JPS60219403A - Rapid closing control device of intercept valve - Google Patents

Abstract

PURPOSE:To enable the action of an intercept valve to be confirmed when a turbine is driven in normal operation, by providing a valve testing circuit in a solenoid control circuit for a rapidly actuating solenoid valve which operates when an opening deviation signal of the intercept valve is in a predetermined value or more. CONSTITUTION:A control device, in which an opening deviation signal E of an intercept valve and a testing signal G from a testing power supply 21 are added in an adder 20, inputs its output to a voltage comparator 9. If a load interruption or the like is caused when a turbine is driven in normal operation, the control device rapidly closes the intercept valve by operating a power load unbalance circit 19 to excite a solenoid 18 and actuate a rapidly actuating solenoid valve 17. When the valve is tested, a testing switch 23 is turned on so as to excite relays 22, 26 and turn off a contact 26a. While the control device confirms a workable condition of the intercept valve by inputting the testing signal G to the adder 20 and causing the voltage comparator 9 to electrify a contact 9a and turn on a lamp 29.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a quick-closing control device for an intercept valve, which is one of the overspeed prevention devices for a steam turbine. Steam valves that generally act as overspeed prevention devices for steam turbines include:
There is a main steam stop valve for emergency shutoff, an intermediate stop valve, and a steam Calo reduction valve and intercept valve for normal control. These steam valves are equipped with a control circuit that immediately closes the six valves to prevent steam from flowing into the turbine if any abnormal condition (e.g., load cutoff) occurs during turbine operation. This control circuit is necessary. If it does not operate as expected, the turbine will run out of control. Therefore, check the above control circuit as often as possible. It is important and necessary to make sure that you can obtain reliable movements.

Among the steam valves, intercept valves installed in intermediate pressure turbines or low pressure turbines have large diameters, so they are particularly reliable in the event of a load cutoff (2) It is necessary to close suddenly to prevent steam inflow. be.

As such a quick closing control device for an intercept valve, a device having a system as shown in FIG. 1 has conventionally been employed.

In Figure 1 (2), the speed deviation signal A based on the difference between the set speed and the actual speed of the turbine is added to the load setting signal B output from the shellfish handling constant circuit 3 in adders 1 and 2, and One is led to the steam control valve control circuit 4, and the other is
The intercept valve control rejuvenation signal is derived as intercept-7f-control signal C.

Note that normally one medium-pressure or low-pressure turbine (two dual intercept valves are provided), the above-mentioned intercept valve control signal C is the control circuit of intercept valve #2 which has the same configuration as the control circuit of intercept valve #1. The control circuit (6) is also guided in the same manner.

The intercept valve control signal C is compared with the valve opening feedback signal in an adder 7, and is output to an amplifier 8 and a magnetic pressure comparator 9 (two operators) as an intercept t4 opening deviation signal E. is input through the amplifier 8 to the servo valve 10 (two people), and the servo valve 10 receives this signal (
By controlling the amount of pressure oil supplied to the two intercept valves, a valve lift signal F is given and the opening degree of the intercept valve is controlled (2). The lift signal is transmitted through the differential transformer 12
(2) is detected via the demodulator 13 and input to the adder 7 as the two-valve opening feedback signal (as described above).

On the other hand, the upper 6 tonnage pressure comparison a9 is determined by the contact point 9a when the intercept valve deviation signal E exceeds a certain set value.
It is designed to conduct. This contact 9a is connected to the control buses p, , N, via a contact 15 and a relay 16, which are conductive above a set load. Further, when the relay 16 is energized, a contact 16a that becomes conductive is connected in series with the solenoid 18 of the quick-acting solenoid valve 17 to control the control amount m.
Pt, connected to N2.

Therefore, the opening degree of the intercept valve is normally (- is,
Based on the load setting signal B and speed deviation signal A, the servo valve 10
(Although it is controlled in two directions, when the load is cut off (- means that the power load unbalance circuit 119 is activated and the contact 19a
is made non-conductive (-contact 19b is made conductive. As a result, the load setting signal B to be output from adders 1 and 2 (both
becomes zero, and the intercept valve opening degree deviation signal E changes rapidly (2 greatly. When the magnetic pressure comparator 9 detects this change in the intercept valve deviation No. 16 E and conducts the contact 9a, the contact 15 The relay 16 is energized and the contact 16a is made conductive because ρ is conductive at a load above a certain level.
1 pressure oil is discharged and the intercept valve is suddenly closed.

Like this (-, intercept valve (second is when the load is cut off, etc.)
There is a +ttlJ control device for closing two sieves, but this quick-closing 16-sieve device is also equipped with a test device so that the operation can be confirmed during normal operation. In order to safely operate a turbine, two things have become essential.

[Purpose of the invention]

The invention has been made based on the above-mentioned points (two layers), and the object is to provide a control device for quickly closing an intercept valve that can check the operation of the turbine during normal operation.

[Summary of the invention]

The present invention provides a quick-actuation solenoid valve (two attached rapid-actuation solenoid valves) for discharging pressurized oil from the intercept valve in order to quickly close the intercept valve once the deviation signal of the intercept valve exceeds a certain value. A solenoid that drives the excitation magnetic valve (a system that supplies two currents (two contact points of 1st and fJ2), a means for generating a test signal when performing a test, and a means for generating a test signal when performing a test. (as long as the above-mentioned
and means for adding the intercept valve opening degree deviation signal and the test signal and making the second contact conductive when the addition result exceeds the predetermined value. The interceptor suddenly closes with #1 device.

[Embodiment J of the invention Hereinafter, an embodiment of the invention will be described using FIG. 2. Note that in the following drawings (2), the same parts as those in FIG.

In Figure 2 (=, the intercept valve opening degree deviation signal E is input to the adder 20 and added to the test signal G from the test 4 source 21 inputted via the contact 22a, and the addition result is compared with the magnetic pressure. There is also a test switch and a contact i9c that becomes non-conductive when the power load unbalance circuit 19 is activated. and when the intercept valve well 2 is suddenly closed + the UII control device 24 is tested (=contact 5 becomes non-conducting and when it is energized (=contact 22a
The relays 22 that conduct are connected in U row l: and 11 relays z6 are connected in parallel with the relay row.

Also, the same < +1ilj all bus line Pt + N
+ (2) When the addition result of the adder 20 is equal to or higher than a constant +FE, the magnetic pressure comparator 9 (2) is the contact 9a that becomes conductive, the contact 15 that becomes conductive above a certain load, and the intercept square #2.
V-27, which drives the adult fish corresponding to contact 5, is connected in series to the quick-closing control device.Furthermore,
Parallel to this relay n (-relay row and intercept valve row, rung Z9 indicating close is connected. On the other hand, between control bus lines Pt and Nt (2 is rapid operation @ solenoid 18 of magnetic valve 17 (= relay in series) A contact 26a which becomes non-conducting when the relay 26 is energized and a contact 28a which becomes conductive when the relay is energized are connected.

Next, the first effect of this embodiment will be explained.

During normal turbine operation (2) If there is a load cutoff, etc. (: indicates power load imbalance IPIINr1
9 operates to make the contacts 19a and 19c non-conductive (-1 contact 19b becomes conductive. As a result, the load setting signal B becomes zero and the intercept valve opening degree deviation signal E suddenly changes, which is converted into a voltage Comparator 9 detects this and makes contact 9a conductive.At this time, since contact 15 is conductive, relay 27
．． 28 is excited and the lamp 29 lights up. When the relay row is energized, the contacts 28 & become conductive, and the relay base 26a becomes conductive since the relay base 19c is non-conductive (2), so the solenoid 18 is energized and rapidly activated. The solenoid valve 17 is activated and the intercept valve is suddenly closed.

Next (=, When testing such an intercept valve quick-closing control device during turbine operation (2), the test should be conducted by turning on the test switch (2). Test switch 23
When the contact 19c becomes conductive, the contact 19c becomes conductive (=When the contact 6 is conductive, the relay array and A are energized, the contact 22a becomes conductive, and the contact 26a becomes non-conducting. However, The test signal G is input to the adder block through the contact 22a, and the pressure comparator 9 detects this and moves the contact 9a four steps.
is conductive during normal turbine operation, so relay 27
．． 28 is energized, and a lamp 29 indicating quick closing is lit. By energizing the upper relay 27, the control circuit for intercept valve #4:2 is suddenly closed and cannot be tested, and by energizing the relay row, the contact 28a becomes conductive. . In addition, at this time, as mentioned above (= since the relay 26 is energized, the contact 26a is non-conducting and 9,
Therefore, even if the contact 28a is conductive, the solenoid 18 is not excited. and test switch b
When the contact point 22a becomes non-conductive, the p-test ends.

Note that when the quick-closing control device of intercept valve #2 is under test (-), the contact section becomes non-conductive, so this contact section 6 and relay n end up simultaneously (intercept valve #1,
It is not possible to test both #2 quick closing control devices. Also, during the test (if a situation such as double load cutoff occurs), the contact 19c becomes non-conductive, so even if the test switch O is conductive, the relay 26 will not be energized A, and therefore the contact 26m will also be conductive. In this case, the solenoid 18 is energized as described above.
The C intercept valve is suddenly closed. However, the test is based on the sudden closing of the intercept valve due to changes in the turbine operating condition M4 (-).
IilJ Go (Secondly, Yen et al.'s influence will not be exerted).

FIG. 3 shows another embodiment, in which a relay side is inserted in parallel with the relay 26 in FIG. a
fr: In parallel (=connected) with contact 15.

With this configuration (2), it is possible to test the intercept valve quick closing 1σIJ control device even when the contact 15 is in a non-conducting state, that is, when the load is extremely low.

In addition, Figure 4 shows the intercept square opening/closing test circuit and Figure 2 (
This figure shows the combination of the embodiment of the present invention in which two are added.
A relay 41 which inputs a closing signal to the intercept valve opening/closing test switch 40 and a servo valve lO when energized (= is connected in series), and a relay 42 is inserted in parallel with this relay 41. Contact point that conducts when this relay 42 is energized = 12a <Double means that the limit switch 43 and relay (1) that conducts when the series C 2 intercept valve is near full p (2 types) are connected. Furthermore, when this relay 50 is energized (in a configuration in which the relay 22 is connected in series with the J point 50a which conducts twice), when the intercept valve opening/closing test switch 40 is made conductive, the relays 41 and 42 are energized. , the intercept box operates in the closing direction (2) under the control of the servo valve 10, and when it is close to fully closed (type 2), the limit switch 43 is conductive. Since the relay 42 is energized, the contact 42a is conductive. , Therefore, when the limit switch 43 becomes conductive, the relay 50 is energized, and the contact 50a becomes conductive.The relay 22 is energized, and as described above, the test signal G is input to the S adder, and the voltage is compared. The action of the device 9 (the 2nd υ contact 9a is conductive, and if the turbine load exceeds a certain set load, the contact 15 is also conductive, so the relay 4 is energized and the V contact 28a is conductive. At this time , the relay station is diode 5
Since the contact 26a is not energized due to the action of 1, the solenoid 18 is energized and the intercept valve is fully closed. Then, when the intercept valve open/close switch 40 is made non-conductive, the intercept valve returns to the controlled state in the reverse order to the above.

Further, when the test switch O is turned on, only the quick-closing control device can be tested regardless of whether the intercept valve is opened or closed, as in the case shown in FIG.

〔Effect of the invention〕

As mentioned above, according to the intercept valve breath closing control device according to the present invention, the test can be performed without any influence on the control of the intercept valve even during turbine operation. It can be said that it is extremely useful for safe driving.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an intercept valve control device including a conventional intercept valve quick-closing control device, and FIGS.
The figure shows an embodiment of the present invention (2 related intercept valve quick closing/+u
FIG. 4 is a system diagram showing the intercept valve control device that includes all of the IJ control devices; FIG. It must be shown in the diagram. 11...Intercept Masuyu Nao, 17...Thinking action-
Valve 18...Solenoid, 26B, 28a...Contact E...Intercept valve opening deviation No. G...Test signal agent Patent attorney Norichika 41G <1 other person) Fig. 2 Fig. 3

Claims (1)

[Claims] In order to quickly close the intercept valve when the intercept valve opening degree deviation signal exceeds a certain value (2), the interseg is attached to the rapid operation dJ tun magnetic valve to discharge the pressure oil on the oil surface.
and the solenoid that drives the quick-acting solenoid valve.
+ Means for stopping the first and second contacts in the system when testing (- Means for stopping the test signal, and when the test signal is generated and Muself・1
・Funtasegt consists of a force "opening deviation" IB and a means for interrogating the 20th contact point of the opening on the pillar when the additional polishing is ○ or more than the above-mentioned certain value by applying the previous 1st test No. 16 UIJ4-. Valve quick closing +lt!l i@l device.