JPS5813263A - Water sealing mechainism disposed on upstream side of inlet valve - Google Patents

Abstract

PURPOSE:To make a movable seal ring follow up the change of water level and to prevent malfunctioning of the seal ring during water sealing operation, by making the differential pressure between the upstream side and the downstream side of an inlet valve act to the seal ring, and providing a ring actuating means which is capable of bringing the ring into contact with a valve seat at the time sealing water and does not restrict the movement of the ring during water sealing operation. CONSTITUTION:In sealing water on the upstrem side of an inlet valve, a movable seal ring 33 is urged into contact with a valve seat 17 by a ring actuating mechanism, and then a water discharge valve in the valve body is opened to reduce pressure in the valve body to zero. At this instant, a sufficient water sealing pressure is developed by the end area of the ring 33. Subseqently, when a valve 29 is opened by loosening a nut 43 and tightening a nut 42, the ring 33 is closed. Here, since the width L is smaller than the area effective to produce a water sealing force, the ring actuating force can be small. Further, if the gaps G1, G2 are made greater than the entire stroke S of the ring 33 during water sealing operation the ring 33 can follow up the change of water level since its movement is not restricted at all. Further, since a strong water sealing force is acted to the ring 33 during water sealing operation, it is enabled to prevent malfunctioning of the ring 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an upstream water sealing mechanism of an inlet valve, particularly to an upstream water sealing mechanism of a spherical artificial valve having a structure suitable for responding to any water level change. It is something.

First, the role played by the water turbine input valve as part of the hydroelectric power generation equipment will be explained using FIG. Water wheel population valve 51 is upper pond 52
The pressure water 54 flowing from the upstream water pipe 53 is transferred to the water turbine 5.
! It plays the role of passing water to or interrupting water flow to s.

When starting the water turbine, the inlet valve 51 is opened to allow water to flow through the water, the large mouth valve 51 is kept open while the water turbine is in operation, and closed when the water turbine is stopped.

In this way, the inlet valve 51 performs only a very simple function during normal operation, but the inlet valve 51 performs only a very simple function during normal operation. During maintenance and inspection of the water discharge channel 51 and the inlet valve s1, the following functions are required.

(1) Complete water stoppage that prevents pressure water s4 from flowing downstream of the inlet valve when the water turbine 55 and generator 1560 are disassembled.

(2) Complete water stop during maintenance and inspection of large mouth valve.

After maintenance, inspection and disassembly of the downstream water sealing mechanism which is the regular water sealing mechanism of the inlet valve 51, the pressure water 54 is completely supplied and interrupted only by the upstream water sealing mechanism which is the emergency water sealing mechanism.

The reason for this is that in such a situation, in the unlikely event that a major
1) If a water leakage accident occurs for some reason, human life may be lost.B - * Nine power stations may be flooded, resulting in major damage K.
Because it will be.

Next, a conventional spherical valve generally used as a large mouth valve 51 will be explained with reference to FIGS.

As shown in FIG. 2, the inlet valve 51 includes an upstream valve body 2 and a downstream valve body 3 that serve as a casing, a valve body 4 that passes and shuts off the flow of pressurized water 54, and a valve body 4 that functions as a casing. tNt to valve I Nz*3! *ems, a so-called servo motor consisting of a cylinder 9, a piston 10, a piston red 11, etc. that open and close the valve body 4 (see Figure 3), a servo motor, and a valve shaft. 5, an operating lever 12, a bin 13, a key 14, etc.

Also, the seal guide 15. An upstream water sealing mechanism consisting of a seal ring 16 and a valve seat 17 attached to the valve body 4 and a seal guide 18. Seal ring 19 and valve body 4
A downstream water sealing mechanism consisting of a valve seat 20 attached to the valve seat 20 is provided, and the seal rings 16 and 19 move in response to the flow of the opening/closing operation pressure fluid 21 or 22, for example. Close operation pressure fluid 2
2, the seal ring 16 will close to the valve seat 1.
7, and the pressure water s4 is sealed.

In addition, the continuous flow side water sealing mechanism is used as a regular water sealing mechanism,
The upstream water sealing mechanism is used as an emergency water sealing mechanism when the downstream water sealing mechanism is damaged. Then, the above-mentioned water turbine 551 and generator 56 are disassembled, the water turbine 55 and the discharge channel, 17
When inspecting the inside of a vehicle, it is common practice to use the upstream and downstream water sealing mechanisms at the same time to ensure double safety.

However, the water sealing mechanism on the downstream side of the large mouth valve 81 is disassembled.

At the time of maintenance 9 inspection, the pressure water 54 must be sealed by only the upstream water sealing mechanism K, and no matter what situation the upstream water sealing mechanism is in, at that time, A so-called upstream seal lock device is added to ensure that the upstream seal ring 16 is pressed against the downstream valve seat 17 during water cutoff.

Below, Figure 4 shows the conventional upper ft tar lock device.
This will be explained using FIG. Although FIGS. 4 and 5 each show different examples, the basic concept of the conventional upstream sealing device is to move the movable seal ring 16 to the closed position (by means of the closing operation pressure fluid 22), and When the seal ring 16 is pressed against the sheet 17 to form a water seal, the back surface of the seal ring 16 is mechanically pressed so that the seal ring 16 does not move backward.

In Fig. 4 i, normally the lock bolt 23 is
The seal ring 16 is pulled out to the position where it can be fully opened and closed, and the seal ring 16 is closed when the pressure fluid 2
According to 2, the nine and the bell, which are in the state of water, are the straw nuts.
4, push the block bolt 23 with the knob 25 until it touches the seal ring 16, and then tighten the nut 24.
The lock bolt 23 is fixed and maintained in this state.

In addition, in FIG. 5, the wedge 26 is connected to the seal ring 1.
6 is pulled out to the position where it can be fully opened and closed.
Hold the position with lock nut 27, and seal ring 1
6 is in the water sealing state position, loosen the I nut 27 and tighten the operation red 28 so that the wedge 26 is in the seal ring 16.
In this state, the operation red 28 is fixed with a p-tuck nut 27 to maintain this state.

However, in FIG.
disassembly, inspection of the water turbine's internal water discharge channel 57, and the large mouth valve 61
9 repairs and inspections of the downstream water sealing mechanism.

In case of disassembly, etc., please contact Kamiike 82. Changes in the water level of Shimoike 58.

When the headrace gate 59 is closed and the headrace drainage valve 60 is opened, the pressure of the pressure water 54 becomes zero, which is far from normal. After draining the water and inspecting it, consider the effect of the water pressure of the lower pond s8 on the inlet pressure 54 when the water discharge channel gate 61 is opened and filled with water, and the situation may change due to incorrect operation of the upper ft@ water sealing mechanism. There must be.

First, the operating procedure for the large mouth valve S1 is as follows. That is, in FIGS. 1 to 5, the water turbine 55 is stopped → the input valve 51 is closed → the water sealing mechanism on the upper input valve and downstream side is closed → the discharge channel gate 61 is closed → the inside of the water turbine S5, water is drained from the discharge area 57 → the valve body is drained valve 2
9 (Fig. 2) Water draining from the valve body by opening → Longer upstream seal lock device → Water turbine 55, inlet valve 51. Disassembly of the generator 56, maintenance 9 inspection work → Remove the upstream seal lock device e Open the tailrace gate 61 Water wheel 55, fill the tailrace 51 → Valve body drain valve 2
9 closed → Valve body water filling valve 30 opened] Valve body filled with water → Upper i side water sealing mechanism → Downstream Qt water mechanism opened → Input valve 51 opened → Water turbine 55 operated.

By the way, if the above-mentioned change in the surrounding situation occurs at the threshold between "applying the upstream seal four-lock device" and "removing the upstream seal locking device" in the above procedure, #! The conventional large mouth valve 51 shown in FIGS. 2 to 5 has the following problems.

That is, when the upstream water sealing mechanism seals the pressure water 54,
As shown in FIG. 6, since an external force acts on a part of the cylindrical portion of the valve body 4Fi, the cylindrical portion is bent into an elliptical shape, and the valve shaft 5.6 is also pressed against the valve body 4. Since the applied water pressure causes deflection, the deflection Δ shown in FIG. 6 is the sum of both deflections, which is the same state as if the valve body 4 had moved somewhat downstream. Therefore, in response to the deflection of the valve body 4, the seal ring 16 also moves downstream to seal water in a circular pattern. Generally, the diameter of the water turbine inlet valve 51 is 2 to 3 m, and the water head used is 300 to 600 m.
m, and the water pressure acting on the valve body 4 is 1000 to 3
000) The above-mentioned deflection of the valve body 4 is 2 to 5.
becomes −.

- By the way, the upstream sealing device of the inlet ff51 is 1
As shown in Figure 4 and Figure S, the movable seal ring 16 is fixed with a lock bolt 23 or a wedge 2@, so that when the water level changes due to a change in the surrounding situation, the valve body 4 will be affected by the change in deflection. The accompanying movement of the seal ring 16 may create a gap between the contact surfaces of the seal ring 16 and the set lockpole 23 or wedge 26, or may cause excessive contact pressure on the contact surfaces.

For example, if the upstream sealing device is set at the water level H4 (minimum hydrostatic pressure) of the upper reservoir 52 in FIG. As the deflection Δ increases, the seal ring 16 also moves downstream and seals with the lock bolt 23 (t or wedge 26). ) A gap is created between the seal ring 16 and the valve seat 17, and pressure water 54 is sprayed from this gap. Furthermore, if the upstream seal lock device is set to 9 when the water level of the upper pond 52 is at Hl, when the water level falls to H4, the deflection Δ of the valve body 4 decreases, and the seal ring 16 moves upstream. Rolling back to the side, in this case the lock bolt 23 (t or wedge 26) will be pushed in with great force. ? −
As a result, the contact force with the back surface of the seal ring 16 becomes excessive, and the contact force between the valve seat 17 and the seal ring 16 becomes excessive. As a result, the lock bolt 23 (
Even if you try to pull out the wedge 26), you will not be able to pull it out.

In addition, if water is drained from the mistakenly locked water pipe Is3, the deflection of the valve body 4 tends to become zero, so the lock bolt 23 (t or wedge 26) ) Not only will it be forced back and become impossible to pull out, but it will also cause damage to the locking device and damage to the water sealing mechanism.

Before locking, set the number 9. Even if the water channel 57 is filled with water, the water pressure on the downstream side of the large mouth valve 51 will increase, which will reduce the deflection of the valve body 4, causing damage to the valve filter and water sealing mechanism. , a situation may occur where the lock device cannot be operated.

Therefore, conventionally, as a countermeasure, rotor 2 bolt 2B < -1, mourning is better than setting a wedge 26). However, even if such an attempt is made, water cannot be drained from the 11 water conduit pipe 53 equipped with the upstream seal lock device,
It is not possible to deal with the human error of filling the water discharge channel 57 with water.

In addition, in Utility Model Publication No. 17372/1972,
The seal ring is pressed against the valve body by the pressing force of the spring and the water sealing force during water sealing, but in this case,
Since no measures have been taken to proactively increase the water sealing force during water sealing, there is a high possibility of water leakage if the spring pressing force is insufficiently set, and if the spring pressing force is too high, it may act on the valve body. If the deflection of the valve body changes as the water level changes, the operating mechanism, including the spring mentioned above, may be damaged. moreover,
Since this is a configuration in which a complete seal cannot be achieved unless a spring pressing force is applied, there is a drawback that large water leakage may occur if the spring pressing force is released due to an erroneous operation.

The present invention has been made in view of the above, and its purpose is to enable the ζro to respond to any change in water level, and to release the ice-sealed state by human error when it is in the water-sealed state. It is an object of the present invention to provide a water sealing mechanism on the upstream side of an inlet valve that does not cause such problems.

A feature of the present invention is that the movable seal ring is configured such that the upper fi side end face is exposed to the water conduit and generates a water sealing force greater than necessary during water sealing by the water pressure acting on this end face, and is attached to the valve body. The starting point of the contact surface with the valve seat coincides with the inner wall of the water conduit, and the width of the contact surface is configured so that the contact area is smaller than a predetermined percentage of the effective hydraulic action area of the end surface, and when sealing water, The necessary water sealing force is generated by the pressure difference between the 1F flow and the valve seat. The seal ring can be brought into contact with the valve seat, and the structure is such that the movable seal ring is not restrained during water sealing.

Hereinafter, the present invention will be explained in detail using nine examples shown in FIG. 7.

FIG. 7 is a partial sectional view showing one embodiment of the upstream water sealing mechanism of the large mouth valve of the present invention, and the overall configuration of the inlet valve except for the upstream water sealing mechanism is the same as in FIGS. 2 and 3. As such, I will omit the explanation here. In FIG. 7, 2 is the upstream valve body, 4
17 is a valve body, 17 is an upstream valve seat fixed to the valve body 4 with bolts 31, 53 is a large flow-side water conduit that is attached to the valve body 2 with bolts 32, and 33 is an upstream water sealing mechanism according to the present invention. The seal ring 33 is a movable seal ring on the upstream side of the water conduit 3.
4 is exposed, and the water pressure acting on the upper part of the exposed part fL@end 35 generates a water sealing force during water sealing.The water pressure acting area of the end 35 is larger than necessary. This is the size that occurs. The starting point 36 of the contact surface of the seal ring 33 with the valve seat 17 is aligned with the inner wall of the water conduit 53, that is, the inner wall of the seal ring 3, and the width of the contact surface is determined by the water sealing force as described above. The width is set to be as small as the necessary minimum (the effective water pressure action area for the generation of water), and the necessary water sealing force acts on the seal ring 33 due to the pressure difference with the downstream side (2) (the loop seat 17 side) during water sealing. That's how it is.

37 is a movable seal ring 33 that can be operated from the outside during water sealing.
An operating mechanism that brings the operating rod 38. into contact with the valve seat 17. Opening side lock nut 39゜opening operation) 40e?
'-)41. Close operation nut 42, close side lock nut 43
1. The operating rod rotation stopper 44) is configured such that the movable seal ring 33 can be brought into contact with the valve seat 17 during water sealing, and the movement of the movable seal ring 38 can be set in a state where the movement is not restricted during water sealing. .

When sealing the upstream side of the large mouth valve S1, the operating mechanism 37 pushes the movable seal ring 33 in still water to the closed position so that it lightly contacts the valve seat 17, and then the valve body drain valve 29 (see FIG. (see) to bring the pressure inside the valve body to zero. FIG. 7 shows the state at this time, and at this time, the water sealing force F- acting on the seal ring 33 is: F m = (Drag) H 4 where %D1 External diameter of the seal ring 33 Ds t
The inner diameter H of the seal ring 33 is the water pressure acting on the seal ring 33 (varies from Hl to H4 as shown in Figure 1), and it is necessary to ensure that this water sealing force is about the same size as the conventional one. The size of reeds is generally several hundred tons, but it is possible to do so by making D larger than D.

The closing operation of the movable seal ring 33 is performed by loosening the closing lock nut 43, feeding the closing operation nut 42 to the support 41, and then closing it in a state where the water pressure in the water conduit 34 and the water pressure in the valve body 2 are balanced. This is done by twisting the operating nut 42 and moving the operating rod 38 to the closed position.
1. Once the seal ring 33 lightly contacts the valve seat 17, open the valve body drain valve 29.

To return the seal ring 33 to the open position, first close the valve body drain valve 29 and open the valve body fill valve 30 (see Figure 2) to balance water pressure in the water conduit and water pressure in the valve body. Then, the inner lock nut 39 is loosened, the opening operation nut 40 is fed by the support 411, and the opening operation nut 40 is further screwed in to move the operation rod 38 in the direction of the open position of the seal ring 33.

The force required for this operation is the sliding friction force between the seal ring 33 and the valve body 2 and the water pressure π acting on the seal ring 33.
/4(DJ-D:) It is sufficient if it is slightly larger than the sum of n.

When the seal ring 33 is fully open, the seal ring 33 can be held in the fully open position by tightening the operating rod 38 with the support 41 between the nuts 39.4-0.42.43. can.

Each operating mechanism 3
7 in sequence. This is K. Valve body 2 and seal ring 3.
It is possible to prevent ζ twisting from occurring in the sliding part with 3.

In addition, as shown in FIG. 7, when the water is sealed, the operating mechanism 37
(for opening and closing operations) 40. Ensure that gaps G, , and G are maintained between 42 and the support 41, respectively.
In addition, if the gaps G, , G are made larger than the full length 8 of the movable seal ring 33, the valve body 4
Since the movement of the seal ring 33 is not restricted, no matter how large the water level change acting on the valve body 4 is, the displacement of the valve body 4 is not restricted either, so that no inconvenience is caused to any component of the large mouth valve 51. K can do it.

In addition, during water sealing, a large water sealing force of several hundred tons is acting on the seal ring 33, so it is impossible to open the seal ring 33 artificially, and water leakage may occur due to the opening operation. There is no need to worry about it occurring.

As described above, according to the embodiment of the present invention, (c) during water sealing, the seal ring 33 is moved to the upstream side only by the water sealing force generated by the water pressure difference between the upstream side and the downstream side of the upstream side movable seal ring 33. It can be made to be crimped onto the valve seat 17.

(b) During water sealing, the movable seal ring 33 will not move in the opening direction due to erroneous operation of the operating mechanism 37, and the occurrence of water fountain accidents can be completely prevented.

As explained above, according to the present invention, it is possible to respond to any water level change during water sealing, and the water sealing state is not released due to human error, completely preventing fountain accidents from occurring. There is an effect that it can be done.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a hydroelectric power plant to explain the role of the large outlet valve, Fig. 2 is a side partial sectional view of a conventional inlet valve, Fig. 3 is a plan sectional view of Fig. 2, and Fig. 4 is FIG. 5 is a cross-sectional view showing the other conventional example of FIG. 4; #I6 is an explanatory diagram of the valve body in FIG.
The figure is a sectional view showing one embodiment of the upstream water sealing mechanism of the inlet valve of the present invention. 2... Upstream valve body, 3... Downstream valve body, 4... Valve body, 17... Upstream valve seat, 33... Upstream side movable seal ring, 34... Water conduit, 35-... Upstream end face of seal ring, 36... Starting point of contact surface, 37-...
・Operating mechanism, 38... Operating rod, 39... Opening side lock nut, 41... Supporter, 42... Closing operation nut, 43... Closing side μ nut nut , 44...Rod 2nd figure Σ 3rd [21 4th- Mouth 1 & 5 Shame

Claims (1)

[Claims] 1. In a spherical inlet valve which is provided with sealing mechanisms on the upstream side and the downstream side and serves as an operating means operated from the outside of the round which brings the seal ring into contact with the valve seat, the movable seal ring is exposed to the water conduit. The upstream end face is configured to generate water sealing force greater than necessary during water sealing by water pressure acting on the end face, and the starting point of the contact surface with the valve seat is aligned with the inner wall of the water conduit, and the width of the contact surface is configured. is configured such that its contact area is smaller than a predetermined percentage of the effective water pressure acting area of the end face, and the operating means can bring the movable sea groove ring into contact with the valve seat during water injection, and the movable sea groove ring during water sealing. A water sealing mechanism on the upstream side of an inlet valve, characterized by having a structure that prevents the seal ring from being restrained.