JPH07260926A - Ultrasonic sensor for sodium fluoroscopic device - Google Patents

Abstract

PURPOSE:To make variable the directivity angle of an ultrasonic sensor in sodium solution, regardless of an external pressure condition. CONSTITUTION:A diaphragm 17 is laid on the front of a sensor body 16, so as to make a directivity angle adjustable, and the sensor body 16 is fitted with a depressurizing and pressurizing nozzle 18 and a pressure detector 19 is fitted to the nozzle 18. Also, the sensor body 16 is provided with a pillar 20 and a cable connector 21. Gas is made to flow in and out of an ultrasonic sensor 1a, and the pressure thereof is arbitrarily controlled via pressure adjustment with the diaphragm 17. The strain of ultrasonic sensor surface is thereby changed and a directivity angle is changed accordingly. Thus, an ultrasonic transmission and receiving range in sodium can be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor for a sodium see-through device installed in a reactor vessel of a fast breeder reactor.

[0002]

2. Description of the Related Art As shown in FIG. 3, a sodium see-through apparatus used in a fast breeder reactor using sodium as a coolant has an ultrasonic sensor 1 for transmitting and receiving ultrasonic waves, and a sodium see-through equipped with this sensor 1. An apparatus main body 2, a drive device 3 that drives the sodium fluoroscopy apparatus main body 2, a signal processing device 4 that processes echoes received and transmitted from the ultrasonic sensor 1, and an operating device 5 that operates the sodium fluoroscopy apparatus main body 2. To be done.

On the other hand, an ultrasonic reflection plate 7 is provided in the reactor vessel 6 at a position facing the sodium see-through device body 2 and the ultrasonic sensor 1. The ultrasonic waves oscillated from the ultrasonic sensor 1 are reflected by the ultrasonic reflection plate 7, and the core 11 and
The presence or absence of obstacles in the gap between the core upper mechanism 9 located above the core 11 is detected.

Further, as shown in FIG. 4, the sodium see-through device body 2 can be swung left and right by a driving device 3 to oscillate ultrasonic waves on an ultrasonic reflecting plate 7 installed in the circumferential direction of the reactor vessel 6. Has become.

The reactor vessel 6 contains sodium 10, which cools the heat from the core 11. In the figure, reference numeral 12 is a shield plug that closes the upper end opening of the reactor vessel 6, 13 is a core support plate installed in the reactor vessel 6, 14 is a plenum, and 15 is a core vessel.

The transmission and reception of ultrasonic waves in the sodium 10 causes distortion on the surface of the ultrasonic sensor 1 depending on the pressure condition outside the ultrasonic sensor 1 and makes the directivity angle unstable. The external pressure condition at the time of use is determined and an inert gas with a constant pressure is filled.

[0007]

In the conventional sodium see-through device, distortion occurs on the surface of the ultrasonic sensor due to external pressure conditions on the surface of the ultrasonic sensor during immersion of sodium, which reduces the directivity angle and narrows the ultrasonic transmission / reception range. There are challenges.

The present invention has been made to solve the above problems, and provides an ultrasonic sensor for a sodium see-through device which can change the directivity angle of the ultrasonic sensor regardless of the external pressure condition in the sodium liquid. Especially.

[0009]

The present invention comprises a sensor body,
A diaphragm provided on an oscillating surface of ultrasonic waves oscillated from the sensor body, a pressure reducing / pressurizing nozzle connected to the sensor body, a pressure detector provided on the pressure reducing / pressurizing nozzle, and the sensor. It is characterized by comprising a pillar and a cable connector provided on the main body.

[0010]

[Function] The gas pressure in the sensor body is controlled by letting gas flow in and out of the sensor body. When the gas pressure is increased, the diaphragm deforms in a convex shape, and when the gas pressure is decreased, the diaphragm deforms in a concave shape.

When it is deformed into a convex shape, the directivity angle is large,
When it is deformed into a concave shape, the directivity angle becomes smaller. Thus, the distortion of the ultrasonic wave oscillating surface oscillated from the sensor body changes due to the gas pressure control in the sensor body, and the directivity angle changes accordingly. Thereby, the ultrasonic transmission / reception range in sodium can be arbitrarily changed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultrasonic sensor for sodium see-through device according to the present invention will be described with reference to FIGS. In the figure, the same parts as those in FIGS. 3 and 4 are designated by the same reference numerals.

As shown in FIG. 1, the ultrasonic sensor 1a according to the present invention has a diaphragm 17 provided on the front surface of the hollow sensor body 16, that is, on the ultrasonic wave oscillating surface. A pressure reducing / pressurizing nozzle 18 for filling or withdrawing gas is connected to the sensor body 16, and a pressure detector 19 is provided in the pressure reducing / pressurizing nozzle 18.

Further, the sensor body 16 is provided with a column 20 and a cable connector 21 on the surface facing the diaphragm 17. The column 20 is for fixing to the sodium see-through device 2, and the cable connector 21 is for taking out an ultrasonic sensor signal.

The pressure reducing / pressurizing nozzle 18 is connected to a gas discharge valve 22 and a gas supply valve 23 as shown in FIG. 2, and the gas discharge valve 22 is connected to an exhaust gas line (not shown),
23 is connected to a gas supply line (not shown).

This ultrasonic sensor 1a is incorporated in the sodium see-through apparatus body 2 as shown in FIG. The sodium see-through device further includes a driving device 3 for driving the ultrasonic sensor, a gas supply valve 23 and an exhaust valve 22 for supplying and discharging gas into and from the ultrasonic sensor 1a to change the strain on the sensor surface.
It is composed of a signal processing device 4 for processing an ultrasonic signal and an operating device 5 for operating the valve and the ultrasonic sensor 1.

An ultrasonic reflection plate 7 is provided in the reactor vessel 6 at a position facing the sodium see-through device main body 2 so that echoes oscillated from the ultrasonic sensor 1a can be efficiently reflected.

In the sodium see-through device, the ultrasonic waves oscillated from the ultrasonic sensor 1a are reflected by the ultrasonic reflecting plate 7 and received again by the ultrasonic sensor 1a. By this echo signal, the core 11 and the core upper part mechanism 9 installed above the core 11
It is possible to detect, for example, the floating state of the fuel assembly and the presence or absence of other obstacles.

At the time of this detection, the gas supply valve 19 pressurizes the inside of the ultrasonic sensor 1a to distort the surface of the diaphragm 17 of the ultrasonic sensor 1a into a convex shape (indicated by a broken line in the figure).
The directional angle can be expanded.

On the other hand, the gas discharge valve 18 allows the ultrasonic sensor 1
By depressurizing the inside of a, the surface of the diaphragm 17 of the ultrasonic sensor 1a is distorted into a concave shape, so that the directivity angle can be reduced.

Thus, the directivity angle can be finely adjusted by the operation of pressurizing or depressurizing the inside of the ultrasonic sensor 1a. The ultrasonic sensor 1a of this embodiment can be applied to an out-of-reactor fuel storage tank having the same environmental conditions as the case shown in FIG.

According to the above embodiment, the pressure of the gas enclosed in the ultrasonic sensor is increased / decreased, the strain of the surface of the ultrasonic sensor is made variable by the action of the diaphragm, and the internal pressure of the ultrasonic sensor is automatically controlled. And a drive device for driving the ultrasonic sensor are combined, and the directivity angle is made variable by finely adjusting the internal pressure to enable focusing on the ultrasonic reflector installed in the reactor vessel.

Further, by applying gas pressure to the inner surface of the diaphragm to make the diaphragm convex, the ultrasonic directivity angle can be narrowed, and by controlling the inner surface pressure of the diaphragm, the ultrasonic directivity angle can be varied. Ultrasonic detection can be focused.

Further, in the above-described embodiment, a drive device capable of swinging the ultrasonic sensor in the left and right direction is provided, or a drive device capable of swinging the angle to the left and right by mounting the ultrasonic sensor via a bellows. Can be provided. It is possible to provide a drive device capable of moving the ultrasonic sensor up and down, and a drive device capable of finely adjusting the vertical angle of the ultrasonic sensor.

Further, it is possible to provide a control device for controlling the vertical and horizontal positioning of the ultrasonic sensor and the pressure on the inner surface of the diaphragm by using the position data of the detection target and enabling the focus of the detection target.

By providing a plurality of reflectors having a certain distance from the ultrasonic sensor, it becomes possible to calibrate the relationship between the diaphragm internal pressure and the focus without changing the focus. A control device that can automatically adjust the focus by calculating the distance of the detection target from the ultrasonic echo, setting the diaphragm internal pressure, and then finely adjusting the diaphragm internal pressure to maximize the reflection intensity of the ultrasonic waves. Can be provided.

[0027]

According to the present invention, gas is allowed to flow in and out of the sensor body, the strain on the sensor surface is changed according to the external pressure of the sensor by adjusting the pressure by the diaphragm element, and the directivity angle is changed accordingly. It is possible to change the ultrasonic transmission / reception range inside. Further, by adjusting the gas pressure, it becomes possible to finely adjust the directivity angle.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an ultrasonic sensor according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a partial block of a reactor vessel incorporating the ultrasonic sensor of FIG.

FIG. 3 is a vertical sectional view schematically showing the inside of a reactor vessel for explaining a conventional sodium see-through device.

FIG. 4 is a cross-sectional view showing an enlarged view by cutting in the direction of arrow AA in FIG.

[Explanation of symbols]

1, 1a ... Ultrasonic sensor, 2 ... Sodium see-through device main body, 3 ... Driving device, 4 ... Signal processing device, 5 ... Operating device,
6 ... Reactor vessel, 7 ... Ultrasonic reflector, 8 ... Missing number, 9 ... Core upper mechanism, 10 ... Sodium, 11 ... Core, 12 ... Shield plug, 13 ... Core support plate, 14 ... Plenum, 15 ... Core tank ,
16 ... Sensor body, 17 ... Diaphragm, 18 ... Pressure reducing / pressurizing nozzle, 19 ... Pressure detector, 20 ... Strut, 21 ... Cable connector, 22 ... Gas discharge valve, 23 ... Gas supply valve.

Claims (1)

[Claims] 1. A sensor main body, a diaphragm provided on an oscillating surface of ultrasonic waves oscillated from the sensor main body, a pressure reducing / pressurizing nozzle connected to the sensor main body, and the pressure reducing / pressurizing nozzle. An ultrasonic sensor for a sodium see-through device, comprising: a pressure detector as described above; and a column and a cable connector provided on the sensor body.