JPS58210374A - Drainage of leakage of guide vane in hydraulic machinery - Google Patents

Abstract

PURPOSE:To facilitate drain of leakage by constituting a drain pipe communicating to the runner side pressure chamber of a drain pipe opening to the runner side pressure chamber, a drain pipe opening to the neighborhood of the outer periphery of the runner and a drain pipe opening between guide vanes and the outer periphery of the runner to incorporate vanes into the respective drain pipes. CONSTITUTION:A first drain pipe 16 is provided in a side pressure chamber 9 inside the outer peripheral edge of a runner 2 of a lower cover 8 with an inlet opening, a second drain pipe 17 provided near the outer peripheral end of the runner 2 with an inlet opening and a third drain pipe provided between a fully closed guide vane 11 and the outer periphery of the runner 2 with an inlet opening respectively. These drain pipes are provided in draft tubes 15 with outlet openings through drain valves 19-21 respectively. After the guide vanes 11 are fully closed, compressed air is supplied into a runner chamber 2 to depress water level for condenser operation while drain valves 19-21 are fully opened to drain water in the runner 2 chamber.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a guide vane water discharge device for a hydraulic machine.
In particular, the present invention relates to a guide vane water draining device for a hydraulic machine that can easily drain water leaking from the guide vane during pump startup operation or phase adjustment operation to prevent a rise in lunch temperature.

[Technical background and problems of the invention]

Recently, in order to adjust the inactive force in the power system,
Phase adjustment operation has come to be performed in which the runners of water turbines or pump turbines are idled to generate and consume reactive driving force while suppressing net power consumption.

To perform this harmonized operation, the movable guide vane is fully closed to cut off the inflow of pressurized water from the casing, and then compressed air is supplied to the flow path inside the lunch chamber, and the water around the lunch is flushed with the compressed air. When the water level in the launch chamber reaches a predetermined position below the lower end of the launch, the runner is driven by the generator engine to reduce the reaction torque and idle operation is performed.

Under such idle running conditions, the water pressure inside the casing is higher than the pressure inside the lunch chamber, so the pressurized water inside the casing leaks into the lunch chamber through the minute gap between the fully closed guide vanes. In addition, seal cooling water is supplied to the back pressure chamber and side pressure chamber of the launch, and this seal cooling water is led out into the launch chamber. The water is stirred by the rotating launcher, thrown outward by centrifugal force, and forms a water film on the inside of the fully closed guide vane. When these water films thicken, the outer rims of the runner blades stir up the stagnant water. When idling operation continues for a long period of time, such as during phase adjustment operation, the shaft input due to idling operation increases.
There is a risk that the launch will thermally expand, narrow the seal gap, and come into contact with the upper or lower cover.

To solve this problem, conventionally a drain pipe was connected between the lower cover and the draft tube to drain water, but the opening position of the drain pipe connected to the lower cover caused a water film to form. Since the area is not directly under the accumulated water, the water film cannot be sufficiently thickened unless the water film is sufficiently thick, and the above-mentioned problem could not be solved.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to properly drain the accumulated water stuck to the inside of the guide vane during phase adjustment operation, thereby reducing the shaft input and preventing the launch temperature from rising. An object of the present invention is to provide a guide vane leakage draining device for a hydraulic machine that enables phase operation.

[Summary of the invention]

In order to achieve the above object, the present invention forms a launch side pressure chamber between a runner band and a lower cover of a hydraulic machine, and a drainage pipe is led out from this side pressure chamber to discharge guide vane leakage water. In the guide vane water leakage draining device for machinery, the drain pipes include a first drain pipe whose inlet opens on the runner side, a second drain pipe whose inlet opens near the outer periphery of the launch, and a guide vane drain pipe when the guide vane is fully closed. and a third drain pipe having an inlet opening on a flow path between the periphery of the launch and the outer periphery of the launch, and each drain pipe is characterized by having a built-in drain valve.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a guide vane water discharge device for a hydraulic machine according to the present invention will be described below with reference to the drawings.

In FIG. 1, a runner 2 is fixed to the lower end of a water turbine main shaft 1, and this runner 2 consists of a runner crown 3, a launch band 4, and a plurality of runner blades 5 held between them.
5, 5. An upper cover 6 is arranged above the runner crown 3, and a runner back pressure chamber 7 is formed between them, while a lower cover 8 is arranged below the launch band 4, and a launch side pressure chamber is formed between them. 9 is formed. Further, a plurality of movable guide vanes 11, 11, . . Furthermore, stay vanes 13 held by speed rings 12 , 12 are disposed outside the movable guide vanes 11 , 11 , . . . 14 are arranged. Note that the lower end of the lower cover 8 has a draft tube 15. is connected.

According to the present invention, the first drain pipe 16. is connected between the lower cover 8 and the draft tube 15. Second drain pipe 17
and a third drain pipe 18 are connected.

The first drain pipe 16 has an inlet opening into the launch side pressure chamber 9 located on the inside of the outer peripheral edge of the runner 2, and a first drain valve 19 is installed on the pipe. Further, the inlet of the second drain pipe 17 opens at a position close to the outer peripheral end of the runner 2, and a second drain valve 20 is installed on the pipe path. In the illustrated embodiment, the opening is in the cylindrical wall surrounding the outer peripheral edge of the runner 2 from the outside, but the opening is not limited to this embodiment.

Furthermore, the inlet of the third drain pipe 18 is opened onto the flow path between the outer peripheral end of the runner 2 and the movable guide vane 11, and a third drain valve 21 is installed on the pipe path. .

According to the present invention, the areas Att and All of the openings of the second drain pipe 17 and the third drain pipe 18 are the diameter of a circle passing through the center of the spindle of the movable guide vane 11, Dg, and the diameter of the circle passing through the center of the spindle of the movable guide vane 11 is When the height of the vane 11 is B.

A1. ≧0.015 X Dg X J3...
・・Town・・・・■A0≧0.015 X Dg X
B ・・・・・・・・・・・・・・・ ■Also, the area Al11 of the opening of the third drain pipe 18 is such that vortices etc. are generated at the opening during power generation operation or pumping operation, and vibrations occur. In order to avoid causing noise, the following conditional expression must be satisfied.

A1. ≦0゜03XNgXB”・・・・・・・・・
. . . ■ However, Ng is the number of movable guide vanes 11 , 11 , . . . , 11.

Next, a mode of phase adjustment operation of the hydraulic machine configured as described above will be explained.

First, the movable guide vane 11 is fully closed 1, and compressed air is supplied to the flow path in the lunch room to push down the water around the runner 2 until the water level reaches a predetermined position below the runner 2. At this time, the first drain valve 19, the second drain valve 20, and the third drain valve 21 are respectively fully opened,
The water in the lunch room is drained through the first drain pipe 16 and the second drain pipe 17.
and draft tube 15 through third drain pipe 18
Drain inward. Then, when the water level in the runner chamber reaches a specified position directly below the lower end of the launch, the runner 2 is rotationally driven in the direction of the water wheel by a starter bolt (not shown).

〔Effect of the invention〕

Next, the effects of the present invention will be discussed with reference to FIG. Figure 2 shows a diagram of the shaft input and temperature rise during phase adjustment operation of a 500m class high-pass differential pump turbine, and the horizontal axis represents water leakage iQg from the guide vane as the rated flow rate Q.

The vertical axis shows the value obtained by dividing the shaft input pt (Mw) by the rated output P0 and the runner temperature rise Δtr [C]. The solid line a indicates the first drain pipe 1 in the embodiment of the present invention.
6. This is a case where all of the second drain pipe 17 and the third drain pipe 18 are utilized. Broken line Dti When only the third drain pipe 18 that opens to the guide vane part of the drain pipe of the present invention is used together with the drain pipe 16, the dashed line C indicates the second drain pipe of the present invention that opens to the outer periphery of the lateral pressure cabinet. When only the drain pipe 17 is used in combination with the drain pipe 16, the two-dot chain line d indicates the case when only the drain pipe 16 is used. As is clear from these diagrams,
In either case, when the amount of water leakage from the guide vane exceeds a certain value, both the temperature rise and the shaft input increase rapidly. This indicates that water begins to accumulate around the outer periphery of the launch chamber at this value, and in order for the launch blade to stir this accumulated water, the shaft input is
A sudden increase in temperature occurs. On the other hand, it has been shown that as long as water does not accumulate around the outer periphery of the poop chamber, both the temperature rise and shaft input are small in all cases. In addition, model tests have confirmed that vibration and noise are extremely small compared to when water stagnates around the outside of the lunch room.

For this reason, even in the conventional example using only the drain pipe 16, by reducing the amount of water leakage from the guide vane, phase adjustment operation can be performed without water remaining around the outer periphery of the lunch room. However, in reality, the water sealing mechanism of the guide vane is not perfect enough to eliminate leakage, and in order to prevent air from the lunch room from leaking into the 9 casing through the small gap in the guide vane, it is necessary to increase the pressure in the casing. Therefore, it is practically impossible to reduce water leakage from the guide vane to the extent that water does not accumulate in curve d of the conventional example.

Considering the aging of the guide vane water sealing mechanism, a drainage pipe is required that will prevent water from accumulating around the runner chamber even if the guide vane water leakage increases slightly. From the above, it is clear that the effects of the present invention are not only superior compared to the conventional example, but also that the second drain pipe 17 on the outer periphery of the lateral pressure chamber 9 or the third drain pipe 18 on the guide vane part is It can be seen that the present invention using both in combination is more effective than the case where each is used alone in combination with the drain pipe 16. In addition, the effect of the present invention is not only to increase the permissible amount of water leakage from the guide vane at which water begins to accumulate around the outer periphery of the runner chamber, but also to increase the leakage rate when water accumulates around the outer periphery of the runner chamber than in other cases.
Shaft input is small.

On the other hand, when considering normal ridge generation or pumping operation other than idling operation, the drainage pipe 18 of the guide vane section that opens above the flowing water surface is
If the opening size is too large, vortices and the like will be generated at the opening, causing vibration and noise.

Furthermore, the opening of the second drain pipe 17 on the outer periphery of the lateral pressure chamber cannot be made infinitely large due to dimensional constraints of the machine. It is obvious that increasing the opening area of the drain pipe will increase the drainage effect, but since the opening area of the drain pipe has the above-mentioned limitations, it is recommended to install a drain pipe with a large opening area only at - locations. However, it is very difficult to do so, and it is effective to install drain pipes in two places, the outer periphery of the lateral pressure chamber and the guide vane part, which can easily improve the drainage effect, as in the present invention. does not have to be a single number, and can be a plurality of small-diameter drain pipes. In this case, the total opening area of each drain pipe only needs to satisfy the above formulas (1), (2), and (2).

As described above, according to the present invention, it is possible to accurately drain the water stuck inside the fully closed movable guide vane during phase adjustment operation, to suppress shaft input and temperature rise, and to maintain adjustment over a long period of time. Phase operation can be made possible.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a guide vane leakage discharge device for a hydraulic machine according to the present invention, and FIG. 2 is a diagram showing the relationship between the amount of guide vane water leakage, shaft input, and runner temperature rise. 2... Runner, 8... Lower cover, 9... Runner side pressure chamber, 11... Movable guide vane, 16. Drain pipe with v<x, 17... Second drain pipe, is. ...Third drain pipe. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] A guide vane for a hydraulic machine, in which a launch side pressure chamber is formed between a launch band and a lower cover of the hydraulic machine, and a drainage pipe is led out from this side pressure chamber to discharge guide vane leakage water. In the water leakage draining device, the drain pipe includes a first drain pipe having an inlet opening in the launch side pressure chamber, a second drain pipe having an inlet opening near the outer periphery of the launch, and a guide vane and the outer periphery of the launch when fully closed. A guide vane leakage draining device for a hydraulic machine, comprising a third drain pipe having an inlet opening on a flow path between the guide vanes and a third drain pipe, each drain pipe having a built-in drain valve. 2. The opening area A of the inlets of the second and third drain pipes is the diameter of the circle passing through the center of the spindle of the guide vane D.
The device according to claim 1, wherein the device is set to satisfy the following relationship: >Ayo0.015XDgXB, where B is the height of the guide vane. 3. The opening area A of the inlet of the third drain pipe is 0. When the number of guide vanes is Ng, the diameter of a circle passing through the center of the guide vane spindle is Dg, and the height of the guide vane is B. 015 XDg X B≦A≦0.03XNgXB
4. The device according to claim 4, wherein the device is set to satisfy the following relationship.