JP2013256957A - Water volume regulating valve control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water volume regulating valve control device which stops and starts a main engine while maintaining safety with respect to a power generation apparatus and incidental facilities when a propeller water turbine generator is disengaged from a system due to a sudden stop or an emergency stop and when the water turbine generator is started.SOLUTION: A water volume regulating valve control device which closes an inlet valve or an outlet valve installed on a propeller water turbine, to which a guide vane is fixed, when blocking off flowing water in such a manner that a relation between a closing time thereof and a valve opening degree is in a curved state or which opens the inlet valve or the outlet valve in such a manner that the relation is in the curved state also during the start thereof.

Description

  The present invention relates to a control device for a water amount adjustment valve (an inlet valve or an outlet valve) of a water turbine for rotationally driving a generator or the like installed in a hydroelectric power plant or the like.

  A turbine for power generation installed in a hydropower station or the like is given a rotational force by running water introduced from a pipe. And the generator is connected to the water wheel, and it is constituted so that the generator may be rotated and generated.

  A water amount adjustment valve is provided on the upstream side of the water wheel, and shuts off the water flow to the water wheel by closing the water amount adjustment valve when the main engine is malfunctioning or abnormal or during internal inspection. In addition, when the main engine is started, water is supplied to the water turbine by opening the water amount adjustment valve.

  As a conventional water amount adjusting valve control device, a configuration shown in FIG. 12 is known. FIG. 12 is a block diagram of a conventional water amount adjusting valve control device. In the figure, 12 is an open command contact, 13 is a close command contact, 14 is a drive motor control device, 2 is a drive motor, 15 is a water amount adjusting valve, and 16 is a water wheel.

  When the open command contact 12 is turned on, an open command signal is generated and supplied to the drive motor controller 14. The drive motor control device 14 causes the drive motor 2 to rotate forward at a rated speed based on the opening command signal, and opens the water amount adjustment valve 15 with the driving force of the drive motor 2 to supply water to the water turbine 16.

  When the close command contact 13 is closed, a close command signal is generated and supplied to the drive motor controller 14. Then, the drive motor control device 14 reverses the drive motor 2 at the rated speed based on the close command signal to close the water amount adjustment valve 15.

  Here, when shifting the water amount adjustment valve from the fully open state to the fully closed state, the pressure in the iron pipe upstream of the water amount adjustment valve increases immediately before the fully closed state. However, this is due to the following reason.

FIG. 13 is a diagram showing the flow characteristics of the propeller turbine. As shown in the figure, the flow characteristics of the propeller turbine increase as the rotational speed increases.
FIG. 14 is a diagram showing the flow rate characteristics of the water amount adjusting valve of the conventional water amount adjusting valve control device. As shown in the figure, the flow rate characteristic of the water amount adjusting valve does not change much even near the full opening.

  Therefore, if the water amount adjustment valve is closed linearly, even if the valve is closed, the flow rate of the turbine is initially greatly affected, and the flow rate passing through the valve increases, causing a water pressure drop on the upstream side of the turbine and a water pressure on the downstream side of the turbine. An increase occurs. When the valve opening is closed to less than half, the flow rate passing through the valve is rapidly reduced due to the valve closing characteristics. As a result, a large increase in water pressure occurs near the fully closed valve.

  In particular, when a propeller water turbine in which a guide vane is fixed to a system having a long pipe on the upstream side or downstream side of the water turbine is used, it is difficult to appropriately prevent such an increase in water pressure because the pipe is long. .

  Therefore, in Patent Document 1, the opening degree of the inlet valve is measured using an opening degree detector, and the opening degree of the inlet valve closes at a high speed until the opening degree of the inlet valve reaches a preset opening degree. Since then, a configuration has been disclosed in which the water pressure rise in the iron pipe is kept within a predetermined range by performing control to close at low speed.

  In Patent Document 2, a limit switch that operates by detecting the opening degree of the inlet valve is provided, and control is performed to switch between the closing speed and the opening speed of the inlet valve at a preset opening degree. In the process of opening the inlet valve, start at a slow speed and increase from a certain opening. In the closing process, start fast and slow down from a certain opening. Thereby, the structure which prevents the water pressure rise in an iron pipe at the time of closing operation of an inlet valve and opening operation is disclosed.

Japanese Utility Model Publication No. 6-43269 Japanese Patent Laid-Open No. 11-82276

However, these conventional water amount adjusting valve control devices have the following problems.
In Patent Document 1, the closing speed of the inlet valve is switched only once. Therefore, when a propeller turbine with a guide vane fixed to a system with long piping on the upstream side or downstream side of the turbine is used, the piping is long, so optimal pressure fluctuation suppression can be obtained with only one switching. It is difficult to keep the water pressure rise properly. Moreover, since it is necessary to provide an opening degree detector, the whole structure will also become complicated.

  Also in Patent Document 2, since the switching speed of the inlet valve is switched only once, similarly, if the piping is long, it is difficult to appropriately prevent an increase in water pressure. In this case, since the opening is detected by the limit switch, it is difficult to detect the opening several times. Therefore, switching can be performed only once. Further, the provision of the limit switch complicates the overall configuration.

  An object of the present invention is to provide a water amount adjusting valve control device that can appropriately prevent an increase in water pressure in a pipe even when the pipe is long, in order to solve the above-described problems.

  In order to achieve the above object, according to the present invention, in the water amount adjustment valve control device comprising a water amount valve adjustment mechanism for driving and controlling the opening and closing of the water amount adjustment valve for adjusting the amount of water flowing into the water turbine, the water amount In order to make the change in the amount of water flowing into the water wheel substantially uniform when the adjustment valve is opened and closed, the opening amount of the water amount adjustment valve is based on the flow characteristics of the opening amount of the water amount adjustment valve and the flow rate flowing through the water amount adjustment valve. A water amount adjusting valve control device comprising a speed control circuit for switching the driving speed of the water amount valve adjusting mechanism so that the relationship between the opening and closing time is curved.

  According to the present invention, in the above configuration, the speed control circuit includes a rotation speed controller that continuously increases or decreases the drive speed of the water amount valve adjusting mechanism. The control valve control device.

According to the present invention, in the above configuration, the water amount adjusting valve is provided in a pipe on the upstream side of the water wheel.
According to the present invention, in the above configuration, the water amount adjusting valve is provided in a pipe on the downstream side of the water wheel.

  According to the present invention, it is possible to provide a water amount adjusting valve control device capable of appropriately suppressing an increase in water pressure in a pipe even when the pipe is long.

It is a figure which shows the relationship between the opening degree of a water quantity adjustment valve, and time in each closing control process of the multistage opening / closing control of the water quantity adjustment valve of the reference example of this invention, and the curve opening / closing control of the water quantity adjustment valve of an Example. It is a figure which shows the circuit of the multistage switching control of the reference example of this invention. It is a figure which shows the relationship between the opening degree of a water quantity adjustment valve at the time of opening operation of the multistage opening / closing control of the reference example of this invention, and time. It is a figure which shows the relationship between the rotation speed (rotation speed) of the drive motor at the time of opening operation of the multistage opening / closing control of the reference example of this invention, and time. It is a figure which shows the relationship between the opening degree of a water quantity adjustment valve at the time of closing operation of the multistage opening / closing control of the reference example of this invention, and time. It is a figure which shows the relationship between the rotation speed (rotation speed) of the motor for a drive at the time of closing operation of the multistage opening / closing control of the reference example of this invention, and time. It is a figure which shows the comparison of the water pressure change of the piping system in the closing control (2 steps) of the water quantity adjustment valve which concerns on a prior art, and the multistage closing control (5 steps) of the other reference example of this invention. It is a figure which shows the comparison of the water pressure change of the piping system in the open control (2 steps) of the water quantity adjustment valve which concerns on a prior art, and the multistage open control (5 steps) of the other reference example of this invention. It is a figure which shows the circuit of the curve opening / closing control of the Example of this invention. It is a figure which shows the relationship between the rotational speed of the drive motor at the time of opening operation of the curve opening / closing control of the Example of this invention, and time. It is a figure which shows the relationship between the rotational speed of the drive motor at the time of closing operation of the curve opening / closing control of the Example of this invention, and time. It is a block diagram of the water quantity adjustment valve control apparatus by a prior art. It is a figure which shows the flow volume characteristic of a propeller turbine. It is a figure which shows the flow volume characteristic of the inlet valve of the conventional water quantity adjustment valve control apparatus.

  Embodiments will be described in the following examples. In the following description, the same reference numerals are assigned to the same parts as those of the conventional structure.

  FIG. 1 is a diagram showing the relationship between the opening and time of the water amount adjusting valve in each closing control process of the multistage opening / closing control of the water amount adjusting valve of the reference example of the present invention and the curve opening / closing control of the water amount adjusting valve of the embodiment. . In the figure, the broken line indicates the multistage closing control, and the solid line indicates the curve closing control.

As shown in the figure, in the closing control of the multistage closing control and the curve closing control, the water amount adjusting valve is suddenly closed when the turbine load is cut off, and then gradually closed slowly.
Thereby, even if it is a case where it has a long piping system, the change of the whole flow rate can be reduced substantially uniformly, and failure of a piping system etc. can be prevented.

Hereinafter, the configuration of the multistage opening / closing control and the curve opening / closing control will be specifically described.
FIG. 2 is a diagram showing a multistage switching control circuit according to a reference example of the present invention. 1 is a start switch, 2 is a drive motor, 3 is a forward rotation (open direction) switch, 4 is a reverse rotation (close direction) switch, and 5a to c are impedances for limiting the number of rotations (forward direction). , 6a-c are reverse rotation (closing direction) rotational speed limiting impedances, 7a-c are forward rotation (opening direction) control timers, and 8a-c are reverse rotation (closing direction) control timers.

  In the opening operation, when the start switch 1 receives an opening command signal for the water amount adjusting valve, the opening command signal is generated to operate the forward rotation (open direction) switch 3. Initially, since the forward rotation (opening direction) rotation speed limiting impedances 5a to 5c are connected in series with the drive motor 2, the drive motor 2 is controlled at a predetermined minimum rotation speed.

  Thereafter, every time set in each of the timers 7a to 7c for forward rotation (opening direction) control elapses, the impedances 5a to 5c for limiting the number of forward rotations (opening direction) are sequentially short-circuited. As a result, the drive motor 2 can be increased stepwise at predetermined rotational speeds.

  Finally, when the set time of the forward rotation (opening direction) control timer 7c elapses, the forward rotation (opening direction) rotational speed limiting impedance 5c is short-circuited, and a predetermined maximum rotational speed (rated rotational speed) is determined. The water adjustment valve is fully opened.

  In this way, by using the forward rotation (opening direction) rotation speed limiting impedances 5a to 5c and the forward rotation (opening direction) control timers 7a to 7c, based on the preset set value, every elapsed time. It is possible to perform control to increase the rotational speed of the drive motor 2 stepwise (multistage).

  In the closing operation, when the starting switch 1 receives the water command valve closing command signal, the closing command signal is generated to operate the reverse rotation (closing direction) switch 4. Initially, the reverse rotation (closing direction) rotation speed limiting impedances 6a to 6c are connected in series with the drive motor 2, so that the drive motor 2 is controlled at a predetermined maximum rotation speed.

  Thereafter, the reverse rotation (closing direction) rotational speed limiting impedances 6a to 6c are sequentially short-circuited each time the time set for each of the reverse rotation (closing direction) control timers 8a to 8c elapses. Thereby, the drive motor 2 can be decelerated step by step for every predetermined rotational speed.

  Finally, when the set time of the reverse rotation (close direction) control timer 8c has elapsed, the reverse rotation (close direction) rotation speed limiting impedance 6c is short-circuited, and a predetermined minimum rotation speed (rated rotation speed) is determined. The water adjustment valve is fully closed.

  As described above, by using the reverse rotation (closing direction) rotation speed limiting impedances 6a to 6c and the reverse rotation (closing direction) control timers 8a to 8c, based on the predetermined set value, every elapsed time. It is possible to perform control to decelerate the rotational speed of the drive motor 2 in a stepwise manner (multiple steps).

  As a result, even when a long piping system is used, it is possible to uniformly reduce the change in the entire flow rate based on the closing characteristics of the water amount adjusting valve by performing control to close the water amount adjusting valve in stages. This can prevent damage to the piping system.

  Therefore, even when the propeller turbine generator is disconnected from the system due to a sudden or emergency stop, and when the turbine generator is started, the main engine must be stopped or started while maintaining safety with respect to the power generation equipment and incidental facilities. Can do.

  In both the opening operation and the closing operation, the water amount adjusting valve is closed in stages by controlling the rotation speed to a predetermined value with the lapse of the set time. It is not necessary to provide a device for detecting the opening of the water amount adjustment valve.

Therefore, even when several timers and impedances are installed for multistage opening / closing control, the entire configuration of the water amount adjusting valve control device can be simplified.
FIG. 3 is a diagram showing the relationship between the opening of the water amount adjustment valve and time during the opening operation of the multistage opening / closing control of the reference example of the present invention.

  Each time set in each of the forward rotation (opening direction) control timers 7a to 7c elapses, the forward rotation (opening direction) rotation speed limiting impedances 5a to 5c are sequentially short-circuited, and the driving motor 2 As shown in the figure, the water amount adjustment valve can be opened stepwise (multistage).

FIG. 4 is a diagram showing the relationship between the rotational speed (rotational speed) of the driving motor and time during the opening operation of the multistage opening / closing control according to the reference example of the present invention.
Each time the time set for each of the timers 7a to 7c for forward rotation (opening direction) control elapses, the impedances 5a to 5c for limiting the number of forward rotations (opening direction) are sequentially short-circuited to drive. As shown in the drawing, the rotational speed of the motor 2 is increased and controlled stepwise (multistage) as the set time elapses.

FIG. 5 is a diagram showing the relationship between the opening of the water amount adjusting valve and time during the closing operation of the multistage opening / closing control according to the reference example of the present invention.
Each time the time set for each of the reverse rotation (closing direction) control timers 8a to 8c elapses, the reverse rotation (closing direction) rotation speed limiting impedances 6a to 6c are sequentially short-circuited, and the driving motor 2 As shown in the figure, the water amount adjustment valve can be closed stepwise (multistage).

FIG. 6 is a diagram showing the relationship between the rotational speed (rotational speed) of the drive motor and time during the closing operation of the multistage opening / closing control of the reference example of the present invention.
Each time the time set for each of the reverse rotation (closed direction) control timers 8a to 8c elapses, the reverse rotation (close direction) rotational speed limiting impedances 6a to 6c are sequentially short-circuited to drive. As shown in the figure, the rotation speed of the motor 2 is controlled to be reduced stepwise (multi-stage) as the set time elapses.

Although this reference example is an example of control in four stages, any multistage characteristic can be easily realized by increasing or decreasing the rotation speed limiting impedance and the control timer.
FIG. 7 is a diagram showing a comparison of changes in water pressure in the piping system between the water amount adjusting valve closing control (two steps) according to the prior art and the multistage closing control (five steps) of another reference example of the present invention.

When the conventional closing control (two steps) is performed, the water amount adjustment valve is linearly closed, and thus a time zone in which the water pressure rapidly rises before the full closing is observed.
On the other hand, when the multistage closing control (five stages) of the reference example of the present invention is performed, such a rapid change in water pressure does not occur, and the change in water pressure is shown to be gradual.

Thus, the occurrence of abnormal water pressure fluctuations in the piping system can be suppressed by the multistage closing control (five stages) of the reference example of the present invention.
FIG. 8 is a diagram showing a comparison of changes in the water pressure in the piping system between the open control (two steps) of the water amount adjustment valve according to the prior art and the multi-stage open control (five steps) of another reference example of the present invention.

When the conventional method of opening control (two steps) is performed, the water amount adjustment valve is linearly opened, so that a water pressure drop occurs immediately after opening.
On the other hand, when the multistage open control (five steps) of the reference example of the present invention is performed, such a rapid change in water pressure does not occur, and the change in water pressure is shown to be gradual.

Thus, the occurrence of abnormal water pressure fluctuations in the piping system can be suppressed by the multistage opening control (five steps) of the reference example of the present invention.
FIG. 9 is a diagram showing a curve open / close control circuit according to the embodiment of the present invention. 9 is a forward rotation (opening direction) command, 10 is a reverse rotation (closing direction) command, and 11 is a rotation speed controller.

FIG. 10 is a diagram illustrating the relationship between the rotational speed of the drive motor and time during the opening operation of the curve opening / closing control according to the embodiment of the present invention.
FIG. 11 is a diagram illustrating the relationship between the rotational speed of the drive motor and time during the closing operation of the curve opening / closing control according to the embodiment of the present invention.

In the opening operation, when the start switch 1 receives an opening command signal for the water amount adjustment valve, the drive motor 2 operates through the rotation speed controller 11 based on a predetermined internal set value.
When the forward rotation (opening direction) command 9 is given, the drive motor 2 is continuously driven by the rotation speed controller 11 according to the set value curve as shown in FIG. 10 according to the elapsed time from that point. Speed increase control.

  In the closing operation, after the driving motor 2 is operated in the same manner, when a reverse rotation (closing direction) command 10 is given, according to the set value curve as shown in FIG. The drive motor 2 is continuously decelerated and controlled by the rotation speed controller 11.

As the rotation speed controller 11, an inverter capable of continuously controlling the rotation speed of the drive motor 2 is used. In general, an inverter can store a set value.
As a result, even when a long piping system is used, the change in the entire flow rate can be uniformly reduced based on the closing characteristics of the water amount adjusting valve by controlling the water amount adjusting valve in a curvilinear manner. This can prevent damage to the piping system.

  In both the opening and closing operations, the water amount adjustment valve is continuously controlled to open and close as the set time elapses. There is no need to provide a device for detecting the degree. Therefore, the whole structure of the water amount adjusting valve control device can be simplified.

DESCRIPTION OF SYMBOLS 1 Start switch 2 Drive motor 3 Forward rotation (opening direction) switch 4 Reverse rotation (closing direction) switch 5a-c Forward rotation (opening direction) rotational speed limitation impedance 6a-c Reverse rotation (closing direction) Rotation speed limiting impedance 7a to c Forward rotation (opening direction) control timer 8a to c Reverse rotation (closing direction) control timer 9 Forward rotation (opening direction) command 10 Reverse rotation (closing direction) command 11 Rotation speed controller 12 Open command contact 13 Close command contact 14 Motor controller for driving 15 Water amount adjustment valve 16 Water wheel

Claims (4)

In a water amount adjustment valve control device comprising a water amount valve adjustment mechanism for driving and controlling the opening and closing of a water amount adjustment valve for adjusting the amount of water flowing into the water wheel,
In order to make the change in the amount of water flowing into the water wheel substantially uniform when the water amount adjustment valve is opened and closed, based on the flow characteristics of the opening of the water amount adjustment valve and the flow rate flowing through the water amount adjustment valve, A water amount adjusting valve control device comprising a speed control circuit for switching a driving speed of the water amount valve adjusting mechanism so that a relationship between an opening degree and an opening / closing time is curved. In the water amount adjusting valve control device according to claim 1,
The speed control circuit includes:
A water amount adjusting valve control device comprising a rotation speed controller for continuously increasing or decreasing the driving speed of the water amount valve adjusting mechanism. In the water amount adjusting valve control device according to claim 1 or 2,
The water amount adjusting valve is provided in a pipe on the upstream side of the water wheel. In the water amount adjusting valve control device according to claim 1 or 2,
The water amount adjusting valve control device, wherein the water amount adjusting valve is provided in a pipe on the downstream side of the water wheel.