JPH02267303A - Safety device of steam turbine - Google Patents

Abstract

PURPOSE:To make it possible to perform the actuation confirmation test of a master trip solenoid valve while a turbine is driven by installing a master trip solenoid lock-out valve between an emergency trip device to actuate at the time of excessive speed and a steam valve which rapidly closes at the time of occurrence of abnormality except for excessive speed. CONSTITUTION:An emergency trip device 3 removes a trip valve 5 and a latch 10 through a trip finger 9 when a steam turbine comes to be in the state of excessive speed and an emergency speed governor 8 actuates and makes the trip valve 5 move to the right with the force of a spring 11. Consequently, operating oil 2 supplied to a steam valve 1 is bled off through a port 12 to quickly close the steam valve 1. Additionally, a master trip solenoid valve(MTSV) 14 is magnetized at the time of the occurrence of abnormality except for excessive speed and makes a dump valve 6 move to the left and quickly closes the steam valve 1 in the same way. ln this case, an MTSV lock-out valve 19 is set between the emergency trip device 3 and the steam valve 1 and the actuation confirmation test of the MTSV 14 is performed in the state where a test valve 25 is open.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a steam turbine safety device for safely stopping a steam turbine when an abnormality occurs in the steam turbine.

(Prior Art) In general, safety devices for power generation steam turbines used in power plants include a system that uses an emergency trip device to quickly open a steam valve that shuts off incoming steam when the steam turbine overspeeds; This abnormal phenomenon is transmitted by an electrical signal and the master trip solenoid valve (
There is a system that excites the steam turbine (hereinafter referred to as MTSv) to suddenly open the steam valve in the same manner as above, and there are two systems that safely stop the steam turbine.

A conventional safety device for a steam turbine is constructed as shown in FIG. The hydraulic oil 2 that drives the steam valve 1 enters the boat 4 of the emergency trip device 3, passes through the lip valve 5,
Furthermore, it is discharged from port 7 via dump valve 6 and supplied to steam valve 1 .

When the steam turbine becomes overspeed while rotating and reaches a specified value, the emergency governor 8 is activated, the latch 10 between the trip finger 9 and the trip valve 5 is released, and the spring force of the spring 11 causes the trip valve 5 to close. Pressed towards the center right. As a result, the hydraulic oil 2 that was being supplied to the steam valve 1 is removed from the boat 12.
The steam valve 1 suddenly closes as the oil pressure decreases.

Further, a trip handle 13 is provided so that the trip valve 5 can be operated manually.

By pulling the trip handle 13 to the left in FIG. 2, the launch 10 comes off in the same manner as described above, and the steam valve 7 can be quickly closed.

When an abnormal event other than overspeed occurs in a steam turbine or the like, a master trip solenoid valve (hereinafter referred to as MTSV) is energized by an electric signal. Then,
The bottle 14a of the MTSV 14 is pushed upward, the finger 15 and the latch 16 of the dump valve 6 are released, and the dump valve 6 is pushed to the left in the figure by the spring force of the spring 17.

Therefore, the hydraulic oil 1 that was being supplied to the steam valve 7 is discharged from the boat 18, the oil pressure of the hydraulic oil 2 decreases, and the steam valve 1 suddenly closes.

(Problems to be Solved by the Invention) By the way, in the safety device for a steam turbine having the emergency trip device 3 and the MTSV 14, the trip valve 5 of the emergency trip device 3 has a problem in that the steam valve 1 must not be suddenly closed during the operation of the steam turbine. Although a test method that can confirm the operation of the trip valve 5 has already been established by combining it with other systems, for the MTSV14, the operation confirmation test should be performed without suddenly closing the steam valve 1 during steam turbine operation. I can't. Therefore, even if a trip electric signal is input to the MTSV 14 due to an abnormality other than overspeed of the steam turbine, if the MTSV 14 and the dump valve 6 are inoperable, the steam turbine cannot be stopped immediately, resulting in a steam turbine accident. There was a problem that there was a risk of

Therefore, the present invention has been made in consideration of the above circumstances.
MT without fully opening the steam valve during steam turbine operation
An object of the present invention is to provide a steam turbine safety device that can perform an SV operation test.

(Structure of the Invention) (Means for Solving the Problems) A safety device for a steam turbine according to the present invention operates an emergency trip device when a steam turbine overspeeds, and activates a master trip solenoid valve when an abnormality other than overspeed occurs. A safety device for a steam turbine that suddenly closes a steam valve that is energized to shut off incoming steam is characterized in that a master trip solenoid lockout valve is installed between the emergency trip device and the steam valve.

(Function) In the steam turbine safety device having the above configuration, by installing the master trip solenoid lockout valve between the emergency trip device and the steam valve, during the steam turbine operation, when testing the master trip solenoid valve, The oil discharged from the emergency trip device is supplied to the steam valve via the master trip solenoid lockout valve, making it possible to test the operation of the master trip solenoid valve without fully closing the steam valve.

(Example) An embodiment of the present invention will be described below with reference to FIG.

Note that the same reference numerals as in FIG. 2 will be used to describe parts that are the same as or correspond to the conventional configuration.

In FIG. 1, the emergency trip device 3 is connected to a boat 4.7.
12, a trip valve 5, and a dump valve 6, and the trip valve 5 is always urged rightward in the figure by the spring force of the spring 11. A trip finger 9 is disposed at the right end of the trip valve 15, and the right end of the trip valve 15 abuts against the finger 9. Therefore, when the steam turbine enters an overspeed state and reaches a specified value, the emergency governor 8 is activated and the trip finger 9 is activated.
rotates clockwise, the latch 10 with the trip valve 5 is released, and the spring force of the spring 11 pushes the trip valve 5 to the right.

The emergency trip device 3 also includes a trip handle 13.
is installed, and by manually pulling the trip handle 13, the trip finger 9 is rotated clockwise, the latch 10 with the trip valve 5 is released, and the spring force of the spring 11 similarly causes the trip valve 15 to move to the right side. will be suppressed and moved.

Here, the hydraulic oil 2 that drives the steam valve 1 that shuts off incoming steam enters the boat 4 of the emergency trip device @ 3, passes through the trip valve 5, is discharged from the boat 7 via the dump valve 6, and is discharged from the boat 7 to the steam valve 8. trip valve 5 as described above.
When is pushed to the right, the hydraulic oil 2 that was being supplied to the steam valve 1 is released from the boat 12, the oil pressure decreases, and the steam valve 1 suddenly closes.

Further, the dump valve 6 is always biased rightward in FIG. 1 by the spring force of the spring 17, and its left end
There is a conflict with The finger 15 is adapted to be rotated clockwise when the master trip solenoid valve (MTSV) 14 is energized and the bottle 14a is pushed upward. Therefore, when an abnormal phenomenon other than overspeed of the steam turbine occurs, the MTSV 14 is excited by an electric signal, the pin 14a is pushed upward as described above, the finger 15 and the latch 16 of the dump valve 6 are released, and the dump valve 6 is pushed to the left by the spring force of spring 17, so steam valve 1
The hydraulic oil 2 that was being supplied to the boat 18 is released from the boat 18, the oil pressure decreases, and the steam valve 1 suddenly closes. In addition, the dump valve 6
The limit switch 27 detects the valve operation.

In addition, the master trip solenoid lockout valve (
The MTSV lockout valve (hereinafter referred to as MTSV lockout valve) 19 is connected to a boat 20 that receives the oil discharged from the emergency trip device 3, a boat 23, 24 that is supplied with another oil, and a port 1 that supplies these hydraulic oils to the steam valve 1. -22, and a piston valve 21, which is always biased leftward in the figure by the spring force of a spring 29 and is pushed and moved rightward.

This movement is detected by limit switch 26. The test valve 25 is energized and "opened" during the operation confirmation test of the MTSVO 14, so that oil is supplied to the boat 23 of one MTSVO take-out valve.

Next, the operation of this embodiment will be explained.

The oil discharged from the emergency trip device 13 enters the boat 20 of the MTSV lockout valve 19 and is discharged from the boat 22 via the piston valve 21 and supplied to the steam valve 7. On the other hand, in addition to the MTSV lockout valve 19, boats t-23 and 24
is supplied with a different oil.

When testing the operation of the MTSV 14, the test valve 25 is first energized and becomes "i" and oil enters the boat 23 of the MTSV lockout valve 19.

This pushes the piston valve 21 to the right, causing the boat 2
4 passes through the boat 22 and is supplied to the steam valve 1, and at the same time the oil that has entered the boat 20 is shut off.

The above state is detected by the limit switch 26, and then the MTSV 14 is excited by this detection signal. As a result, as described above, the boat 7 of the emergency trip device 3
The hydraulic oil that has exited is conversely discharged from the boat 18. The operation of the dump valve 6 is detected by the limit switch 27, and when this operation is confirmed, oil is supplied to the boat 28 to reset the dump valve 6, thereby returning the MTSV 14 and the dump valve 6 to their original states. do.

Next, when the test valve 25 is de-energized, it is "closed".

Then, the piston valve 21 of the MTSV lockout valve 19 is returned to the left side by the biasing force of the spring 29 and returns to its original state, completing the operation confirmation test of the MTSV 14.

In the above embodiment, if an electrical trip signal is input to the MTSV 14 during the operation test, the test valve 25 is instantly de-energized to release the MTSV lockout valve 19, i.e. The test can be canceled and the steam turbine can be safely stopped.

〔Effect of the invention〕

As explained above, according to the present invention, since the master trip solenoid lockout valve is installed between the emergency trip device and the steam valve, the operation confirmation test of the master trip solenoid valve can be performed during operation of the steam turbine. . As a result, the most important reliability of the security device can be improved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a steam turbine safety device according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing a steam turbine safety device according to a conventional example. 1...Steam valve, 3...Emergency trip device, 5...
Trip valve, 6... Dump valve, 14... Master trip-lenoid valve (MTSV), 19... Master trip solenoid lockout valve (MTSV lockout valve), 21... Piston valve, 25...・Test valve.

Claims (1)

[Claims] Activates the emergency trip device when the steam turbine overspeeds,
In a steam turbine safety device that energizes a master trip solenoid valve to quickly close a steam valve that shuts off incoming steam when an abnormality other than overspeed occurs, a master trip solenoid lock is provided between the emergency trip device and the steam valve. A steam turbine safety device characterized by the installation of an out valve.