JPH05332916A - Cell for detector for monitoring of particle - Google Patents

Abstract

PURPOSE:To improve the reliability and the accuracy by detecting abraded particles in a fluid of a quick flow velocity as a clear image and cleaning the dirt of a sampling window at all times. CONSTITUTION:A fluid is supplied into a main body 3 of a cell via a sampling piping 2 from a system piping 1. A stay part 4 to settle abraded particles 11 is provided in the main body 3. A sampling window 6 for photographing the settling abraded particles 11 is formed at the bottom of the main body 3. There are also provided a flushing line 8, flow rate regulating valves 9, 10 and a supersonic vibrator 7 to remove the settling abraded particles 11 and to keep tone sampling window 6 clean.

Description

Detailed Description of the Invention

[0001]

The present invention can in-line monitor wear particles generated from piping, rotating equipment, etc. in nuclear power plants, etc. flowing with the fluid in the system piping, and also grasp changes over time. Yes, damage to rotating equipment,
And a particle monitor detector cell for detecting advance prediction of anomalous symptoms.

[0002]

2. Description of the Related Art Conventionally, in a nuclear power plant, abnormal events are monitored by monitoring the vibration of equipment and analyzing the quality of system water flowing in system piping. It is impossible to directly detect the generated wear particles, and these data have been used as reference information in subsequent diagnosis and analysis.

Further, it is impossible to quickly detect the generation of wear particles based on information such as conductivity and ionic species obtained from the results of water quality analysis, and even when carbon or the like is used as a material for equipment. It was impossible to detect by conductivity, ionic species, etc.

Another method is to use a turbidimeter, which is suitable for iron oxide particles having a particle size of 0.1 μm to 10 μm, but has a size of several μm to 100 μm as shown in FIG. This method is not suitable for the worn wear particles 11.

On the other hand, a method has been considered in which these wear particles 11 are captured by a particle monitor as a still image and detected, but it is very difficult to capture wear particles in a fluid having a high flow velocity with a clear image. At present, it is difficult to constantly monitor in-line due to difficulties and interference due to contamination of the sampling window.

It is known that a clad having a particle size smaller than that of wear particles is deposited at the bottom of horizontal pipes and pipes of nuclear power plants and the like, valves of sampling lines, and water retention portions such as branches. The present invention utilizes the fact that wear particles are deposited in the fluid retention portion based on this finding.

[0007]

In the prior art, a strobe is used as a light source, and wear particles are caused to emit light to be captured as a still image by an image camera. However, since such an image camera enlarges and captures the wear particles 11, the depth of resolution is very narrow and the flow velocity of the fluid is fast with respect to the decomposition performance of the camera. It was difficult to capture the particles and make them still images.

Further, there is a problem that the sampling window of such an optical system becomes soiled due to the adhesion of wear particles and finer particles of corrosion products (clads) and the like, making it impossible to perform sampling.

The present invention has been made to solve the above problems, and is a particle monitor detection that constantly monitors wear particles generated due to a malfunction of a rotating device or the like to promptly detect an abnormal sign of a rotating body or the like in advance. To provide a container cell.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a cell body, a retention portion for depositing wear particles mixed in the fluid sampled in the cell body, and a stationary portion of the wear particles at the bottom of the retention portion. A sampling window for mounting a camera with a built-in strobe tuning for taking an image, a flushing line for removing deposited wear particles on the sampling window, and keeping the sampling window clean, a valve, and an ultrasonic transducer are provided. Characterize.

[0011]

[Function] By providing a retention portion in the cell body in the fluid flow path, the flow velocity of wear particles mixed in the fluid is slowed, and the flow particles are changed to retain the wear particles, whereby the wear particles are collected at the bottom sampling window of the cell body. Sink to. By depositing wear particles in the sampling window, it is possible to suppress the movement of the particles and collect many particles within the depth of field of the camera for taking a static image of the wear particles.
The detection sensitivity of particles is improved.

By interlocking a flushing line, a valve controlling the flushing line, and an ultrasonic transducer with the sampling of the wear particle image, the deposited wear particles on the sampling window are separated and removed, and the sampling image is updated.
It is possible to monitor the concentration (number of particles) of wear particles, the particle size distribution, the particle shape, etc. by image analysis while tracking the change over time.
Further, the deposited wear particles on the sampling window are removed every time, the sampling window is kept clean, the detection accuracy is improved, and the apparatus maintenance is reduced. The valve operation of the flushing line and the operation of the ultrasonic transducer can be controlled according to the frequency of image sampling.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the particle monitor detector cell according to the present invention will be described with reference to FIGS. It should be noted that in FIG. 1, the flushing line is closed and wear particles are collected in the sampling window.
FIG. 2 shows a state in which 11 is accumulated and water is being passed through the flushing line (ultrasonic cleaning operation).

Reference numeral 1 in FIG. 1 shows a part of system piping of a nuclear reactor plant. A sampling piping 2 is connected to the system piping 1, and a particle monitoring detector cell body 3 is connected to the sampling piping 2. Set up. The cell body 3 is provided with a fluid retention portion 4, and a sampling window 6 to which the imaging camera 5 with a built-in strobe tuning can be connected is provided at the bottom portion thereof.

An ultrasonic transducer 7 is installed on the outer wall surface of the cell body 3, and the cell body 3 serves as an ultrasonic cleaner. A flushing line 8 is connected downstream of the bottom of the cell body 3, and the flushing line 8 and the sampling pipe 2 are provided with a first flow rate control valve 9 and a second flow rate control valve 10 capable of controlling the respective flow rates. There is.

In this system pipe 1, wear particles generated due to malfunctions of equipment are mixed in the reactor coolant and flow while floating. Even if the sampling window 6 is directly installed in the system pipe 1, it is difficult to capture the wear particles as a still image because of the high flow velocity and the narrow depth of field of the imaging camera.

Therefore, the wear particle sampling pipe 2 is used.
From the fuel cell to the cell body 3, the flow velocity is reduced in the retention section 4 to change the flow and retain it, and by passing water for a certain period of time, the reactor coolant, which is a fluid, flows downstream as it is, but wear particles are deposited at the bottom sampling window To do.

At this time, the second flow rate control valve 10 installed in the sampling pipe 2 is fully opened, and the first flow rate control valve 9 installed in the flushing line 8 is fully closed. The accumulated wear particles are captured as a still image by the imaging camera 5 with built-in strobe tuning, and the concentration (number of particles), particle size distribution, particle shape, etc. of wear particles are measured using a computer and an image analysis device.

FIG. 3 shows an example of a still image with simulated wear particles. After the sampling of the static image of the wear particles deposited on the sampling window 6 is completed, the ultrasonic transducer 7 is controlled to operate in conjunction with it, and then the first flow rate control valve installed in the flushing line 8 9
Is normally closed and is opened, and the flow rate of the second flow rate control valve 10 installed in the sampling pipe 2 is controlled to be narrowed.

The wear particles at the bottom of the detector cell are swept through the flushing line 8 due to the effect of ultrasonic cleaning and the flow of fluid. After the wear particles are removed from the detector cell for a certain period of time, the first flow rate control valve 9 is closed and the second flow rate control valve 10 is returned to the fully open state to start the next sampling. It will be.

In this method, it is difficult to quantify the wear particles as an absolute value, but by prolonging the sampling time in which the fluid is retained, the concentration of the wear particles is concentrated in the cell body 3, and the detection is performed. There is an advantage that the sensitivity is improved.

In the embodiment, the wear particles are introduced from the system pipe 1 having a large pipe diameter to the cell body 3 by the sampling pipe 2, but the pipe having a small diameter is directly connected to the cell body 3 or the pump bearing seal is used. Water, etc. is more effective if the sampling pipe is directly led from the equipment.

[0023]

According to the present invention, the wear particles floating and flowing in the system piping can be captured inline as a still image, and the reliability and accuracy of the particle monitor that can be processed in real time are improved. As a result, it is possible to quickly detect the sign of abnormality of the rotating equipment and the like, which is an effective means for early detection of equipment abnormality.

[Brief description of drawings]

FIG. 1 is a system diagram showing wear particle accumulation and a flushing line closed in an embodiment of a particle monitor detector cell according to the present invention.

FIG. 2 is a system diagram showing a flushing line in FIG. 1 and an ultrasonic cleaning operation.

FIG. 3 is a copy diagram showing an example of a still image using simulated wear particles.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... System piping, 2 ... Sampling piping, 3 ... Cell main body, 4 ... Retaining part, 5 ... Imaging camera, 6 ... Sampling window, 7 ... Ultrasonic transducer, 8 ... Flushing line, 9 ...
1st flow control valve, 10 ... 2nd flow control valve, 11
... wear particles.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G21C 17/003

Claims (1)

[Claims] 1. A cell main body, a retention part for accumulating wear particles mixed in a fluid sampled in the cell main body, and a strobe tuning built-in for taking a static image of the wear particles at the bottom of the retention part. The sampling window to which the camera is attached and the accumulated wear particles on this sampling window are removed,
A particle monitor detector cell, further comprising a flushing line for keeping the sampling window clean, a valve, and an ultrasonic transducer.