JP2007120459A - Guide vane closing control device for power generation hydraulic machine, and method for controlling it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To find out an appropriate closing speed per unit-hour according to the magnitude of a guide vane opening equivalent, and to controllably closing a guide vane at the closing speed. <P>SOLUTION: This guide vane closing control device is provided with a distributing valve 3 for supplying/discharging oil to/from the cylinder of a hydraulic servomotor 2 having a piston operating the guide vane 1 in opening/closing, a drain oil amount regulating valve 4 arranged in the middle of the drain oil channel of the distributing valve 3 and throttling a flow rate of drain oil flowing through the channel, and a closing control part 5 which calculates and outputs the closing speed per unit-hour of the guide vane so that the closing speed is increased or reduced if a load or a guide vane servo stroke immediately before inputting the emergency stop condition of a main machine is large or small, and controls the valve opening of the drain oil amount regulating valve. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a guide vane closing control device for closing a guide vane when a power generation hydraulic machine is stopped, and a control method thereof, and more particularly to a power generation hydraulic machine when an emergency stop occurs due to load interruption or the like. The present invention relates to a guide vane closing control device and a control method thereof.

  In hydraulic machines such as Francis type turbines or pump turbines, a plurality of guide vanes are provided near the inlet where water from the upper pond flows into the runner. And are in equilibrium. By the way, when an emergency stop of a main engine in power generation operation is performed by shutting off a load or the like, the closing speed per unit time of a hydraulic servomotor for guide vane operation, that is, a guide vane is conventionally controlled by a guide vane closing control device regardless of the magnitude of the load. The closing speed is controlled to be constant.

  Therefore, a characteristic diagram of the turbine wheel output (load) P shown in FIG. 9 and the stroke of the operation rod of the hydraulic servomotor for guide vane operation (hereinafter referred to as guide vane servo stroke) Stg and the closure of the guide vane shown in FIG. As can be seen from the characteristic diagram of the time Tc and the guide vane servo stroke Stg, the guide vane closing speed T is constant because the guide vane closing speed is constant. Close to. When this guide vane closes suddenly, the water pressure in the hydraulic iron pipe may rise abnormally.

  9 and 10, the symbol Stg1 is the servo stroke when the turbine output (load) is maximum P1, and Stg2 is the servo stroke when the output P2 is low, and the relationship is Stg1> Stg2. In FIG. 10, Tc1 is the closing time when the servo stroke is Stg1, Tc2 is the closing time when the servo stroke is Stg2, and Tc1 is longer than Tc2 (Tc1> Tc2). .

As described above, since the closing speed per unit time of the hydraulic servomotor for guide vane operation, that is, the closing speed of the guide vane is constant regardless of the magnitude of the load, if the guide vane servo stroke Stg is short, the closing time Tc is As a result, the pressure in the hydraulic iron pipe increases, and the thickness of the hydraulic iron pipe, casing, and water turbine main machine must be increased accordingly, and the GD ^{2 of} the generator becomes large and high in cost. .

In order to avoid this even in the past, as shown in FIG. 11, the two-stage hip-fold closing method in which the closing speed of the hydraulic servomotor for operating the guide vane is slowed from the middle, and the two-stage hip-fold closing method are further improved. There is also a guide vane closing method that controls the closing speed of the hydraulic servomotor for guide vane operation based on the rotation speed of the water turbine detected by the detector or the water pressure in the water pressure pipe detected by the water pressure detector. It has been devised (for example, see Patent Document 1).
JP 2001-90648 A.

  However, in the technique described in Patent Document 1, the rotational speed corresponding unit that generates the guide vane closing speed control signal based on the deviation between the rotational speed of the turbine and the predetermined set value, the water pressure in the hydraulic iron pipe and the predetermined setting. Select either the hydraulic pressure control unit that generates a signal to control the hydraulic servo motor operating speed (guide vane closing speed) based on the deviation from the value, the guide vane closing speed control signal, and the hydraulic servo motor operating speed It is necessary to provide a switching device or the like, and the configuration is inevitably complicated. In addition, it is difficult to determine the final closing speed that satisfies the specifications after performing analysis of prior transient characteristics from large loads to small loads and verifying them.

  Accordingly, an object of the present invention is to prevent the main engine from being used in an emergency so that the closing speed per unit time of the servo motor for operating the guide vane is not extremely increased even when the turbine load to be cut off is small without using a complicated device. Hydropower for power generation that obtains an appropriate closing speed per unit time according to the load just before stopping or the amount of guide vane opening equivalent amount such as guide vane servo stroke, and closes the guide vane at this closing speed. It is an object to provide a guide vane closing control device for a machine and a control method therefor.

  To achieve the above object, a guide vane closing control device for a power generating hydraulic machine according to claim 1 is a hydraulic servomotor having a piston for opening and closing a guide vane of the power generating hydraulic machine, and the hydraulic servomotor. A pressure distribution valve that sends and discharges pressure oil to the cylinder, a drainage amount adjustment valve that is provided in the middle of the drainage oil flow path of the pressure distribution valve and throttles the flow rate of the drainage oil that flows through the flow path, When an emergency stop condition is input, a closing speed signal per unit time of the guide vane is output so that the guide vane opening equivalent amount immediately before it is large, and if it is small, the closing speed signal per unit time is output. And a closing control unit that controls the valve opening degree.

  Further, the invention of the guide vane closing control method of the power generating hydraulic machine according to claim 5 is the guide vane closing control method of closing control of the guide vane of the power generating hydraulic machine, in the case of emergency stop of the main engine during the power generation operation, The closing speed of the guide vane per unit time is controlled so that the guide vane opening degree immediately before the emergency stop is large if the amount corresponding to the guide vane opening is large and small if it is small.

  The guide vane closing control device and its control method for a power generating hydraulic machine according to the present invention has a size equivalent to a guide vane immediately before stopping without using a complicated device when an emergency stop occurs. It is possible to determine the optimum guide vane closing speed per unit time according to the conditions, and it is not necessary to use an unreasonable closing characteristic. Water pressure fluctuation can be reduced.

As a result, penstocks, casing, reducing the maximum design pressure reduction and generators GD ² in such inlet valve becomes possible and the guide vane hydraulic servo motor capacity also significant hydraulic turbine since it is possible to reduce Cost reduction can be achieved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, common items will be described before the description of each embodiment.
FIGS. 1 and 2 are configuration diagrams common to all the first to fifth embodiments of the present invention. FIG. 1 is a configuration diagram of a guide vane closing control device for a power generation hydraulic machine, and FIG. 2 is a guide vane closing. It is a conceptual block diagram of the closing control part which is the principal part of a control apparatus.

  In FIG. 1, a guide vane closing control apparatus 100 includes a guide vane operating hydraulic servomotor 2 mechanically connected to a guide vane 1 (strictly speaking, a shaft 1 of a guide vane opening / closing mechanism), and a pressure oil (not shown). The pressure oil sent from the apparatus is supplied to the hydraulic servo motor 2 or discharged from the hydraulic servo motor 2, and the amount of oil discharged from the pressure distribution valve 3 is reduced to reduce the guide vane closing speed. An oil discharge amount adjusting valve 4 for controlling, a closing control unit 5 for outputting a guide vane closing speed V (dTc / dt) signal obtained at the time of emergency stop of the main engine to the oil discharge amount adjusting valve 4, and a guide vane opening degree A servo stroke detection unit 7 is provided as means for detecting a substantial amount of turbine output or load. The servo stroke detection unit 7 is configured to detect the opening degree of the guide vane by detecting the operation amount of the operation rod 6 of the guide vane opening / closing mechanism, that is, the servo stroke.

  In FIG. 1, the servo stroke detector 7 is provided as means for detecting the magnitude of the guide vane opening equivalent amount, but the present invention is not limited to this, for example, a generator (not shown) The output P may be detected.

Incidentally, the hydraulic servo motor 2 actuates the piston _2-2 by pressure oil is the pressure oil and the discharge is supplied to the cylinder 2 _-1, configured to open and close operation of the guide vanes 1 via the operating rod 6 ing. Moreover, the distribution valve 3, depending on the position of Hai圧piston 3 _-1, to supply hydraulic fluid to the open side oil chamber 2a of the hydraulic servo motor 2 of the cylinder 2 _-2, and closed side oil of the same hydraulic servo motor 2 A first state in which the pressure oil is discharged from the chamber 2b (guide vane opening operation state), and a second state in which the pressure oil is supplied to the closed side oil chamber 2b and the pressure oil is discharged from the open side oil chamber 2a ( The guide vane closing operation state) is switched.

Next, the conceptual configuration of the closing control unit 5 will be described with reference to FIG.
In FIG. 2, the closing control unit 5 sequentially inputs a servo stroke signal Stg from the servo stroke detection device 6 or a load P detected by a generator (not shown) and temporarily stores it, and a control panel (not shown) When the main engine emergency stop signal is input, the load P or the servo stroke signal Stg immediately before the main engine emergency stop operation is output from the stored information. storage means _5-1 which is, may be set load P or per unit corresponding time servo stroke signal Stg guide vane closing speed signal V a (= dTc / dt) as a pre-function, the storage means 5 _-1 When the load P or servo stroke signal Stg immediately before the emergency stop of the main engine output from is input, the guide vane closing speed signal corresponding to the input signal And a No. V (= dTc / dt) and outputs a closing time signal generator _5-2 Prefecture.

  Since the description of the elements common to the respective embodiments has been completed, the description of the respective embodiments will be started next. In each of the following embodiments, the closing time signal generator 5-2 of the closing control unit 5 is replaced. So only this will be explained.

(Embodiment 1)
Figure 3 is a diagram showing characteristics of the closing time signal generator 5 _{-2 A} of the present embodiment.
The closing time signal generator 5 _-2 A shown in FIG. 3 takes a load P detected from a guide vane servo stroke Stg or an output terminal of a generator (not shown) on the horizontal axis, and guide vane closing speed V ( With dTc / dt) as a vertical axis, the guide vane closing speed V (dTc / dt) per unit time increases linearly up to the maximum load P1 with respect to the load P or the servo stroke Stg. Yes.

  For example, in the case of the maximum load P1 (servo stroke; Stg1 at this time), the fastest guide vane closing speed V1 is obtained, and in the case of the load P3 smaller than the maximum load P1 (servo stroke; Stg3 at this time), the guide vane A closing speed V3 is obtained, and a guide vane closing speed V4 lower than the guide vane closing speed V3 is obtained in the case of a load P4 (servo stroke at this time; Stg4. Stg3> Stg4) smaller than the load P3.

  FIG. 4 is a diagram showing the relationship of the guide vane servo stroke Stg to the closing time Tc. In the case of the servo strokes Stg3 and Stg4, the closing times Tc3 and Tc4 can be made sufficiently longer than the conventional Tc2 of FIG. Show. In other words, the closing time is controlled to be substantially constant regardless of the magnitude of the guide vane servo stroke Stg.

  Thus, the guide vane closing speed V (dTc / dt) is not a constant value as in the conventional example shown in FIG. 10, and the guide vane servo stroke Stg is shorter as shown in FIG. The vane closing speed V (dTc / dt) becomes gentle. As a result, even if the guide vane servo stroke Stg is short, the guide vane closing time (Tc) is not shortened as in the conventional case.

As described above, in the first embodiment, it is possible to apply the optimum guide vane closing speed V (dTc / dt) per unit time according to the load immediately before the stop, for example, the turbine output is low. Even in such a case, the guide vane closing time (Tc) is not shortened as before, and the pressure in the hydraulic iron pipe does not become abnormal. As a result, it is possible to reduce verification by transient characteristics analysis and to reduce the fluctuation of water pressure in the entire load range.Therefore, it is possible to reduce the design maximum water pressure of hydraulic iron pipes, casings, inlet valves, etc. GD ² can be reduced, and the capacity of the guide vane servo motor can be reduced, so that the cost of the water turbine can be significantly reduced.

(Embodiment 2)
Next, Embodiment 2 will be described with reference to FIG.
In the present embodiment, the closing time signal generator 5 ₋ having the characteristics shown in FIG. 5 is used instead of the closing time signal generator 5 ₋₂ A having the characteristics shown in FIG. ₂ B is provided, and the others are the same as those in the first embodiment.

The closing time signal generator 5 _-2 B shown in FIG. 5 takes a guide vane servo stroke Stg or a load P detected from a generator (not shown) on the horizontal axis, and guide vane closing speed V (dTc / dt) per unit time. The guide vane closing speed V (dTc / dt) per unit time is linear up to a guide vane servo stroke Stg5 corresponding to 70% load (P5) or 70% load with respect to the load P or servo stroke Stg. And has the characteristic of maintaining the maximum closing speed value up to the maximum load P1 (Stg1) with the 70% load (P5; Stg5) as a boundary.

  In FIG. 5, when the load is 70% load P5 (servo stroke; Stg5) or more, the fastest guide vane closing speed V1 is obtained. For example, when the load is 30% load P6 (servo stroke; Stg6), guide vane closing is slower than V1. A speed V6 is obtained.

  Thus, also in this embodiment, the guide vane closing speed V (dTc / dt) is not a constant value as in the conventional example shown in FIG. 10, and the guide vane servo stroke is small, that is, the turbine output is low. The guide vane closing speed V (dTc / dt) becomes gentle as the guide vane closing time (Tc) is not shortened as in the prior art even if the guide vane servo stroke is small.

  As described above, also in the present embodiment, it is possible to apply the guide vane closing speed V (dTc / dt) per unit time according to the magnitude of the load immediately before the main engine stops, for example, the turbine output is Even if the output is low, the guide vane closing time will not be shortened and the pressure inside the hydraulic iron pipe will not become abnormal.

As a result, it is possible to reduce verification by transient characteristics analysis and to reduce fluctuations in water pressure in the entire load range. Therefore, it is possible to reduce the design maximum water pressure of iron pipes, casings, inlet valves, etc. ² can be reduced, and the capacity of the guide vane servo motor can be reduced. Therefore, the cost and effect of the water turbine can be significantly reduced. Can do.

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIG.
This embodiment, as a closed time signal generator which is incorporated in a closed control unit 5, the closing time signal generator _5-2 having the characteristics of FIG. 6 in place closing time signal generator _{5-2 A} having the characteristics of FIG. 3 C is provided, and the others are the same as those in the first embodiment.

The closing time signal generator 5 _-2 C shown in FIG. 6 has the load P or guide vane servo stroke Stg on the horizontal axis and the guide vane closing speed V (dTc / dt) per unit time on the vertical axis. The guide vane closing speed V (dTc / dt) per unit time with respect to the servo stroke Stg is, for example, 0 to 30% load (P6), 30% (P6) to 70% load (P5), 70% load (P5). ) It is configured to be divided into three stages of closing speeds (V6, V5, V1) up to the maximum load (P1).

  Also in the present embodiment, it is possible to apply the guide vane closing speed V (dTc / dt) per unit time according to the load P immediately before the main engine stop, as in the first and second embodiments. Even if the turbine output is low, the closing time (Tc) is shortened as before and the pressure in the hydraulic iron pipe does not become abnormal.

As a result, it is possible to reduce verification by transient characteristics analysis and to reduce fluctuations in water pressure in the entire load range. Therefore, it is possible to reduce the design maximum water pressure of iron pipes, casings, inlet valves, etc. ² can be reduced, and the capacity of the guide vane servo motor can be reduced, so that the cost reduction of the water turbine can be achieved. Can play.

(Embodiment 4)
Next, Embodiment 4 will be described with reference to FIG.
This embodiment, as a closed time signal generator which is incorporated in a closed control unit 5, the closing time signal generator _5-2 having the characteristics of FIG. 7 in place closing time signal generator _{5-2 A} having the characteristics of FIG. 3 D is provided, and the others are the same as those in the first embodiment.

The closing time signal generator 5 _-2 D shown in FIG. 7 has the load or guide vane servo stroke StgP on the horizontal axis and the guide vane closing speed (dTc / dt) per unit time on the vertical axis, and the load P or servo stroke. The guide vane closing speed V (dTc / dt) per unit time is steeply increased with respect to Stg up to the maximum load (P1).

  In the case of FIG. 7 as well, a guide vane closing speed V1 is obtained for the maximum load P1 (servo stroke; Stg1), and a guide vane closing speed slower than V1 for the load P7 (servo stroke; Stg7, Stg1> Stg7). V7 is obtained.

  As described above, also in this embodiment, the guide vane closing speed V (dTc / dt) is not a constant value as in the conventional example shown in FIG. 10, and the smaller the load, that is, the guide vane servo stroke, the lower the guide vane closing speed. V (dTc / dt) becomes gentle.

  As a result, the guide vane closing time (Tc) is not shortened as in the prior art even if the guide vane servo stroke is small, and the same effects as in the first to third embodiments can be achieved.

(Embodiment 5)
Next, Embodiment 5 will be described with reference to FIG.
This embodiment, as a closed time signal generator which is incorporated in a closed control unit 5, the closing time signal generator _5-2 having the characteristics of FIG. 8 in place closing time signal generator _{5-2 A} having the characteristics of FIG. 3 E is provided, and the others are the same as those in the first embodiment.

Closing time signal generator 5 _{-2 E} shown in FIG. 8, the guide vane servo stroke Stg or horizontal axis of the detected load P from the output of the not-shown generator per unit time guide vane closing speed (dTc / dt ) On the vertical axis, the guide vane closing speed V (dTc / dt) per unit time increases in a curve up to 70% load with respect to the load P or servo stroke Stg, and exceeds 70% to reach the maximum load P1. It is configured to have a characteristic of holding a constant value.

  In FIG. 8, when the servo stroke is 70% load or more, the fastest guide vane closing speed V1 is obtained, and when the servo stroke is, for example, 30% load P6, a guide vane closing speed V6 slower than V1 is obtained.

  As described above, in this embodiment as well, in the same manner as in the first to fourth embodiments, the guide vane closing speed V (dTc / dt) is not a constant value as in the conventional example shown in FIG. The smaller the Stg, the slower the guide vane closing speed, and the guide vane closing time (Tc) is not shortened as in the prior art even if the guide vane opening is small.

  As a result, also in the present embodiment, the guide vane closing time (Tc) is not shortened as in the prior art even when the guide vane opening is small, and the same effects as in the first to fourth embodiments can be achieved. .

The block diagram of the guide vane closing control apparatus of the hydraulic machine for electric power generation. The conceptual block diagram of the principal part of a guide vane closing control apparatus. The figure which shows the characteristic of the closure control part which concerns on Embodiment 1 of this invention. The figure which shows the relationship between the guide vane closing time and guide vane servo stroke which concern on Embodiment 1 of this invention. The figure which shows the characteristic of the closure control part which concerns on Embodiment 2 of this invention. The figure which shows the characteristic of the closure control part which concerns on Embodiment 3 of this invention. The figure which shows the characteristic of the closure control part which concerns on Embodiment 4 of this invention. The figure which shows the characteristic of the closure control part which concerns on Embodiment 5 of this invention. The figure which shows the relationship between a turbine output and a guide vane servo stroke. The figure which shows the relationship between guide vane closing time and a guide vane servo stroke. The figure which shows a guide vane 2 step | paragraph closing characteristic.

Explanation of symbols

1 ... guide vane (guide vane closing mechanism shaft), 2 ... hydraulic servo motor, 3 ... distributing valve, 4 ... drain oil amount adjusting valve, 5 ... closing control unit, _{5-1 ...} storage _{unit, 5-2,} 5 _{- 2 A to} 5 _-2 E: Closing time signal generator, 6 ... Operating rod, 7 ... Servo stroke detector, 100 ... Guide vane closing control device.

Claims (7)

  A hydraulic servomotor having a piston that opens and closes a guide vane of a hydraulic machine for power generation; a pressure distribution valve that sends and discharges pressure oil to and from a cylinder of the hydraulic servomotor; and a passageway for the oil discharge of the pressure distribution valve. When the oil amount control valve for restricting the flow rate of the waste oil flowing through the flow path and the emergency stop condition of the main engine are input, it is faster if the equivalent amount of the guide vane opening immediately before is larger, and slower if smaller. And a closing control unit that outputs a closing speed signal per unit time of the guide vane and controls a valve opening degree of the oil discharge amount adjusting valve. Control device.   The closing control unit sequentially inputs and temporarily stores the guide vane opening equivalent amount, and outputs the guide vane opening equivalent amount immediately before the main engine emergency stop from the stored information when the main engine emergency stop signal is input. And a closing speed signal per unit time of the guide vane corresponding to the guide vane opening equivalent amount is determined in advance, and the guide vane opening equivalent amount immediately before the main engine emergency stop output from the storage means 2. The guide vane closing control device for a power generating hydraulic machine according to claim 1, further comprising: a closing time signal generator that outputs a closing speed signal of a guide vane according to the input content of the input.   The closing time signal generator changes the relationship between the closing speed signal per unit time of the guide vane corresponding to the guide vane opening equivalent amount in a linearly changing characteristic, a curve changing characteristic, and two or more stages. 3. The guide vane closing control device for a power generating hydraulic machine according to claim 2, wherein the characteristic is one of a characteristic that changes linearly or in a curve up to a predetermined guide vane opening equivalent amount.   The guide vane closing device for a power generating hydraulic machine according to any one of claims 1 to 3, wherein the guide vane opening equivalent amount is a load or a guide vane servo stroke.   In the guide vane closing control method that controls the closing of the guide vanes of the hydroelectric machine for power generation, when the main engine is emergency stopped during power generation operation, the guide vane opening equivalent amount immediately before the emergency stop is large, and if it is small, it is slow A guide vane closing control method for a power generating hydraulic machine, wherein the closing speed per unit time of the guide vane is controlled.   When the closing speed per unit time of the guide vane or the servo motor for operating the guide vane is controlled so that the guide vane opening equivalent amount immediately before the emergency stop is large, it will be slow if it is small. 6. The guide vane closing control method for a power generating hydraulic machine according to claim 5, wherein the speed is controlled by a linear characteristic, a curved characteristic, a step characteristic, or a combined characteristic obtained by combining these characteristics.   7. The guide vane closing control method for a power generating hydraulic machine according to claim 5, wherein the guide vane opening equivalent amount is a load or a guide vane servo stroke.

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