JPH033071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to hydraulic machines such as water turbines, pump water turbines, and pumps, and more particularly to a hydraulic machine that drains leakage water accumulated on the outer periphery of a runner while the runner is idling.

[Technical background of the invention and its problems]

Hydraulic machines such as water turbines and pump water turbines have a so-called runner bottom-opening structure in which the runner is disassembled and assembled from the lower cover side, so disassembly and inspection of the runner can be carried out in a very short period of time and easily compared to general hydraulic machines. It has the advantage of being able to By the way, when starting the pump or performing phase-adjusting operation of this hydraulic machine with a bottom runner structure, please refer to Figures 1 and 2 in the same way as with general hydraulic machines.
As shown in the figure, the guide vane 2 is fully closed, the water level in the draft tube 5 is pushed down by compressed air, and the runner 1 is idled to reduce load torque and power loss.

In this case, in order to prevent the compressed air from leaking, the water pressure on the outside of the guide vane 2 is made higher than the pressure on the inside, so a considerable amount of water leaks from the small gap in the guide vane 2 to the runner side, resulting in A large amount of water will remain between the outer periphery of the runner 1 and the guide vane 2. Since the runner 1 stirs up this accumulated water, a very large power loss occurs.

Conventionally, in order to reduce this power loss, the pressure difference between the pressure P ₁ on the outer periphery of the runner 1 and the pressure P ₂ on the draft tube side is used to direct the water leakage from the guide vane through the gap on the outer periphery of the runner 1 to the lower cover 4 and the upper cover. Water is drained into a draft tube 5 through a drain pipe 6 provided on the cover 3 or both. In order to simplify the structure of the drain pipe 6, a steel pipe is attached directly to the lower cover 3 or the upper cover 3, and the opening 8 of the lower cover into which water leaks from the outer periphery of the runner flows is also set to match the circular cross section of the drain pipe. As shown in Figure 3, it is circular.

In operation where the idling time is relatively short, such as during normal pump startup, there is no problem even with the guide vane leakage drainage structure using the drain pipe 6 shown in Figs. 1, 2, and 3. Problems occur when idle operation is performed for a long period of time, such as during phase operation or phase adjustment operation. That is, as shown in Figure 3,
Leakage water drained through the outer circumferential gap of the runner 1 is influenced by centrifugal force due to the rotation of the runner 1, and forms a thin curtain-like water film 9 along the outer circumference.
By the way, even if a large-diameter drain pipe 6 is used to drain this water film 9 to the draft tube side, since the drain pipe 6 has a circular cross section, the drain opening 8 will also have a circular shape, and it will not be possible to actually drain water. The effective area is only the portion indicated by reference numeral 8a.
Therefore, when idling continues for a long time, such as during standby operation or phase adjustment operation, leakage water that cannot be drained away from the effective area 8a of the drain opening 8 gradually accumulates, and as a result, A curtain-like water film 9 due to water leakage also grows one after another and increases to the position indicated by the dotted line 9a. As the thickness of the water film 9 increases in this way, the power loss caused by stirring the water film 9 by the runner 1 gradually increases, and the temperature inside the runner chamber increases accordingly. The stirring of water creates an unstable operating condition, and in some cases, induces abnormal vibrations, etc., which reduces the safety of operating the hydraulic machine and reduces the life of the machine.

Therefore, recently, a guide vane water leakage drainage structure has been adopted in which an additional opening 14 is provided just inside the guide vane, and an additional drainage pipe is connected to this to drain water to the draft tube 5, as shown in FIG. With this structure, the opening area of the expansion opening 14 is completely provided as an effective drainage area, so the drainage effect is greatly enhanced. On the other hand, since each expansion opening is connected to an expansion drain pipe, the area under the lower cover is The shuffling of the layout results in a very congested layout. In particular, as shown in Fig. 5, in the case of a runner with an under-opening structure, the additional opening is provided, and the additional drainage pipe must be taken out from between the lower cover flange and the speed ring flange to which the additional drainage pipe is connected. Part 1
4 and the additional drain pipe 11 are connected inside the bottom ring 10, which is very congested structurally and is also extremely difficult to manufacture.

[Purpose of the invention]

The present invention was made in order to solve the above problems, and it is possible to utilize the structural features of hydraulic machines such as water turbines and pump turbines that have a runner undercut structure, even when the runners idle for a long time. To provide a hydraulic machine which can drain water leakage through a guide vane very effectively, has a very simple guide vane leakage drainage structure, and is easy to manufacture.

[Summary of the invention]

In order to achieve the above object, the hydraulic machine of the present invention has a bottom ring with a watertight structure inside, an opening opening on the inner periphery of the guide vane on the flow path side, and a drain pipe attached to the speed ring. The present invention is characterized in that leakage water flowing in from the opening is drained to a draft tube by a drain pipe.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 6 to 8. In Figures 6 and 7, an upper cover 3 is placed above the runner 1, and a lower cover 4 is placed below the runner 1.
A guide vane 2 is provided near the outer periphery of the runner 1. A bottom ring 10 is installed at the lower part of the guide vane 2, and the bottom ring 10 has an additional opening 14 for the guide vane 2.
It is located just inside. bottom ring 10
is attached to a speed ring 15, and the inside of the bottom ring 10 is made watertight except for the expansion opening 14 by a packing 13. Further, an additional drain pipe 11 is connected to the speed ring 15 at one or several locations, and communicates with the inside of the bottom ring. The additional drain pipe 11 is the drain valve 1
2 to the draft tube 5. Further, the inside of the bottom ring 10 is in communication throughout its entire circumference.

Next, the effect will be explained. Water leakage from the guide vane at the outer periphery of the runner is partially drained into the draft tube 5 through the opening 8 of the conventional lower cover ₄ due to the pressure difference between the pressure P ₁ at the outer periphery of the runner 1 and the pressure P 2 at the draft tube side. However, most of the water leaking from the guide vane is absorbed into the bottom ring 1 through the additional opening 14 whose opening area is completely provided as an effective drainage area.
Guided to the inside of 0. Furthermore, the guide vane leakage water guided into the inside of the bottom ring 10 flows into the additional drain pipe 11 connected to the speed ring 15 and communicating with the inside of the bottom ring 10, and then flows into the drain valve 12.
It is discharged to the draft tube 5 through. Furthermore, the presence of the packing 13 prevents casing pressure water from entering the bottom ring, and prevents water leakage from the guide vane inside the bottom ring from leaking to the outside. Furthermore, one or several additional drain pipes 11 are connected to the speed ring 15, but since they are drawn out to the outer periphery of the speed ring where there is ample piping space, convergence with other pipes is sufficiently avoided. It will be done. Furthermore, when the main engine is operating, the drain valve 7
Closing the drain valve 12 will not cause any trouble to the operation. Also bottom ring 10
The interior of the drain pipe 11 is a water chamber that communicates with the entire circumference, so there is no need to connect the extension opening 14 and the extension drain pipe 11 with piping, and the drain pipe 11 can be located at a convenient location for piping.

〔Effect of the invention〕

As explained above, according to the present invention, in hydraulic machines such as water turbines and pump water turbines having a runner under-opening structure, guide vane water leakage can be prevented even if the runner continues to idle for a long period of time, such as during standby operation or phase adjustment operation. It has the excellent effect of not only allowing drainage to be carried out effectively, but also eliminating the congested pipes that were present in the past.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a conventional general hydraulic machine, Fig. 2 is a schematic sectional view showing a hydraulic machine with a conventional runner undercut structure, and Fig. 3 is viewed from the − direction arrow in Figs. 1 and 2. A plan view, FIG. 4 is a schematic sectional view showing a general hydraulic machine with a conventional additional drainage pipe, FIG. 5 is a schematic sectional view showing a hydraulic machine with a runner undercut structure and a conventional additional drainage pipe, and FIG. 7 is a schematic sectional view of a hydraulic machine with a runner undercut structure showing an embodiment of the present invention, FIG. 7 is a partially enlarged plan view of FIG. 5, and FIG. 8 is a YY sectional view of FIG. 7. 1...Runner, 2...Guide vane, 3...Upper cover, 4...Upper cover, 5...Draft tube,
6... Drain pipe, 7... Drain valve, 8... Opening, 9
... Water film, 10 ... Bottom ring, 11 ... Additional drain pipe, 12 ... Drain valve, 13 ... Packing, 1
4...Extension opening, 15...Speed ring, 1
6... Guide vane boss.

Claims (1)

[Claims] 1. In a hydraulic machine having a plurality of guide vanes arranged on the outer periphery of a runner, a bottom ring that supports the guide vanes, and a speed ring that connects to the bottom ring, the inside of the bottom ring has a watertight structure, and An opening is provided in the inner periphery of the guide vane on the flow path side, and a drain pipe is further attached to the speed ring, and leakage water flowing from the opening is drained to the draft tube by the drain pipe. Hydro machinery.