JPS6388410A - Monitor for loose part generated in fluid path of nuclear reactor - Google Patents

Abstract

PURPOSE:To enable the estimating of the position of a loose part and an impact force when a different sound is generated from a time difference between signals, the position of sensors and a signal waveform, by mounting sensors at least at three points of the wall of a fluid path to detect a different sound signal from these sensors. CONSTITUTION:When a vibration sound is sensed with accelerometers (sensors) 2-12 for detecting sound waves arranged tightly on a piping 100, the vibration sound is amplified with line drivers 13-24 and detected with loose part detectors 25-36. At the time of detecting a signal larger than a fixed size, the detectors 25-36 generate an alarm signal. The alarm signal is sent to a digital loose part locator 37 to judge the propriety thereof and the locator generates a loose part alarm 38 when it is proper while a signal waveform data sampled with a first event recorder 39 is transferred to an analysis section 40, where the position of a loose part is detected by a specified arithmetic processing. Then, attenuation characteristic as obtained when an impact generated near the sensors is recorded beforehand at the analysis section 40 thereby enabling the detection of an impact force of a part from the characteristic, part position and the peak value of a signal waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for monitoring fallen parts by detecting vibration sounds (noise) emitted from fallen parts in a fluid flow path. The present invention relates to a device for suitably monitoring fallen parts in a fluid path.

(Prior art) When equipment parts fall off in various circulation systems consisting of pipes through which reactor steam and liquid flow, such as a nuclear reactor and the steam generation section connected to it, these fallen parts (loose parts) occur.
This causes problems such as damage to various devices and obstruction of internal fluid flow. Nuclear technology requires greater safety than other technical fields, and it is necessary to reduce the occurrence of loose parts as much as possible, and if loose parts occur, it is necessary to detect the fact as soon as possible and prevent it from occurring. It is necessary to accurately detect the location and the movement state of this loose part. For this reason, various countermeasures have been considered in the past, and the applicant of the present application also applied for patent application No. 57-178567
No., Patent Application No. 57-212687, Patent Application No. 1982-119
An application similar to No. 834 has been filed.

(Problem to be Solved by the Invention) When loose parts occur in an atomic coupler, the location and movement state of the loose parts are used to determine whether or not they will cause a serious problem in plant operation. It is necessary to understand this and also to detect the impact energy when loose parts collide with the wall of the reactor circulation system.

In other words, if the impact energy exceeds a specified value, it is necessary to consider stopping the operation because various devices may be damaged.

Conventionally, loose rules were used as a guideline for judgments such as those mentioned above.

It was not possible to estimate the position of the parts or the impact energy.

(Means for Solving the Problems) The present invention has been made to solve the above problems.
In a system for monitoring loose parts generated in a reactor fluid path, at least three sensor devices are attached to the wall of the fluid path, abnormal noise signals from these sensor devices are detected, and the time difference between each signal and each sensor are detected. Based on the peak value of the signal waveform from each sensor device and the estimated position of the loose part! The present invention provides a loose parts monitoring device including a device for estimating the impact energy of the loose parts during in-life.

(Example) Embodiments of the present invention will be specifically described below with reference to the drawings.

In FIG. 1, reference numerals 1 to 12 are acceleration needles (sensors) for detecting sound waves placed in close contact with the object to be measured 100 such as the primary system piping of a nuclear power plant, 13 to 24 are line drivers connected to these, and 25 to 36 is a loose parts detector installed for each channel. 37 is digital
A loose parts locator, 38 is a mask alarm connected thereto, and 39 is a first event recorder.

Reference numeral 40 denotes a loose parts data analysis section connected to the control system configured as described above. This analysis section is a data analysis section centered on the arithmetic unit 41, and has a circuit configuration to detect the position and energy of loose parts. 42 is a CRT display for displaying the results on the screen, and 43 is a line printer. 44 is a data recorder, and 45 is a hard disk.

In the above configuration, the loose parts detectors 25 to 3
G is a signal whose vibration sound detected by the sensors 1 to 12 attached to the object to be measured 100 is amplified by the line drivers 13 to 24, and which has a magnitude greater than a certain ratio compared to normal hack ground noise. If it detects a signal with a certain value, it will issue an alarm signal.

The alarm signal from each loose parts detector 25-36 is sent to a digital loose parts locator 37,
Here, depending on the alarm generation pattern of each channel,
A determination is made as to whether the alarm signal is correct or incorrect. If the signal is determined to be positive here, a mask alarm 38 issues a loose parts warning. At the same time, the signal waveform data sampled in the first event recorder 39, which has a large capacity endless signal recording device, is transferred to the loose parts analysis section 40. Here, the position of the loose part is first detected from the impact waveform signal data caused by the collision or vibration of the loose part.

That is, as shown in Figure 2, the coordinates of sensor A are (Xl, y
l), the coordinates of sensor B are (X2,)'2), the coordinates of sensor C are (χ3,)':+), the coordinates of impact position P are (x, y), and the distance from sensor A to P is dl, the distance from sensor B to P is d2, and the distance from sensor C to P is d3, the following equation holds true.

dz (distance between APs) = (Xl-x) ” +
0't)') ”-fieldzDistance between CBP)'= (X2 x)2↓(72)')2-+2)
d: + (distance between CPs gtt) = (x3-x)'
+ (y3y) 2-i31 Here, as shown in FIG. 3, the time difference t1, t,
Therefore, if the speed of sound is ν, the impact wave arrival time difference indicates the difference in distance from the impact point, so dl-
d2zuνXt, ... (4) ctl - d3=ν
Xt3...(5). Therefore, (1)
, (.2), (3), (4), and (5), the coordinates, that is, the position of the impact point P (x, y) can be determined.

Once the loose parts occurrence position is determined, based on this, the distances d1 and d2 from each sensor to the loose parts occurrence position are determined.
, d3 can be calculated.

Next, calculate the energy level. First, as shown in FIG. 4, the magnitude of the detected acceleration (detected G) at each sensor is obtained from the peak value of the signal waveform.

The data analysis unit 40 in Table 1 records the attenuation characteristics when an impact occurs near the sensor of each channel (circulation path) in a test conducted in advance. That is, taking sensor A as an example, the attenuation characteristics when an impact occurs near sensor A are recorded as shown in Table 1. The detected acceleration decreases linearly as the transmission distance increases as shown in Fig. 5, so if the distance between sensor A and sensor B is d12, the attenuation characteristic of the sound wave from the point of impact to sensor A reaches go ( Detected acceleration/applied energy) is expressed by proportionally distributing the damping characteristics of sensor A and sensor B (Table 1). Also, the estimated impact acceleration G of the desired point.

In sensor A, let G1 be the detected acceleration determined from the peak value of the signal waveform, g with reference to FIG.

becomes.

The estimated impact energy E at this time is E=Go/g
It is denoted by t.

By using such a method, the loose parts data analysis section detects the impact energy and impact position of the loose parts, and outputs the results to the CRT display 42 and line printer 43.

Note that the above-described nuclear reactor noise monitoring device has the following practical problems.

When a loose parts alarm occurs, the first event recorder 39 stops sampling data after two seconds and then transfers the data to the storage device.

Therefore, even if an abnormal sound occurs again during data transfer, the data at this time cannot be recorded (see FIG. 7).

The loose parts alarm usually occurs two or three times in a row, and then the abnormal noise may stop occurring again. Analysis of loose parts requires a judgment that combines the abnormal noise analysis results of several cases, so if the abnormal noise data from the second time onward is lost, it can seriously impede the analysis. Therefore, in another embodiment of the present invention, by transmitting the waveform while continuing sampling by the first event recorder, it is possible to record the waveform of abnormal noise that occurs during data transmission, and after all data is saved, the waveform can be recorded. , made it possible to analyze.

FIG. 8 shows a system diagram in another embodiment of the present invention described above. The difference from FIG. 1 is that the signal from the first event recorder 39 passes through the data recorder 44 or the hard recorder 45, and It is now being sent to the parts data analysis section 40.

FIG. 9 shows the detailed configuration of the first event recorder (FER) in the embodiment of FIG. 8,
51 is an A/D converter, 52 is a main memory for storing signal data, and 53 is a D/Ai converter.

54 is the controller of the A/D converter, 55 is the overall main controller of the first event recorder 39, 56 is the D/A controller, 57 to 68 are analog signal input terminals, 69 to 80 are analog signal output terminals, 81
Reference numerals 82 to 93 indicate loose parts v-information input terminals, and digital signal output terminals 82 to 93.

In another embodiment of the invention shown in FIGS. 8-9, the 191 signal from each loose parts detector 25-36 is sent to a digital loose parts locator 37, where the alarm generation pattern for each channel A determination is made as to whether the alarm signal is correct or incorrect. As described above, if the signal is determined to be positive, the mask alarm 38 issues a loose parts warning.

At this time, in FIG. 9, the A/D converter 5 inside the FER
1 always converts the signal data input from the analog input terminals 57 to 68 into digital signals and writes them into the endless main memory 52. However, when a loose parts alarm is confirmed at the loose parts alarm input terminal 81, the main According to the command from the controller 55, 0 before the alarm occurs.
．． Signal data from 5 seconds to 2 seconds after generation is transferred to the hard disk 45 through digital output terminals 82-93. Similarly, this data is converted into an analog signal by the D/A converter 53 according to a command from the D/A controller 56.
The data is transferred to the data recorder 44. These A/D conversions,
Since the D/A conversion and the writing and reading processes of the main memory 52 are independently controlled by the A/D controller 54, main controller 55, and D/A controller 56, parallel processing can be performed. A/
D-input, analog and digital data can be transferred to the storage device without stopping sampling of the signal data.

In this way, the loose parts signal data from the FER is transferred to the data recorder 44 and hard disk 45 in FIG. 8, and the data is N8.

These data are sent to the data analysis section 40, and an internal calculation section 41 calculates the position of the loose part Q4 by triangulation. This analysis result is output to the CRT display 42 and line printer 43.

(Effects of the Invention) As described above, in the present invention, the accurate position of a loose part when a loose part occurs is determined based on the signal from the sensor device provided on the wall of the reactor fluid path, and
Since the impact energy generated from loose parts can be accurately estimated, safe operation of the atomic couplant can be guaranteed.

[Brief explanation of the drawing]

Fig. 1 is an overall system diagram of the loose parts monitoring device according to the present invention, Fig. 2 is a diagram showing how to determine the impact point of loose parts, and Fig. 3 is a diagram showing the time difference between signals from each sensor. Figure 4 is a diagram showing how to determine the peak value, Figure 5 is a diagram showing the attenuation characteristic, Figure 6 is an explanatory diagram of acceleration calculation, and Figure 7 is the diagram showing how to determine the peak value. 8 is an overall system diagram showing another embodiment of the present invention, and FIG. 9 is a detailed diagram of the first event recorder in the embodiment of FIG. 8. It is. 1 to 12... Accelerometer (sensor), 13 to 29...
Line driver, 25-36...Loose parts detector, 37...Digital loose parts locator, 38...Mask alarm, 39...First
Event recorder, 40... Loose parts data analysis section, 41... Arithmetic device, 42... CRT display, 43... Line printer, 100... Measured object. Agent Patent Attorney Takenaga Kawakita Fig. 1 1oO Measured object Fig. 2 Fig. 3 Fig. 4 Wave height Fig. 5 Fig. 6 Fig. 7 '°゛Data during this period cannot be recorded Fig. 8 Situation 1: 1. ,l Soj Procedural Amendment Commissioner of the Patent Office Black 1) Mr. Akio
,. 1. Monitoring device for displaying the case 3. Person making the amendment Relationship with the case Patent applicant address: 2-6-2 Otemachi, Chiyoda-ku, Tokyo Name:
Babcock Hitachi Co., Ltd. Representative: 1) Part 4, Agent: 103 Address: 11-8-7, Kayabacho-Chome, Nihonbashi, Chuo-ku, Tokyo
, Contents of amendment (1) Distance between CAPs from line 10 to line 12 on page 6 of the specification) - (X+ -X) 2+ (Yt-)')"
・=(11(distance between BPs A!tt) = (x, −
x) 2+ (yz -y) "-+2+distance between ccp')-(xco-X)" + C13-y) 2-
f31J is (distance between APs!II)-(xI-x) 2+ (yl-
y)" ・=+11 (distance between BPs) - (X2-x)
2” (y2 y) 2-(21 (distance between CPs)
= (xt x) ” + (y3-y) ”
...Change to f31. that's all

Claims (1)

[Claims] In a system for monitoring loose parts generated in a reactor fluid path, at least three sensor devices are attached to the wall of the fluid path, abnormal noise signals from these sensor devices are detected, and the time difference between each signal and each sensor are detected. A device for estimating the position of the loose part based on the position of the loose part, and a device for estimating the impact energy of the loose part when an abnormal noise occurs based on the peak value of the signal waveform from each sensor device and the estimated position of the loose part. A system for monitoring loose parts generated in a reactor fluid path.