JPS60179691A - Control-rod driving hydraulic device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a control rod drive hydraulic device that controls the flow direction of drive water that operates a control rod drive groove, and particularly relates to a control rod drive hydraulic device that controls the flow direction of drive water that operates a control rod drive groove. The present invention relates to a control rod drive hydraulic device that appropriately adjusts the amount of drive water supplied to the control g rod drive groove during operation.

[Technical background of the invention and its problems]

In general, the output of a boiling water reactor is controlled not only by controlling the flow rate of coolant but also by inserting or withdrawing control rods into the core of the reactor. The insertion and withdrawal of the control rods is automatically operated by the control rod drive mechanism, which is supplied with control rod drive water (hereinafter referred to as drive water) at an appropriate pressure from the control rod drive hydraulic system. It is driven by this.

A large number of control rod drive mechanisms of this type are installed vertically at the bottom of a nuclear reactor, corresponding to the number of control rods installed in and removed from the reactor core, and these control rod drive mechanisms operate independently of each other. There is. The control rod drive mechanism is a locking piston groove structure that is driven by the hydraulic pressure of drive water, and by applying water pressure above or below the drive piston, the valves of the control rod drive hydraulic device, which will be described later, are operated. Driven by. That is, the lower end of the control rod is connected to the top of an index tube mounted on the drive piston, and the control rod is inserted and withdrawn in conjunction with the vertical movement of the drive piston. In addition, a retaining notch is provided on the outer peripheral surface of the index tube, and this notch is recessed in multiple stages in the axial direction, and collet fingers are retained in these notches to position the index tube, that is, the insertion position of the control rod. to hold. On the other hand, remove the collet finger retainer,
When the drive piston is lowered, 1llll? f[
The tl rod is now being pulled out. This collet finger is operated by the vertical movement of a collet piston on which the collet finger is mounted, and a metal collet piston seal is used to seal the collet piston with the cylinder.

By the way, the conventional control rod drive hydraulic system that supplies drive water at the required pressure to such a control rod drive mechanism is configured as IIc+1 as shown in FIG. In addition to being connected to the drainage pipe 3, an insertion line 4 and a withdrawal line 5 to the control rod drive mechanism described above are connected to the drain pipe 3.
It is connected to the. The control rod drive hydraulic system 1 has a valve circuit in which four sets of directional control valves 6 , 7 , 8 9 are sequentially and annularly connected, and an insertion line 4 is connected to the water supply pipe 2 and the drainage fi 3 through this valve circuit. and to the drawing line 5, respectively.
Directly connected. When a control rod (not shown) is to be withdrawn, the directional control valve 6.8 is opened as shown in FIG. The water supply pipe 2 is communicated with the drawing line 5 via the directional control valve 8 which is opened, and drive water is supplied to the control fall rod drive mechanism A from a water supply facility (not shown). At the same time, the drainage pipe 3 is communicated with the insertion line 4 via the directional control valve 6, which is opened, so that the return water from the control rod drive mechanism A is drained to a drainage facility (not shown).

The driving water supplied to the control rod drive groove A through the withdrawal line 5 is divided into two directions here, and one side is discharged above a drive piston (not shown) to push the drive piston downward. The other is discharged to the underside of a collet piston (not shown) and serves to push the collet piston upwardly and permanently disengage the collet fingers. By pushing down the drive piston, the driving water on the drive piston F side becomes return water and is drained to the drainage equipment via the insertion line 4, the directional control valve 6, and the drainage pipe 3, and the drive piston is lowered. In conjunction with this, the control rod also descends and is withdrawn.

However, when pulling out such a control rod, in the unlikely event that
If the drive water discharged to the lower side of the collet piston (not shown) leaks from the collet piston seal and this leakage amount increases, sufficient water pressure necessary to push the collet piston upward will be applied to the collet piston. cannot be made to act. Moreover, in such a case, the conventional control rod drive hydraulic system cannot adjust the flow rate of drive water supplied to the control rod drive mechanism.
It is not possible to compensate for the water pressure comparable to the amount leaking from the collect piston seal, and it is not possible to obtain sufficient water pressure necessary to push the collet piston upwardly and release the collet fingers. For this reason, there is a fear that the control WJJm may not be pulled out smoothly.

[Purpose of the invention]

The present invention was made in view of these circumstances, and in the unlikely event that
Even if the amount of drive water leaking from the corent piston seal of the control rod drive mechanism increases, sufficient drive water pressure can be obtained to release the collet fingers, and the control rod can always be pulled out smoothly. The purpose of the present invention is to provide a control rod-driven hydraulic device that can perform the following operations.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention is configured as follows.

connected to the water supply equipment and the drainage equipment through the water supply piping and the drainage piping, respectively, and connected to a control rod drive mechanism that drives the control rod through the insertion line and the withdrawal line,
In a control rod drive hydraulic device having a directional control valve that controls the flow direction of drive water supplied to the control rod drive mechanism and its return water, the valve opens when the control rod drive mechanism pulls out the control rod, and Arrangement f with a directional control valve that connects the water supply pipe to the drawing line! A flow rate adjustment valve was interposed therein, so that the flow rate of drive water supplied to the control rod drive mechanism when the control rods were withdrawn was configured to be adjustable.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic system diagram of the control rod drive hydraulic device according to the present invention, and the reference numeral [0 in the figure indicates the control rod drive hydraulic device. This control rod drive hydraulic system [0 is the drainage side extraction control valve 11,
Drainage side insertion control valve 12, flow rate adjustment valve [3, water supply side withdrawal control valve [4], water supply side insertion control valve [5] in sequence in piping,
and are connected in a ring. The middle of the piping connecting the water supply side withdrawal control valve [4] and the water supply side insertion control valve [5] is connected to the water supply pipe 17A Vc via the inflow side withdrawal pipe [6, and the water supply pipe 17A is connected to a water supply pipe (not shown). It is connected to the equipment and supplies drive water to the control rod drive hydraulic system tOVc. There is still an outflow side pull-out pipe E8 in the middle of the piping that connects the flow rate adjustment valve [3 and the drain fl11 insertion control valve E2].
It is connected to the extraction line [9] to the control rod drive mechanism via the control rod drive mechanism.

The middle of the piping connecting the drainage side extraction control valve 11 and the drainage side insertion control valve 12 is connected to the drainage piping 17B via the outflow side insertion W20, and the drainage piping 17B is connected to drainage equipment (not shown). The control rod drive hydraulic system [0] is connected to drain the return water from the control rod drive hydraulic system [0].

In addition, there is a control valve [1] for drawing out the drainage side and a control valve [1] for inserting the water supply side.
5 is connected to the insertion line n of the control rod drive machine +1A via the inflow side insertion pipe 21.

Therefore, the driving water supplied from the water supply equipment (not shown) to the control rod driving hydraulic system IO is applied to the four sets of control valves 11, 12, 14 of the control rod driving hydraulic system [0].

The flow direction is appropriately controlled according to the valve operation of 15. As shown in FIG. 2, when both the water supply side withdrawal control valve [4] and the drainage side withdrawal control valve [1] are opened, driving water flows in the direction of the arrow, and this driving water is controlled via the withdrawal line 19. If the return water flows into the rod drive mechanism (#A), and on the other hand, the return water flows out through the insertion line n to the control rod drive hydraulic system [0 and is drained to a drainage facility (not shown), the control rod drive mechanism A Driven to pull out a control rod (not shown).
When the drive water flows in the direction opposite to the direction of the arrow shown in FIG. 2, the control rod drive mechanism A is driven to insert a control rod (not shown).

The four sets of control valves 11, 12, 14, and 15 are electromagnetic valves that perform fully open-to-fully open valve operations in response to valve signals from a central control room (not shown), and are designed for drain side withdrawal. The control valve [1] and the water supply side withdrawal control valve [4] are both fully opened when a withdrawal signal is received. Further, both the drain side insertion control valve 12 and the water supply side insertion control valve 15 are fully opened by the insertion signal.

The water supply side extraction control valve 141c has a flow rate adjustment valve [3 disposed adjacently and in parallel on its downstream side (when the control rod is extracted).
This allows the amount of driving water supplied to the control rod drive mechanism A to be adjusted appropriately when the control rod is withdrawn.
In the unlikely event that the water pressure of the drive water in the control rod drive mechanism groove A is reduced for some reason, the opening degree of the flow rate adjustment valve L3 is further expanded to compensate for the water pressure, and the control rod drive mechanism A is It is now working properly. In other words, the flow rate regulating valve L3 is set in advance so that its opening degree is slightly narrowed rather than fully open, and in this state, under normal conditions, the control rod drive mechanism A
is now operating normally.

By the way, the control rod drive mechanism A is constructed as shown in FIG. 3, and has a locking piston structure driven by the hydraulic pressure of the drive water, and the drive piston (9) is moved by applying water pressure to the upper side of the drive piston (9). is lowered, and the control rod B connected to the top of the index tube 31 mounted on the drive piston is pulled out.

In addition, water pressure is applied to the lower side of the drive piston blade to raise the drive piston blade, and the control rod B is inserted. is insertion line n
are connected to each other.

A notch groove 31a is provided on the outer peripheral surface of the index tube 31.
are provided around the circumference, and are arranged in multiple stages in the axial direction.

The collet fingers of the pawl mechanism that are engaged with the notch grooves 31a are arranged in a circular manner around the outer periphery of the index tube 31, and the above-mentioned It is designed to engage and release the engagement.

A collet piston seal 36 is attached to the collet piston 35IC to seal the cylinder housing the collet piston 35. In addition, the reference numeral 37 in FIG. 3 is a guide cap for guiding the collet finger (mf't).

Next, the operation of the above-described embodiment will be described.

When inserting the control rod B, both the drain side insertion control valve [2] and the water supply side insertion control valve (5) in the control rod drive hydraulic device 10 are fully opened in response to an insertion signal sent from the central control room. On the other hand, both the drainage side withdrawal control valve 11 and the water supply side withdrawal control valve 14 are kept in a fully closed state, and the drive water supplied to the control rod drive hydraulic device 10 via the water supply pipe t7A is
The water is guided by the opened water supply side insertion control valve [5] and flows into the control rod drive machine l'I4A through the inflow side insertion neck 21 and insertion line 22, and the lower side of the drive piston 30. Water pressure is applied to the area and acts to push it upward. At this time, the driving water above the drive piston 30 becomes return water and is discharged into the control rod driving hydraulic system [0] through the withdrawal line [9]. Here, the water is guided to the opened drainage side insertion control valve [2, inserted into the outflow side, and drained to a drainage facility (not shown) via the drainage pipe 17B.

As a result, the drive piston blade rises, and the control rod B connected to the index tube 31 is inserted into the reactor.

On the other hand, when withdrawing control rod B, the second
As shown in the figure, both the drainage side withdrawal control valve ti and the water supply side withdrawal control valve [4] in the control rod drive hydraulic system [0] are fully opened, and the control rod control valves 12, 12, 15 both maintain a fully closed state. For this purpose, the water supply pipe 17A
The drive water supplied to the control rod drive hydraulic system 0 through the control rod drive hydraulic system 0 was opened. 1@ It is guided by the water side withdrawal control valve [4] and the flow rate adjustment valve [3, and flows into the control rod drive groove A through the outflow side withdrawal pipe [8] and the withdrawal line [9], respectively. Here, the incoming drive water is divided into two directions, one of which is discharged above the drive piston blade, and acts to push the piston 30 downward. The other part is discharged to the lower side of the collet piston 35 and pushes the collect piston 35 up. For this purpose, the collet finger 34 erected on the collet piston rises, and is guided by the guide cap 37 that abuts the top of the collet finger 34 to expand the collet finger 34 in the outer radial direction, thereby opening the notch. The engagement with the groove 31a is released. The driving water below the drive piston blade is discharged as return water into the control rod driving hydraulic device 10 through the insertion line n by pushing down the drive piston I, and the drain side is drawn out by opening the valve here. The water is guided to the control valve [1] and drained to a discharge facility (not shown) via the outflow side draw pipe 17B and the drain pipe 17B. As a result, control rod B is withdrawn from the reactor.

However, when the control rod B is withdrawn, driving water may leak from the collet piston seal 36.
If a situation occurs in which sufficient water pressure necessary to push up the collet piston 35 cannot be obtained, the engagement of the collet finger 34 with the notch groove 31a is not released, and the control rod B
It becomes impossible to pull out. In such a case, the opening degree of the flow rate adjustment valve 13 is adjusted to further expand the amount of drive water supplied to the control rod drive groove A, which is necessary to push up the collet piston 35. A sufficient water pressure is applied to the collet piston 35.

Therefore, even if drive water leaks from the collet piston seal 36 and the leakage amount increases, the collet finger 34 can be operated normally.

〔Effect of the invention〕

As explained above, the control gIJ rod drive hydraulic device according to the present invention is equipped with a control valve that appropriately controls the flow direction of drive water, and also connects water supply piping to the withdrawal line of the control rod drive mechanism when withdrawing the control rod. A flow rate adjustment valve is interposed in the drawing-out communication passage in the vicinity of the control valve, so that it is possible to adjust the amount of driving water supplied to the control rod drive mechanism when the control rod is pulled out. Therefore, according to the present invention, even if drive water leaks from, for example, the collet piston seal in the control rod drive groove and the amount of leakage increases, the flow rate adjustment valve will be opened. It is possible to compensate for the drop in operating pressure due to leakage by adjusting the pressure, and the effect is that the sea bream control rod can be reliably pulled out.

[Brief explanation of the drawing]

Figure 1 is a schematic system diagram of a conventional control rod drive hydraulic system;
The figure is a schematic system diagram of a control rod drive hydraulic device according to the present invention, and FIG. 3 is a longitudinal sectional view showing the overall configuration of a general control rod drive mechanism. DESCRIPTION OF SYMBOLS 10... Control rod drive hydraulic device, 11... Control valve for drainage side extraction, L2... Case law valve for drainage side insertion, 13...
Flow rate adjustment valve, 14... Water supply side withdrawal control valve, [5...
・Water supply side insertion control valve, 16...Inflow side withdrawal pipe, L7
A...Water supply pipe, 17B...Drainage pipe, -18...
・Outlet side extraction pipe, 19... Pullout line, addition... Outflow side insertion tube, 21... Inflow side insertion tube, 22... Insertion line, 30... Drive piston, 31-mount index tube , 31a...notch groove, 32...outlet hoard, 33...inlet port, 34...
Collet finger, ah... collet piston, :36
... Collet piston seal, 37... Guide cap, A... Control rod drive mechanism, B... Control rod. Applicant's agent Hisashi Hatano

Claims (1)

[Claims] 1. A control rod drive mechanism that is connected to water supply equipment and drainage equipment through water piping and drainage piping, respectively, and drives the control rod through an insertion line and a withdrawal line. In a control rod drive hydraulic system having a directional control valve that is connected to the control rod drive groove and controls the flow direction of drive water supplied to the control rod drive groove and its return water, the control rod drive groove opens when the control rod is pulled out. A flow rate regulating valve is interposed in the piping equipped with a directional control valve that communicates the water supply piping with the withdrawal line, and the driving water is supplied to the control rod drive groove when the control rod is withdrawn. A control rod J pivot hydraulic device, characterized in that the flow rate can be adjusted. 2. The control rod drive hydraulic system according to claim 1, wherein the directional control valve is a solenoid valve that opens and closes in response to a control rod insertion or withdrawal signal.