JP2539426B2 - Pelton turbine controller - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a Pelton turbine, and in particular, in a hydroelectric power plant equipped with a Pelton turbine, when the power generation operation becomes impossible due to a system accident or the like, only the deflector is suddenly closed to make it a turbine. The present invention relates to a control device suitable for stopping the discharge tank and continuing the discharge operation without changing the water level. [Prior Art] A conventional apparatus is disclosed in JP-A-59-229062 or JP-A-59-229062.
As described in JP-A-60-195384, when the turbine is suddenly stopped by the Pelton turbine, the interlocking of the deflector and the needle is released by the control valve or the off-cam switching valve, the deflector is fully closed, the needle is fully open, and the turbine is closed. At the same time it stopped, the discharge operation was continued. [Problems to be Solved by the Invention] Generally, Pelton turbines are impulse turbines applied at high heads, and horizontal axis type and vertical axis type are adopted. The outline of the horizontal axis Pelton turbine shown in FIG. 2 will be described below. The pressure water from the penstock 10 is distributed to the two nozzles 1 and 2 by the inlet bent pipes 11a and 11b and accelerated by the respective nozzles 1 and 2 to form the high speed jets 12a and 12b, and the water is added to the bucket 5a. After working, it is discharged into the lower discharge channel 14. During normal operation, the needles 1a and 2a in the nozzles 1 and 2 are opened and closed by the servomotors 1c and 2c provided in the nozzles 1 and 2 according to the load, and the flow rates thereof are adjusted. Each nozzle 1,
Deflectors 1b and 2b are rotatably supported by the nozzles 1 and 2 between the runner 5 and the runner 5, and when the load suddenly decreases or a failure occurs, the servomotor 6
Via the link mechanism 7 by the respective deflectors 1b, 2
b is interlocked and simultaneously rotated to deflect the jet from the direction of the bucket 5a, thereby controlling the increase in the rotational speed of the water turbine. On the other hand, control of the needles 1a, 2a and the deflectors 1b, 2b, for example, the case of closing will be described with reference to FIG. When the oil switching valve 103 is raised in the arrow direction A, the pressure oil flows in the pipe, the piston in the servomotor 6 moves in the arrow direction A, and the deflector 1b is rotated rightward to close and the deflector 1b. The turning power of the tracking cam via the lever
It is transmitted to 1E. The tracking cam 1e rotates in the direction of arrow A with the support seat 1X supporting the needle 1a in the nozzle 1 as a fulcrum, the cam rod moves in the needle pressure distribution valve 1f, and the pressure oil in the pressure oil tank 104 is switched off cam. Needle servo motor 1 via valve 102
Supply to C and press needle piston 1Y to
a moves in the direction of closing the nozzle 1 and maintains a constant opening, and the discharge operation is continued from the nozzle 1 communicating with the water tank. When the nozzle 1 is opened, the direction of the pressure oil arrow may be opposite to the above-described arrow direction A. By the way, from heavy load with high power demand to light load,
When the rotation speed of the water turbine increases and the frequency rises above the system frequency under heavy load, the frequency rise detection device (this device operates when the system frequency rises abnormally above the system frequency) is stopped by the off-cam switching valve 102. The command is input and the off-cam switching valve 102 is stopped. Then, needle 1a
While the nozzle 1 is moving in the direction of closing the nozzle 1, the needle 1a does not move to the control position, the nozzle 1 does not have a constant opening degree, and the discharge of water cannot be constant. However, in the above-mentioned conventional technology, since the tracking cam and the needle are released from the interlock depending on the frequency increase value, a failure stop in which a frequency increase does not occur, that is, a failure stop due to a mechanical failure causes the deflector to remain connected to the system. Since the system is disconnected suddenly after it is fully closed and the system is not closed, the frequency does not rise.When such a failure stop occurs, the off-cam switching valve does not operate and the tracking cam and needle interlock are released. Since it is not possible, the needle is fully closed like the deflector, and it is impossible to achieve the purpose of continuing the discharge operation by flowing or cutting off the water only by the deflector. Further, once the tracking cam and the needle are released from the interlock, and after fixing the needle to a certain opening, the needle opening is not controlled at all with respect to the amount of spillage from the water level of the aquarium that changes sequentially,
Since a fixed amount of water is always discharged, there is a risk that an overflow of the water tank or an abnormal decrease in the water level of the water tank will occur, making it impossible to restart the tank. Furthermore, since the tracking cam and needle are released and used by the off-cam switching valve, when switching from the released state to the use state, there is a deviation from the normal interlocking state. It is almost impossible to prevent this. Therefore, when the interlocking is restarted, the needle operates in a direction of canceling this deviation, which causes a problem of load fluctuation. INDUSTRIAL APPLICABILITY The present invention enables a discharge operation by a needle under any condition when a discharge operation is required in a Pelton turbine, can constantly control the discharge amount, and can also shift from discharge operation to load operation. An object of the present invention is to provide a control device for a Pelton turbine that enables smoothness and improves the safety of a power plant without an spillway. (Means for solving the problem) The high signal selection circuit 100 provided between the tracking cam 1e and the needle pressure distribution valve 1f of the present invention is used when the water level is higher or lower than the set water level of the water tank. A surplus water amount setting cam 13 that rotates according to opening and closing to set a setting position, a tracking cam 1e
The tracking cam 12 rotates according to the opening and closing of the track, and the tracking cam 12 descends according to the rotation of the residual water amount setting cam 13 to set the open and close setting position, and moves up and down according to the rotation of the tracking cam 12. The setting lever mechanism 100A that stops the descent at the setting position moves up and down according to the opening and closing directions of the setting lever mechanism 100A, and the two-way switching valve 11 switches the pressure oil to move up and down in the opening and closing directions. It consists of an adjusting lever mechanism 100B that holds the setting servo motor 10 in the position, and sends the pressure oil of the needle pressure distributing valve 1f to the needle servo motor 1c by the setting position signal of the setting servo motor 10 to move the piston 1Y to the setting position. The purpose is to maintain the water level in the upper water tank at the set water level by opening the needle 1a at the set position of the nozzle 1 and discharging water.

[Action]

As described above, according to the present invention, since the turning power of the tracking cam 12 is always limited to the setting position of the extra water amount setting cam 13, the rod of the tracking cam 12 cannot rotate any further, and the tracking cam 12 cannot rotate.
The rod of 1e can move only to the set position in the needle pressure distribution valve 1f, and the needle 1a discharges water at the set position of the nozzle 1,
Since the water level in the upper water tank is maintained at the set water level, it is possible to constantly discharge a certain amount of water from the nozzle 1. [Example] An example of the present invention will be described below. FIG. 1 is a system diagram of the present invention, which is different from the conventional device in that a high signal selection circuit 100 is provided between the needle pressure distribution valve 1f and the tracking cam 1e. The switch 100S provided between the high signal selection circuit 100 and the adder 100K is a changeover switch when either one of the two water systems is used. The surplus water setting device 101 determines the set position according to the set water level of the water tank. For example, when the water level of 90% of the water tank is set as the set water level and more water than the set water level overflows from the water tank, the needle 1a is moved to the right to open the water outlet of the nozzle 1. When there is less water than the set water level and water is stored in the water tank, the needle is moved to the left (-) to close the water outlet of the nozzle 1.
The tracking cam 1e rotates so as to move the 1a, but this rotation power is a high signal indicating a closed signal (-) in which the rotation is restricted by the remaining water amount setting device 101 at the setting position of the remaining water amount setting cam 13. Input from the selection circuit 100 to the adder 100K. According to the closing signal (-) from the adder 100K, the signal (+) that the needle pressure distribution valve 1f and the needle servomotor 1c have moved to the set position in the closing direction is fed back so that the adder 100K always keeps ± 0. Is controlled to open the needle 1a at the set position of the nozzle 1 to maintain the water level in the upper water tank at the set water level. Further, FIG. 4 is a detailed view of the essential portions of the present invention in which the high signal selection circuit 100 is arranged between the tracking cam 1e and the needle pressure distribution valve 1f shown in FIG. The high signal selector 100 includes an opening setting servomotor 10 for setting the needle opening and a two-way switching valve 11
And a tracking cam 12 that rotates according to the control target needle opening signal from the tracking cam, and a spillage amount setting cam 13 that rotates according to the control target needle opening signal from the spillage volume setting device, and are connected by a lever mechanism. Has been done. Further, the force for connecting the tracking cam 12 and the surplus water amount setting cam 13 and the setting lever 100A is attached to each lever and given by a weight. Therefore, when an upward force larger than that of the weight acts, the connection between the tracking cam 12, the surplus water amount setting cam 13 and the setting lever 100A can be easily released. Normally, Pelton turbines perform a water level adjustment operation that takes a load according to the water level.
If you set the needle opening for water level adjustment operation to 101 and put it,
The control target needle opening signal output from the tracking cam 1e and the surplus water amount setting device 101 are substantially the same. A tracking cam
The signal from 1e has a control delay due to the deflector control system before and after the tracking cam 1e, and is slightly behind the signal from the surplus water amount setting device 101. As a result, if the signal from the tracking cam 1e interferes with the signal from the surplus water amount setting device 101 and causes a problem, it is easy to set the signal from the surplus water amount setting device 101 to a slightly low opening degree. Solvable. In this device, the deflector 1b is fully closed when there is a stop command for the water turbine, so the control target needle opening signal from the tracking cam 1e linked to the deflector becomes a closing signal, and the tracking cam 12 also has a low cam height. Rotate in the closing direction. On the other hand, since the water level adjusting needle opening is set in the remaining water amount setting device, the control target needle opening from the remaining water amount setting device remains unchanged unless the water level changes. Therefore, when the tracking cam 12 rotates in the closing direction, the lever mechanism causes the weight of the weight to cause the tracking cam 12 to move.
It moves downwards in conjunction with, and point X is point Y with point Z as a fulcrum.
Moves downward with. Due to the movement of this lever mechanism, the two-way switching valve 11 is turned off and the opening setting servomotor 10
Since the pressure oil is discharged, the opening setting servomotor 10 operates to the closing side and drives the needle pressure distribution valve to the closing side. During this operation, the point Y is also moving downward, but when the lever B between the point Y and the surplus water amount setting cam 13 comes into contact with the surplus water amount setting cam 13, the surplus water amount setting cam 13 remains unchanged. Since it is kept, a force in the upward direction larger than that of the weight attached to the lever A acts to release the interlocking between the lever A and the tracking cam 12 and stop the downward movement of the point X. Further, since the opening degree setting servomotor 10 feeds back the operation so as to make the two-way switching valve 11 in the neutral state, the position X at the stop position, that is, the remaining water amount setting provided by the remaining water amount setting cam 13 is set. When the control target needle opening from the device coincides with the control target needle opening, the two-way switching valve 11 is in a neutral state, and the operation of the opening setting servomotor 10 stops, that is, according to the high signal selection circuit of the present invention, When the amount of movement of the rod in the needle pressure regulating valve exceeds the setting position of the surplus water amount setting device, the high signal selection circuit is activated to move the rod of the tracking cam to the setting position in the needle pressure regulating valve. Since the needle is held at the set position in the nozzle, it is possible to constantly discharge a constant amount of water from the nozzle 1 regardless of the increase in the system frequency. Further, the operation of the high signal selection circuit 100 will be described with reference to FIG. 4 as an example in which the needle 1a moves the nozzle 1 in the closing direction. When the amount of water is less than the set water level and water is stored in the upper water tank, the needle 1a is moved in the direction in which the water outlet of the nozzle 1 is closed. The setting position is determined by the setting lever mechanism 100A which rotates from the spillage amount setting device 101 in accordance with the closing command and moves up and down via the spillage amount setting cam 13 and the fulcrum Z. In this state, when a closing command is issued to the deflector 1b via the speed adjusting devices 100H and 103, the tracking cam 1e rotates in the closing direction, but this turning power only turns to the setting position of the setting lever mechanism 100A. I can't move. The adjusting lever mechanism 100B moves to the chain line position 100C, the pilot rod 11A of the two-way switching valve 11 descends, the oil of the setting servomotor 10 is wasted 11C as shown by the dotted line of the two-way switching valve 11, and the setting servomotor The oil in 10 is exhausted, the pilot rod 10A of the setting servomotor 10 rises, and the two-way switching valve 11 accordingly rises again to maintain the adjusting lever mechanism 100B and the pilot rod 10A at the set position 100D. As a result, the set position signal (closed signal) of the pyroid 10A
Moves the rod of the needle pressure regulating valve 1f in FIG. 3 to the right,
The pressure oil is caused to flow into the system A, the piston 1Y is moved to the water discharge port side, the needle 1a is moved to a setting position where the water discharge port of the nozzle 1 is narrowed, and water is discharged, and the water level in the water tank is maintained at the set water level. Further, when there is more water than the set water level and it overflows from the water tank, the pressure oil may be passed through the B system contrary to the above. According to the present embodiment, since the discharge operation can be smoothly switched to the load operation, it is possible to provide the control device for the Pelton turbine that can improve the stability and safety of the power plant without the spillway. [Effect of the Invention] According to the present invention, the discharge operation can be continued at any stop for which the discharge operation is required, and the discharge amount can be controlled at all times so that an appropriate amount of spillage is discharged and the discharge operation is performed. It is possible to prevent abnormal changes in the water level of the aquarium.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an outline of a Pelton turbine, FIG. 3 is a system diagram of a conventional control device, and FIG. 4 is an explanatory diagram of main parts of the present invention. Is. 1,2 ... Nozzle, 1a, 2a ... Needle, 1b, 2b ... Deflector.

Claims (1)

(57) [Claims] 1. A needle 1a capable of advancing and retreating, a nozzle 1 communicating with a water tank opened and closed by advancing and retracting the needle, a jet 5 for jetting water from the nozzle into a bucket 5a, and a runner 5 rotating by its impulse, A rotatable deflector 1b that deflects the jet direction from the runner, a tracking cam 1e that moves the needle back and forth by acting on a needle pressure distribution valve 1f that controls the pressure oil to the needle servomotor 1c in conjunction with the rotation of the deflector. In the Pelton turbine equipped with, the high signal selection circuit 100 provided between the tracking cam 1e and the needle pressure regulating valve 1f is opened and closed depending on whether the water level is higher or lower than the set water level of the upper water tank. A spillage cam 13 that rotates to set the setting position, a tracking cam 12 that rotates in response to opening and closing of the tracking cam 1e, and a descent to open and close in accordance with the rotation of the spillage cam 13. Sets a set position, setting lever mechanism from moving up and down according to rotation of the tracking cam 12 stops the descent in the set position
100A, setting lever mechanism 100A moves up and down according to the opening and closing directions, and the two-way switching valve 11 switches the pressure oil, moves up and down directions to open and close, and holds the setting servomotor 10 at the setting position. It consists of the mechanism 100B, and sends the pressure oil of the needle pressure distribution valve 1f to the needle servomotor 1c by the setting position signal of the setting servomotor 10,
A control device for a Pelton turbine characterized in that 1Y is moved to a set position, the needle 1a is opened at the set position of the nozzle 1 and water is discharged to maintain the water level in the upper water tank at the set water level.