JPH09209902A - Hydraulic machine and operation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the seal gap of a seal part to be adjusted automatically in compliance with an operational state. SOLUTION: A movable seal ring 12 is able to adjust the size of a seal gap G by being placed opposite to the seal surface 5a of a runner 5 and by its movement in an arrow direction. Position detecting sensors 16, 17 attached to an upper cover 13 detect the position of the runner 5 in relation to a stationary part. A controller 15 drives the movable seal ring 12 via a driving device 14 on the basis of the detection signals of the position detecting sensors 16, 17 so as to adjust the size of the seal gap G.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic machine such as a turbine or a pump turbine, and a method of operating the same, and more particularly to a hydraulic machine configured to adjust the size of a seal gap in a seal portion in a runner back pressure chamber or a side pressure chamber. The present invention relates to a machine and its operating method.

[0002]

2. Description of the Related Art Water turbines and pump turbines used in hydroelectric power stations convert the head energy between an upper pond and a lower pond into rotational energy through a runner.

FIG. 3 shows a conventional Francis type turbine. Pressure water from a casing 1 flows into a runner chamber 4 through a stay vane 2 and a guide vane 3, and a runner 5 in the runner chamber 4 is rotated. And flows out from the suction pipe 6. The runner 5 is connected to the main shaft 7, and the runner chamber 4 includes a back pressure chamber 8 on the runner crown side and a side pressure chamber 9 on the runner band side.
It is composed of Guide vane 3 to runner room 4
A part of the pressure water flowing into the runner 5 does not enter the runner 5 and the back pressure chamber 8
And leaks to the side pressure chamber 9. If the amount of water leaking into the back pressure chamber 8 and the side pressure chamber 9, that is, the amount of water flowing other than the runner 5, increases, the conversion efficiency of the water turbine decreases. Therefore, seal portions 10 and 11 are formed in the back pressure chamber 8 and the side pressure chamber 9, respectively, to reduce water leakage. Each of the seal portions 10 and 11 is composed of a seal surface of the runner and a stationary portion opposed to the seal surface with a slight gap. The gap is made as small as possible and the seal portions are arranged in multiple stages to reduce water leakage.

[0006] Generally, the gap of the sealing portion of the water turbine,
That is, the size of the seal gap is determined by the manufacturing and assembly limits of the turbine. Therefore, in a large turbine, since the size of the seal gap is relatively small with respect to the size of the runner, the amount of leaked water can be relatively small with respect to the total flow rate. However,
In a relatively small turbine, the size of the seal gap is relatively large with respect to the size of the runner, so the amount of leaked water is also relatively large with respect to the total flow rate, leading to a decrease in turbine efficiency. There is.

Therefore, Japanese Utility Model Laid-Open No. 51-10448 discloses a hydraulic machine in which the sealing surface is inclined so that the size of the seal gap can be adjusted. This is because the size of the seal gap of the seal portion can be adjusted when the turbine is assembled, so that the seal gap can be set to a desired value for a turbine of any size regardless of the size of the turbine. . The size of this seal gap is preferably as small as possible from the viewpoint of water leakage prevention, but the main shaft should be kept in contact even if shaft runout or vibration of the main shaft occurs during water turbine operation. The clearance is selected in consideration of the effects of shaft runout and vibration.

[0006]

However, in the hydraulic machine disclosed in Japanese Utility Model Laid-Open No. 51-10448, the adjustment of the seal gap of the seal portion cannot be performed automatically, which requires a great deal of skill and skill. There is a problem that it takes time.

Furthermore, since the seal gap cannot be adjusted during operation, there is a problem that the seal gap cannot be adjusted according to the operating condition.
Then, the objective of this invention is providing the hydraulic machine which can adjust the seal gap of a seal part automatically. Another object of the present invention is to provide a hydraulic machine that can adjust the seal gap of the seal portion according to an operating state, and an operating method thereof.

[0008]

In order to achieve this object, the invention described in claim 1 is a hydraulic power plant such as a water turbine or a pump turbine having a runner and a back pressure chamber and a side pressure chamber surrounding the runner. In the machine, a movable seal ring which is provided in at least one of the back pressure chamber and the side pressure chamber and faces the seal surface of the runner, a detection unit which is attached to a stationary portion of the hydraulic machine and detects the position of the runner, A control device that generates a control signal that determines the amount of the gap between the movable seal ring and the seal surface of the runner based on the detection output of the detection unit; and the gap by driving the movable seal ring based on the control signal. And a driving device for controlling the quantity.

When the detector detects the position of the runner, the control device generates a control signal for determining the amount of the gap between the movable seal ring and the seal surface of the runner based on the detected output.
The drive device drives the movable seal ring based on this control signal to control the gap amount. In this way, the hydraulic machine can automatically adjust the amount of clearance between the movable seal ring and the seal surface of the runner.

According to a second aspect of the present invention, in the hydraulic machine according to the first aspect, the movable seal ring is provided in each of the back pressure chamber and the side pressure chamber, and a seal surface of the runner is provided. The opposing sealing surfaces are inclined and are moved in parallel with the main axis of the hydraulic machine to adjust the above-mentioned gap amount.

With this, it is possible to automatically adjust the gap amount between the seal portions of both the back pressure chamber and the side pressure chamber, and since the sealing surfaces are inclined, the movable seal ring is used as the main shaft of the hydraulic machine. The amount of gap can be adjusted by moving in parallel.

According to a third aspect of the present invention, in the hydraulic machine according to the first aspect, the detecting portion detects the position of the runner during operation of the hydraulic machine, and the drive unit during operation of the hydraulic machine. The movable seal ring is driven based on a control signal from the control device.
Since the detection unit detects the position of the runner during the operation of the hydraulic machine, the seal gap of the seal unit can be adjusted according to the operating state.

According to a fourth aspect of the present invention, the hydraulic machine according to the third aspect further includes a sensor for detecting vibration of the hydraulic machine or shaft runout of the main shaft, and the control device has a detection output of the sensor. On the basis of the above-mentioned vibration or abnormality of the shaft runout of the main shaft, an abnormality signal indicating the abnormality is generated, and the drive device drives the movable seal ring in the direction in which the gap amount increases based on the abnormality signal. It is characterized by that. If due to some reason, abnormal vibration of the hydraulic machine or abnormal shaft run-out occurs, it is detected and the movable seal ring is driven in advance to expand the gap amount. Can be prevented.

According to a fifth aspect of the present invention, in the hydraulic machine according to the third aspect, the control device generates an abnormal signal prior to the sudden change of the operating state based on a signal for suddenly changing the operating state of the hydraulic machine. The drive device drives the movable seal ring in a direction in which the gap amount increases based on the abnormality signal. When the operation state suddenly changes such as when the operation is started or stopped or when the output is abruptly changed, the movable seal ring is driven in advance to expand the gap amount, so that the seal portion can be prevented from being damaged.

The invention described in claim 6 is a runner,
In a method for operating a hydraulic machine, which comprises a movable seal ring provided in at least one of a back pressure chamber and a side pressure chamber and facing a seal surface of the runner, and a detection unit provided in a stationary portion for detecting the position of the runner. , The position of the runner is detected by the detection unit during the operation of the hydraulic machine, and the movable seal ring is driven based on the detection output of the detection unit so that the gap between the movable seal ring and the seal surface of the runner is increased. It is characterized by controlling the quantity. Since the position of the runner is detected during the operation of the hydraulic machine, the seal gap of the seal portion can be adjusted according to the operating state.

According to the invention described in claim 7, in the method for operating a hydraulic machine according to claim 6, when the rotation abnormality of the runner is detected, the movable seal ring is driven in a direction in which the gap amount increases. It is characterized by doing. Even if the runner is abnormally rotated for some reason, the movable seal ring is immediately driven to expand the gap amount, and thus the seal portion can be prevented from being damaged.

According to an eighth aspect of the invention, in the operating method of the hydraulic machine according to the sixth aspect, when abnormal vibration of the hydraulic machine or abnormal shaft run-out of the main shaft is detected, the above-mentioned gap amount expands. It is characterized by driving a movable seal ring. Even if vibration abnormality of the hydraulic machine or shaft runout abnormality of the hydraulic machine occurs due to some reason, the movable seal ring is immediately driven to expand the gap amount, thereby preventing damage to the seal portion. .

According to a ninth aspect of the present invention, in the method for operating a hydraulic machine according to the sixth aspect, the gap amount is expanded prior to the sudden change in the operating state based on a signal for suddenly changing the operating state of the hydraulic machine. The movable seal ring is driven in the direction. Even when the operating state of the hydraulic machine suddenly changes, the movable seal ring is driven in advance to expand the gap amount, so that damage to the seal portion can be prevented.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a hydraulic machine and an operating method thereof according to the present invention will be described below with reference to FIGS. 1 and 2 in which the same parts as those in FIG. FIG.
Shows the first embodiment of the present invention. The back pressure chamber seal portion 10 is composed of a seal surface 5a of the runner 5 and a movable seal ring 12, and the seal surface 5a of the runner 5 is inclined. The sealing surface 12a of the movable seal ring 12 facing the inclined sealing surface 5a is also inclined.
The movable seal ring 12 extends upward through the upper cover 13, and the piston 12b at the tip is housed in the cylinder 25 and is slidable in the direction parallel to the main axis as indicated by the arrow. . A return spring 26 is elastically mounted under the piston 12b. The drive device 14 includes a hydraulic device 14a and drives the movable seal ring 12 in the arrow direction by supplying pressure oil from the hydraulic device 14a. The controller 15 generates a drive control signal, and the drive device 14 drives the movable seal ring 12 in response to the drive control signal.

At least two position sensors 16 and 17 are attached to the upper cover 13, one position sensor 16 detects the position of the runner 5 in a direction parallel to the main axis, and the other position sensor 17 is perpendicular to the main axis. The position of the runner 5 in a different direction, that is, the radial direction is detected. The detection device 18 detects the relative position of the runner 5 with respect to the stationary portion, that is, the upper cover 13, based on the detection outputs of both the position sensors 16 and 17. The position determination device 19 determines the position of the movable seal ring 12 based on the output of the detection device 18, and sends a position signal representing the determined position to the controller 15. The controller 15 controls the drive device 14 according to this position signal. The position sensors 16 and 17 and the detection device 18
And constitute a detection part, and the controller 15 and the position determination device 19 constitute a control device.

Further, the position determining device 19 sends an abnormal signal to the controller 15 when the detection signals of the position sensors 16 and 17 indicating the position of the running runner 5 indicate the abnormal rotation of the runner 5.

Although not shown in the drawings, the movable seal ring, the driving device, the hydraulic device, the controller, the two position sensors, the detecting device, and the position determining device, which are exactly the same as those described above, are also installed in the side pressure chamber seal portion. There is.

Next, the operation of this embodiment will be described. At the time of assembling the water turbine, the sensors 16 and 17 and the detection device 18 detect the relative position of the runner 5 with respect to the upper cover 13.
The position determination device 19 determines the position of the movable seal ring 12 that provides the preset seal gap G based on the output of the detection device 18. The controller 15 sends a control signal to the driving device 14 based on the output of the position determining device 19, and in response thereto, the driving device 14 drives the movable seal ring 12 in the direction of the arrow to obtain the gap amount, that is, the seal gap G. Adjust to the value.

In the side pressure chamber seal portion, the seal gap is adjusted to a desired value in exactly the same manner.

Next, during operation, the position sensor 1
6 and 17 detect the position of the rotating runner 5, and the detection device 18 detects the position of the runner 5 based on the detection output of the position sensors 16 and 17.
Eccentricity of runner 5 and runner 5 with respect to upper cover 13
To detect the relative position of. The position determination device 19 is the detection device 1
Based on the output of 8, the position of the movable seal ring 12 that gives the preset seal gap G is determined.
The controller 15 controls the drive device 14 based on the output of the position determining device 19, whereby the movable seal ring 12 is moved in the arrow direction, and the seal gap G is adjusted to a desired value. In this way, the position of the runner 5 during operation is detected and the position of the movable seal ring 12 is adjusted. Therefore, the seal gap G is adjusted in consideration of the eccentricity of the runner 5 and the deformation of the runner 5 due to the centrifugal force of rotation. Is possible.

Further, when the rotation of the runner 5 falls into an abnormal state, the position determining device 19 causes the position sensors 16, 1
A rotation abnormality of the runner 5 is detected from the detection signal of 7 and an abnormality signal is sent to the controller 15. The drive device 14 immediately moves the movable seal ring 12 in the direction in which the seal gap G is enlarged in response to the abnormal signal from the controller 15. By this movement, contact between the runner 5 and the movable seal ring 12 is prevented, and damage to the movable seal ring 12 can be prevented.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the following structure is added to the structure of the first embodiment.

In FIG. 2, a detection device 20 for detecting the shaft runout of the main shaft 7 and the vibration of the water turbine is a shaft runout detection sensor 21.
And a vibration detection sensor 22. The shaft shake detection sensor 21 is installed so as to face the side surface of the main shaft 7, and the vibration detection sensor 22 is attached to the upper cover 13. The abnormality determination device 23 determines an abnormality during operation based on the output of the detection device 20, and generates an abnormality signal. Controller 2
4 drives the movable seal ring 12 shown in FIG. 1 in the direction in which the seal gap G expands via the drive device 14 shown in FIG. 1 based on the abnormality signal from the abnormality determination device 23. This prevents damage to the seal portion due to abnormal operation. The abnormality determining device 23 and the controller 2
4 constitutes a control device.

In an unstable operation state in which the operation is started or stopped or a sudden output change occurs, a large vibration may occur temporarily. At this time, if the seal gap size is small, the seal portion will be May come into contact and damage.

Therefore, in the second embodiment, in order to avoid such a situation, a signal for changing the operating state is input to the controller 24. This signal is for changing the operating state of the hydraulic machine, and the controller 24 determines whether or not the input signal is for starting or stopping the operation or for abrupt output change,
In that case, the movable seal ring 12 shown in FIG. 1 is driven in the direction in which the seal gap G increases. This prevents the seal portion from coming into contact and being damaged due to an unstable operation state.

After that, based on the detection signals of the shaft shake detection sensor 21 and the vibration detection sensor 22 and the detection signals of the position sensors 16 and 17 shown in FIG. Adjusts the seal gap of the seal portion to a desired value. In the above description, the movable seal ring mechanism is installed in both the back pressure chamber seal part and the side pressure chamber seal part, but it goes without saying that the effect of the present invention can be obtained even when installed in only one of them. Is.

[0032]

As is apparent from the above description, claim 1
According to the invention described in (1), when the detection unit detects the position of the runner, the control device generates a control signal that determines the gap amount between the movable seal ring and the seal surface of the runner based on the detection output, and the drive device Since the movable seal ring is driven based on this control signal to control the gap amount, the gap amount between the movable seal ring and the seal surface of the runner can be automatically adjusted.

According to the third and sixth aspects of the present invention, the detector detects the position of the runner during the operation of the hydraulic machine, so the seal gap of the seal should be adjusted according to the operating condition. You can

According to the fourth, seventh and eighth aspects of the present invention, when an abnormality occurs in the operation, the movable seal ring is driven so that the gap amount increases based on the abnormality signal. It is possible to prevent damage due to contact of the seal portion.

According to the fifth and ninth aspects of the invention, when a sudden change in the operating state occurs, the movable seal ring is driven so that the gap amount becomes large on the basis of the abnormal signal. It is possible to prevent damage due to contact with the.

[Brief description of drawings]

FIG. 1 shows a first hydraulic machine and a method of operating the same according to the present invention.
Sectional drawing which showed the Example of this.

FIG. 2 is a second part of the hydraulic machine and the operating method thereof according to the present invention.
Sectional drawing which showed the Example of this.

FIG. 3 is a sectional view showing a conventional Francis turbine.

[Explanation of symbols]

 5 runner 5a seal surface of runner 8 back pressure chamber 9 side pressure chamber 10 seal part 11 seal part 12 movable seal ring 15 controller 16 position sensor 17 position sensor 18 detection device 16, 17, 18 detection part 19 position determination device 15, 19 Control device

Claims (9)

[Claims] 1. A hydraulic machine such as a water turbine or a pump turbine having a runner and a back pressure chamber and a side pressure chamber surrounding the runner, wherein the seal surface of the runner is provided in at least one of the back pressure chamber and the side pressure chamber. A movable seal ring opposite to the above, a detector mounted on a stationary portion of the hydraulic machine for detecting the position of the runner, and a gap between the movable seal ring and the seal surface of the runner based on the detection output of the detector. A hydraulic machine comprising: a control device that generates a control signal that determines an amount; and a drive device that drives the movable seal ring based on the control signal to control the gap amount. 2. The movable seal ring is provided in each of the back pressure chamber and the side pressure chamber, and the seal surface facing the seal surface of the runner is inclined, and is parallel to the main axis of the hydraulic machine. The hydraulic machine according to claim 1, wherein the hydraulic machine is moved to adjust the gap amount. 3. The detector detects the position of the runner during operation of the hydraulic machine, and the drive unit drives the movable seal ring based on a control signal of the control unit during operation of the hydraulic machine. The hydraulic machine according to claim 1, wherein: 4. The sensor further includes a sensor for detecting vibration of the hydraulic machine or shaft runout of the main shaft, and the control device determines the abnormal condition by determining abnormality of the vibration or shaft runout of the main shaft based on a detection output of the sensor. 4. The hydraulic machine according to claim 3, wherein the drive device drives the movable seal ring in a direction in which the gap amount expands based on the abnormal signal. 5. The control device generates an abnormal signal based on a signal for suddenly changing the operating state of the hydraulic machine before the sudden change in the operating state, and the drive device increases the gap amount based on the abnormal signal. The hydraulic machine according to claim 3, wherein the movable seal ring is driven in the direction of. 6. A runner, a movable seal ring which is provided in at least one of the back pressure chamber and the side pressure chamber and faces the seal surface of the runner, and a detection unit which is provided in a stationary portion and detects the position of the runner. In the method of operating a hydraulic machine, the position of the runner is detected by the detection unit during operation of the hydraulic machine, and the movable seal ring is driven based on the detection output of the detection unit. A method for operating a hydraulic machine, which comprises controlling a gap amount between the runner and a seal surface. 7. A method of operating a hydraulic machine according to claim 6, wherein when the abnormal rotation of the runner is detected, the movable seal ring is driven in a direction in which the gap amount increases. 8. The hydraulic machine according to claim 6, wherein the movable seal ring is driven in a direction in which the gap amount increases when an abnormal vibration of the hydraulic machine or an abnormal shaft runout of the main shaft is detected. how to drive. 9. The movable seal ring according to claim 6, wherein the movable seal ring is driven in a direction in which the gap amount increases before a sudden change in the operating state based on a signal for suddenly changing the operating state of the hydraulic machine. How to operate a hydraulic machine.