JPS61200381A - Discharge operating method for pelton turbine - Google Patents

Abstract

PURPOSE:To eliminate the necessity for making a conduit the accompanying pressurized conduit for a Pelton turbine and thereby reduce the civil engineering expenses related to the conduit by controlling an needle opening in accordance with water level and deflector openings in line with the number of rotation of the water turbine when the electric power system of the turbine is cut off. CONSTITUTION:To a conduit 31, branch pipes 32, 32a are linked while, at the tip of these branch pipes, nozzles 36, 36a for injecting jet water flows toward the bucket 37a of a Pelton turbine 37 are formed. The quantity and direction of water flows from the nozzles are controlled through a needle 33 and deflector 38, 38a, with the number of rotation of the water turbine being controlled accordingly. Since a needle opening controlled in accordance with water level in a head tank, and deflector openings are adjusted with to the number of rotation of the water turbine when the electric power system is cut off, it is possible to wait for the restoration of the system while continuing discharge operation. And since no pressure increase occurs in the conduit, it structure can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for operating a Pelton turbine in a run-of-river power plant in which a spillway is omitted.

[Prior art and its problems]

Figure 3 shows an overview of the main structural parts of a Pelton turbine.

In FIG. 2, a water guide pipe 31 that leads water from a head tank (not shown) is provided with a plurality of branch pipes 32, 328. In the branch pipes 32 and 328, a needle shaft 33a having a needle 33 at its tip passes through the bent pipes 34 and 34a, respectively, and is supported by a bearing (not shown) provided in the nozzle pipe 35°358.
It is reciprocated by a drive device (not shown). The needle 33 is moved to the nozzle 36 by the reciprocating motion of the needle 33a
, 368, the opening of the nozzle is adjusted, and the water flow from the head tank is ejected as a jet water stream at this opening. This jet water stream hits buckets 37a provided on the runner 37, causing the runner 37 to rotate in the direction of the arrow. Then, a generator connected to the shaft 37b of the runner 37 can be driven to extract electric power.

The deflector 38 is rotatably provided to cover the nozzle, and a deflector tracking controller allows the needle and the deflector to have an optimal position due to the correlation characteristics between the needle and the deflector. The deflector covers the nozzle so as to change the direction of the jet water flow ejected from the nozzle when the system is shut off, thereby preventing an abnormal increase in the rotational speed of the runner and a sudden pressure increase in the penstock. In a Pelton turbine in a run-of-river power plant, a water level regulator is installed in the head tank, and the opening degree of the needle and nozzle is adjusted according to the water level, and the electric power corresponding to the jet water jet ejected from the opening degree is transmitted via the runner 37. It is extracted by a generator, and so-called wood-like operation is performed. In this case, the frequency of the generator is the frequency of the parallel power grid.

In addition, a frequency setter, controller, etc. are installed to set and control the rotation speed of the Pelton water turbine, and set the rotation speed of the water turbine during no-load operation when disconnected from the power grid.

I try to control it.

In the above-mentioned operation of a Pelton turbine, when the system is cut off from the power grid, the deflector is suddenly closed, and the direction of the jet water ejected from the nozzle is changed to prevent it from hitting the runner packets, thereby reducing the runner rotation speed. We are trying to suppress the rise and also close the needle.

Next, a control circuit for a conventional vane water turbine in wood-type operation will be explained. FIG. 3 is a circuit diagram of the main part of the control circuit of the Pelton turbine. In Fig. 3, the needles provided in the two groups of branch pipes are reciprocated by servo motors 1 and 1a which are adjusted by opening adjusters 2 and 2a, respectively, and are inserted into and withdrawn from the nozzles to adjust the opening of the needles. is adjusted,
The respective opening degrees are detected by opening degree detectors 3.3a.

The deflector is adjusted by an opening adjuster 5, rotated by a servo motor 4 so as to cover the multiple nozzles, and the opening is detected by an opening detector 6 that indicates the opening.

The water level adjustment opening setting device 7 that is controlled by the water level of the head tank that supplies water to the Pelton turbine and adjusts the water level is an adder 8.
, 8a, the detected openings from the opening detectors 3, 3a are fed back, and the reciprocating movement of the needle is controlled by the servo motors 1, 1a. Also, the deflector tracking controller 10
The detected opening from the deflector opening detector 6 is added to the adder 9 via the adder 9, and the servo motor 4 controls the deflector opening.

On the other hand, the frequency setter 11 for setting and controlling the rotation speed of the runner during no-load operation disconnected from the power grid is an adder 1.
2.13 and a PID controller 14, one is connected to the servo motors 1 and 1a via adders 8 and 8a, and the other is connected to the servo motor 4 via a deflector tracking controller 10 and an adder 9. The adder 13 includes an opening detector 3,
The detected opening degree from 3a is calculated by an adder 15, and this is fed back to the adder 13 via a rigidity restoring controller 16. Note that the detected frequency from the frequency detector 17 is added to the adder 12.

In the above-mentioned control circuit, when the Pelton turbine is operated in a wooden manner, the water level adjustment opening setting device 7 that adjusts the water level in the head tank controls the needle so that the water level in the head tank is adjusted by the servo motor 1.1a. The opening degree is maintained, and the water sent to the branch pipe is ejected from this opening degree as a jet water stream. This jet water flow is then applied to the runner's nozzle, and electricity is extracted from the generator according to the amount of water being conveyed.

On the other hand, the optimal position of the needle and deflector of the deflector is maintained by a deflector tracking controller, and the deflector is rotated and positioned by a servo controller 4.

When a system interruption occurs and the rotational speed of the runner increases, the frequency detector 17 detects the increase in rotational speed, and the PID controller causes the servo motor 4 to cover the nozzle and change the direction of the jet water stream. so that it does not hit the packet.

Conventionally, the opening of the needle is simultaneously closed by the servo motors 1 and 1a.

Therefore, if the spillway is omitted in a run-of-the-river power plant that operates as described above, the flow rate in the penstock will decrease due to the closure of the needle opening, and as the water level in the head tank rises, water will flow into the headrace. is full. For this reason, the channel serving as the waterway must be a pressurized channel, which poses a problem in that the civil engineering costs for the channel are expensive.

[Name of invention]

In view of the above-mentioned points, it is an object of the present invention to provide a Pelton water turbine discharge operation method that can reduce the civil engineering costs for the headrace in a Pelton water turbine power plant where a spillway is omitted.

[Summary of the invention]

According to the present invention, the above objects include a runner, a needle that can freely adjust the nozzle opening degree by inserting and pulling out the nozzle provided in the branch pipe, and an opening that changes the direction of the jet water jet ejected from the opening degree. Equipped with an adjustable deflector;
The opening of the needle and deflector is determined by a circuit consisting of a water level adjustment opening setting device for adjusting the water level of the head tank that supplies water to the branch pipe, a single frequency setting device, a frequency detector, an adder, and a controller. is adjusted by the water level adjustment opening setting device to drive the runner by the ejection of the jet water stream; the increase in the rotational speed of the runner at the time of grid interruption is detected by the frequency detector. When a predetermined value is detected, the needle opening adjustment circuit and the deflector opening adjustment circuit are separated, and the needle opening is adjusted via the water level adjustment opening setting device. This is achieved by controlling the frequency setting device and the controller to maintain the rotational speed of the runner at the same speed during no-load operation without discharging the needle opening. .

[Embodiments of the invention]

The present invention will be described in detail below based on the drawings.

(2) The first pongee is a circuit diagram of a main part of a control circuit for wood-like operation of a Gibelton water turbine according to an embodiment of the present invention. In FIG. 1, needle servo motors 1 and 1a and opening degree adjusters 2 and 2a are provided in two groups of branch pipes.

Opening detectors 3 and 3a, deflector servo motor 4° opening adjuster 5. Opening degree detector6. Opening setting device 7 for water level adjustment
．． Deflector tracker IQ, PID controller 14. The circuit configuration and functions of the rigid body restoring controller 162, frequency setter 119, frequency detector 17, etc. are the same as those of the prior art.
A changeover switch 23 is attached to the runner 0 and the circuit 22, which is linked to the increase in the rotational speed of the runner detected by the frequency detector 17. In this changeover switch 23, the switch contact 23a is open and both 23b and 23C are closed during normal woodworking operation, and when the rotational speed of the runner detected by the frequency detector 17 increases, the switch contact 23a is closed and 23b is closed. and 230 are both open.

Therefore, during wood tone operation, the needle and deflector are operated as described above via the closed switch contacts 23b and 23C in response to the signal from the water level adjustment opening setting device that adjusts the water level in the head tank. water is sent to the Pelton turbine while maintaining the water level.

However, when the system is cut off, the frequency detector 17 detects an increase in the rotational speed of the runner and the switch is contacted as described above. Therefore, the needle is controlled by a circuit consisting of the opening regulators 2 and 2a, the servo motors 1 and 1a, the opening detectors 3 and 3a, and the rigid body restoring controller 16 according to the signal from the water level adjustment opening setting device 7. The opening degree of the needle is adjusted, the water flow from the head tank is discharged at this opening degree, and the water level in the head tank is maintained. At the same time, the deflector includes a frequency setter 11°, a frequency detector 17, a PID controller 14. Opening adjuster5. Servo motor 4. A circuit consisting of an opening detector 6 covers the jet water jet ejected from the nozzle and changes its direction to prevent an abnormal increase in the rotational speed of the runner, and a frequency setting device, a PID controller, etc. act to control the jet water flow. The opening is maintained so that a portion of the fuel is ejected to the runner, and the set rotational speed during no-load operation is maintained. In this case, the frequency dead band controller 26 is inserted between the adders 28 and 27 to immediately oscillate the deflector at a small number of revolutions, and after the addition, the changeover switch 23 can be switched to perform normal operation. can.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a run-of-river power plant equipped with a Pelton turbine without a spillway, water is discharged to adjust the water level in the head tank without closing the needle opening when the system is shut off. By using a deflector to control the rotation speed of the water turbine during no-load operation, it can be quickly paralleled to the power grid in the event of multi-system restoration, and the passageway of the headrace does not need to be a pressurized passageway, making it easier for civil engineering. Costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a main part of a control circuit of a Pelton turbine in a run-of-river power plant according to an embodiment of the present invention, Fig. 2 is a partial sectional view of a main part of a Pelton turbine structure, and Fig. 3 is a Pelton turbine of a conventional run-of-river power plant. It is a principal part circuit diagram of the control circuit of a water turbine. 1, Ia: = - dollar servo motor, 2, 2a: Opening adjustment 9.12, 13, 15, 27: Adder, 10: Deflector tracking controller, 11: Frequency setter, 14: PI
D controller, 16: Rigid body restoring controller, 17: Frequency detector, 23: Changeover switch, 32,328: Branch pipe % 3
3a: Needle, 36° 36a: Nozzle, 37: Runner, 38, 38a: Deflector.

Claims (1)

[Claims] A runner, a needle that can freely adjust the nozzle opening by inserting and pulling out the nozzle provided in the branch pipe, and a needle that can freely adjust the opening to change the direction of the jet water jet ejected from the opening. a deflector; a water level adjustment opening setting device for adjusting the water level of the head tank that supplies water to the branch pipe, a frequency setting device, a frequency detector, an adder, and a controller, the needle A discharge operation method for a Pelton turbine, in which the opening degree of the runner and the deflector is adjusted by the water level adjustment opening setting device, and the runner is driven by the ejection of the jet water stream; When a predetermined value is detected by the frequency detector, the needle opening adjustment circuit and the deflector opening adjustment circuit are separated, and the needle opening adjustment is performed via the water level adjustment opening setting device. A discharge operation method for a Pelton water turbine, characterized in that the opening degree of the deflector is adjusted via the frequency setting device and the controller. 2) A discharge operation method for a Pelton water turbine according to claim 1, characterized in that the opening degree adjustment of the deflector is stabilized by a frequency dead band controller.