JPS58100729A - Confirming method for normality of cooling material leakage detector - Google Patents

Abstract

PURPOSE:To confirm the normality of the detector of an oscillation detecting device securely by simulating break oscillation through a piezoelectric exciter for simulated sound oscillation. CONSTITUTION:A piezoelectric exciter 16 for simulated sound oscillation is installed where a simultated sound propagates securely to an oscillation detector 4 as a confirmation object. By a signal from a random noise generator 18 installed outside of a storage container, simulated oscillation 17 of >2 MHz from said exciter 16 propagates to a water drum 7 through a waveguide rod 5. This simulated oscillation 17 is detected by an oscillation detector 4, whose output is led to a signal processing circuit 6 to detect whether the simulated oscillation is received or not, thus confirming the condition of the detector. Since the frequency of the simulated oscillation is other than the frequency of the object of detection, the normality of the detector is confirmed remotely at optional time and even during the confirmation test, the channel maintains the leakage detection function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for checking the health of a vibration detector for detecting coolant leakage, and particularly to a method suitable for reliably checking the health of a vibration detector.

The health of a vibration detection device used in a place where there is constant vibration can be confirmed by comparing the outputs of multiple detection devices or, for the same detection device, by comparing the current detector output with the past output history. It was possible. However, if it is installed for the purpose of detecting coolant leakage due to a rupture in a healthy pipe, the above method can be used because the pipe does not experience much vibration, and the signal output during normal operation is much smaller than the noise inherent in the signal processing circuit. There was a drawback that there was no

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a reliable method for confirming the soundness of a vibration detector of a vibration detection device for detecting coolant leakage.

The health of a vibration detection device used in a place with constant vibration can be confirmed by comparing the outputs of multiple detection devices or, for the same detection device, by comparing the current detector output with the past output history. However, if it is installed for the purpose of detecting coolant leakage due to a rupture in a healthy pipe, the output signal during normal operation will be due to noise unique to the signal processing circuit (electrical noise, etc.)
It is much smaller and cannot be confirmed.

The present invention uses a piezoelectric vibrator for simulating sound oscillation to provide a simulated breaking vibration that is larger than the direct inherent noise to the object to be detected and is outside the frequency band of the object to be detected. It is possible to check the soundness.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 shows a schematic diagram of a pressure tube reactor equipped with a coolant leak detection device.

In the figure, 1 is a calandria tank, 2 is a pressure pipe, 3 is an inlet pipe, 4 is a vibration detector, 5 is a waveguide rod, 6 is a signal processing circuit, and 7 is a water drum.

In Fig. 1, when the inlet pipe 3 breaks and the coolant leaks, the vibration generated by the leak propagates through the inlet pipe 3, water drum 7, and waveguide rod 5, and is transmitted to the vibration detector 4. The vibration is converted into an electrical signal, and the signal processing circuit 6 performs signal processing to determine the presence or absence of leakage.

FIG. 2 shows the mounting position of the vibration detector on the water drum.

The vibration detector 4 is attached near the connection part of the inlet pipe.

FIG. 3 shows the configuration of the signal processing circuit.

In the figure, 4 is a vibration detector, 8 is an amplifier, 9 is a bandpass filter, 10 is an effective value converter, 11 is a signal processing unit comparator, 12 is a signal processing unit timer, 13 is a signal processing unit output circuit, and 14 is a signal processing unit output circuit. The signal processing section comparator setting value 15 is the signal processing section timer setting value.

In Fig. 3, the output signal of the vibration detector 4 is amplified to a level that can be processed by the amplifier 8, and... Frequency (300KHg to 2MH) that makes it easy to judge leakage
g) is selected, and the effective value converter 10 performs noise processing. The output signal of the effective single-direction converter 10 is subjected to a leakage determination via a signal processing section comparator 11 and a signal processing section timer 12, and a leakage signal is outputted from a signal processing section output circuit 13 at the time of leakage.

Note that the vibration detector 4 and amplifier 8 are installed inside the containment vessel. In addition, to check the health of the bandpass filter 9 and beyond, the simulated signal is sent to the bandpass filter 9 as in the conventional method.
You can check by inputting it to the input side of .

FIG. 4 shows the installation location of the piezoelectric vibrator for simulating sound oscillation of the present invention.

In FIG. 4, 16 is a piezoelectric exciter for oscillating simulated sound. In the figure, the piezoelectric vibrator 16 for oscillating simulated sound is installed at a position where the simulated sound is reliably transmitted to the vibration detector 4 to be checked.

Figure 5 shows a diagram of the principle of the detector integrity confirmation method.

In FIG. 5, 17 is a simulated vibration generated by a piezoelectric exciter for oscillating simulated sound, and 18 is a random noise generator.

In FIG. 5, a signal from a random noise generator 18 installed outside the containment vessel causes a simulated sound oscillation piezoelectric exciter 16 to generate a simulated vibration 17 exceeding 2 MHg on a waveguide rod 5.
The signal is transmitted to the water drum 7 via.

This simulated vibration 17 is detected by the vibration detector 4 and guided to the signal processing circuit 6 to detect whether or not the simulated vibration has been received, thereby confirming the detector.

A method for checking the detector 4 using the above method will be explained with reference to FIG.

FIG. 6 is a diagram showing the signal state of each part when the present invention is applied. In the figure, 19 is a simulated signal confirmation device, 20 is a normally detected flow noise level from piping, and 21 is a noise specific to the signal processing circuit.

In FIG. 6, the output of the detector 4 normally detects only the flowing noise 20 with a low output level and sends it to the amplifier 8.

In the amplifier 8, the signal from the pre-detector 4 is amplified, and the unique noise 21 of the signal processing circuit, which exceeds the flow noise 20, is outputted and sent to the bandpass filter 9.

The bandpass filter 9 extracts only signals between 300KHg and 2MHg, and signals in other frequency bands are attenuated. When a simulated signal is input in this state, outputs of the simulated signal appear at the outputs of the vibration detector 4 and the amplifier 8. Therefore, simulated vibrations also appear in the simulated signal confirmation device 19 that receives the signal from the output side of the amplifier 8. As described above, if a simulated vibration appears on the simulated signal confirmation device when the simulated vibration is transmitted, it can be said that the vibration detector 4 is healthy. Further, even if the simulated vibration is transmitted, since the frequency of the simulated vibration exceeds 2 MHg, no change appears in the output via the bandpass filter 9, and subsequent signal processing is not affected.

According to the present invention, the following effects can be achieved by using frequencies other than the detection target frequency.

(1) It is possible to check the health of the detector at any time.

(2) It is possible to check the integrity of the detector from a distance.

(3) The channel can maintain its leak detection function even during the integrity verification test.

(4) It is possible to check the health of only any channel during plant operation.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the installation of the coolant leakage detection device, Figure 2 is an illustration of the installation location of the vibration detector on the water drum, Figure 3 is a configuration diagram of the signal processing circuit, and Figure 4 is the piezoelectric exciter for simulating sound oscillation. Installation location explanatory diagram, Figure 5 is a principle diagram of the detector integrity confirmation method, Figure 6
The figure is a diagram showing the signal state of each part when the present invention is applied.

Claims (1)

[Claims] 1. A vibration detection device for detecting coolant leakage consisting of a vibration detector and a signal processing circuit is characterized by being equipped with a piezoelectric vibrator that can be operated remotely in order to confirm the soundness of the vibration detector. A method for confirming the integrity of a coolant leak detection device.