drive line, a vibration measurement unit is arranged at the bottom of the test container to detect the vibration of the test container, and the displacement sensor receiver, the stress measurement unit and the vibration measurement unit are electrically connected to the processing unit respectively.

[0013] Furthermore, the relative height position of the displacement sensor receiver is adjustable.

[0014] Furthermore, the stress measuring unit adopts a strain gauge.

[0015] Furthermore, the vibration measuring unit adopts a vibration accelerometer and is connected to the processing unit through an amplifier.

[0016] The present invention has at least the following advantages and beneficial effects: through calibration of the reference position and the reference position stress value σ0, and real-time collection of the displacement data L, vibration data A, stress data σ and the collection time T corresponding to each data during the falling process of the driving line, the displacement time series, the vibration time series and the stress time series relationship diagrams are generated respectively, the coupling analysis is used to determine the starting point and the end point of the rod drop, and the impact force and the rod drop time are determined, thereby improving the accuracy and reliability of the experimental results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1A schematic flow chart of a method for measuring the rod drop time and impact force of a control rod drive line provided by the present invention;

[0019] Figure 2 A schematic diagram of the structure of a device for measuring the rod drop time and impact force of a control rod drive line provided by the present invention;

[0020] Icon: 1-driving line, 2-test container, 31-displacement sensor probe, 32-displacement sensor receiver, 4-stress measurement unit, 5-vibration measurement unit, 6-processing unit. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example

[0024] like Figure 1 As shown, in this embodiment, a method and device for measuring the rod drop time and impact force of a control rod drive line are mainly disclosed, including the following steps:

[0025] S1, drop the driving wire 1 into the bottom of the test container 2 and keep it still, calibrate the reference position and the reference position stress value σ0, at this time, the reference position corresponds to the standard rod drop end point of the driving wire 1, and the reference position stress value σ0 is the stress generated by the gravity of the driving wire 1 itself;

[0026] S2, lifting the driving line 1 to the design height, and calibrating the initial rod position L0. Specifically, the initial rod position L0 is the sum of the reference position and the design height;

[0027] S3, release the driving line 1, and collect the displacement data L of the free falling rod of the driving line 1, the vibration data A of the test container 2, the stress data σ on the bottom of the test container 2, and the collection time T corresponding to each data in real time; specifically, during the falling process of the driving line 1, the displacement data L of the driving line 1 are collected at microsecond time intervals, and when the driving line 1 falls to the bottom of the test container 2, the stress data σ on the bottom of the test container 2 and the vibration data A of the driving line 1 on the test container 2 during the entire impact process of the driving line 1 are monitored;

[0028] S4. Generate a displacement time series, a vibration time series and a stress time series respectively according to the displacement data L, the vibration data A, the stress data σ and the acquisition time T corresponding to each data. The displacement time series reflects the relationship between the displacement and time during the entire falling process of the driving line 1 (with time as the horizontal axis and the displacement as the vertical axis). The vibration time series reflects the relationship between the vibration generated by the driving line 1 on the test container 2 during the entire falling process of the driving line 1 and time (with time as the horizontal axis and vibration as the vertical axis). The stress time series reflects the relationship between the stress generated by the driving line 1 on the bottom of the test container 2 during the entire falling process of the driving line 1 and time (with time as the horizontal axis and stress as the vertical axis).

[0029] S5. According to the displacement time series, the point where the displacement data L starts to change is taken as the starting point of the rod drop, and the starting time T0 corresponding to the starting point of the rod drop is recorded. The displacement time series, the vibration time series and the stress time series are coupled to process, and the end point of the rod drop is determined. The difference between the stress value σ1 at the end point of the rod drop and the stress value σ0 at the reference position is recorded as the rod drop impact force, and the difference between the end point time T1 corresponding to the end point of the rod drop and the starting time T0 is the rod drop time.

[0030] Through calibration of the reference position and the reference position stress value σ0, and real-time collection of the displacement data L, vibration data A, stress data σ and the collection time T corresponding to each data during the falling process of the driving line 1, the relationship diagrams of the displacement time series, vibration time series and stress time series are generated respectively. The coupling analysis is used to determine the starting point and end point of the rod drop, and the impact force and time of the rod drop are determined, thereby improving the accuracy and reliability of the experimental results.

[0031] Further, in specific implementation, the above-mentioned rod drop endpoint provided in the embodiment of the present invention is the point where the vibration data A value is the largest, the stress data σ value is the largest, and the change value of the displacement data L and the initial rod position L0 meets the design height value, that is, the endpoint time corresponding to the judged rod drop endpoint should simultaneously satisfy the requirements that the vibration data A value in the vibration time series is the largest, the stress data σ value in the stress time series is the largest, and the difference between the rod drop endpoint position and the initial rod position L0 is the design height value; if one of the items is not met, it means that the set of measurement data is invalid and needs to be remeasured.

[0032] like Figure 2As shown, in this embodiment, a control rod drive line rod drop time and impact force measuring device is also disclosed, including a drive line 1, a test container 2 and a processing unit 6. A displacement sensor probe 31 is provided at the top of the drive line 1, and a displacement sensor receiver 32 is provided above the displacement sensor probe 31 to cooperate with the displacement sensor probe 31 to detect the displacement of the drive line 1. A stress measuring unit 4 for detecting the impact stress of the drive line 1 is provided at the bottom of the test container 2, and a vibration measuring unit 5 for detecting the vibration of the test container 2 is provided at the bottom of the test container 2. The displacement sensor receiver 32, the stress measuring unit 4 and the vibration measuring unit 5 are electrically connected to the processing unit 6 respectively. Specifically, the test container 2 can adopt the existing technology and is a cylindrical structure for accommodating the drive line 1. A buffer structure is provided at the bottom of the test container 2. The processing unit 6 has a high acquisition frequency and can collect and record the acquisition time of each data.

[0033] Furthermore, in a specific implementation, the relative height position of the above-mentioned displacement sensor receiver 32 provided in the embodiment of the present invention is adjustable. Specifically, the displacement sensor probe 31 is fixed on the top surface of the driving line 1 and moves with the driving line 1. The displacement sensor receiver 32 is arranged at a certain distance directly above the displacement sensor probe 31 through tooling, and is relatively fixed and does not contact the driving line 1, so as to adapt to different experimental requirements and improve the flexibility and applicability of the equipment.

[0034] Furthermore, in a specific implementation, the stress measurement unit 4 provided in the embodiment of the present invention adopts a strain gauge, which has the characteristics of high sensitivity, strong adaptability, and the ability to capture tiny stress changes, thereby enhancing the accuracy of stress measurement.

[0035] Furthermore, in a specific implementation, the vibration measurement unit 5 provided in the embodiment of the present invention adopts a vibration accelerometer and is connected to the processing unit 6 through an amplifier, which effectively improves the detection capability of tiny vibration signals and ensures that stable data can still be obtained under high-frequency vibration conditions.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring the rod drop time and impact force of a control rod drive line, characterized in that: The following steps are involved: S1, drop the driving wire (1) into the bottom of the test container (2) and keep it still, and calibrate the reference position and the reference position stress value σ0; S2, lifting the driving line (1) to a designed height and calibrating an initial rod position L0; S3, releasing the driving wire (1), and collecting in real time the displacement data L of the free-falling rod of the driving wire (1), the vibration data A of the test container (2), the stress data σ on the bottom of the test container (2), and the collection time T corresponding to each data; S4, generating a displacement time series, a vibration time series and a stress time series respectively according to the displacement data L, the vibration data A, the stress data σ and the acquisition time T corresponding to each data; S5. According to the displacement time series, the point where the displacement data L starts to change is taken as the starting point of the rod drop, and the starting time T0 corresponding to the starting point of the rod drop is recorded. The displacement time series, the vibration time series and the stress time series are coupled and processed to determine the end point of the rod drop, and the difference between the stress value σ1 at the end point of the rod drop and the reference position stress value σ0 is recorded as the rod drop impact force, and the difference between the end point time T1 corresponding to the end point of the rod drop and the starting time T0 is the rod drop time.

2. A method for measuring the rod drop time and impact force of a control rod drive line according to claim 1, characterized in that: The rod drop end point is a point where the vibration data A value is the maximum, the stress data σ value is the maximum, and the change value between the displacement data L and the initial rod position L0 meets the design height value.

3. A device for measuring the rod drop time and impact force of a control rod drive line according to any one of claims 1 to 2, comprising the drive line (1), the test container (2) and a processing unit (6), characterized in that: A displacement sensor probe (31) is provided at the top of the driving line (1); a displacement sensor receiver (32) is provided above the displacement sensor probe (31) and cooperates with the displacement sensor probe (31) to detect the displacement of the driving line (1); a stress measurement unit (4) is provided at the bottom of the test container (2) to detect the impact stress of the driving line (1); a vibration measurement unit (5) is provided at the bottom of the test container (2) to detect the vibration of the test container (2); and the displacement sensor receiver (32), the stress measurement unit (4) and the vibration measurement unit (5) are respectively electrically connected to the processing unit (6).

4. A control rod driving line rod drop time and impact force measuring device as claimed in claim 3, characterized in that: The relative height position of the displacement sensor receiver (32) is adjustable.

5. A control rod driving line rod drop time and impact force measuring device as claimed in claim 3, characterized in that: The stress measuring unit (4) adopts a strain gauge.

6. A control rod driving line rod drop time and impact force measuring device as claimed in claim 3, characterized in that: The vibration measuring unit (5) adopts a vibration accelerometer and is connected to the processing unit (6) through an amplifier.

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