JPS6153408A - Emergency stop device for turbine - Google Patents

Abstract

PURPOSE:To facilitate preservance and inspection by enabling a mechanical trip valve and a master trip valve to be independently, separated by closing a lock- out valve in a device for giving emergency stop to a steam turbine by reducing the pressure of emergency oil in an emergency oil line. CONSTITUTION:An emergency oil line 32 connected to a working oil line 30 through a hydraulic relay type shut-off valve 31 is connected to a main steam stop valve and the like (not shown). In this case, a mechanical trip branch path 33 and a master trip branch path 36 leading to drain lines D are respectively branched from the emergency oil line 32. And in the respective branch paths 33, 36 are interposed respectively normally opened type lock-out valves 34, 37 closed in the input of lock-out electric signals E1, E2 and normally closed type trip valves 35, 38 opened instantly by springs 35b, 38b in the reduction of oil pressure to operative sections 35a, 38a. And the trip valve 35 and the trip valve 38 are controlled respectively according to the output of an emergency governor and the electric trip signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a turbine emergency stop device for emergencyly stopping a steam turbine in the event of an abnormality in a steam turbine power generation device.

[Technical cost of invention and its problems]

Steam turbines are equipped with an emergency stop device called an emergency trip device. During normal operation of the steam turbine, this emergency trip device releases emergency oil to the main steam stop valve at the turbine inlet or the reheat stop valve. I am sending oil to and listening to the valve, but
If an abnormal situation occurs that makes it impossible to continue operating the turbine, the pressure of the emergency oil is reduced and each steam stop valve is promptly closed to bring the turbine to an emergency stop.

FIG. 2 shows an example of a conventional emergency trip device. During normal operation of the steam turbine, the hydraulic oil from the pressure oil source 1 is
The oil passes through the mechanical trip valve 2, lockout valve 3, and master trip valve 4 in order and reaches the emergency oil line 5, where it is sent to the main steam stop valve, reheat stop valve, etc. (not shown), and resists the spring force. Then, each stop valve is opened.

Therefore, the emergency governor 6 detects overspeed of the steam turbine.
detects an overspeed condition, rotates the lever 7. This lever 7 normally locks a spring-biased piston 8, but this lock is released by the above rotation. Due to this unlocking, the piston 8 moves due to the spring force, and the rod 9,
The upper two mechanical trip valves 2 are actuated via the shaft 10 and rod 11. As a result, the mechanical trip valve 2 cuts off the hydraulic oil from the pressure oil source 1, connects the emergency oil line 5 to the drain boat, and reduces the hydraulic pressure of the emergency oil.
Then, close each steam stop valve and bring the turbine to an emergency stop.

The emergency governor 6 is equipped with an oil trip valve 12 and a hydraulic oil line 13 for performing 1g of its operation.
Furthermore, a relet valve 15, which can drive the piston 8 against the spring force via the lever 14 and lock it by the lever 7, can also be actuated by the rod 17.1 by actuation of the handle 16.
A separate manual mechanical trip mechanism is provided for forcibly releasing the lock by driving the lever 7 via the lever 8.

The lockout valve 3 is also provided with a solenoid valve 19 that is energized by a lockout signal, and when this solenoid valve 19 is energized, it cuts off communication between the mechanical trip valve 2 and the emergency oil line 5, and separates the mechanical trip valve 2 from the emergency oil line 5. The emergency oil line 20 is connected to the emergency oil line 5.

In this way, the lockout valve 3 shuts off the pressure oil source 1 of the mechanical trip valve 2 and the emergency oil line 5 when confirming the operation of the emergency regulator, and simultaneously connects another hydraulic oil line 20 to the emergency oil line. 5 to maintain the main steam stop valve and reheat stop valve in the valve state.

The master trip valve 4 includes a master trip solenoid valve 2.
1.22 are arranged in series, these solenoid valves 21.2
2 is energized when the turbine is in normal operation, communicates the lockout valve 3 with the emergency oil line 5, and sends the hydraulic oil from the lockout valve 3 to each steam stop valve as emergency oil. Due to the electric trip signal generated in abnormal situations such as increased wear of the thrust bearing, decreased bearing oil pressure, and decreased vacuum level of the condenser, both the solenoid valves 21 and 22 are demagnetized, and the lockout valve 3 and the emergency oil line are demagnetized. 5 and connects the emergency oil line 5 to the drain line to lower the oil pressure of the emergency oil, close each steam stop valve, and bring the steam turbine to an emergency stop. The reason why two master trip solenoid valves are provided is that even if one of them is demagnetized due to a solenoid failure, normal operation of the turbine can be ensured by normal operation, and This is to enable side-side operational testing of the master trip valve to be performed during turbine operation.

In this way, the conventional emergency stop device has a lockout valve 3.
Because of this function, the mechanical trip valve 2 can be disconnected from the emergency oil line while maintaining the supply of hydraulic oil to the master trip valve 4, so it is possible to check the emergency control function even while the turbine is operating. Ri-burying etc. can be performed.

However, regarding the master trip valve 4, it is only possible to check the performance of each of the I check valves 21 and 22, and inspection and repair of the trip valve itself is not possible during turbine operation. Furthermore, since the mechanical trip valve and the master trip valve are connected in series, on-road maintenance of either one is impossible.

[Purpose of the invention]

Therefore, the purpose of the present invention is to perform maintenance and inspection of mechanical trip valves and master trip valves even during turbine operation.
It ]! I! An object of the present invention is to provide a turbine emergency stop device capable of executing a windshield.

[Summary of the invention]

To achieve this objective, the present invention provides emergency oil in an emergency oil line in response to the output of an emergency governor for detecting overspeed of the turbine and an electrical trip signal generated during other turbine abnormalities, respectively. In a non-1i shutdown device that reduces the pressure of the steam turbine and makes an emergency stop of the steam turbine, normally hydraulic oil is supplied to the emergency oil line, and the output of the emergency governor or
A shutoff valve that shuts off the supply in response to the electrical trip signal, and a tight seat type lockout valve that is installed in a mechanical trip branch branched from the emergency oil line and that can open and close at will. . A mechanical trip valve is provided in the mechanical trip branch path via the lockout valve and discharges emergency oil from the emergency oil line in accordance with the output of the emergency governor, and is connected in parallel with the mechanical trip branch path. a tight-seat type lockout valve that is provided in a master trip branch path branching from the emergency oil line and that can be opened and opened at will; The present invention is characterized by comprising a master trip valve that discharges emergency oil from the emergency oil line in response to the electrical trip signal.

[Example of invention in action]

An embodiment of the turbine emergency stop Ll device according to the present invention will be described below with reference to the drawings.

'; In Fig.
When the oil pressure to the valve decreases, the valve opens instantly by the force of the spring 31b. The emergency oil line 32 is connected to a main steam stop valve, a reheat stop valve, etc. (not shown), and a mechanical trip branch path 33 that leads to a drain line D branches from this emergency oil line 32. 33, a mechanical lockout valve 34 and a mechanical trip valve 3 are sequentially installed.
5 are arranged. This mechanical lockout valve 34 is normally open, but when the lockout electric signal E1 is input to the solenoid 34a, it closes against the force of the spring 34b. The mechanical trip valve 35 is normally closed, and when the oil pressure to the operating portion 35a decreases, the mechanical trip valve 35 instantaneously opens due to the force of the spring 35b.

The emergency oil line 32 further has a master trip branch path 36 that is connected to the drain line D and branches in parallel to the mechanical trip branch path 33 . An electric power rotor out valve 37 and a master trip valve 38 are disposed in this branch path 36 in this order. This lockout valve 37 is normally open, and when the lockout electric signal E2 is input to the solenoid 37a, it closes against the force of the spring 37b. The above master trip valve 38
The valve is normally closed at t, and when the hydraulic pressure to the operating portion 38a decreases, the valve opens instantly by the force of the spring 58b.

A branch passage 39 from the hydraulic oil line 3o is connected to an orifice 40.
The operating portion 31a of the cutoff valve 31 and the lockout electric signal E1. They are respectively connected to isolation solenoid valves 41 and 42 which open when receiving E2. This one solenoid valve 41 is in contact with the operating portion 35a of the mechanical trip valve 35 and the mechanical trip pilot valve 44 via an orifice 43 having a larger area than the orifice 40, and the pilot valve 44 is connected to the rod 45. It is connected to an emergency governor (not shown) via a rotating shaft 46, and is closed during normal operation of the turbine, and instantaneously opened by the force of a spring 44a when the turbine is overspeeding. The other solenoid valve 42 has an orifice 40
The operating portion 38a of the master trip valve 38 and the master trip [
1 valve 48. This solenoid valve 48 is opened during normal operation of the turbine, and is activated by electric trip signals E3a and E3b when the turbine is abnormal.
, 48b are both excited, the valve rests on the horn of the spring 48c and opens instantly.

Next, the operation of this emergency stop device will be explained.

During normal operation of the turbine, both the mechanical trip pilot valve 44 and the master trip 71[4i valve 48 are closed. Therefore, the operation part 31 of the cutoff valve 31
Since the high hydraulic pressure of the hydraulic oil is applied to a, the shutoff valve 31 is opened. Further, due to the closure of the pilot valve 44, high hydraulic pressure is also applied to the operating portion 35a of the mechanical trip valve 35, so this mechanical trip valve 35 is also closed. Similarly, the master trip valve 38 is also closed by closing the master trip solenoid valve 48. By opening the G shutoff valve 31 and closing both trip valves 35 and 38, the hydraulic oil passes through the emergency oil line 32 and opens the main steam stop valve and the reheat stop valve.

If the turbine overspeeds to the trip speed, the detection output of the emergency governor acts on the mechanical trip pilot valve 44 via the shaft 46 and rod 45 to instantly open it. Due to this valve opening, the hydraulic oil in the hydraulic oil line 30 is discharged to the drain line D through the orifices 40 and 43. Then, due to the effect of the orifice 40, the oil pressure of the operation part 31a of the cutoff valve 31 decreases, the cutoff valve 31 is closed by the spring 31b, and the emergency oil line 3
2 is cut off from the hydraulic oil line 30. Further, due to the effect of the orifice 43, the oil pressure of the operating part 35a of the mechanical trip valve 35 also decreases, and this trip valve 35 is operated by the spring 3.
The valve opens instantly by the force of 5b, and the emergency oil in the emergency i+h line 32 is discharged to the drain line D. Therefore, the main steam stop valve, reheat stop valve, etc. are closed, and the turbine is brought to an emergency stop.

Further, when an electric trip signal is generated due to an abnormality itself such as a decrease in the vacuum level of the condenser, the pair of solenoids 4.8a and 48 of the master trip solenoid valve 48
Electric trip signals j%E3a and E3b are input to b, respectively. As a result, the solenoid valve 48 opens and discharges the hydraulic oil in the hydraulic oil line 30 to the drain line D via the orifice 40.47. As a result, the shutoff valve 31 closes in the same manner as in the case of the above, and the master trip valve 38 instantly closes due to the force of the spring 38b as the oil pressure of its operating portion 38a decreases due to the effect of the orifice 47, and the emergency hl+ is activated. Discharge to drain line D. The turbine is therefore brought to an emergency shutdown in the same way as in the case of turbine overspeed described above.

Next, we will explain how to test the operation of the trip system while the turbine is in operation.

In the case of an operation test of the emergency governor, first, the lockout electric signal E1 is applied to the mechanical lockout valve 34 and the solenoid valve 41 at the same time.

The mechanical lockout valve 34 closes when the solenoid 34a is energized by the application of the electrical signal E1, and the emergency oil line 32 and the mechanical trip valve 35 are separated. Further, the solenoid valve 41 is excited and opened by the electric signal E1, and the mechanical trip pilot valve 44
from the shutoff valve 50, etc. Under this condition, for example, an oil trip test is performed by operating the oil trip valve 12 shown in FIG. 2, and the mechanical pilot valve 44 and the mechanical trip valve 35 are actually operated. Of course, the operation of the pilot valve 44 and trip valve 35 is as follows.
The closing of the solenoid valve 41 and the closing of the lockout valve 34 do not affect anything else.

When checking the operation of the master trip valve 38, the lockout electric signal E2 is sent to the electric lockout valve 3.
7 and solenoid valve 42 at the same time. The lockout valve 37 is closed by the excitation of the resolenoid 37a upon application of the electric signal ME2, and the emergency oil line 32 and the master trip valve 38 are separated. Further, the solenoid valve 42 is energized and closed by the electric signal F2, so that the master trip solenoid valve 48 is easily disconnected from the cutoff valve 31 or the like.

In this state, electric trip valves E3a and E3b are applied to the master trip solenoid valve 48 to actually operate the master trip valve 38. Of course in this case b, JI-7
The IG oil line will not be affected in any way.

In the above embodiments, a spool valve type trip valve is used, but a ball valve type can also be used, and in this case, the capacity can be increased.

Further, the isolation solenoid valves 41 and 42 may be of a hydraulic relay valve type operated by hydraulic pressure from the A boat of the lockout valve 34 or 37, for example.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, hydraulic oil is normally supplied to the emergency oil line, and emergency control 21! A shutoff valve that cuts off the supply in response to the output of d or an electric trip signal, and a tight seat type lockout valve that is installed in the mechanical 1-lip branch branched from the emergency oil line and can be opened and opened at will. , a mechanical trip valve that is installed in the mechanical trip branch path via this lockout valve and discharges emergency oil from the emergency oil line according to the output of the emergency governor, and an emergency oil line that is connected in parallel to the mechanical trip branch path. A tight-seat type lockout valve is provided in the master trip branch path branching from the master trip branch, and can be opened and closed at will. Since it is equipped with a master trip valve that discharges emergency oil from the emergency oil line, the mechanical trip valve and master trip valve can be isolated from the emergency oil line independently by closing the corresponding lockout valve.
Even while the turbine is operating, it is possible to check the operation of the mechanical trip valve and master trip valve, improving the operating efficiency of the turbine. In addition, the lockout valve is a timed seat and has a lock-out shape with no leakage, so the mechanical trip valve and master trip valve can be buried in ice and replaced even during turbine operation.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing essential parts of an embodiment of a turbine emergency stop device according to the present invention, and FIG. 2 is a system diagram showing a conventional turbine emergency stop device. 6... Emergency governor, 30... Hydraulic oil line, 31...
...Shutoff valve, 32...Emergency oil line, 33...Mechanical trip branch, 34...Lockout valve, 3
5... Mechanical trip valve, 36... Master trip branch, 37... Lockout valve, 38...
Master trip valve, El, E2...Lockout electrical signal.

Claims (1)

[Claims] 1. The pressure of the emergency oil in the emergency oil line is reduced in response to the output of the emergency governor that detects turbine overspeed and the electric trip signal generated in the event of other turbine abnormalities, and the steam turbine is brought to an emergency stop. The emergency stop device usually includes a shutoff valve that supplies hydraulic oil to the emergency oil line and cuts off the supply in response to the output of the emergency governor or the electrical trip signal, and a branch from the emergency oil line. A tight-seat type lockout valve is installed in the mechanical trip branch and can be opened and closed at will. Accordingly, a mechanical trip valve for discharging emergency oil from the emergency oil line and a master trip branch path branched from the emergency oil line in parallel with the mechanical trip branch path are provided, and the valve can be opened and closed at will. A tight-seat type lockout valve, and a master trip valve that is provided in the master trip branch path via the lockout valve and discharges emergency oil from the emergency oil line in response to the electrical trip signal. A turbine emergency stop device characterized by: