JPH0678962B2 - Soundness confirmation method for coolant leakage detector - Google Patents

Description

The present invention relates to a soundness confirmation method for a vibration detection device for coolant leakage detection, and more particularly to a confirmation method suitable for surely confirming the soundness of a vibration detector.

To confirm the soundness of the vibration detection device used in a place where there is constant vibration, check the output by comparing the outputs of multiple detection devices and, in the case of the same detection device, by comparing the current detector output with the past output history. It was possible. However, when it is installed for the purpose of detecting coolant leakage due to breakage of sound piping, the vibration of the piping is small, so the signal output during normal operation is much smaller than the noise inherent in the signal processing circuit, and the above method can be used. There was a defect that it was not there.

An object of the present invention is to achieve soundness of a vibration detector of a vibration detecting device for detecting coolant leakage reliably and without interfering with coolant leakage detection.

The soundness of the vibration detection device used in the place where there is constant vibration can be confirmed by comparing the outputs of multiple detection devices or by comparing the current output of the detector with the past output history for the same detection device. However, when provided for the purpose of detecting coolant leakage due to breakage of sound pipes, the output signal during normal operation will be the noise peculiar to the signal processing circuit (electrical noise, etc.).
It is much smaller and cannot be confirmed.

The present invention provides a vibration detector that receives vibration from a detection target through which a coolant is passed, and a signal corresponding to a detection target frequency band region with a bandpass filter among signals corresponding to the reception frequency of the vibration detector. In a vibration detection device for detecting coolant leakage supplied to a signal processing circuit, a piezoelectric vibrator that can be remotely operated is provided on the detection target, and the piezoelectric vibrator excites noise unique to the detection target. A larger vibration corresponding to the outside of the detection target frequency band region is added to the detection target as a simulated vibration, and the simulated vibration is detected by the vibration detector to confirm the simulated signal before being input to the bandpass filter. A soundness confirmation method for a coolant leakage detection device, characterized by determining whether or not a signal corresponding to the simulated vibration is received by the device, which is used for confirming the soundness of the coolant leakage detection device. When a vibration that is larger than the noise specific to the detection target and corresponds to the outside of the detection target frequency band region is added to the detection target as a simulated vibration, the simulated vibration passes through the detection target. The signal corresponding to the simulated vibration received by the vibration detector and input to the simulated vibration detected by the band pass filter is input to the simulated signal confirmation device in the previous stage, and the signal specific to the detected object is more likely to be detected than the noise specific to the detected object. Since the simulated vibration is large, the simulated vibration was confirmed without being hidden by the noise, it was found that the detection system was normal, and a coolant leak occurred while checking the soundness of the coolant leakage detection device. In this case, the vibration caused by the leakage passes through the bandpass filter, the signal corresponding to the simulated vibration does not pass through the bandpass filter, and both are mixed in the signal processing circuit. Without its signal corresponding to the vibration caused by the leakage is inputted, is disturbed Without being coolant leak detection simulated vibration can be achieved continuously nacelle, effect that can.

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

FIG. 1 shows a schematic view of a pressure tube reactor equipped with a coolant leakage 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 leakage propagates through the inlet pipe 3, the water drum 7, and the waveguide rod 5, is transmitted to the vibration detector 4, and vibrates at the vibration detector 4. Is converted into an electric signal, and the signal processing circuit 6 performs signal processing to determine whether or not there is a leak.

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

The vibration detector 4 is attached near the connecting portion of the inlet pipe.

FIG. 3 shows a signal processing circuit configuration.

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,
Reference numeral 14 is a signal processing unit comparator set value, and 15 is a signal processing unit timer set value.

In FIG. 3, the output signal of the vibration detector 4 is amplified by the amplifier 8 to a level at which signal processing is possible, and the bandpass filter 9 selects only the frequency (300 KHg to 2 MHg) at which leakage can be easily determined, and the effective value is converted. The noise is processed by the device 10. RMS converter
The output signal of 10 is determined for leakage through the signal processing unit comparator 11 and the signal processing unit timer 12, and the leakage signal is output from the leakage signal processing unit output circuit 13.

The vibration detector 4 and the amplifier 8 are installed inside the storage container. The soundness confirmation after the band pass filter 9 can be confirmed by inputting a simulated signal to the input side of the band pass filter 9 as in the conventional method.

FIG. 4 shows the installation place of the piezoelectric vibrator for simulated sound oscillation of the present invention.

In FIG. 4, 16 is a piezoelectric vibrator for simulated sound oscillation. In the drawing, the piezoelectric vibration exciter 16 for oscillating a simulated sound is installed at a position where the simulated sound surely propagates to the vibration detector 4 to be confirmed.

Fig. 5 shows the principle diagram of the detector soundness confirmation method.

In FIG. 5, 17 is a simulated vibration generated by a piezoelectric vibration exciter for simulated sound oscillation, 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 vibration 17 exceeding 2 MHg from the piezoelectric vibrator 16 for simulated sound oscillation via the waveguide rod 5 to the water drum 7. Be propagated to.

The simulated vibration 17 is detected by the vibration detector 4, guided to the signal processing circuit 6 to detect whether the simulated vibration is received, and the detector is checked.

A method of confirming the detector 4 by the above method will be described with reference to FIG.

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

In FIG. 6, the output of the detector 4 normally detects only the flow noise 20 having a small output level and sends it to the amplifier 8. The amplifier 8 amplifies the signal from the pre-detector 4 and
The noise 21 peculiar to the signal processing circuit, which exceeds the flow noise 20, is output and sent to the bandpass filter 9. The bandpass filter 9 extracts only the signal between 300 KHg and 2 MHg, and attenuates the signals in other frequency bands.
When a simulation signal is input in this state, the vibration detector 4
Also, the output of the simulated signal appears at the output of the amplifier 8. Therefore, the simulated vibration also appears in the simulated signal confirmation device 19 which inputs the signal on the output side of the amplifier 8. As described above, when the simulated vibration appears in the simulated signal confirmation device when the simulated vibration is transmitted, it can be said that the vibration detector 4 is sound. Further, even if the simulated vibration is transmitted, since the frequency of the simulated vibration exceeds 2 MHg, the output through the bandpass filter 9 does not change and the subsequent signal processing is not affected.

According to the present invention, the following effects are obtained by using a frequency other than the detection target frequency.

(1) It is possible to confirm the soundness of the detector at any time.

(2) The integrity of the detector can be confirmed from a distance.

(3) The channel can maintain the leak detection function even during the soundness confirmation test.

(4) It is possible to confirm the soundness of only an arbitrary channel during plant operation.

[Brief description of drawings]

FIG. 1 is a schematic diagram of mounting a coolant leakage detection device, FIG. 2 is an explanatory view of installation locations of vibration detectors on a water drum, FIG. 3 is a signal processing circuit configuration diagram, and FIG. 4 is a piezoelectric vibration exciter for simulated sound oscillation. Illustration of installation location, Fig. 5 is the principle diagram of detector integrity confirmation method, No. 6
The figure is a signal state diagram of each part when the present invention is applied. 1 ... Calandria tank, 2 ... Pressure tube, 3 ... Inlet tube, 4 ... Vibration detector, 5 ... Waveguide rod, 6 ... Signal processing circuit, 7 ... Water drum, 8 ... Amplifier , 9 band pass filter, 10 effective value converter, 11 signal processing section comparator, 12 signal processing section timer, 13 signal processing section output circuit, 14 signal processing section comparator Set value, 15 …… Signal processing unit timer set value, 16 …… Piezoelectric vibrator for simulated sound oscillation, 17 …… Simulated vibration, 18 …… Random noise generator, 19
…… Simulation signal confirmation device, 20 …… Flowing noise, 21 …… Specific noise of signal processing circuit.

Claims (1)

[Claims] 1. A vibration detector that receives vibration from a detection object through which a coolant passes, and a signal corresponding to a detection target frequency band region by a bandpass filter among signals corresponding to the reception frequency of the vibration detector. In a vibration detecting device for detecting coolant leakage, which supplies a signal to a signal processing circuit, a piezoelectric vibrator that can be remotely operated is provided on the detection target, and the piezoelectric vibrator excites a vibration peculiar to the detection target. A vibration that is greater than noise and corresponds to outside the detection target frequency band region is added to the detection target as a simulated vibration, and the simulated vibration is detected by the vibration detector and a signal before being input to the band pass filter is simulated signal. A soundness confirmation method for a coolant leakage detection device, characterized in that the presence or absence of a signal corresponding to the simulated vibration is received by a confirmation device.