JPS621103B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method and device for draining water from iron pipes in a Pelton water turbine, which allows water to be drained from iron penstocks in a short time with less vibration and noise. It is something.

Pelton water turbines used for hydroelectric power generation etc. require water to be drained from the penstock during periodic inspection and maintenance. Because Pelton turbines are used at high heads (high water pressures), the drainage valves should generally have a strong structure, do not generate vibration or noise, and should be made of materials that are less susceptible to erosion due to cavitation. is desired.

In the past, a valve dedicated to draining water was connected to the penstock, but as mentioned above, this valve had to have a strong structure, making it very expensive, and it also generated vibration and noise. There was also the drawback that the drainage area was eroded by high-pressure drainage. This erosion sometimes caused holes in the concrete.

The present invention aims to eliminate these drawbacks and provide a method and device that can drain water from a penstock in a short time while minimizing vibration and noise.

Next, the method and apparatus of the present invention will be explained, but first, one embodiment of the apparatus will be explained.

In the figure, reference numeral 1 denotes a casing, which has an occluded circular shape that gradually becomes smaller in diameter. This casing 1
is arranged so as to surround the outer periphery of a runner 3 having a bucket 2 on the outer periphery, and the bucket 2 is emitted from a plurality of nozzles 4 provided inside the casing 1.
It is designed to spray water towards. Pressure water is introduced into the casing 1 from a penstock (not shown).

A needle 5 is provided at the center of the tip of the nozzle 4 so as to be able to move forward and backward, and the amount of water injected toward the bucket 2 can be changed by changing the opening area of the nozzle 4. The needle 5 is integrally attached to the tip of the rod 6, and the proximal end of the rod 6 is
It is attached to a piston 8 located inside a servo motor 7 that serves as a mechanism for moving the needle 5 forward and backward.
This piston 8 is moved back and forth by a spring 9 which urges the needle 5 in a direction to close the nozzle 4 and by hydraulic pressure applied into the chamber 11 through a conduit 10.

A threaded rod 13 having a thrust bearing 12 attached to its tip is screwed into the servo motor 7. The base end of the threaded rod 13 is exposed outside the servo motor 7, and a handle 14 is attached thereto. When the handle 14 is rotated in the direction in which the threaded rod 13 advances, the thrust bearing 12 approaches the piston 8, eventually comes into contact with the piston 8, and thereafter pushes the piston 8. This causes the needle 5 to be locked in the closed position. Of the four nozzles 4 shown in the figure, the drive mechanism of the servo motor 7 and needle 5 will be explained for only one of them, but all nozzles 4 have the same structure.

A deflector 15 is provided at the front of the nozzle 4 to block the gap between the nozzle 4 and the bucket 2. This deflector 15 rotates around a shaft 16, and is connected to a lever 17 and a rod 18.
and all deflectors 1
5 are designed to rotate at the same time. This deflector 15 is controlled by a speed governor, and bends the water jetted from the nozzle 4 in the event of a sudden decrease in the load on the water turbine.On the other hand, the needle 5 advances in conjunction with the movement of this deflector 15, thereby regulating the speed increase. It is now possible to keep it within the specified range. Furthermore, the deflector 15 is controlled by a sudden stop valve (not shown) and is always locked in the closed position by supplying hydraulic pressure from a pressure distribution valve.

That is, one end of a link 19 is connected to a portion of the lever 17, and the other end of this link 19 is connected to one end of a tracking cam 20. Tracking cam 20
The other end is pivotally connected to the tip of a return shaft 21 attached to a rod 6 integral with the needle 5 through a shaft 22, and is configured to rotate around a pin 22. The cam surface of the tracking cam 20 is a curved surface, and the roller 25 at the tip of the plunger 24 of the pressure distribution valve 23 is in contact with this cam surface. With this mechanism, during normal operation, the deflector 15 and needle 5
The positional relationship with

The pressure distribution valve 23 supplies and discharges drive pressure oil to the servo motor 7 when the needle 5 opens and closes, and switches to supply oil when the needle 5 is open and to drain oil when the needle 5 is closed. This pressure distribution valve 23 operates in conjunction with the movement of the deflector 15 described above, and is
Three connection ports 26, 27, and 28 are provided, and the connection port 26 is connected to a drain pipe 30 via a throttle 29, and the connection port 27 is connected to a throttle 3.
A refueling pipe line 32 is connected via 1.
The aperture 31 is for setting the opening speed of the needle 5, and the aperture 29 is for setting the closing speed. Note that a stop valve 33 is connected to the pipe line 32 in the middle thereof.

One connection port of a three-way switching valve 35 is connected to the connection port 28 via a conduit 34 . This three-way switching valve 35 is connected to the pipe line 1 connected to the servo motor 7.
0, to connect the pipe line 34 connected to the pressure distribution valve 23, or to connect the pipe line 36 connected to another connection port for lubricating during manual operation of the needle 5. be. Pressure distribution valve 23
A floating valve 37 is provided inside, and in conjunction with the plunger 24 described above, the supply and discharge of pressure oil from the pipe line 34 is controlled.

This apparatus configured as described above is used in the following manner to realize the method of the present invention.

First, the lever 17 is operated to a fully closed position by a speed governor (not shown), and in conjunction therewith, the needle 5 fully closes the nozzle 4 to stop the runner 3.

When draining the iron pipe in this condition,
First, the stop valve 33 is fully closed and the pipe line 32 to the pressure distribution valve 23 is closed to prevent the pressure distribution valve 23 from operating due to malfunction. Next, handle 14
is rotated in the direction in which the threaded rod 13 advances, the thrust bearing 12 is pressed against the piston 8, and this is further advanced to move the needle 5 into the nozzle 4.
Locks in the fully closed state.

At this point, the pin 22 connecting the return shaft 21 of the servo motor 7 and the tracking cam 20 is removed to disconnect them. This is done manually,
When the needle 5 is fully closed and the deflector 15 is fully closed, when only the needle 5 is opened and water is drained from the penstock from the water port of the nozzle 4, the movement of the needle 5 is transmitted through the return shaft 21 and the tracking cam 20. This is to prevent problems caused by acting on the link 19 and the pressure regulating valve 23.

Next, the three-way switching valve 35 is switched, and the needle 5 is opened for draining the oil from the refueling pipe 3.
6 and a pipe line 10 for supplying oil on the open side of the servo motor 7. As a result, hydraulic pressure is applied to the piston 8 that operates the needle 5 to obtain a driving force for opening the needle 5 . Next, the handle 14 that had been keeping the needle 5 in the fully closed state is rotated to the open side of the needle 5, thereby gradually opening the needle 5 and injecting water in the penstock (not shown) from the nozzle 4. and drain the water. This jetted water is bent by the fully closed deflector 15 and does not hit the bucket 2 of the runner 3.

The tip of the threaded rod 13 attached to the handle 14 receives a thrust load due to hydraulic pressure and comes into pressure contact with the piston 8, but since a thrust bearing 12 is attached to the tip, even if the handle 14 is rotated, No problems such as galling with the piston 8 or mixing of metal powder into the operating oil due to galling occur. Further, the position of the needle 5, that is, the opening degree of the nozzle 4 can be arbitrarily selected by rotating the handle 14, and by adjusting the opening degree, a desired water removal time can be obtained.

In the closing operation of the needle 5, the closing operation during fine adjustment of the opening degree is performed by rotating the handle 14. In addition, for long strokes and fully closed operations, the three-way switching valve 3
5 to connect the conduit 10 to the conduit 34,
This is done by discharging the opening side pressure oil of the servo motor 7 via the pressure distribution valve 23. At this time, the force for closing the needle 5 is obtained by the spring 9.

At this time, the pressure regulating valve 23 is in such a state that the position of the floating valve 37 communicates the pipe line 34 with the drain oil pipe line 30, and the open side pressure oil of the servo motor 7 is discharged through the throttle 29. Therefore, the closing movement of the needle 5 will be limited to a preset closing speed.

In the embodiment described above, all four nozzles 4 have the same mechanism, and water is drained from the penstock by operating the four nozzles in exactly the same way and simultaneously jetting water from the four nozzles. However, it is also possible for only any number of the four nozzles 4 to operate in this manner.

Since the present invention uses the method and device as described above, it does not require the expensive valve dedicated to draining water that has been conventionally used, and the device can be constructed with a simple structure and at low cost. Further, since the nozzle 4 generally has a larger diameter than the above-mentioned dedicated valve, the amount of water flowing out per unit time is large, so that water can be drained in a short time. In addition, water removal originally has the function of injecting pressurized water into the bucket 2 of the runner 3, and is therefore carried out inside the casing 1 using a strongly manufactured nozzle 4, which has the advantage of extremely low vibration and noise. There is also.

[Brief explanation of the drawing]

The figure is a system diagram of an embodiment of a water removal device for iron pipes in a Pelton water turbine based on the present invention. 1... Casing, 2... Bucket, 3... Runner, 4... Nozzle, 5... Needle, 7... Servo motor, 8... Piston, 13... Threaded rod,
14...handle, 15...deflector.

Claims (1)

[Claims] 1. In a state where the nozzle is closed by operating the needle and the deflector is positioned in front of the nozzle and the runner is stopped, first, the needle is manually locked in the closed state of the nozzle, After that, the interlock between the deflector and the needle is released to prevent the deflector from opening, and then the needle is unlocked and the needle is gradually retreated by hydraulic pressure to open the nozzle. A method for draining water from a penstock in a Pelton water turbine, characterized by draining water from the penstock by injecting water from the penstock. 2. A runner having a bucket on the outer periphery, a needle provided in a nozzle facing the runner so as to be able to move forward and backward so as to open and close the nozzle, and a servo motor that advances and withdraws the needle;
a mechanism for manually locking the needle in a closed state; a deflector located between the bucket on the outer periphery of the runner and the nozzle to shut off or open the gap; a mechanism for interlocking the deflector and the needle; and the deflector. 1. A water removal device for iron pipes in a Pelton water turbine, comprising: a mechanism for manually releasing the interlock between the servo motor and the needle; and a mechanism for supplying pressure oil to the servo motor and withdrawing the needle.