JPH0643269U - Turbine inlet valve control device - Google Patents

Abstract

(57) [Summary] [Purpose] Even when the inlet valve is moved from the fully open state to the fully closed state, the rise in water pressure in the iron pipe is kept within a predetermined range, which prevents damage to the iron pipe upstream of the turbine. Prevent it in advance. [Structure] When a closing command signal is input, the opening of the inlet valve 6 falls below a preset opening based on the opening detection signal output from the opening detector 5 by the speed control circuit 3. Until then, the inlet valve 6 is closed at high speed, and when the opening degree of the inlet valve 6 becomes equal to or less than the set opening degree, the inlet valve 6 is closed at low speed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a turbine inlet valve control device for controlling opening and closing of an inlet valve capable of shutting off running water in a hydroelectric power plant.

[0002]

[Prior art]

 At a hydroelectric power station, when inspecting the inside of the turbine, water is stopped, the amount of water leakage is reduced when the turbine is stopped, or even if the guide vane / servomotor fails, the turbine can be stopped safely. An inlet valve capable of shutting off running water is installed on the upstream side of the turbine, and by closing this inlet valve the running water to the turbine can be shut off.

In this case, normally, before starting the turbine, the inlet valve is moved from the fully closed state to the fully open state to fill the casing, and when the turbine is stopped, the guide vane is fully closed. The inlet valve is changed from the fully open state to the fully closed state on condition that it is in the state.

In this way, the opening degree of the inlet valve is controlled to either the fully closed state or the fully open state.

Therefore, such a turbine turbine inlet valve control device that controls the opening and closing of the inlet valve is configured to open and close the inlet valve with a constant torque by a hydraulic mechanism or an electric mechanism.

[0006]

[Problems to be solved by the device]

 However, the conventional turbine inlet valve control device described above has the following problems.

That is, in such a hydroelectric power station, when the inlet valve is moved from the fully open state to the fully closed state, as shown in FIG. 4, immediately before the fully closed state, the pressure in the iron pipe upstream of the inlet valve suddenly increases. Will increase.

Therefore, in such a system, the time required for closing the inlet valve is set to about 2 minutes so that even if such a rise in water pressure in the iron pipe occurs, the iron pipe does not burst or the like. However, if the length of the iron pipe is long, the increase in water pressure in the iron pipe may exceed the allowable limit of the iron pipe even if the time required to close the inlet valve is set to about 2 minutes.

In view of the above circumstances, the present invention can keep the water pressure increase in the iron pipe within a predetermined range even when the inlet valve is moved from the fully open state to the fully closed state, thereby causing an accident such as iron pipe breakage. It is an object of the present invention to provide a water turbine inlet valve control device capable of preventing the above problems.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a turbine inlet valve control device for opening and closing an inlet valve provided in a hydroelectric power plant, detects the opening of the inlet valve, and opens based on the detection result. The opening of the inlet valve is preset based on the opening detection signal output from the opening detector when the opening detector that generates the opening detection signal and the closing command signal are input. And a speed control circuit that closes the inlet valve at high speed until the opening becomes less than or equal to the opening, and closes the inlet valve at low speed when the opening of the front entry valve becomes less than or equal to the set opening. It is characterized by that.

[0011]

[Action]

 In the above configuration, when the closing command signal is input, the opening of the inlet valve becomes less than or equal to the preset opening based on the opening detection signal output from the opening detector by the speed control circuit. Up to, the inlet valve is closed at high speed, and when the opening degree of the inlet valve becomes equal to or less than the set opening degree, the inlet valve is closed at low speed.

[0012]

FIG. 1 is a block diagram showing an embodiment of a water turbine inlet valve control device according to the present invention.

The turbine inlet valve control device shown in this figure includes an open command contact 1, a close command contact 2, a speed control circuit 3, an operating motor 4, and an opening detector 5, When the contact 1 is turned on, the operating electric motor 4 is normally rotated at the rated speed, the inlet valve 6 is opened by the driving force of the operating electric motor 4 to supply water to the water turbine 7, and the closing command contact 2 is closed. When this occurs, the operating electric motor 4 is first reversed at the rated speed to close the inlet valve 6, and when this falls below a certain opening, the rotational speed of the operating electric motor 4 is lowered and the inlet valve 6 is closed. Completely close.

The open command contact 1 is a contact that is closed when the inlet valve 6 is opened. When the open command contact 1 is closed, an open command signal is generated to generate the open command signal. Supply to the control circuit 3.

The closing command contact 2 is a contact that is closed when the inlet valve 6 is closed. When the closing command contact 2 is closed, a closing command signal is generated and Is supplied to the speed control circuit 3.

The speed control circuit 3 provides a rated forward drive voltage, a rated reverse drive voltage, and a low speed reverse drive voltage based on the outputs from the open command contact 1, the close command contact 2, and the opening detector 5. It is generated and supplied to the operating motor 4 for control.

The operating motor 4 drives the inlet valve 6 based on the drive voltage from the speed control circuit 3 to open and close it.

The opening detector 5 detects the rotation speed of the operating motor 4 to detect the opening of the inlet valve 6, and generates an opening detection signal based on the detection result. Is supplied to the speed control circuit 3.

Next, the inlet valve opening / closing operation of this embodiment will be described with reference to the flowchart shown in FIG.

First, the speed control circuit 3 checks whether or not the close command contact 2 is closed and a close command signal is output (step ST1). If this is output, the opening detector is detected. 5 is taken in and the opening of the inlet valve 6 is set in advance based on the value of this opening detection signal, for example, below the set opening A shown in FIG. It is checked whether or not (step ST2).

When the opening degree of the inlet valve 6 is larger than the set opening degree A, the speed control circuit 3 generates a rated reverse rotation drive voltage and supplies it to the operating motor 4 to set the inlet valve 6 at the rated speed. To close (step ST3).

After that, when the opening degree of the inlet valve 6 becomes smaller than the set opening degree A (step ST2), the speed control circuit 3 generates a low speed reverse rotation drive voltage instead of the rated reverse rotation drive voltage, and this The inlet valve 6 is closed at a low speed by supplying it to the operating motor 4, thereby preventing the water pressure in the iron pipe upstream of the inlet valve 6 from rapidly increasing, while gradually closing the inlet valve 6. To close (step ST4).

Then, when the inlet valve 6 is completely closed, the speed control circuit 3 stops the generation of the low speed reverse rotation drive voltage and stops the rotation of the operating motor 4.

When it is checked whether the close command contact 2 is closed and the close command signal is output (step ST1), if this is not output, the speed control circuit 3 determines that the open command contact 1 is It is checked whether or not the open command signal is output in the closed state (step ST5). If this is output, the rated forward drive voltage is generated and supplied to the operating motor 4 to supply the inlet valve. 6 is opened at the rated speed, and when it is completely opened, the rotation of the operating motor 4 is stopped (step ST6).

When it is checked whether the closing command contact 2 is closed and a closing command signal is output (step ST1), this is not output and the opening command contact 1 is closed. When it is checked whether or not the open command signal is output when the status is set, if it is not output (step ST5), the speed control circuit 3 sets the rated forward drive voltage, the rated reverse drive voltage, and the low speed reverse drive voltage. The generation is stopped to keep the operating motor 4 in a stopped state (step ST7).

As described above, in this embodiment, when the open command contact 1 is turned on, the operating motor 4 is normally rotated at the rated speed to open the inlet valve 6 to supply water to the water turbine 7. When the closing command contact 2 is closed, the operating electric motor 4 is first reversed at the rated speed to close the inlet valve 6, and when this is below a certain opening, the rotational speed of the operating electric motor 4 is lowered. Since the inlet valve 6 is completely closed, even if the inlet valve 6 is moved from the fully open state to the fully closed state as shown in FIG. 3, the rise in water pressure in the iron pipe can be kept within a predetermined range. This makes it possible to prevent accidents such as breakage of iron pipes.

[0027]

[Effect of device]

 As described above, according to the present invention, even when the inlet valve is moved from the fully open state to the fully closed state, it is possible to keep the water pressure increase in the iron pipe within a predetermined range. Accidents can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a water turbine inlet valve control device according to the present invention.

FIG. 2 is a flowchart showing an operation example of the turbine inlet valve control device shown in FIG.

FIG. 3 is a table showing an example of the relationship between the opening of an inlet valve controlled to be opened and closed by the turbine inlet valve control device shown in FIG. 1 and the water pressure in the iron pipe.

FIG. 4 is a table showing an example of the relationship between the opening of an inlet valve controlled to be opened and closed by a conventional turbine inlet valve control device and the water pressure in the iron pipe.

[Explanation of symbols]

 1 Open command contact 2 Close command contact 3 Speed control circuit 4 Operation electric motor 5 Opening detector 6 Inlet valve 7 Water turbine

Claims (1)

[Scope of utility model registration request] 1. A hydraulic turbine inlet valve control device for controlling opening / closing of an inlet valve installed in a hydroelectric power plant, wherein an opening detector for detecting an opening of the inlet valve and generating an opening detection signal, and a closing command. When a signal is input, the inlet valve is closed at high speed until the opening degree of the inlet valve becomes equal to or less than a preset set opening degree based on the opening degree detection signal output from the opening degree detector. A water turbine inlet valve control device comprising: a speed control circuit that closes the inlet valve at a low speed when the opening degree of the inlet valve becomes equal to or less than the set opening degree.