JPS5920842B2 - Trip test equipment for steam turbines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to test devices for trip devices used in steam turbines, such as vacuum trip devices, backup governor trip devices, bearing oil pressure drop trip devices, and thrust protection trip devices.

Traditionally, trip devices used in steam turbines cannot be tested during turbine operation;
The turbine must be shut down and tested.

To eliminate this inconvenience, some emergency governors, which are one type of trip device, are equipped with a lockout device so that tests can be performed even while the turbine is operating.

In addition, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 50-20110,
We are proposing a test method that allows testing to be performed without stopping an operating turbine.

However, such trip devices also have a significant drawback in that they cannot trip the steam turbine if one trip device trips while another trip device trips.

In other words, in order to perform a test during turbine operation, if one of the multiple test items is being tested, for example the condenser vacuum trip, and if another trip device, for example the backup governor trip, trips, then It must be possible to trip the turbine.

However, with the conventionally proposed technology for trip testing during turbine operation, it is impossible to trip the turbine with a trip signal caused by something other than the item being tested.

A conventional trip device for a turbine will be explained with reference to FIG. 1. 2 is a bellows into which vacuum pressure 1 from a condenser (not shown) is introduced, 3 is a lever operated by the bellows 2, and 4 is a lever 3. 6 is a servo piston operated by pressure oil 5 introduced through the servo pilot valve 4; 7 is a servo piston 60 rod connected to a limit switch 16 and a trip lever 7;
is operated, and the rotating shaft 9 is rotated clockwise by the trip lever 7.

10 is a stopper 1 that presses the trip valve rod 12
1 and a compression spring that presses the rotating shaft 9 counterclockwise, 1
3 is a trip valve that cuts off the operating pressure oil 15; 14 is a presser spring that constantly presses the trip valve 13 so as to cut off the operating pressure oil 15; 17 is the trip valve 13 that has reached the position where it cuts off the operating pressure oil 15. This is a trip limit switch that operates when the

A rotary pilot valve 18 is moved up and down depending on the rotational speed of a governor (not shown), which cuts off the pressure oil 19 and operates the backup governor trip cylinder 20.

As a result of this operation, the rod 22 rises against the force of the presser spring 21, rotates the rotary shaft 9 clockwise, and activates the limit switch 23 in the event of tripping.

24 is a bearing oil pressure drop signal 47 and a thrust protection signal 4
The rotation shaft 9 is rotated clockwise by the operation of this solenoid 24.

25 is a reset solenoid that moves the piston 27 to the left against the force of the spring 26; 29 is a reset piston operated by the pressure air 28 supplied through the piston 27; 30 is a spring that presses the reset histone 29; 32 is connected to the trip valve rod 12 via the piston rod 31
33 is the reset piston 29
34 is a reset limit switch 33 that operates when the reset limit switch reaches the reset position.
This is a limit display lamp that blinks.

Reference numeral 35 denotes a backup governor cylinder, which rises against the force of a spring 36 to cut off the pressure oil 19 and operate the backup governor trip cylinder 20.

44 is a main steam valve stroked by a hydraulic cylinder 50 to which operating pressure oil 15 is supplied via a hydraulic line 54 and a control valve 51; 45 is inflow steam; and 46 is outflow steam.

The operation of the conventional trip device having the above structure will be explained.

When the trip vacuum pressure 1 set by the condenser is introduced into the bellows 2, the servo pilot valve 4 is activated via the lever 3.
is lowered, the pressure oil 5 acts on the servo piston 6 and raises it, so the piston rod 7 also rises and rotates the rotary shaft 9 clockwise via the trip lever 8.

As a result, the stopper 11 separates from the trip valve rod 12, so the trip valve 13 is raised to the trip position by the spring 14, and the operating pressure oil 15 supplied to the main steam valve 44 is cut off.

Therefore, the main steam valve 44 is suddenly closed due to the drop in oil pressure, blocking the inflow of steam 45 and tripping the turbine.

In this case, it can be confirmed that the vacuum trip device is activated by the limit switch 16, and that the trip device is activated by the trip limit switch 17.

Further, when the rotary pilot valve 18 rises to the trip position set by a governor (not shown), the supply of pressure oil to the backup governor trip cylinder 20 is cut off, so that the rod 22 of the cylinder 20 is moved by the force of the spring 21. It is lowered and rotates the rotary shaft 9 clockwise, thereby tripping the turbine as described above.

In this case, it can be confirmed that the backup governor trip device is activated by the limit switch 23, and that the trip device is activated by the trip IJ and the 5-way switch 11.

Furthermore, when the master trip solenoid 24 is actuated by trip signals 47 and 48 from the pressure switch of the bearing oil pressure drop trip device and the pressure switch of the thrust protection trip device (both not shown), the rotating shaft 9 rotates clockwise. Trip the turbine in the same way.

In this case as well, each trip device is activated by the pressure switch, and it can be confirmed by the trip limit switch 17 that each trip device is activated.

To reset when tripped as described above, when the reset solenoid 25 is activated, the reset solenoid piston 27 is moved to the left against the force of the spring 26.

This movement to the left causes the pressure air 28 to act on the reset piston 29 via the piston 27, causing it to rise, and at the same time, against the force of the spring 30, causes the piston rod 31 to rise.

For this purpose, the trip valve rod 12 is
is lowered, and the trip valve 13 returns to its original position.

At the same time, the stopper 11 is engaged with the trip valve rod 12, and the rotating shaft 9 is rotated counterclockwise to return to its original position, so that the trip device can be reset.

The reset operation of the trip device can be confirmed by turning on the reset indicator lamp 34 using the reset limit switch 33.

As mentioned above, in the past, a trip was performed by cutting off the operating pressure oil 15 supplied to the main steam valve 44 via the trip valve 13, so it was impossible to operate and test each trip device at any time. It was possible.

Currently, most of the turbines in operation are used to generate electricity, so stopping them from generating electricity is not only a problem.
This can cause problems with starting and stopping, and shorten the lifespan of the turbine.

On the other hand, not inspecting the trip device without stopping power generation is even more dangerous and reduces the reliability of the turbine.

In view of the above, it is an object of the present invention to enable long-term continuous operation and to improve the reliability of a steam turbine.A lockout device is provided in a turbine trip device formed by combining various trip devices, and the lockout device is provided with a lockout device. By properly operating the equipment and each trip device, each trip device can be tested at any time without changing the predetermined load, and if another trip device trips during the test, lockout is possible. The device is released to trip the steam turbine.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 2 and subsequent figures.

In FIG. 2, the same reference numerals as shown in FIG. 1 indicate similar or corresponding components.

The outline of this trip test device is as follows.

This device includes a pressure detection device that detects the degree of vacuum in the condenser, a speed detection device that detects the turbine rotational speed, and a main steam valve 44 that adjusts or shuts off the amount of steam flowing into the turbine.

The pressure detection device of this example is constructed based on introducing trip vacuum pressure 1 into bellows 2, similar to the conventional example explained using FIG.

The speed detection device of this example is likewise embodied as an arrangement based on a rotary pilot valve 18 .

The main steam valve 44 is configured to be operated by operating pressure oil 15.

On the other hand, by providing trip devices that output trip signals based on the pressure detection signal and speed detection signal of the above-mentioned detection devices in correspondence with these detection devices, it is possible to reduce the number of trip devices installed. The operating pressure oil 15 for operating the main steam valve 44 is configured to be controlled based on a signal from the trip device.

In this example, in addition to installing a vacuum trip device which is a trip device based on a pressure detection signal and a backup governor trip device which is a trip device based on a speed detection signal, a trip device based on thrust protection and bearing oil is also installed. Equipped with

The basic configuration and operation of the vacuum trip device and the backup governor trip device are as follows in this example.
This is the same as explained using the figures.

This trip test device is provided with a lockout device that switches the supply of operating pressure oil 15.

The lockout device allows the operating pressure oil 15 to bypass the trip valve 13.

Therefore, with this device, it is also possible to perform a trip test while the turbine is in operation.

Furthermore, in this device, when one trip device is tested during turbine operation, a lockout release device is provided which releases the lockout device based on the trip of the other trip device (when there is an emergency signal). interlock device).

With this configuration, the turbine can be tripped even when a device other than the trip device being tested is tripped.

The specific structure of this lockout release device will be described in detail later based on the example of FIG.

More specifically, the specific configuration of this embodiment is as follows.

In Figure 2, 37 is a lockout solenoid, 38
39 is a spring acting to press the lockout valve 38 in the right direction; 40 is a vacuum pressure 1 on the bellows 2; 41 is a normally open solenoid valve provided in the middle of the line that supplies atmospheric pressure 42 to the bellows 2; 43 is a bank up governor provided in the backup governor cylinder 35; Solenoids 52 and 53 are hydraulic lines that connect the trip valve 13 and the lockout valve 38 of the lockout device, and 54 is a hydraulic line that connects the lockout valve 38 and the hydraulic cylinder 50 of the main steam valve 44 via the control valve 51. It is.

The rest of the structure is the same as that in FIG. 1, so a description thereof will be omitted.

This embodiment has the above-described configuration, and when testing each trip device during load operation, the lockout solenoid 37 is energized and the lockout valve 38 is moved to the left against the force of the spring 39. let

By moving the valve 38 to the left, the operating pressure oil 15 bypasses the trip valve 13 and is supplied to the hydraulic cylinder 50 via the hydraulic line 54 and the control valve 51, so the steam turbine is tripped by the operation of the main steam valve 44. Not done.

In this case, when testing each trip device, for example, a vacuum trip device, the solenoid valve 40 for 1 vacuum pressure 1 line is closed, and at the same time the solenoid valve 41 for 9 atmospheric pressure 42 lines is opened to operate bellows 2. I do.

Also back up when testing the governor trip device (pan) quap governor sole.

: Excite the loid 43 to raise the backup governor cylinder 35, and cut off the supply of pressure oil 1i to the bank-propelled governor trip cylinder 20 to perform a test.

Also, when testing the bearing oil pressure low trip device and the thrust protection trip device, the test is performed by activating the pressure trip solenoid 24 via the trip signals 47 and 48 transmitted from the respective pressure switches.

Each of the above tests is performed during load operation, so if one trip device is tested and another trip device trips, the beam lockout device must be released to allow the steam turbine to trip. .

For example, during testing of a trip device other than a vacuum trip device, if the vacuum trip device trips, this should cause the turbine to trip, and in such a case the lockout valve 38 of the lockout device should be activated. It is necessary to reset the steam turbine so that the trip valve 13 cuts off the operating hydraulic pressure 15 and trips the steam turbine.

Accordingly, the present invention provides a lockout release device that exhibits such an effect.

FIG. 3 shows a luminaire circuit which is an example of such a lockout release device, and this embodiment employs this as a specific device.

The lockout release device of FIG. 3 includes test circuits 110, 120, 130° 140 for each trip device, a lockout circuit 200, and a lockout release circuit 300.

The test circuits include a thrust protection test circuit 110, a bearing oil test circuit 120, a governor test circuit 130, and a vacuum test circuit 140, corresponding to each trip device as described above. , only the vacuum test circuit 140 is shown.

The vacuum test circuit 140 includes a test button switch 74 and a vacuum trip relay 84, but each of the other test circuits 110, 120, 130 also includes a test button switch 71, 72, 73 and a trip relay 81, 82.
, 83.

91a is a contact point of the lockout relay 91, which is common to each test circuit.

In the lockout circuit 200, 101 is a lockout button switch, 92b is a contact of the lockout release relay 92, and 91 is a lockout relay.

In the lockout release circuit 300, 91a is a contact of the lockout relay 91, and 16a is the limit switch 16.
The contacts 84b are the contacts of the vacuum trip relay 84, 92
is a lockout release relay.

Note that this lockout release circuit also includes contacts 84a of the vacuum trip relay 84, as well as contacts 84a of the vacuum trip relay 84, corresponding to each test circuit.
Each of the trip relays 81, 82, and 83 has a contact point, and a contact point corresponding to the switch 16a is provided, but for the sake of simplicity, only the components related to the vacuum trip are represented.

Next, the operation of the interlock device having the above structure will be described.

When testing each trip device during load operation,
When the lockout button switch 101 is pressed, the lockout circuit 200 is closed and the lockout relay 91 is closed.
is activated.

The lockout solenoid 37 (see FIG. 2) is energized by the operation of the lockout relay 91, and the operating pressure oil 15 biases the trip valve 13 as described above.
The steam turbine is not tripped because it is supplied directly to the hydraulic cylinder 50 of the main steam valve 44 through the lockout valve 38.

In this case, if one of the two or more trip devices is being tested and the other trip device is tripped, the steam turbine is tripped despite the above configuration.

This configuration will be described in detail in accordance with this embodiment as follows.

In this example, each trip device is equipped with a vacuum trip, a backup governor trip, a thrust protection trip, and a low bearing oil trip. A turbine trip will be explained when the trip device of the turbine outputs a trip signal.

(Regarding each trip test) (a) When performing a vacuum test When performing a vacuum trip test, first, the lockout button 101 of the lockout circuit 200 is closed.

Since 92b is a normally closed contact, the lockout relay 91 is energized to operate the lockout solenoid 37 and switch the lockout valve 38 as indicated by the broken line in FIG.

Next, the test button 74 of the vacuum test circuit 140 is closed.

At this time, since the lockout relay 91 is already energized, the vacuum trip relay 84 is activated, and the solenoid valve 41.
42 is switched to introduce the atmosphere into the bellows 2 to perform a trip operation.

(b) When performing a governor test In this case, if you close the lockout button 101 and then close the governor test button 73, the governor trip relay 8
3 acts and operates the governor trip relay noid 43.

(e) In the case of thrust protection trip or bearing oil drop trip test, if the lockout button 101 is closed and then the trip button 71 or 72 is closed, the trip relay 81 or 82 is activated and the master trip renoid 24 is activated.

During the tests (a), (b), and (c) above, the lockout release circuit 300 does not operate.

For example, when performing a vacuum test, 91a is closed and 16a is closed due to the extension of bellows 2, but 84b in series with 16a is the vacuum trip relay 84.
When the lockout release relay 92 is energized, the lockout release relay 92 is not energized because it is a so-called normally closed contact that is open.

92b therefore remains closed.

Similarly, in the case of the test (bXc), the lockout release relay 92 is not energized.

(When another trip device trips during the test) As mentioned above, when performing each trip test, the lockout release relay 92 is not energized in principle.

However, if a trip signal other than the one being tested is received during any of the tests (a), (b), and (c), the lockout release relay 92 is activated and the turbine is tripped.

That is, for example, if the vacuum in the condenser drops to a level that trips the turbine during the governor test in (b) above, bellows 2 will extend and limit switch 1
Since 6 and 16a are closed and 84b is closed (84b is closed when not in a vacuum test), 91a-
92 is energized through 16a-84b, opening contact 92b (so lockout solenoid 37 is deenergized and lockout valve 38 returns to the solid position).

As the bellows 2 expands, the rotating shaft 9 is rotated via the trip lever 7 and the trip valve 13 is shut off, so that the turbine trips.

In addition, if the oil pressure drop trip signal and thrust protection trip signal are input during the test (a), 48a and 48a, respectively,
When 47a closes, relay 92 operates to release the lockout and trip the turbine.

As discussed above, the use of a lockout release device allows the lockout device to be released and the trip valve to trip the steam turbine if another trip device trips during each test.

After testing each trip device, the test button is released to activate the reset device, and then the lockout button switch is released to release the lockout device and return to the normal state.

As explained above, according to the present invention, it is possible to test a trip device during load operation, which was considered impossible in the past, and it is also possible to trip the steam turbine if another trip device trips during the test. can.

Therefore, it is no longer necessary to frequently stop the steam turbine to check the operation of each trip device, which not only enables long-term continuous operation, but also extends the life of the turbine. Reliability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional steam turbine trip device, Fig. 2 is a system diagram showing an embodiment of a steam turbine trip test device according to the present invention, and Fig. 3 is an interlock used in the present invention. This is the electrical circuit of the device. 2... Bellows, 6... Servo piston, 9... Rotating shaft, 13... Trip valve, 15... Operating pressure oil, 16, 23...
... Limit switch, 24 ... Master trip solenoid, 18 ... Rotary high lot valve,
20...Backup governor trip cylinder, 37...Lockout solenoid, 38...
... Lockout valve, 44 ... Steam valve, 50 ... Hydraulic cylinder.

Claims (1)

[Claims] 1. A pressure detection device that detects the degree of vacuum in the condenser, a speed detection device that detects the number of rotations of a turbine, and a steam valve that adjusts or shuts off the amount of steam flowing into the turbine. The valve is configured to be operated by operating pressure oil, and at least two or more trip devices are installed by providing corresponding trip devices that each output a trip signal based on the pressure detection signal and speed detection signal of the detection device. The operating pressure oil is controlled based on a signal from the trip device, and a lockout device is provided for switching the supply of the operating pressure oil, and the lockout device allows the operating pressure oil to bypass the trip valve. This configuration makes it possible to perform a trip test during turbine operation, and when testing one of the two or more trip devices during turbine operation, it is possible to perform a trip test based on the trip of the other trip device (in an emergency). A trip test device for a steam turbine, characterized in that a lockout release device is provided that releases the lockout device in response to a signal, and the turbine is tripped by tripping of a device other than the trip device being tested. A trip test device for a steam turbine according to claim 1, wherein the operation of the lockout device is released by a detection signal from one of the pressure detection device and the speed detection device. .