JPS59138912A - Apparatus for detecting opening degree of isolating valve of main vapor - Google Patents

Abstract

PURPOSE:To detect exactly an opening degree signal of a main vapor isolating valve by constituting a detector from a combination of a transmitter and a receiver of light or ultrasonic beam, etc. and a reflecting plate or an intercepting plate moving in accordance with the opening degree of the main vapor isolating valve. CONSTITUTION:The main vapor isolating valve 11 has a very long stroke, and drives a valve rod 5 against a spring 13 attached at outer circumference of a guide rod 12 to open the valve by an isolating valve driving mechanism 4. An apparatus 10 for detecting the opening degree of the main vapor isolating value is constituted from two photoelectric detectors 15a, 15b provided on an attaching plate 14 fixed to the main vapor isolating valve main body 1, on the line parallel to the valve stroke direction and at the positions corresponding to 10% and 90% opening degrees, and the reflecting plate 16 attached at the one end of a spring receiving plate 6 fixed vertically to the center axis direction of the rod 5 driven by an isolating valve driving mechanism 4, parallelly to the valve stroke direction and in opposition to the front surface of the directions 15a, 15b.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention detects the valve opening position of a main steam isolation valve in a boiling water nuclear power plant and supplies a main steam isolation valve opening position signal during that time. The present invention relates to a degree detection device.

[Technical background of the invention and its problems]

In a boiling water nuclear power plant, the steam generated in the reactor pressure vessel passes through the main steam pipe and is led to the turbine, which drives the turbine and generates electricity. Because it contains radioactive materials, if the main steam pipe ruptures, the main steam pipe must be installed in the reactor to prevent radioactivity from being released outside and to prevent reactor cooling water from flowing out. Main steam isolation valves are installed on the inside and outside of the part that penetrates the outer wall of the containment vessel.A total of eight main steam isolation valves are installed, two on each main steam pipe, which are normally four in parallel. The valve has a very long stroke and is operated by air or nitrogen gas.The main steam isolation valve is part of the plant protection system, and its opening signal is
In addition to simply lighting the open/close indicator light, it is also used for various interlock signals and computer input signals.
It is characterized by detecting the engaged opening position or the accurate opening position in the middle of the valve stroke equivalent to 90% opening, and supplying the signal.

As shown in FIG. 1, a conventional main steam isolation valve opening degree detection device has a mounting plate 2 fixed to a main steam isolation valve main body 1, and a 10
Two glue switches 3a (for 10 engagement opening) and 3b installed at positions ii' and 1' corresponding to the engagement opening and 90% opening device
(for 90 degrees of opening) and a striker 8 fixed with a mounting bolt 7 to one end of a spring receiving plate 6 attached to a valve stem 5 driven by a main steam valve drive mechanism 4. The limit switches 3a and 3b are of a type in which the operating arm 9 is mechanically actuated by a striker 8 that moves according to the opening degree of the main steam isolation valve, and is reset by the reverse operation of the main steam isolation valve. is adopted.

Limit switches 3a and 3b are each rotated 10 degrees accurately.
% and the opening degree is 90%, the positions of the limit switches 3a and 3b can also be adjusted to some extent.
It is mainly adjusted by the length and direction of the striker 8. However, the operating points of the limit switches 3a and 3b are not necessarily proportional to tn of the striker 8, and even if the striker 8 is shifted by the necessary adjustment dimension, the direction and length of the striker 8 will change somewhat at the same time, and the limit switch 3a.

3b to the point where it makes contact with the operating arm 9 (h) is shifted and the adjustment dimension changes beyond the desired adjustment dimension, or the adjustment dimension is insufficient, and the adjustment has to be repeated, making it extremely troublesome to adjust the opening A. It was a lot of work and took a lot of time.

Furthermore, the main steam isolation valve was installed in an area with high radiation levels, and the work environment was poor, requiring triple-layered gloves and a full-face mask, posing many difficulties in adjusting work there. .

In addition, main steam isolation valves are disassembled and inspected during periodic plant inspections, so they require adjustment as described above at each periodic inspection.
At present, it takes several days for adjustment, etc., and conventional main steam isolation valve opening detection devices have many drawbacks, such as requiring a long time for the θ111 operation.

[Purpose of the invention]

This invention was made in view of the above circumstances, and it is possible to easily and easily obtain accurate and reliable opening signals for main steam isolation valves in boiling water nuclear power plants without the need for troublesome adjustment work. It is an object of the present invention to provide a main steam isolation valve opening detection device that can be taken out.

[Summary of the invention]

The main steam isolation valve opening detection device according to the present invention is an improvement on the conventional isolation valve opening detection device which uses a limit switch and operates it by mechanical contact. Attach the detection H1ζ, which is a combination of transmitter and receiver, such as a light or ultrasonic beam, in the position where it was installed, and also detect the valve to be detected on a line parallel to the valve stroke direction of the main steam isolation valve. A light or ultrasonic reflecting plate or blocking plate fixedly attached to a position corresponding to the opening position of the main steam isolation valve is moved according to the opening position of the main steam isolation valve. Alternatively, the position of the shielding plate should be adjusted in advance, and when the valve opening position of the main steam isolation valve reaches the set position, the detector will detect the reflected wave from the reflection plate or the beam wave due to the shielding plate. This device detects the shutoff and supplies the desired valve opening position signal, and detects the valve opening position without contact, without using any mechanical contact that is troublesome to adjust. The feature is that it is made as follows.

[Embodiments of the invention]

One embodiment of the main steam isolation valve opening degree operating device Q'l according to the present invention is shown in FIGS. 2 and 3, and another embodiment of the main steam isolation valve opening degree detection device according to the present invention is shown in FIG. 4. and fifth
This will be explained using figures.

FIG. 2 shows a main steam isolation valve opening detection device 10 according to the present invention.
FIG. 3 is a side view of the main steam isolation valve opening degree detection device 10, which is older than the direction of the arrow A-A in FIG. The stroke is very long, and the isolation valve and the ringing mechanism 4 are used to open the valve by ringing the valve rod 5 against the spring 13 provided on the outer periphery of the guide rod 12 (the second (The figure shows when the valve is closed), and the valve opening signal is normally obtained by detecting two types of opening degrees during the opening and closing of the valve: 10 closing degree and 90 closing degree.

The main steam isolation valve opening degree detection device 1o is arranged on the mounting plate 14 fixed to the main steam isolation valve body 1 at positions corresponding to the 10% opening degree and the 90% engagement degree on a line parallel to the stroke direction of the valve. Two photoelectric detectors 15a (for 10% opening), 1
5b (for 90% opening) and the valve stem 5 driven by the isolation valve drive mechanism 4, perpendicular to the central axis direction of the valve stem 5.
It consists of a reflecting plate 16 attached to one end of a fixed spring receiving plate 6 so as to be parallel to the stroke direction of the valve and facing directly to the photoelectric detectors 15a, 151).

Although not shown in the drawing, the optical detectors 15a and 15b include a light beam transmitter that emits a light beam and a light receiver that converts the light beam reflected from the reflection plate 16 into a signal. However, it is secured with a bolt 17 so that the valve can be adjusted and moved in the direction of the rotor. In addition, the reflector 16
A light reflective tape 18 is attached to the entire surface facing the front surface of the light beam type detectors 15a and 15b to improve reflection.

When the main steam isolation valve 11 is fully open, the spring receiving plate 6 is at the 6a position and the reflecting plate 16 is at the 1 position, as shown by the two-dot chain line.
6a, the light beams from the optical detectors 15a and 15b are not reflected by the reflecting plate 16, so the optical detector 15a is located at the position 6a.

There is no air output from either 1 or 5 b. When the valve closing operation of the main steam isolation valve 11 begins, the position of the reflector plate 16a also moves downward in the drawing in accordance with the movement of the valve, and the position of the reflector plate 16a moves downward in the drawing. When the reflective surface I8 reaches the front surface of the 10th closing layer number (90 closing signal) moonlight set detector 15b whose position has been adjusted in advance, the photoelectric detector 15b detects the reflected light and Gives a close (90 open) signal. Fourth, when the valve closing operation progresses and the reflective surface 18 of the reflector plate 16 is in front of the optical detector 15a for the 90% closed signal (10 candy open signal), the optical four-type detector 15a will reflect. Detects light and issues a 90% closed signal (10 engaged closed signal).

When operating the main steam isolation valve, the operation is the opposite of the closing operation, so if the point in time when the electrical output from the photoelectric detectors 15a and 15b disappears is detected, 10 engagement signals and 90
A locking signal is obtained.

Next, FIG. 4 is a front view of a main steam isolation valve opening detection device 20 according to another embodiment of the present invention attached to the main steam isolation valve 11, and FIG. FIG. 2 is a side view of the main steam isolation valve opening degree detection device 20 as seen from the direction.

In this case, the opening degree of the valve is detected by blocking the light beam using a blocking plate that moves according to the movement of the main steam isolation valve. Optical beam transmitters 21a (for ]-0% opening), 21. b (for 90% opening), optical receivers 22a (for 10% closing), 22b (90%
% opening) are separately attached to mounting plates 23 and 24 which are fixed to the main steam isolation valve body 1 and are located parallel to the stroke direction of the valve and opposite to each other. The valve is mounted between the mounting plate 23 to which the beam transmitters 21a, 21b are attached and the mounting plate 24 to which the optical receivers 22a, 22b are attached, by being attached to the spring support plate 6 fixed to the valve stem 5. Corresponding to the movement of , the optical a-cut root 25, which moves in parallel in the direction of the stroke of yf, moves parallel to the respective surfaces of the double claw plates 23 and 24.

Therefore, the 10% opening signal and the 90% opening signal can be extracted using the same method as in the case of FIG. 2, which utilizes the 9th reflection.

The embodiment shown in FIGS. 2 to 5 above uses a light beam to detect the opening position 1a. With this configuration, it is possible to detect the valve opening position.

In any of the above cases, since mechanical contact is not used to detect the valve opening position as in the conventional case, the vertical adjustment of one opening position is simplified and the adjustment work time is significantly shortened.

〔Effect of the invention〕

As described in detail in the previous section, the main steam isolation valve opening detection device according to the present invention detects the 10% opening position and the 90% opening position of the valve on a mounting plate fixed to the main steam isolation valve body. A detector that combines a signal transmitter and a signal receiver is placed at a position corresponding to the position, and the signal is reflected or blocked by a reflecting plate or blocking plate that moves according to the opening and closing movement of the main steam isolation valve. Since the valve opening position signal is extracted by detecting the valve opening position, there is no need for mechanical contact to generate heat as in conventional valve opening position detection devices, and therefore, the operation is 6' max. and reliability is improved. At the same time, the opening position of the detector can only be adjusted by adjusting the position in the stroke direction of the valve.
Since the adjustment is only 1'+iJ, the adjustment work time is significantly shortened, and therefore, the radiation exposure of workers is significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional main steam isolation valve opening detection device, FIG. 2 is an explanatory diagram of an old main steam isolation valve opening detection device according to an embodiment of the present invention, and FIG. 4 is an explanatory diagram of a main steam isolation valve opening detection device in another embodiment of the present invention, and FIG. 5 is a side view as viewed from the direction of arrow B-B in FIG. 4. It is a diagram. 10.20...Main steam isolation valve opening detection device, 11...
・Main steam isolation valve, 1.5a, 15b...Optical detector, 16...Reflector, 21a, 21b...Light beam transmitter, 22a, 22b・Optical receiver, 25...Shutoff Board. (7317) Agent Patent attorney Yu Norikonji (and 1 other person)

Claims (6)

[Claims] (1) Opening detection device for detecting the valve opening position of the main steam isolation valve installed in the main steam pipe of a water nuclear power plant [n] A detector of f=1 digit beam wave is fixed at a position corresponding to the opening position of the valve to be detected on a plane parallel to the stroke direction of the main steam isolation valve. and a reflector plate that follows the detector and moves parallel to the direction of the valve striker along the front surface of the detector, and reflects the signal from the detector at the set position 11.Z-. Characteristic main steam isolation valve opening detection wave 11rZ. (2) Main steam isolation valve opening degree detection device 1'1' described in item 1 of the scope of the patent Air claim, in which the detector is an optical detector.
. (3) Claim 1 where the detector is an ultrasonic detector! Self-described main steam isolation valve opening detection device. (4) δlj In the opening detection device that detects the valve opening position of the main steam isolation valve installed in the main steam pipe of the M water type nuclear power station, the position corresponding to the opening position of the valve to be detected. and a detector in which a beam wave transmitting part and a beam receiving part are fixedly attached separately and facing each other on a line parallel to the valve stroke direction of the main steam isolation valve, and r'+jl Following the movement of the main steam isolation valve,
The transmitter of the beam wave of the detector (6) moves parallel to the stroke direction of the valve between the detector and the receiving section, and cuts off the signal from the IB section to the receiving section at the set position. A main steam isolation valve opening detection device characterized by: (5) The main steam isolation valve opening detection device according to claim 4, wherein the detector is a photoelectric detector. (6) The main steam isolation valve opening detection device according to claim 4J, wherein the detector is an ultrasonic detector.