JPS62131905A - Turbine control device - Google Patents

Abstract

PURPOSE:To reduce the resetting time after a steam valve is closed, by furnishing pressure sensors at an emergency oil pressure line at the upper stream side of a quick action electromagnetic valve and at the lower chamber of a disk damp valve, and controlling the steam valve depending on the detected signals of both sensors. CONSTITUTION:At a hydraulic cylinder 12 to drive a steam valve, a disk damp valve 17 is furnished, and the first pressure sensor 28 is connected to the upper stream side of an emergency oil pressure line of a quick action electromagnetic valve 20. Also at the lower chamber 19 of the disk damp valve 17, the second pressure sensor 31 is connected. Then, signals from the both sensors 28 and 31 are input to an adder 30 through pressure converters 29 and 32, and after compared with a set value 34a in a comparator 34, it is input to an OR circuit 35. The steam valve is controlled by the output of the circuit 35. Therefore, the steam valve can be opened accurately and immediately, since the resetting after the steam valve is closed in a load cutoff condition is performed based on the pressure sensor signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a turbine control device for a steam turbine in a nuclear power plant, for example. The present invention relates to an opening/closing detection device for a disc dump valve.

[Technical background of the invention and its problems]

Generally, in a nuclear power plant, it is necessary to scram the reactor to protect it from malfunctions that would impair the safety of the reactor.

On the other hand, nuclear reactors require a high degree of reliability because unnecessary scrams must be avoided.

Therefore, one of the scram conditions for a nuclear reactor is a rapid closing operation of the turbine steam control valve. The rapid closing operation of this steam control valve is required to shut off the steam head flowing into the turbine when the turbine load is cut off, so that it is required to operate quickly together with other turbine control valves.

Moreover, the rapid closing operation of the steam valve to the scram of the nuclear reactor is also desired to be performed quickly from the standpoint of protecting the reactor.

On the other hand, in a power system that transmits electricity over large capacity over long distances, if there is an accident such as a short circuit or ground fault for some reason, it will cause fluctuations in the power system, so it is necessary to minimize the fluctuations in the power system. It is necessary to quickly bring about stable power transmission in the power system.

As a technical means to improve the stability of power transmission, E and V
, A (EargValve Actuation)
There is. These E, V, and A are designed to restrict the steam flowing into the low-pressure turbine in the event of a power system accident by quickly closing and opening the intercept valve, temporarily reducing the output of the steam turbine's generator, and generating electricity. We are trying to maintain the stability of the system. Therefore, the above-mentioned intercept valve-based steam valve is required to perform severe operations such as rapid valve closing and rapid opening.

In this way, the opening/closing operation of the intercept valve is performed by the movement of the disk dump valve built into the hydraulic cylinder. However, in a steam valve using a steam control valve or an intercept valve, when the valve closes rapidly, the disk dump valve is released. After the disk dump valve is seated (opened), it will be seated (closed) due to the elasticity of the return spring, but conventionally, the time required to reach this seat is unclear, so a timer is activated to close the valve after a certain amount of time has elapsed. It is designed to shift to valve closing operation.

In other words, the rapid closing operation of the steam valve by the steam control valve or intercept valve is detected by the hydraulic pressure in the lower chamber of the disk dump valve or the limit switch that indicates the operation of the quick-acting solenoid valve, but this is not true for the actual disk. Since this is not due to the operation of the dump valve, there is a risk of reactor scram due to malfunction, which poses a reliability problem.

On the other hand, the means for confirming the seating of the disk dump valve uses a timer, which is set to one hour with a certain amount of time, so that the time required for the return operation of the steam valve to the rapid opening state by the intercept valve is There is a waste of money,
Moreover, since it is not possible to clearly confirm that the disk dump valve is seated, if the reset timing of the rapid-acting solenoid valve is reset before the valve is seated, the oil pressure fluctuation of the hydraulic cylinder containing the disk dump valve will increase.
This may lead to a turbine trip due to malfunction.

Turbine control devices for steam turbines of this kind that have already been proposed are configured as shown in FIGS. 6 to 8.

That is, in FIG. 6, for example, steam generated in a steam generator (boiler) 1 such as a nuclear reactor passes through the main steam stop valve 2.
and is transferred to the high pressure turbine 4 through the steam control valve 3,
The steam that has completed its work is transferred to the low-pressure turbine 6 through the intercept valve 5, where it performs work and drives the generator 7, while the steam that has completed its work is transferred to the condenser 8. The water is sent to the steam generator 1, where it is condensed, and then refluxed to the steam generator 1. On the other hand, the main steam stop valve 2, the hot air control valve 3, and the intercept valve 5 are operated at the time of turbine trip.
In response to the trip signal, the valve is quickly closed to cut off the steam flowing into the turbine 4.6, and the operation of the turbine is stopped.

On the other hand, during reactor scram, the steam control valve 3 and intercept valve 5 are rapidly closed. Furthermore, the above E,
At times V and A, the intercept valve 5 instantly closes or opens rapidly to reduce the work of the low-pressure turbine 6, thereby temporarily reducing the output of the generator 7. .

In this way, the turbine control device in a steam turbine is
During load interruption, the working fluid (steam) flowing into the turbine is rapidly shut off to keep the turbine rotation speed as low as possible.
A steam valve or safety valve is provided to control the speed and load, and in addition to the normal speed and load control device,
A device is provided which allows the eight valves to be quickly closed.

FIG. 7 is a diagram showing a steam valve control device using the intercept valve 5, in which the valve body 5a of the intercept valve 5 is connected to the hydraulic piston 13 of the hydraulic cylinder 12 via the connecting rod 10 and the valve rod 11. The hydraulic piston 13 is urged in the direction of fully opening the valve by a valve fully opening spring 14 attached to the upper part of the hydraulic cylinder 12, and the lower chamber 15 of the hydraulic piston 13 has a turbine control High-pressure control oil is supplied through a servo valve 16 operated by a valve position command signal from a device 25, and this high-pressure control oil is configured to operate the hydraulic piston 13 in the valve opening direction. Furthermore, the hydraulic cylinder 12
In the lower cylinder 12a is a disk dump valve 17.
due to the elasticity of the return spring 18, the valve seat 12b1. of the cylinder 12a. The lower chamber 19 of this disc dump valve 17 is supplied with pressure oil from an emergency hydraulic line 21 via a quick-acting solenoid valve 20, and during normal operation, , the disk dump valve 17 is fully closed. Further, a part of the pressure oil that has passed through the quick-acting electromagnetic valve 20 is supplied to a cutoff valve 22 that cuts off and supplies high pressure control oil to the servo valve 16.

On the other hand, an opening position detector 23 for detecting the opening of the intercept valve 5 as a steam valve is provided on the valve rod 11 of the hydraulic cylinder 12 via a switch rod 24. Also, the emergency hydraulic line 20 of the quick-acting solenoid valve 20
A pressure detector 26 is attached to a, and this pressure detector 26 can operate a timer 27.

Therefore, during normal operation, the disk dump valve 17 is fully closed, so the intercept valve 5 is open. or,
The opening degree of the intercept valve 17 is controlled via the valve rod 11 and the connecting rod 10 by supplying and discharging high pressure control oil from the high pressure control oil line 16a to the piston lower chamber 15 of the hydraulic cylinder 12 under the control of the servo valve 16. be done.

On the other hand, when the quick-acting solenoid valve 20 is switched, the pressure oil in the lower chamber 19 of the disc dump valve 17 is drained,
As shown in FIG. 8, the disk dump valve 17 opens rapidly, the hydraulic piston 13 rapidly lowers, and the intercept valve 5 quickly closes.

In this way, the intercept valve 5 is rapidly closed to control the amount of steam flowing into the steam turbine 4.6 during normal operation and to control the steam turbine overspeed υ during load cutoff.

On the other hand, at the time of resetting, the quick-acting solenoid valve 20 is activated after a certain period of time due to the pressure reduction operation of the emergency oil line 20a.
The excitation is canceled by the operation of a timer 27 linked to the pressure detector 26. That is, the quick-acting solenoid valve 2o is switched and the emergency oil in the emergency oil line 21 is forced to the lower part of the disk dump valve 17, so that the disk dump valve 17 is seated on the valve seat 12b of the cylinder 128.

On the other hand, the shutoff valve 22 is moved back with the closing operation of the disk dump valve 17, and the hydraulic cylinder 1
The pressure oil in the lower chamber 15 of the hydraulic piston 13 of No. 2 is transferred to the servo valve 1.
6 through the high-pressure control oil line 16a, whereby the intercept valve 5 is opened in the reverse operation described above.

Note that the opening degree of the intercept valve 5 is detected by an opening position detector 23 connected via a switch rod 24.

Incidentally, the operation of the above-mentioned intercept valve 5 is similar to that of the steam control valve 3, which has the same structure and has the same effect.

On the other hand, at times E, V, and A, it is desirable that the intercept valve 5 quickly closes and then quickly opens, but as shown in FIG. Because the high-pressure control oil in the lower chamber 15 of 13 is pressed downward until it is discharged, at the time of rapid closing,
A drop in the oil pressure of the emergency oil in the emergency oil line 20a is detected by the oil pressure detector 26, which activates the timer 27, and after a certain period of time, the disk dump valve 17 is closed by the emergency oil from the quick-acting solenoid valve 20. Therefore, even if oil pressure is applied to the lower chamber 15 of the hydraulic piston 13, the closing operation of the disk dump valve 17 is maintained by the oil pressure due to the difference in the upper and lower areas of the disk dump valve 17.

As described above, since the disk dump valve 17 performs the reset operation using the preset timer 27, there is a lot of wasted time.
In addition to being a hindrance to the stability of the control system, it also accurately detects the unseating (I71 valve) and seating (valve closing) of the disk dump valve 17, reducing the reset time for rapid valve closing and rapid valve opening. difficult to do.

On the other hand, in an atomic saw power plant, when a load is cut off, the rapid operation i11 solenoid valve is linked to the steam control valve 3, and the disk dump valve 1 is linked to the intercept valve 5 described above.
7 to detect a rapid valve closing operation and perform a reactor scram, the timer 2 equipped with the pressure detector 26 described above is used.
With the control means according to No. 7, it is difficult to shorten the reset time and improve the efficiency of normal operation.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and the present invention detects the unseating and seating of the disk dump valve with a pressure sensor attached to the lower chamber of the disk dump valve. The purpose of this system is to quickly close the intercept valve or steam control valve accurately and quickly using the detection signal, and to control the steam valve by shortening the reset time, as well as to improve the efficiency of normal operation. A turbine control device is provided.

[Summary of the invention]

The present invention provides a turbine control device in which a hydraulic cylinder equipped with a disk dump valve is connected to a steam valve, and a servo valve, a quick-acting solenoid valve, and a position valve are connected to the hydraulic cylinder, and the upstream side of the quick-acting solenoid valve is A first pressure sensor is attached to the emergency oil line, a second pressure sensor is provided in the lower chamber of the disc dump valve, a comparator is connected to the detection line connecting both pressure sensors, and this comparator The steam valve is directly or indirectly controlled via the servo valve.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In addition, in the present invention, the same reference numerals are given to the same constituent members as in the above-described specific example, and detailed explanation thereof will be omitted.

In FIG. 1, reference numeral 12 denotes a hydraulic cylinder that is operated via a connecting rod 10 and a valve stem 11 to a steam valve formed by the intercept valve 5, for example. The connected hydraulic pistons 13 form a lower chamber 15 and are slidably provided (see FIG. 7), and a disk dump valve 17 is provided with a return spring in a cylinder 12a located below the hydraulic pistons 13. The valve seat 12a is seated on the valve seat 12b of the cylinder 12a by the elasticity of the valve 18. Further, an emergency hydraulic line 21 of a quick-acting electromagnetic valve 20 is connected to the lower chamber 19 of the disc dump valve 17, and a cutoff valve 22 and a shutoff valve 22 are connected to the emergency hydraulic line 21 as shown in FIG. A servo valve 16 is connected, and a high pressure control oil line 16a of the servo valve 16 is connected to supply and drain oil to the lower chamber 15 of the hydraulic piston 13.

On the other hand, in the emergency hydraulic line 21 upstream of the quick-acting solenoid valve 20, a first pressure sensor (first pressure detector) 28 is provided.
A pressure transducer 29 is connected to the first pressure sensor 28 in such a way that it can transmit data to an adder 30 . Further, a second pressure sensor (second pressure detector) 31 is attached to the lower chamber 19 of the disk dump valve 17 in the hydraulic cylinder 12, and a pressure transducer 32 is attached to the second pressure sensor 31. It is connected so that it can transmit the detected pressure from the first pressure sensor 2B to the adder 30 and add it thereto. Zarani, both of the above 1. A comparator 34 that determines a pressure setting value 34a is connected to the detection line 33 of the adder 30 that connects the second pressure sensors 28 and 31. An OR circuit 35 connected to the detection line 36 is connected, and this OR circuit 35 controls the opening and closing of the steam valve by the intercept valve 5 via the servo valve 16 and the turbine control device 25.

Therefore, when the load of the steam turbine is interrupted, the quick-acting solenoid valve 2
When 0 is switched, the pressure oil in the lower chamber 19 of the disc dump valve 17 is drained, and the disc dump valve 17 descends against the elasticity of the return spring 18 to open rapidly and the hydraulic cylinder 12 is opened. The hydraulic piston 13 descends rapidly and the steam valve by the intercept valve 5 closes.

On the other hand, when the disk dump valve 17 is reset, the rapid-acting electromagnetic valve 20 detects the first pressure sensor 28 and the second pressure sensor 31 in the lower chamber 19 due to the pressure reduction operation of the emergency hydraulic line 21. The two cylinders 1. The rain detection signal of the second pressure sensor 28.31 is transmitted to each pressure transducer 29.32.
The added signal added in this step is input to the comparator 34 on the detection line 33, and in this step,
The output signal of the comparator 34 is inputted to the OR circuit 35 when the preset pressure setting (a34a is exceeded) is again compared with the detection signal from the first pressure sensor 28, and the OR circuit 35 The output signal de-energizes the rapid-acting solenoid valve 20 via the servo valve 16 and the turbine controller @25.

That is, the quick-acting solenoid valve 20 is switched and the emergency oil in the emergency hydraulic line 21 is forced into the lower chamber 19 of the disc dump valve 17.
is seated on the valve seat 12b of the valve seat of the cylinder 12a. Therefore, the hydraulic piston 1 of the hydraulic cylinder 12
3 rises, whereby the steam valve 5 by the intercept valve 5 is reopened.

The graph shown in FIG. 2 shows the opening degree and hydraulic operating time of the disk dump valve 17. At time E, V, A, the disk dump valve 17 is at time T1 at E, V, A.
When the valve full-open signal from A is input through the servo valve 16, the quick-acting solenoid valve 20 is energized, and the disk dump valve 17 is lowered and opened as described above. Also, time T
After 2, the intercept valve 5 as a steam valve closes, and after a total of m hours (T2-T1) of the valve, the rapid-acting solenoid valve 20 closes.
becomes de-energized and pushes up the disk dump valve 17 to close it, and at the same time, the opening position detector 23 confirms these operations.

In this case, in the above-mentioned turbine control device using a timer, the valve is fully opened (T-T1), which is longer than the fully-opened time (T2-T1), resulting in wasted time; however, in the present invention, As is clear from the graph in FIG. 2, the time can be reduced compared to using a timer.

On the other hand, during a reactor scram, the disk dump valve 17 operates accurately and reliably because the rapid-acting solenoid valve 20 is operated by reliably detecting the pressure by the first and second pressure sensors 28.31. It is possible to improve sexual performance.

Next, another embodiment of the present invention shown in FIG. 3 is one in which a second pressure sensor 31' equipped with a pressure transducer is embedded in the valve seat 12b in contact with the disk dump valve 17, and the second pressure sensor 31' is provided with a pressure transducer. It has the same configuration as the first embodiment.

On the other hand, in another embodiment of the present invention shown in FIG. 4, a fixed sensor 36a is provided on the valve seat 12b, and a movable sensor 36b that contacts this is provided on the disk dump valve 17. The fixed sensor 36a and the movable sensor 36b are combined into a current detector 3 which functions as a current generator 37 and a comparator.
4', and this current detector 34'.
is connected to the OR circuit 35, thereby detecting whether the disk dump valve 17 is unseated (valve open) or seated (valve closed) on the valve seat 12b, and can send a signal to the OR circuit 35. .

Finally, another embodiment of the present invention shown in FIG. It is connected to the comparator 34 and has the same contents as the embodiment described above.

〔Effect of the invention〕

As described above, according to the present invention, the hydraulic cylinder 12 equipped with the disk dump valve 17 is connected to the steam valve, and the servo valve 16 and the quick-acting solenoid valve 20 are connected to the hydraulic cylinder 12.
and a turbine control device connected to the cutoff valve 22,
Emergency oil line 21 upstream of the quick-acting solenoid valve 20
A first pressure sensor 28 is attached to the lower chamber 19 of the disk dump valve 17, a second pressure sensor 31 is attached to the lower chamber 19 of the disk dump valve 17, a comparator 34 is connected to the detection line 33 connecting both pressure sensors 28 and 31, Since the steam valve connected directly or indirectly to the comparator 34 via the servo valve 16 or the like is controlled, not only can the reset time be shortened and the steam valve can be controlled; Can quickly close and open valves accurately.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of the turbine control device according to the present invention, FIG. 2 is a graph showing the opening degree and operating time of the disk dump valve incorporated in the present invention, and FIGS. 3 to 5 6 is a system diagram of a steam turbine, FIG. 7 is a system diagram of an intercept valve control device that has already been proposed, and FIG. 8 is a diagram showing other embodiments of the present invention. FIG. 3 is a cross-sectional view of a disc dump valve connected to a valve. 5... Intercept valve, 12... Hydraulic cylinder,
13... Hydraulic piston, 16... Servo valve, 17.
...Disk dump valve, 19...Lower chamber, 20...
Rapid-acting solenoid valve, 21...Emergency oil hydraulic line, 22.
...Shutoff valve, 2B...First pressure sensor, 31...Second pressure sensor, 34...Comparator, 35...OR circuit. Applicant's representative Mr. Sato Figure 5 Figure 6 IO Figure 7

Claims (1)

[Claims] In a turbine control device in which a hydraulic cylinder equipped with a disk dump valve is connected to a steam valve, and a servo valve, a quick-acting solenoid valve, and a cutoff valve are connected to this hydraulic cylinder, an emergency hydraulic line is provided upstream of the quick-acting solenoid valve. A first pressure sensor is attached to the disc dump valve, a second pressure sensor is provided in the lower chamber of the disc dump valve, a comparator is connected to the detection line connecting both pressure sensors, and a comparator is connected to the comparator via the servo valve. A turbine control device characterized in that it controls the steam valves connected directly or indirectly.