JPH08200009A - Regulating valve control step-up system - Google Patents

Abstract

PURPOSE: To avoid the immediate stoppage of a turbine by providing an AND gate to input an electronic governor shut-down signal, output a valve closing signal and close respective electromagnetic valves and maintaining the opening of a regulating valve even right before the shutdown of the electronic governor CONSTITUTION: Since electromagnetic valves 14, 15 are opened during the normal running of a steam turbine, a pilot valve 5 freely moves as the output lever 3 of a heavy oil converter 2 moves. On the other hand, when other turbine trip signals are absent and signals 22, 23 are inputted to an AND gate 20 during the parallel running of the steam turbines, a shutdown signal 21 is generated by the failure of an electronic governor and inputted to the AND gate 20 to immediately fully close the electromagnetic valves 14, 15. As a result, the position of a piston 13 is fixed to one right before the electronic governor 1 is shut down. Thus, the opening of a regulating valve is maintained so that the immediate stoppage of the steam turbine can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustable valve control booster applied to a steam turbine or the like.

[0002]

2. Description of the Related Art A conventional booster control valve booster for a steam turbine will be described with reference to FIG. In FIG. 2, a current signal output from the electronic governor 1 is input to the electro-oil converter 2, and the output lever 3 of the electro-oil converter 2 moves up and down in response to this current signal.

The movement of the output lever 3 is transmitted to the pilot valve 5 via the pilot valve lever 4, and when the pilot valve 5 moves up and down, the flow of control oil flowing to the servo motor 6 via the oil supply / discharge oil line 8 is increased. And the output shaft 9 of the servo motor 6 is moved up and down.

The movement of the output shaft 9 is transmitted to the regulating valve 11 via the regulating valve lever 10, and the amount of steam to the steam turbine is regulated. On the other hand, the pilot valve 5 is moved in the vertical direction via the feedback lever 12 connected to the servomotor output shaft 9, and is stopped at a balanced position.

The operation of the above device will be described more specifically. For example, when a reduction signal is output from the electronic governor 1, the output lever 3 of the electro-oil converter 2 moves upward. As a result, the pilot valve 5 is pulled upward through the pilot valve lever 4, so that the control oil supplied to the servo motor 6 is discharged to the outside from the supply / discharge oil line 8, and the output shaft 9 of the servo motor 6 It will move upwards. Further, this operation causes the regulating valve 11 to move in the closing direction via the regulating valve lever 10.

On the other hand, the movement of the output shaft 9 is transmitted to the pilot valve 5 via the feedback lever 12 and pushes down the pilot valve 5, so that the flow 8 of the control oil flowing out from the servo motor 6 is stopped and the servo is stopped. Motor 6
Will stop moving.

[0007]

In the conventional apparatus, when the electronic governor fails for some reason and shuts down, the signal from the electronic governor becomes zero, so that the electro-oil converter moves in the fully closed direction. Therefore, the regulator valve is also fully closed, and the turbine has an immediate trip problem.

In order to solve the above-mentioned problems, the present invention is intended to realize a device capable of avoiding an immediate stop of a turbine by maintaining the control valve opening degree immediately before shutdown even when the electronic governor shuts down. is there.

[0009]

The control valve booster of the present invention is an electro-oil converter for moving an output lever up and down by inputting an electric signal from an electronic governor, and a vertical movement of an output lever of the electro-oil converter. In the control valve booster with a servomotor for controlling the control valve by transmitting and receiving the control oil through the pilot valve and the control oil supplied through the pilot valve, A hydraulic cylinder whose piston is connected to the output lever of the converter via a link,
Solenoid valve for oil supply provided on the oil supply line connected to the upper side and lower side of the piston of the hydraulic cylinder, and electromagnetic oil for discharge provided on the oil discharge line connected to the upper side and lower side of the piston of the hydraulic cylinder. It is characterized by including a valve and an AND gate for inputting an electronic governor shutdown signal and outputting a valve closing signal to close each of the solenoid valves.

[0010]

In the above operation, during normal operation, the solenoid valves for oil supply and oil discharge are in the open state, so control oil can freely flow in and out of the upper and lower sides of the piston of the hydraulic cylinder, and the pilot valve can be turned on. It moves freely according to the movement of the oil converter output lever.

When the electronic governor fails during the above operation and a shutdown signal is issued and input to the AND gate, a closing signal is sent from the AND gate to each solenoid valve, and the solenoid valve is fully closed immediately. . As a result, oil for controlling the hydraulic cylinder does not flow in and out, and the position of the piston is fixed at the position just before the electronic governor shuts down.

Therefore, the opening degree of the regulator valve is maintained in the same state as immediately before the shutdown, and when the device of the present invention is applied to the steam turbine, the operation of the steam turbine is continued as it is.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A steam turbine control valve booster according to an embodiment of the present invention will be described with reference to FIG.

In this embodiment, the electric signal output from the electronic governor 1 is input and the output lever 3 moves up and down, and the output lever 3 of the converter 2 moves up and down by the pilot valve lever 4. The control oil supplied from the oil supply line 7 to the pilot valve 5 transmitted via the pilot valve 5 is supplied via the pilot valve 5 and the oil supply / drain oil line 8 to the servo motor output shaft 9 and the adjusting valve lever. A feedback that is connected between the pilot valve lever 4 and the servomotor output shaft 9 and a feedback signal is transmitted by the servomotor 6 whose vertical movement is transmitted to the control valve 11 via 10 to open and close the control valve 11. The present invention relates to an adjustable valve control booster equipped with a control lever 12 and its operation is the same as that of a conventional one, and therefore its explanation is omitted.

In the device of the present embodiment shown in FIG. 1, in addition to the device described above, a piston 13 is connected to an output lever 3 of the electro-hydraulic converter 2 via a link 24, and a hydraulic cylinder 25 and the same hydraulic pressure are provided. Oil quantity adjusting valves 16a, 16 connected to the upper side and lower side of the piston of the cylinder 25, respectively.
b, refueling line 1 connected to the adjusting valves 16a and 16b
8, the oil supply solenoid valve 14 provided in the collecting portion, the oil amount adjusting valves 17a and 17b connected to the piston upper side and the piston lower side of the hydraulic cylinder 25, and the adjusting valve 17a, respectively.
Electromagnetic governor shutdown signal 21 and turbine trip, which are connected to the oil discharge solenoid valve 15 provided at the collecting portion of the oil discharge line 19 connected to 17b, and the oil discharge solenoid valve 15 and the oil supply solenoid valve 14, respectively. Condition not satisfied signal 2
AND gate 20 to which the signal 23 during parallel operation is input
It has.

In the above description, during normal steam turbine operation, since the solenoid valves 14 and 15 are open, the control oil above and below the piston 13 of the hydraulic cylinder 25 can freely flow in and out, and the pilot The valve 5 moves freely according to the movement of the output lever 3 of the electro-hydraulic converter 2.

On the other hand, there is no other turbine trip signal,
When the steam turbines are in parallel operation and the signals 22 and 23 are input to the AND gate 20, the electronic governor 1
Shutdown signal 21 is issued due to the failure of AN
When input to the D gate 20, a closing signal is sent from the AND gate 20 to the solenoid valves 14 and 15, and the solenoid valves 14 and 15 immediately.
15 is fully closed.

As a result, since the control oil in and out of the hydraulic cylinder 25 does not come in and out, the position of the piston 13 is fixed at the position just before the electronic governor 1 is shut down. Therefore, the opening degree of the regulator valve 11 is also maintained in the same state as immediately before the shutdown, and the operation of the steam turbine is continued.

The piston 13 in the hydraulic cylinder 25
It is conceivable that the regulator valve 11 will gradually move in the closing direction due to its own weight and the force that tries to make the output of the electro-hydraulic converter 2 zero, but since there is a time margin, some measures can be taken during this time. Is. Further, it is also possible to manually change the control valve opening degree by releasing the closing signal to the solenoid valves 14 and 15 and adjusting the opening degree of the oil amount adjusting valves 16 and 17.

[0020]

In the control valve booster of the present invention, the electro-oil converter inputs an electric signal from the electronic governor to move the output lever up and down, and the pilot valve which inputs the electric signal outputs a hydraulic signal. In the control valve booster that controls the opening and closing of the control valve by the servo motor, the hydraulic cylinder whose piston is connected to the output lever via a link, and the upper and lower sides of the piston of the hydraulic cylinder are respectively connected. By providing the refueling solenoid valve and the refueling solenoid valve respectively provided in the refueling line and the refueling line, and the AND gate that inputs the electronic governor shutdown signal and outputs a close signal to each of the solenoid valves. Even if the electronic governor fails and shuts down during normal steam turbine operation, the control valve opening just before shutdown is maintained, It is possible to avoid an immediate stopping of the turbine.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an adjustable valve control booster according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional device.

[Explanation of symbols]

 1 Electronic Governor 2 Electro-Oil Converter 3 Electro-Oil Converter Output Lever 4 Pilot Valve Lever 5 Pilot Valve 6 Servo Motor 7 Lubrication Line 8 Lubrication / Discharge Line 9 Servo Motor Output Shaft 10 Control Valve Lever 11 Control Valve 12 Feedback Lever 13 Piston 14 Solenoid valve for oil supply 15 Solenoid valve for oil discharge 16, 17 Oil amount adjustment valve 18 Oil supply line 19 Oil discharge line 20 AND gate 21 Electronic governor shutdown signal 22 Turbine trip condition not satisfied signal 23 Parallel operation signal 24 Link 25 Hydraulic cylinder

Claims (1)

[Claims] 1. An electro-oil converter for moving an output lever up and down by inputting an electric signal from an electronic governor, a pilot valve to which vertical movement of an output lever of the electro-oil converter is transmitted, and control via the pilot valve. In an adjustable valve control booster equipped with a servomotor that is supplied with oil and transmits the vertical movement of its output shaft to control the adjustable valve, the piston is connected to the output lever of the electro-hydraulic converter via a link. Hydraulic cylinder,
Solenoid valve for oil supply provided on the oil supply line connected to the upper side and lower side of the piston of the hydraulic cylinder, and electromagnetic oil for discharge provided on the oil discharge line connected to the upper side and lower side of the piston of the hydraulic cylinder. An adjustable valve control booster equipped with a valve and an AND gate for inputting an electronic governor shutdown signal and outputting a valve closing signal to close each of the solenoid valves.