JP6754721B2 - Steam system water level detector - Google Patents

Description

The present invention relates to a steam system water level detecting device, for example, comprise a de Len valve that is installed to draining the steam system detection in a pipe of a nuclear power plant to the outside, the drain level measuring instrument and the pipe The present invention relates to a steam-based water level detector suitable for such a device.

Generally, in the steam system of a nuclear power plant, a steam water level detector equipped with a drain water level measurement detector is known in order to measure the drain water level of equipment such as feed water heaters and drain tanks and piping. There is.

This steam water level detector consists of a pressure guide tube from the equipment and piping to the drain water level measurement detector, a detection source valve that separates the equipment from the instrument, an instrument inlet / outlet valve that isolates the instrument during instrument inspection, and a steam water level detection pipe. It is roughly composed of a drain valve that discharges the drain inside to the outside.

The steam system water level detector in a nuclear power plant is a detection piping system installed in an area isolated from a normal area because it is a system containing a high dose of steam.

Before normal operation of the plant, check the open / closed state of the instrumentation valve installed in the steam system water level detector, check if there is any abnormality in the instrumentation valve, and check from the outside whether the instrumentation valve is damaged. We have confirmed the soundness of the steam water level detector by checking the appearance damage, but since we have not inspected the inside of the valve, we cannot deny the possibility that an abnormality will occur during operation.

In particular, the drain valve is a normally closed operation valve, and this drain valve serves as an isolation valve between the steam system and the outside. However, if an abnormality such as a leak or valve damage occurs in the drain valve, the drain water level can be measured. An error may occur, and steam may be discharged to the outside of the system via the drain socket.

In addition, there is a method of installing a thermometer to detect abnormalities in the drain valve, but since the steam system water level detector is equipped with a heat insulating material to prevent drainage due to heat dissipation, the surface of the pipe The heat insulation effect of heat retention is high, and it may take some time for the thermometer to detect signs of abnormality.

A technique for detecting the water level in a drain tank in a nuclear power plant is described in Patent Document 1.

Japanese Unexamined Patent Publication No. 5-223206

However, in the above-mentioned conventional technique, in order to ensure the soundness of the steam system water level detection piping system, it is necessary to confirm the soundness of the piping and the drain valve by disassembling and checking the drain valve and performing a pressure resistance test before starting the plant. is there.

In addition, if an abnormality such as a seat leak is confirmed from the drain valve during plant startup or operation, it is necessary to take measures to prevent steam outflow, but since steam piping is installed in a high dose area, it is necessary to take measures. It takes a lot of labor and time to prevent steam outflow.

The present invention has been made in view of the above, it is an object of earlier signs of an abnormal, it is possible to accurately detect, the steam-based level detection apparatus that can prevent the system expelling steam To provide.

In order to achieve the above object, the steam-based water level detector of the present invention is installed in the middle of a pressure guiding tube for measuring drain water in an apparatus and a pipe, and is composed of a valve body and a valve rod. A drain valve equipped with a thermometer for measuring the temperature of the valve body and discharging the drain in the steam system water level detection pipe to the outside, a backup valve installed in the pressure guiding pipe on the downstream side of the drain valve, and the drain valve. A control device for opening and closing the backup valve based on the temperature of the valve body measured by the thermometer is provided, and the control device determines whether or not the temperature of the valve body measured by the thermometer is abnormal. If the judgment by the control device is that the temperature inside the valve body is abnormal, the backup valve is automatically closed or
Alternatively, it is installed in the middle of the pressure guiding tube that measures the drain water in the equipment and piping, consists of a valve body and a valve rod, and the valve rod is equipped with a thermometer that measures the temperature of the valve body to detect the steam system water level. The drain valve that discharges the drain in the pipe to the outside, the backup valve installed in the pressure guiding pipe on the downstream side of the drain valve, and the valve body temperature measured by the thermometer of the drain valve. A remote manual device for operating a backup valve is provided, and the remote manual device determines whether or not the temperature of the valve body measured by the thermometer is abnormal, and the remote manual device determines whether or not the temperature of the valve body is abnormal. If the internal temperature is abnormal, the remote manual device closes the backup valve.

According to the present invention, signs of abnormality can be detected more quickly and accurately, and steam can be prevented from being released from the system.

It is a schematic block diagram which shows Example 1 of the drain valve of this invention. It is a system diagram which shows Example 1 of the steam system water level detection apparatus of this invention. It is a partial system diagram which shows Example 2 of the steam system water level detection apparatus of this invention.

Hereinafter, the steam-based level detection device of the present invention will be described with reference to the embodiments shown. In each figure, the same reference numerals are used for the same components.

FIG. 1 shows Example 1 of the drain valve of the present invention, and FIG. 2 shows Example 1 of a steam-based water level detection device provided with the drain valve.

As shown in FIG. 1, the drain valve of this embodiment is composed of a valve body 3 and a valve rod 1, and the valve rod 1 is provided with a thermometer 2 for measuring the temperature of the valve body 3 (hereinafter, this drain valve). Is referred to as a drain valve 10 with a temperature detection function), and the thermometer 2 is provided with a connection terminal 4 for transmitting the measured temperature of the valve body 3 to the outside. Reference numeral 5 is a valve body.

That is, the drain valve 10 with a temperature detection function of this embodiment has a thermometer 2 inserted inside a valve rod 1 of a manual ball valve and a bellows seal to enable temperature measurement of the valve body 3. is there. The signal of the thermometer 2 has a structure of being transmitted to the outside (control device 14 described later) at the connection terminal 4.

Further, the drain valve 10 with a temperature detection function of this embodiment has a structure in which a thermometer 2 is installed. However, when temperature measurement is not required, the thermometer 2 can be removed and used in the past. It can also be applied to the place where it is (also as a normal drain valve).

Further, since the drain valve 10 with a temperature detection function can measure the internal fluid temperature, it can be applied to equipment that requires internal fluid temperature measurement.

Next, a steam-based water level detection device provided with a drain valve 10 with a temperature detection function will be described with reference to FIG.

The steam system water level detection device of this embodiment is, for example, a device such as a water supply heater or a tank, a pressure guiding tube 7 for measuring drain water of a pipe 6, a detection source valve 8 for separating the meter 12 from the steam system, and a pressure guiding tube. At the time of calibrating the instrument 12 installed in the middle of No. 7 (when replacing the instrument 12), the instrument inlet valve 9a and the instrument outlet valve 9b that isolate (close) only the instrument 12 and the configuration described with reference to FIG. A drain valve 10 with a temperature detection function for draining the drain, a backup valve 11 that isolates the system when the drain valve 10 with a temperature detection function is abnormal, and a valve measured by a thermometer 2 of the drain valve 10 with a temperature detection function. It is roughly composed of a control device 14 that controls opening and closing of the backup valve 11 based on the temperature of the body 3, and a cable 13 that connects the control device 14, the drain valve 10 with a temperature detection function, and the backup valve 11, respectively.

Then, in the steam system water level detection device of this embodiment, the control device 14 determines whether or not the temperature of the valve body 3 measured by the thermometer 2 is abnormal, and the determination by the control device 14 is the inside of the valve body 3. If the temperature is abnormal (for example, a temperature higher than a predetermined threshold value), the backup valve 11 is automatically closed.

That is, during the normal operation of the plant, the fluctuation is transmitted to the instrument 12 by the pressure guiding pipe 7 to the drain water in the equipment and the pipe 6, and the water level is measured.

The drain valve 10 with a temperature detection function will continue plant start-up and operation with drain water on the upstream side, and the temperature of the drain valve 10 with a temperature detection function will stabilize at a constant temperature within a few hours after the start-up. ..

When an abnormality such as a seat leak occurs in the drain valve 10 with a temperature detection function, the high-temperature drain water and steam upstream of the drain valve 10 with a temperature detection function are discharged to the outside of the system, so that the drain valve with a temperature detection function The thermometer indication of 10 rises, that is, the detection temperature of the drain valve 10 with a temperature detection function displayed on the control device 14 rises, and an alarm is issued to the control device 14 via the cable 13.

When an alarm is detected by the control device 14, the backup valve 11 is closed by the closing signal of the backup valve 11 from the control device 14, and the system can be automatically isolated.

With the configuration of this embodiment as described above, in the steam system water level detection device of the nuclear power plant, the thermometer 2 incorporated in the drain valve 10 with the temperature detection function enables the abnormality of the drain valve 10 with the temperature detection function to be detected at an early stage. It becomes possible to detect the vapor at an early stage.

Further, by detecting an abnormality in the drain valve 10 with a temperature detection function and automatically closing the backup valve 11 installed downstream of the drain valve 10 with a temperature detection function, it is possible to prevent steam from being released from the system at an early stage. Therefore, exposure can be reduced by preventing a decrease in plant output due to system isolation and eliminating the need for repair work for abnormal valves.

Therefore, according to this embodiment, the signs of abnormality can be detected more quickly and accurately, and the vapor can be prevented from being released from the system.

FIG. 3 shows Example 2 of the steam-based water level detection device of the present invention. FIG. 3 shows that the remote manual device 15 is used instead of the control device 14 of FIG.

That is, in the first embodiment shown in FIG. 2, the backup valve 11 was automatically isolated by using the control device 14, but when the control device 14 is not applied, the remote manual operation is performed as in the present embodiment. It is also possible to close the backup valve 11 with the device 15.

That is, the remote manual device 15 determines whether or not the temperature of the valve body 3 measured by the thermometer 2 is abnormal, and the determination by the remote manual device 15 is that the temperature inside the valve body 3 is abnormal (for example, predetermined). If the temperature is higher than the specified threshold value), the remote manual device 15 closes the backup valve 11.

Even with such a configuration of this embodiment, in the steam system water level detection device of the nuclear power plant, the thermometer 2 incorporated in the drain valve 10 with the temperature detection function enables the abnormality of the drain valve 10 with the temperature detection function to be detected at an early stage. It becomes possible to detect the vapor at an early stage.

Further, by detecting an abnormality in the drain valve 10 with a temperature detection function and closing the backup valve 11 installed downstream of the drain valve 10 with a temperature detection function by the remote manual device 15, the steam is released to the outside of the system at an early stage. Since it can be prevented, exposure can be reduced by preventing a decrease in plant output due to system isolation and eliminating the need for repair work of an abnormal valve.

Therefore, according to this embodiment, the signs of abnormality can be detected more quickly and accurately, and the vapor can be prevented from being released from the system.

It should be noted that the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 ... valve rod, 2 ... thermometer, 3 ... valve body, 4 ... connection terminal, 5 ... valve body, 6 ... equipment, piping, 7 ... pressure guiding tube, 8 ... detection source valve, 9a ... instrument inlet valve, 9b ... Instrument outlet valve, 10 ... Drain valve with temperature detection function, 11 ... Backup valve, 12 ... Instrument, 13 ... Cable, 14 ... Control device, 15 ... Remote manual device.

Claims (2)

It is installed in the middle of the pressure guiding pipe that measures the drain water in the equipment and piping, and consists of a valve body and a valve rod. The valve rod is equipped with a thermometer that measures the temperature of the valve body, and inside the steam system water level detection pipe. The backup valve is based on the drain valve that discharges the drain to the outside, the backup valve installed in the pressure guiding pipe on the downstream side of the drain valve, and the temperature of the valve body measured by the thermometer of the drain valve. Equipped with a control device that controls the opening and closing of
The control device determines whether or not the temperature of the valve body measured by the thermometer is abnormal, and if the judgment by the control device is that the temperature inside the valve body is abnormal, the backup valve is automatically operated. A steam-based water level detector characterized by being closed. It is installed in the middle of the pressure guiding pipe that measures the drain water in the equipment and piping, and consists of a valve body and a valve rod. The valve rod is equipped with a thermometer that measures the temperature of the valve body, and inside the steam system water level detection pipe. The backup valve is based on the drain valve that discharges the drain to the outside, the backup valve installed in the pressure guiding pipe on the downstream side of the drain valve, and the temperature of the valve body measured by the thermometer of the drain valve. Equipped with a remote manual device to operate
The remote manual device determines whether or not the temperature of the valve body measured by the thermometer is abnormal, and if the judgment by the remote manual device is that the temperature inside the valve body is abnormal, the remote manual device is used. A steam-based water level detection device characterized in that the backup valve is closed by the device.

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