JPH0343607A - Testing device for emergency speed governing device - Google Patents

Abstract

PURPOSE:To prevent occurrence of a trip accident by testing for a testing device for checking the normal in operation of a steam turbine by making it possible to release the locking of a locking device provided at a test handle when a specified operation condition is detected. CONSTITUTION:An emergency speed governing device 13 installed at a turbine shaft is connected with an emergency trip device 19 through a latch 15, and a manual trip device 4 is provided at the latch. The emergency trip device 19 has a lockout valve 21 and a reset piston 11 connected with a lockout handle 1 and a reset handle 2 as test handles through pressure oil respectively, and a damp valve 16. In this case, the lockout handle 1 is provided with a lock device 20. This lock device 20 releases the lock when a reset switch 10B provided at the end of the reset piston 11 detects the reset position of the damp valve 16, and a pressure switch 17 detects the normal of pressure oil at the part of the damp valve 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention particularly relates to an emergency governor test device for checking the normality of the emergency governor during operation of a steam turbine.

(Prior art) Conventionally, steam turbines have had an emergency governor which is a safety device, and if the turbine shaft overspeeds for some reason, the emergency governor closes and gives a signal. to block steam.

As mentioned above, since the emergency governor requires quick response, it has an emergency trip device that responds to the movement of the emergency governor, which is directly connected to the turbine shaft. The emergency trip device is a cylinder type that operates using pressure oil and spring force.
The steam valve opens and closes by moving a dump valve built into this cylinder. This cylinder has a built-in dump valve, lockout valve, and reset valve.

(Problem to be Solved by the Invention) This type of device is extensively tested even during normal operation to ensure that it will operate reliably even in the unlikely event that the turbine shaft overspeeds. In this case, there is no way to provide a closing signal to the steam valve, and the emergency trip device under test remains locked out.

In this state, the emergency trip device is tested for operation, but the worker must visually check the lamp display to ensure that the device is locked out and that the emergency trip device has been reset after the test. Therefore, there is a risk that this test may cause a trip accident due to misidentification or incorrect operation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a test device for an emergency governor device that can perform tests completely and reliably.

[Structure of the invention]

(Means for Solving the Problem) An emergency governor test device of the present invention is a test device for an emergency governor that cuts off steam flowing from a steam generator to a turbine when a turbine shaft runs out of control. A test lock device is attached to the handle, and the locked state of the test lock device is determined by a limit switch provided on the rod of the dump valve of the emergency trip device and a pressure switch that detects the hydraulic pressure in the emergency trip device. The test handle is characterized in that it detects that the position and oil pressure are normal and releases the signal based on the detection signal, allowing the test handle to be operated in sequence.

(Function) In the present invention, the locking device locks the lockout handle by pulling the lockout handle.

The lockout valve limit switch is also activated. This releases the locking device of the oil trip handle, making it possible to perform an oil lip test (the emergency trip device is in the tripped state). When the dump valve is reset again after the test, the dump valve position detection limit switch and pressure switch are activated, and when the two signals from the limit switch and pressure switch are aligned, the locking device of the lockout handle is released and erroneous operation is prevented. It will be possible to test the operation of the emergency governor without any problems.

(Example) The present invention will be described below with reference to FIGS. 1 and 2. Fig. 1 shows an embodiment of the present invention, and Fig. 2 shows a conventional technique.In order to quickly understand the present invention, we will first explain the conventional emergency governor shown in Fig. 2. This will be explained starting from a schematic system diagram.

In FIG. 2, the emergency governor 13 is attached to a turbine shaft (not shown), and is mechanically connected to an emergency trip device 19 via a latch 15, which has a manual trip device 4. is attached.

On the other hand, the emergency trip device 19 includes a dump valve 16, a lockout valve 21, and a reset piston 11.

The lockout valve 2■ and the reset piston 11 are connected to test handles called a lockout handle 1 and a reset handle 2, respectively, via pressure oil.

An oil trip nozzle 14 is directed toward the emergency governor 13, and pressurized oil can be fed by operating the oil trip handle 3 during testing.

Therefore, when testing whether or not the emergency governor 13 and the emergency trip device 19 operate properly during turbine operation, the lockout handle 1 can be operated to
This is done by sending pressure oil from a to lock the lockout valve 21.

That is, when the locked state is reached, the pressure oil 8A flows to the pressure oil 9 within the lockout valve 21 without passing through the dump valve 16.

In this state, by operating the oil trip handle 3, pressure oil is sent from the pipe 3a to actually operate the emergency governor 13, and in response, the latch 15 is released and the dump valve 1
6 will be activated. However, since the pressure oil 8A does not pass through the dump valve 16, there is no effect on the pressure oil 9, so the steam valve (not shown) will not close.

In this way, the operation of the emergency governor 13 and the emergency trip device 19 is tested.

However, in the above operation test, the worker used lockout handle 1, oil trip handle 3, and reset handle 2.
The lockout handle 1 is released and the lockout handle 1 is released, but whether the lockout valve 21 is in the normal open position is visually confirmed by the display of the lamp 5 by the limit switch 10, and the following operations of each test handle are also confirmed in the same way. These steps are performed sequentially, but there is a risk of misidentification or erroneous operation if only this human confirmation is performed.

For example, the oil lip handle 3 is operated even though the lockout is not complete, causing the emergency governor to actually operate and stopping the turbine. Also, the resetting of the dump valve 16 after the completion of the operation test is not complete (the emergency trip device 1
9 remains in operation), the lockout handle 1 is returned to its original position, causing a problem such as the turbine being stopped.

Therefore, as shown in FIG. 1, the present invention locks the locking device 20 of each test handle under the condition that the lockout valve 21 and the dump valve 16 are in the normal position and have normal oil pressure, respectively, in order to prevent misidentification and erroneous operation. This function releases the status and prevents erroneous operations. That is, FIG. 1 shows a schematic system diagram of the present invention.

FIG. 3 is a block diagram thereof, and FIGS. 4 and 5 are diagrams showing the locking and unlocking states of the locking device.

In FIG. 1, the operation of the operational test is the same as in the conventional method. Next, the operation of the emergency governor test device of the present invention will be explained using FIG. 3 and FIG. First, as shown in FIG. 4, when the lockout handle 1 is operated, the locking device 20 locks the lockout handle 1. At this time, the limit switch 18 detects the locked position and keeps the locking device 20 locked.

Next, the oil trip handle 3 is operated, and this handle 3 is locked by a locking device 20' added in advance according to the present invention.

This locking device 20' is unlocked when the limit switch 10A provided at the shaft end of the lockout valve 21 receives a position detection signal indicating that the lockout valve 21 is in the test position, and the oil trip handle 3 can be operated. Become. In other words, the oil trip handle 3 cannot be operated unless the lockout valve 21 is in the test position.

Also, after completing the operation test by oil trip.

The dump valve 16 is controlled by the limit switch 10B additionally installed at the end of the reset cylinder piston 11 according to the present invention.
The pressure switch 17 detects that the is in the reset position and that the pressure oil in the dump valve 16 is normal.When these two conditions are met, a timer activates the locking device of the handlebar after approximately 5 seconds. 20, and the lockout handle l can be returned to its original position. If the two conditions are not met, the lock device 20 cannot be unlocked and an alarm is issued by the AND circuit.

By automatically locking or releasing the locking device 20 of each test handle in this manner, it becomes possible to safely test the operation of the emergency governor while the turbine is in operation.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the reliability of the locking device in this type of field is further increased by restricting the operation of each test handle using signals from a limit switch and a pressure switch. control can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic control system diagram showing a test device for an emergency speed governor according to the present invention, FIG. 2 is a schematic system diagram showing a conventional emergency speed governor, and FIG. 3 is a block diagram illustrating the operating procedure of the present invention. 4 and 5 are structural diagrams showing the locked state and unlocked state of the locking device used in the present invention. 1...Lock handle 2...Reset handle 3...Oil lip handle 4...Master trip handle 5.6.7...Indication lamp 8,8A...Pressure oil 9...Emergency pressure Oil 10...Limit switch 11...Reset piston 13...
Emergency governor 14...Oil trip nozzle 15...
・Latch 16...Dump valve 17...
Pressure switch 18...Limit switch 19.
...Emergency trip device 20.20'...Lock device
21... Lockout valve 22... Fulcrum pin 23... Lock lever, bar 24... Spring

Claims (1)

[Claims] In a test device for an emergency governor device that shuts off steam flowing from a steam generator to a turbine when a turbine shaft runs out of control, a test lock device is provided on the test handle, and the locked state of the test lock device is detected by dumping the emergency trip device. The dump valve is configured to be released by a detection signal indicating that the dump valve position and oil pressure of the emergency trip device are normal, using a limit switch provided on the valve rod and a pressure switch that detects the oil pressure in the emergency trip device. Emergency governor test equipment.