JPS585408A - Equipment for opening and closing main steam shutoff valve - Google Patents

Abstract

PURPOSE:To maintain the soundness of a nuclear reactor and prevent the damage of piping and a main steam shutoff valve of self-presure type, which is closed in the emergency of the reactor, by providing slowly operating valve and a second check valve for the main shutoff valve to slowly close its valve element at the regular checkup of function. CONSTITUTION:To check up the function of a main steam shutoff valve 4 during the normal operation of a nuclear reactor, a second open valve 15 is closed and a slowly operating valve 24 is opened so that high-pressure steam in the casing 5 of the valve 4 flows into its second chamber 12. Subsequently, a first open valve 14 is closed and a pressurizing valve 17 is opened so that the steam in the valve casing 5 flows into its first chamber 11 as well and the pressure of the chambers 11, 12 becomes equal to that in the valve casing. As a result, the valve element 7 of the main shutoff valve 4 is slowly closed by the elastic force of a spring 10. The position of the valve element 7 is found out by a detector 13. When the valve element 7 has reached a prescribed degree of opening, the detector 13 applies its output to open the first valve 14 and close the pressurizing valve 17 to move the valve element back upwards into full opening.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a main steam valve opening/closing device which is suitable for nuclear reactor plants and is capable of switching the closing speed of a self-pressure main steam isolation valve into two stages, slow and fast.

No. 111 shows a schematic configuration of a nuclear reactor, in which main steam generated from the reactor pressure vessel 1 is led out through the main steam pipe 2 to the outside of the reactor containment vessel SO, and is supplied to the reactor.

Main steam isolation valves 4-4 are inserted before and after the main steam piping IK Tsuji containment vessel penetration part, and in the event of an emergency such as a nuclear reactor accident, the Hiera O valve 4.4 closes in an emergency to remove radioactive materials. Constructed to prevent leakage.

2@ shows the main steam isolation valve 1lWI4 scissor placement, the main steam isolation valve 4 has a pressure receiving body accommodation capacity C connected to the valve shaft 10 upper part 11, and the valve body I has a valve body r, Pressure receiving bodies are housed inside (inside the valve body 1) the pressure receiving bodies 1 with a large pressure receiving area are respectively housed, and both are connected so that they can move up and down as one, and are connected to the valve body 7 and have nine valve shafts. 9 is introduced into the pressure receiving body housing i16 through the center hole of the pressure receiving body 8, and electricity is distributed around the periphery 11 of the valve shaft 9 so that the nine snoring ring 10 always biases the valve body 1 in the closing direction. ing.

Note that the internal space of the pressure receiving body storage chamber 6 is based on the pressure receiving body a)
1st W! It is airtightly divided into il 1 and 21111. (9) A detector 13 is attached to the upper end of the pressure receiving chamber 6, and the detector IJ is configured to detect the position of the valve body 7 by detecting the position of the valve stem. There is.

Each of the pressure receiving chambers 11 and 12 has a release valve (electromagnetic valve) 14. II+ to the atmosphere. A pressurizing valve 1r is connected to the closed valve II5 via a high pressure priority type Mezl check valve 1σ, and this check valve 1#, pressurizing valve (
The high pressure steam in the valve box 5 is made to flow into the first @ 11 via the solenoid valve) 11 and the oriice 1a. Note that during normal operation, the pressurizing valve 11 is closed.

1 is maintained. In addition, a separate round pipe 19 for supplying high-pressure water and diner gas is connected to the check valve 1#.

Therefore, during normal reactor operation, high-pressure steam generated in the reactor pressure vessel IK flows into the main steam isolation valve 40 and into the valve box 5 through its inlet 20, pushing up the valve body 1 against the spring 10. , flows out through the outlet 11 of the valve box 5 and reaches the turbine.

For example, in the event of a nuclear reactor accident, when the isolation signal is generated, the pressurizing valve 1r is opened, and at the same time, the release valve 14 communicating with the first chamber 11 is closed, whereby the steam in the valve box 5 is released. Check valve 16. It flows into the first chamber 11 through the pressure valve 11 and the oriice 18, pressurizes the pressure receiving body 1, and rapidly closes the valve body 1. If the steam pressure inside the valve box 1 is not very high, the high-pressure water tank 9 injects nitrogen gas into the first fiJJ through the piping 19 and the Sidanol check valve 1#, and 1 is suddenly closed.

At this time, the time for closing the valve body 1 is approximately 0.2 to 0.
It is 3 seconds. Also, the pressure valve 11 is closed, and the release valve 1 is closed.
By opening the main steam isolation valve 4, the main steam isolation valve 4 is again connected to the valve box l.
It is pushed up by the high pressure steam inside and opens. In addition, if the steam pressure in the valve box 5 is not very high (approximately 4 or less), the open valve 1s communicating with the 2nd@IJ is closed, and the 21st is connected to the 11th through the pipe. to high pressure (approximately i 0 k#/
a1m) o Inject nitrogen gas to raise the valve body 1.

Main steam isolation valve 4 used in nuclear reactor plants.
However, during normal operation of the reactor, repeated rapid closures may cause severe transient changes to the reactor during function inspections of the main steam isolation valve, which are periodically carried out. There is a risk of damage to the integrity of the reactor core due to the pressure generated in the main steam piping and the impact when the valve element of the main steam isolation valve hits the valve seat. This is not desirable as it may cause damage to the isolation valve itself.

The present invention was made based on these circumstances,
The purpose of this is to enable rapid emergency closure of the main steam isolation valve in the event of an emergency such as a nuclear accident, and also to enable the main steam isolation valve to be closed during periodic functional inspections of the main steam isolation valve during normal reactor operation. An object of the present invention is to provide a main steam isolation valve opening/closing device that can be closed slowly.

In other words, the main steam isolation valve opening/closing device according to 1jiK of the present invention,
The valve body is airtightly divided into a valve body having an inlet and an outlet and housing a valve body, a pressure receptor housing chamber connected to this valve body, and a second w&. a pressure receiving body, a slinder housed in the pressure receiving body housing chamber and urging the valve body in the closing direction, and a first valve that selectively permeates each of the first and second valves into the atmosphere. ．． 2nd C) A flA release valve is connected to the valve box through a 10th reversal valve to selectively flow high-pressure steam in the valve box into the 1/s1 rich interior to close the valve body. a pressurizing valve; and a slow operation valve that selectively causes high-pressure steam in the valve box to flow into the second valve via a second check valve and provides resistance to the closing operation of the valve body. , further comprising a steam outlet path connected between the slow operation valve and the second chamber.

Therefore, with the above configuration, in the event of an emergency such as when a nuclear reactor accident occurs, the P main steam isolation valve can be quickly and urgently closed by closing the release valve communicating with No. 1II and opening the pressurizing valve. It is possible to prevent the release of radioactive materials by making the first check during the function inspection of the main steam isolation valve, which is carried out periodically during normal operation of the reactor. By closing the second release valve and opening the slow operation valve and pressurizing valve, the valve body is closed slowly to maintain the integrity of the reactor and prevent damage to the piping and the main steam isolation valve itself. You can get nine excellent effects such as:

The details of the present invention will be explained below based on the embodiment shown in FIG. Note that the same parts as in FIGS. 1 and 2 will be described with the same reference numerals.

The ninth 1st section is divided by the pressure receiving body 8. The 1st iiJ 1 of the 2nd valves JJ and JJ communicates with the valve box 5 via a first check valve (Dasol check valve) 16, a pressurizing valve 11 and an orifice 18, and also communicates with the pre-pressurizing valve IJ. Through valve box 5
is connected to. The high-pressure steam that has passed through the first check valve 1- is configured to flow into the second chamber 11 via the slow operation valve 24 and the second check valve 25. Furthermore, a second check valve 2 is provided between the slow operation valve 24 and the second chamber.
A vapor outlet orifice 16 is inserted in parallel with j. On the other hand, an orifice 21 is also inserted between the first chamber 11 and the first release valve 14 communicating therewith.

Therefore, during normal reactor operation, high-pressure steam generated in the reactor pressure vessel 1 flows into the valve box 5 of the main steam isolation valve 4 through the inlet 20 and passes through the valve body 1! It is pushed up against the ring 10, flows out through the outlet 21 of the valve box 5, and reaches the Kuhn.

For example, when an isolation signal is generated, such as when a nuclear reactor accident occurs, the pressurizing valve 11 opens and at the same time the first release valve 14 opens.
is closed, and as a result, the steam in the valve body 5 flows into the first chamber 11 through the first check valve 1#, the pressurizing valve 11, and the orifice 1s, pressurizes the pressure receiving body 1, and pressurizes the valve body 1. close down rapidly. If the steam pressure in the valve box 5 is not high atb, high-pressure water and nitrogen gas are injected into the coiling chamber 11 through the piping 19 and the check valve 1-, and the valve body 1 can be closed quickly.

By closing the pressurizing valve 11 and opening the release valve 14, the main steam isolation valve 4 is again pushed up by the high pressure steam in the valve box 5 and opened. In addition, if the steam pressure in the valve box 1 is not high (approximately 4 to 3" or less), high pressure (approximately 1 Okg/
The valve body 1 can be raised by injecting nitrogen gas of "exa").

Before performing a functional test of the main steam isolation valve 4 during normal reactor operation, the second release valve 15 is closed and the slow operation valve 24 is opened, and the high pressure steam in the valve box 5 is
When the open valve 14 of the first valve 1 is closed and the pressurizing valve 11 is opened, the steam in the valve box 5 flows into the first valve 1.
111, and the pressure inside both 1i [J 1 * 1 j becomes the same pressure as inside the valve box 5, so the valve body 1
Closes slowly due to zero elasticity. In addition, at this time, the second
Although the pressure in the chamber 12 increases due to the lowering of the pressure receiving body 8, the steam in the second iiiJj gradually flows into the first wealth 11 via the orifice 2#, the slow operation valve 24, and the pressurizing valve 11. The closing operation of the valve body 1 is not hindered.
Then, the position of the valve body r is detected by the detector 1j, and when it reaches a predetermined opening degree (for example, 10- or fully closed),
The first release valve 14 opens according to the output from the detector IJ, the pressurizing valve 11 closes, and the valve body 1 returns to the upper position to be fully opened. Note that the orifices xg and 1F are for adjusting the closing speed during the closing function test. Therefore, by changing the dimensions of the orifices xg, xv), the closing speed of the valve body 1 can be arbitrarily adjusted.
It is possible to adjust the speed, etc. of the valve seat. Also,
Pressurizing valve
Otherwise, it becomes clear that the check valve 16 does not operate.

As described in detail above, according to the present invention, the nematode steam isolation valve can be rapidly and urgently closed in the event of an emergency in the event of a nuclear reactor accident, and the main steam isolation valve can be closed periodically during normal reactor operation. It is possible to provide a main steam isolation valve opening/closing device that can slowly close the isolation valve during a function test of the main steam isolation valve.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of a nuclear reactor, FIG. 2 is a sectional view showing a conventional example, and FIG. 3 is a sectional view showing an embodiment of the present invention. 1... Reactor pressure vessel, 2... Main steam piping, 1...
- Reactor containment vessel, 4... Main steam isolation valve, 5-- Valve box, 6-- Pressure receiving body storage chamber, 7... Valve body, I... Pressure receiving body, 10... Suffling, 11...first wealth, 12.
...Second room, 14. Jl...Open valve, 16...1st
Check valve, 11... Pressure valve, 20... Inlet, 21
...Outlet, 24...Slow speed operation valve, 2s...Second
check valve. Applicant's attorney: Takehiko E, Patent Attorney Haruki Shimada, Commissioner of the Patent Office 1. Indication of the case Patent application No. 56-101621 No. 2, Title of the invention Main steam isolation valve opening/closing device 3, Person making the amendment Relationship to the case Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4, Agent 5, Spontaneous amendment Commissioner of the Japan Patent Office Shima 1) Haruki Tono1, Case Indication Special No. 56-1016212, Name of the invention Main steam isolation valve opening/closing device 3, Person making the amendment Relationship with the case Patent originator (307) Tokyo Shibaura Electric Co., Ltd. 4, Agent 2, Claims (υ: a valve box having an inlet and an outlet 1 and containing a valve body, the valve body ε: a pressure receiving body housing chamber connected thereto, and the valve body Body deformation - The pressure receiving body storage chamber (: two pairs, which are accommodated and partitioned into airtight 4 chambers 1M and I82, and the pressure receiving area from the valve body) a large pressure-receiving body, the pressure-receiving body housing chamber (two sugerindas housed therein and biasing the first valve body in the closing direction, and a large pressure-receiving body in each of the first and second chambers; 1. The valve body 62 is connected through a second open valve and a first check valve, and the high pressure steam in the valve body selectively flows into the first m to close the valve body. A pressurizing valve to be operated, and a steam outlet path connected between the far end and the second chamber to direct high pressure steam in the valve box into the second iI through a second check valve. A main steam isolation valve opening/closing device characterized by: (1) The main steam isolation valve according to claim (l), wherein the tenth check valve is a high pressure priority type double check valve. Switchgear.

Claims (2)

[Claims] (1) A nine-valve ring which has an inlet and an outlet and accommodates a valve body, and a first child who is connected to the valve body and is accommodated in the pressure receiving body housing chamber so as to be able to move forward and backward; a pressure-receiving body having a large pressure-receiving area (the valve body), which is airtightly divided into a second valve body and a second valve body; 1st and 2310th ports selectively communicating with the atmosphere. The 20th open valve is connected to the valve box through the 111th check valve, and the high pressure steam in the valve stem selectively flows into the 111st valve to open the valve body. Pressure valve and high pressure steam inside the valve box
20 through the check valve to selectively flow into the gz imperial chamber and the valve body 0IIF! A main steam isolation valve opening/closing device comprising a slow operating valve that provides resistance to forceful operation, and a steam outlet path connected to the slow operating valve and the above-mentioned No. 211. (2) The main steam isolation valve opening/closing device according to claim 11, wherein the first check valve is a high-pressure priority type maple check valve.