JP3688348B2 - Hydraulic machine and operation method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a hydraulic machine such as a water wheel or a pump wheel, and more particularly to a hydraulic machine such as a water wheel or a pump wheel that uses water containing a lot of earth and sand, and a method for operating the same.
[0002]
[Prior art]
FIG. 5 is a cross-sectional view showing a schematic configuration of a Francis turbine as an example of a conventional hydraulic machine. As shown in the figure, a stay vane 2 disposed on the inner periphery of a casing 1 connected to an iron pipe 20 that conducts water from an upper pond (not shown), and a runner that is attached to the lower end of the main shaft 3 and transfers energy. 4, a cover 5 and the lower cover 6 on which is disposed so as to surround the runner 4 is disposed on the outer periphery of the runner 4, the gas Idoben 7 for adjusting the flow rate, is connected below the lower cover 6, A suction pipe 8 or the like for guiding the water flow from the runner 4 to the lower pond 13 is formed. A gap formed between the upper cover 5 and the runner 4 is a back pressure chamber 9, and a gap formed between the lower cover 6 and the runner 4 is a side pressure chamber 10. The back pressure chamber 9 is provided with a runner seal 12. Further, on the inner peripheral side of the runner seal 12 of the runner 4, a plurality of balance holes 11 for reducing axial thrust are provided on the circumference. If operating the hydraulic machine having such a structure, the water guide from the upper reservoir iron pipe 20, the casing 1, stearyl Lee vanes 2, flows into the runner 4 through the guide vane 7, rotates the runner 4. The water flowing into the runner 4 also flows into the back pressure chamber 9 and the side pressure chamber 10, but these waters are not converted into rotational energy. Rather, when this amount is large, the efficiency of the hydraulic machine is lowered. . For this reason, the runner seal 12 reduces the amount of water leakage.
[0003]
[Problems to be solved by the invention]
By the way, in a hydraulic machine using water with a lot of earth and sand, water containing earth and sand also flows into the back pressure chamber 9 and the side pressure chamber 10. Therefore, the runner 4, the upper cover 5, and the lower cover 6 cause earth and sand wear due to the earth and sand water. In the lateral pressure chamber 10 side is larger sediment specific gravity than water is likely to flow out into the draft tube 8 with water leakage along the bottom cover 6, there is no so large sediment wear. On the other hand, on the back pressure chamber 9 side, the earth and sand are affected by the runner 4 and moved by viscous force and centrifugal force, so that the runner 5 also has earth and sand wear as well as the upper cover 5 on the stationary side. Due to this earth and sand wear, there was a problem that the outer peripheral side with a larger centrifugal force was worn more violently. Furthermore, the earth and sand flowing into the back pressure chamber 9 also flows into the runner seal 12 due to the pressure difference. For this reason, the runner seal 12 is worn and the gap 12a becomes large, and water leakage from this portion increases, resulting in a problem of reducing the efficiency of the hydraulic machine. Conventionally, as a countermeasure, the thickness of the part subjected to wear is increased, or the part is replaced every fixed period, or this part is repaired and used.
[0004]
The present invention has been made to solve the above-described problems, and its purpose is to reduce sediment wear and improve efficiency and availability even in a hydraulic machine using water containing a large amount of sediment as a working fluid. It is to provide a high performance and economical hydraulic machine and its operation method.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 includes a stay vane disposed on an inner peripheral portion of a casing connected to an iron pipe that conducts water from an upper pond, a runner attached to a lower end portion of a main shaft, In a hydraulic machine such as a water turbine, a pump turbine, etc., having an upper cover and a lower cover surrounding the runner, and a suction pipe that is connected to the lower part of the lower cover and guides the water flow from the runner to the lower pond . a discharge pipe having one end to the back pressure chamber is opened and the other end which is formed by said over and cover the runner is open to one of the draft tube or the lower reservoir via the discharge control valve, provided in the middle of the exhaust pipe and sediment concentration detection device for one end provided with a water supply pipe the other end through the open filtration apparatus and the water supply control valve to the iron pipe is open to the back pressure chamber, a high pressure fresh water before xenon pressure chamber by the water supply pipe Before injecting It is characterized in that it has arranged to discharge the earth and sand in the back pressure chamber to the outside.
[0006]
According to a second aspect of the present invention, in the hydraulic machine according to the first aspect, when a predetermined operation time of the hydraulic machine is exceeded, the discharge control valve is opened, and the sediment concentration detected by the sediment concentration detector is predetermined. The discharge control valve is closed when the set value falls below the set value.
[0007]
[Action]
According to the first aspect of the present invention, the drainage control valve inserted in the discharge pipe that opens to the back pressure chamber is opened after a certain period of operation, so that the sediment accumulated in the back pressure chamber is It is discharged from the outer peripheral side to the suction pipe or the lower pond by the discharge pipe. Therefore, the accumulation of sediment with high concentration can be avoided, so that sediment wear on the upper cover and the runner can be reduced.
[0008]
Further, according to the invention of claim 2 , since the earth and sand concentration detecting device is provided in the middle of the discharge pipe, the drainage control valve is opened after the operation for a certain period, and the earth and sand density falls below a predetermined set value. Can be detected and closed. Therefore, water that is an energy source can be effectively used, and sediment can be discharged efficiently.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a cross-sectional view of a hydraulic machine showing a first embodiment of the present invention, an example of application to a Francis-turbine. The difference between this embodiment and the conventional example shown in FIG. 6 is that the discharge pipe 14 is provided on the outer peripheral side of the back pressure chamber 9, and the others are the same. The description is omitted.
[0010]
One end of the discharge pipe 14 opens to the outer peripheral side of the back pressure chamber 9, and the other end opens to the lower basin 13, and a sediment concentration detector 15 and a drainage control valve 16 are provided in the middle. Furthermore, a control device 21 that controls the opening / closing of the drainage control valve 16 by a concentration detection signal from the earth and sand concentration detection device 15 is provided.
[0011]
Next, the operation of this embodiment will be described. The drainage control valve 16 inserted in the discharge pipe 14 opened in the back pressure chamber 9 is opened by the control device 21 after a certain period of operation, so that the sediment accumulated in the back pressure chamber 9 is on the outer periphery side by centrifugal force. Is discharged to the suction pipe 8 or the lower basin 13 by the discharge pipe 14. Therefore, the accumulation of sediment with high concentration can be avoided, so that sediment wear of the upper cover 5 and the runner 4 can be reduced.
[0012]
Further, since the sediment concentration detector 15 is provided in the middle of the discharge pipe 14, the drainage control valve 16 is opened after a certain period of operation, and the sediment concentration detector 15 indicates that the sediment concentration has fallen below a predetermined set value. The drainage control valve 16 is also closed using the control device 21. Therefore, water that is an energy source can be effectively used, and sediment can be discharged efficiently.
[0013]
Incidentally, in another example of the present embodiment, without equipped with sediment concentration detecting device 15, the discharge control valve 16 may be closed operation after a certain period of time. Further, the other end of the discharge pipe 14 may be opened to the suction pipe 8 instead of the lower pond.
[0014]
Figure 2 is a sectional view showing a second embodiment of the present invention, in which in addition to the first embodiment described above, providing the water supply pipe 17 that opens to the outer periphery of the side position of the runner seal 11 of the back pressure chamber 9 is there. The other end of the water supply pipe 17 is connected to an iron pipe 20 on the upstream side of the casing 1 through a water supply control valve 18 and a filtration device 19.
[0015]
Next, the operation of this embodiment will be described. As in the first embodiment, by opening the drainage control valve 16, the sediment accumulated in the back pressure chamber can be discharged by centrifugal force. However, according to this embodiment, The high pressure water from the iron pipe 20 can be injected into the back pressure chamber 9 together with the centrifugal force to discharge the earth and sand. At this time, although high-pressure water from the iron pipe 20 also contains earth and sand, since this earth and sand is removed by the filtering device 19, fresh water is injected into the back pressure chamber 9. Therefore, since the earth and sand water in the back pressure chamber 9 is replaced with fresh water every fixed period, the amount of accumulated earth and sand can be suppressed and the earth and sand wear of the upper cover 5 and the runner 4 can be reduced. Furthermore, since the amount of earth and sand flowing into the runner seal 12 is reduced, the wear of the runner seal 12 can be reduced, and the amount of water leakage from this portion can be reduced to improve the efficiency of the hydraulic machine.
[0016]
In addition, since the high pressure water from the iron pipe 20 can be poured into the back pressure chamber 9 and the earth and sand can be discharged, the earth and sand can be discharged not only during operation but also during stoppage. 3 and 4 show another embodiment of the present embodiment, respectively. FIG. 3 shows the shape of the opening of the water supply pipe 17 to the back pressure chamber 9 facing the outer periphery side. The tip of the opening has a nozzle shape. By adopting such a shape, high-pressure water flows to the outer peripheral side, and sediment can be discharged more efficiently.
[0017]
【The invention's effect】
As described above, according to the present invention, even a hydraulic machine that uses water containing a lot of earth and sand as a working fluid, a high-performance and economical hydraulic machine that improves the efficiency and operating rate by reducing earth and sand wear, and its A driving method can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of a hydraulic machine according to the present invention.
FIG. 2 is a cross-sectional view showing a second embodiment of the hydraulic machine of the present invention.
FIG. 3 is a sectional view of an essential part showing another embodiment of the second embodiment of the present invention.
FIG. 4 is a cross-sectional view of an essential part showing another embodiment of the second embodiment of the present invention.
FIG. 5 is a cross-sectional view showing an example of a conventional hydraulic machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Casing 4 ... Runner 5 ... Upper cover 6 ... Lower cover 8 ... Suction pipe 9 ... Back pressure chamber
10 ... Side pressure chamber
12 ... runner seal
12a ... Gap
13 ... Shimoike
14 ... Drain pipe
15 ... Sediment concentration detector
16 ... Drain control valve
17 ... Water pipe
18 ... Water supply control valve
19 ... Filtration equipment
20 ... Iron pipe
21 ... Control device

Claims (2)

A stay vane disposed on the inner periphery of the casing connected to the iron pipe that conducts water from the upper pond, a runner attached to the lower end of the main shaft, an upper cover and a lower cover surrounding the runner, and a lower part of the lower cover is connected has a draft tube for guiding the water flow from the runner to the lower reservoir, waterwheel using laden water sediment, in the hydraulic machine such as a pump-turbine, a back pressure chamber formed by the upper cover and the runner a discharge pipe having one end opening to the other end opening into one of said draft tube, or lower reservoir via the discharge control valve, and the sediment concentration detecting device provided in the middle of the discharge tube, one end opening into the iron pipe filtration A water supply pipe having the other end opened to the back pressure chamber via a device and a water supply control valve is configured to inject high-pressure fresh water into the back pressure chamber and discharge the sediment in the back pressure chamber to the outside through the water supply pipe. did Hydraulic machinery that characterized the door. In the hydraulic machine according to claim 1 , when a predetermined operation time of the hydraulic machine is exceeded, the discharge control valve is opened, and when the earth and sand concentration detected by the earth and sand concentration detecting device falls below a predetermined set value, hydraulic machine operating method characterized by closing the exhaust control valve.

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