JPS59165871A - Multistage hydraulic machine - Google Patents

Abstract

PURPOSE:To prevent the deviation of the opening of a guide vane in each stage by detecting the deviation of a servomotor in each stage and adjusting the guantity of lift of the main distributing valve for a servomotor which is to be adjusted, based on the detected signals. CONSTITUTION:The openings of the upper- and lower-stage guide vanes are detected by means of guide-vane opening detectors 19a, 19b respectively, and the quantity of deviation is fed to a lift quantity correcting device 23 through an amplifier. The lift quantity correcting device 23 changes the fulcrum positioned midway on a link 18b, in accordance with the quantity of deviation and corrects the lift of a main distribution valve 10b by a certain amount, thereby preventing the deviation of the opening of a guide vane in each stage during a long time operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a guide vane control device for a multi-stage hydraulic machine, in particular a multi-stage hydraulic machine in which at least two stages are provided with controllable guide vanes. be.

[Prior art]

As a guide vane control system for multi-stage hydraulic machinery, for example, a speed governor, actuator, and auxiliary servo motor are provided in common for each stage, and a main pressure distribution valve and a servo motor are provided for each stage to control the guide vanes of each stage. A method for controlling this has been proposed.

FIG. 1 is an explanatory diagram of a two-stage hydraulic machine in which the guide vanes are controlled in this manner, where the letter a at the end of each symbol indicates the upper hydraulic machine, and b indicates the lower hydraulic machine. In this figure, 1-a t' and 1-b are the runners of the water wheel.

2-a, 2-b ID l'j ID vane, 3 is a spiral casing, 4 is a letter guide, 5 is a draft tube, 6 is a water turbine main shaft, 7-a, 7-b is a guide ring.

8-a, 8-b are main servo motors, +9-a, 9
-b is a throttle valve that adjusts the opening and closing speed of the kite vane, 10-
a.

10-b is a main pressure distribution valve, 11-a and 11-b are return wires, 12 is a reference frequency setter, 13 is a frequency detector that detects the rotation speed of the water turbine main shaft 6, 14 is an amplifier,
15 is an actuator solenoid, 16 is a pilot valve, and 17 is an auxiliary surf motor.

1.8-a and 18-b indicate links.

In a two-stage hydraulic machine with such a guide vane control device, when the rotational speed of the water turbine increases, the frequency detector 1
3, the frequency signal is compared with a reference frequency from a reference frequency setter 12, and after being amplified by an amplifier 14, a lowering signal is given to the actuator solenoid (15), pilot pulp 16, and auxiliary servo motor 17. This lowering signal is transmitted via the links 18-a and 18-b and moves the main pressure distribution valves 10-a and 10-b downward, so the main servo motors 8-a and 8-b are supplied with pressure oil on their closing sides. The guide vanes 2-a and 2-b are closed via the guide rings 7-a and 7-b.When the main servo motors 8-a and 8-b are closed to a predetermined opening degree, the guide vanes 2-a and 2-b are closed. The main pressure distribution valve 10-a is located via the return wires 11-a and 11-b.

It is fed back to the position of 10-b, blocks the pressure oil, and guide vanes 2-a and 2-b stop at predetermined positions.

That is, in the guide vane control method of the multi-stage hydraulic machine, when the rotational speed of the main shaft 6 of the water turbine increases, the guide vanes 2-a and 2-b are closed to decrease the speed of the water turbine, and the reference frequency setting device 12 The speed is controlled to maintain the reference frequency set by . In addition, 1. When the rotational speed is lower than the reference frequency, the guide vanes';p, -a undergo an operation completely opposite to that described above.

2-b is opened, and the rotational speed of the water wheel is controlled to always be kept constant.

In the guide vane control of multi-stage hydraulic machinery, in principle, the opening degrees of the guide vanes at each stage must be controlled in a consistent manner. Figure 2 shows this necessity, with the horizontal axis showing the model performance test results for a two-stage water turbine.

The vertical axis shows the water turbine output (%) and relative efficiency (%), respectively. When A (solid line) indicates that the upper and lower guide vanes are operating, B (dotted line) indicates that the upper and lower guide vanes are operating. In the case of a fixed guide vane, the water pressure pulsation waveform and size of the water pressure pulsation in each case are shown by the size of the circle)
is shown.

In C, the size of the circle in the case of water pressure pulsation with both amplitudes of 5% is shown as a reference. This figure shows that when the upper and lower guide vanes have different opening degrees, compared to when the upper and lower guide vanes operate in unison, hydraulic efficiency decreases and water pressure pulsation increases, resulting in less efficient hydraulic machinery. This indicates that this is not desirable in terms of the lifespan of the two operating devices.

From this point of view, in the conventional control device described above, the auxiliary servo motor 17o is common to each stage, and the main servo motors 8-a and 8-b are in principle matched to the upper and lower stages. Although the main servo motors 8-2 and 8-b are adjusted to operate properly, if they are operated for a long period of time, the main servo motors 8-2 and 8-b will start to deviate in opening due to elongation of the return wires 11-a and 11-b. In addition, temporarily, the main pressure distribution valve 10-a,
10-b Main servo motor 8-a due to wear of various parts,
8-b may occur, and there is a risk that a decrease in hydraulic efficiency and an increase in water pressure pulsation, which are harmful to the operation of the main engine, may occur.

[Purpose of the invention]

The present invention aims to eliminate such problems and provide a multi-stage hydraulic machine having a guide vane control device that can prevent deviations in the opening degree of the guide vanes at each stage during long-term operation. be.

[Summary of the invention]

The present invention provides a guide vane control device for a multi-stage hydraulic machine in which controllable guide vanes are provided in at least two stages, in which one of the side-controllable guide vanes is used as a reference guide vane, and each of the above-mentioned A guide vane opening detection device is provided for each stage, and a guide vane opening correction device is provided for each stage other than the reference guide vane to detect the opening deviation from the reference guide vane opening. That is.

In other words, the deviation of the servo motor at each stage is detected, and the servo motor's main pressure distribution valve refrigeration is corrected based on the detected signal.
The amount can be adjusted.

Fig. 3 is a diagram showing the basic configuration of a side tilting device for a two-stage hydraulic machine to which the present invention is applied, where 9-a and 19-b indicate the respective opening degrees of the upper and lower guide vanes 2-a and 2-b. Detector, 20
is a bias amount setter, and 21 is an amplifier.

Reference numeral 22 indicates an abnormality detection alarm, and reference numeral 23 indicates a lift amount corrector. In this configuration, a deviation of 1 degree in the opening of the upper and lower guide vanes is detected by the output difference of the guide vane opening degree detectors 19-a, 19-b, and the lift of the main pressure regulating valve is determined via the amplifier 21 according to the detected value. is corrected using the Lift Co. corrector 23. The abnormality detection alarm 22 includes a guide vane opening degree detector 19-a,
19. - If the deviation in the guide vane opening degree detected by the output difference of b is not corrected even after a predetermined period of time,
It is installed as necessary to issue six warnings or stop the main engine when a deviation of more than a predetermined amount occurs.

The bias amount setting device 20 is installed as necessary, especially when operating the upper and lower guide vanes by intentionally shifting the opening degrees, such as when starting or stopping.

[Embodiments of the invention]

FIG. 4 is an explanatory diagram of a two-stage hydraulic machine as an example, and the same parts as in FIG. 1 are given the same symbols, 19-
Reference numerals a and 19-b indicate opening degree detectors for the upper and lower guide vanes, respectively, and 23 indicates a lift corrector for correcting the lift amount of the lower main pressure distribution valve 10-b. In the device of this embodiment, the upper and lower guide vane openings are detected by guide vane opening detectors 19-a and 19-b, respectively, and the amount of deviation is detected as a lift amount via an amplifier (not shown). It is applied to the corrector 23. The lift amount corrector 23 changes the fulcrum point in the middle of the link 18-b according to the amount of deviation to correct the lift of the main pressure distribution valve 10-b by a predetermined amount. In this case, the lift amount corrector 2 should be
It goes without saying that the time constant 3 needs to be sufficiently coordinated with the time constant of the main control system.

In this embodiment, the lift amount corrector 23 is connected to the link 18-b.
Although it was provided on the side, the side provided on the return wire 11-b side,
The intended purpose can be achieved even if it is placed in any other suitable location.

In addition, even in hydraulic machines that have three or more stages of guide vanes, the opening degree of any one guide vane is used as the standard.
If the opening degrees of the other guide vanes are made to match, they will operate in the same way and the same effect can be obtained. Furthermore, it is also possible to implement a multi-stage hydraulic machine that has fixed guide vanes in addition to controllable guide vanes, for example, when it has three stages of guide vanes, one of which is fixed and the remaining two are controllable. can achieve the desired purpose.

The multi-stage hydraulic machine of this embodiment operates while constantly aligning the guide vanes, so it is possible to operate with high efficiency and reliability even during long-term operation. The configuration is also simple.

〔Effect of the invention〕

The present invention makes it possible to provide a multi-stage hydraulic machine having a guide vane control device that can prevent deviations in the opening degree of the guide vanes of each stage during long-term single rotation, and has great industrial effects. It is.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional guide vane control device for a two-stage hydraulic machine, FIG. 2 is a performance explanatory diagram, and FIG. 3 is a basic configuration diagram of a guide vane control device for a multi-stage hydraulic machine of the present invention. FIG. 4 is also an explanatory diagram of one embodiment. ILa, tb... water wheel runner, 2-. 11.2-
b... Guide vane, 7-a, 7-b...
Guide ring, 8-a, s-b pressure valve, 11-a,
11-b...Return wire, 12...Reference frequency setter, 13...Frequency detector (which detects the rotation speed of the main shaft of the hydraulic wheel), 14...Amplifier, 15...Actuator tanlenoid, 16...Pilot valve, 17-,
, auxiliary servo motor, 1 s-a', l 8ffb
... Link, 19-a, 19-, b... Guide vane opening degree detector, 20... Bias amount setter, 2
1... Amplifier, 22... Abnormality detection f-register, 23...
・Lift amount corrector. Agent Patent attorney Hiroo Nagasaki (and 1 other person) Cod I Zu Rabbit 2 Zu Ke 30

Claims (1)

[Claims] 1. In a guide vane control device for a multistage hydraulic machine in which controllable guide vanes are provided in at least two stages, one of the controllable guide vanes is used as a reference guide vane, and a guide vane is provided for each stage. A multi-stage hydraulic machine, characterized in that an opening detection device is provided, and each stage other than the reference guide vane is provided with a guide vane opening correction device for adjusting the opening deviation with the opening of the reference guide vane. .