JPS6055681B2 - Steam turbine warm-up device for driving boiler feed water pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a warm-up device for a steam turbine for driving a boiler feedwater pump in steam turbine equipment for power generation, and more particularly to a warm-up device for a high-pressure steam introduction section for main steam.

In large-capacity power generation steam turbines, in order to increase the thermal efficiency of the power generation platform, a method is adopted in which the boiler feed water pump is driven by a boiler feed water pump driving steam turbine (hereinafter referred to as BFP turbine). is common.

There are two types of steam sources for powering the BFP turbine: high-pressure steam and low-pressure steam.

High-pressure steam refers to main steam, and low-pressure steam refers to steam extracted from an appropriate stage of the main turbine, such as from the intermediate-pressure turbine exhaust. When the main turbine is operated under high load, the steam extracted from the main turbine (low-pressure steam) has enough thermal energy to cover the required output of the BFP turbine. high pressure steam)
It is not necessary to introduce

However, when the main turbine is started or when the main turbine is operated at low load, the steam source to the BFP turbine is low pressure steam due to its low thermal energy (zero at the time of main turbine startup). ) cannot provide sufficient driving force. To avoid this situation, BFP to J.
It is necessary to introduce high-pressure steam from the turbine. As mentioned above, the high pressure steam is the main steam, and its pressure and temperature are the same for the main turbine. Generally the pressure is 150~
246 to 9/cril-g temperature 530-566°C. Since such high-temperature and high-pressure steam is used, BF
Warming up the main steam inlet of the P-turbine is an essential element to protect the turbine from moderate thermal stresses. In addition, in low-pressure steam systems, the steam pressure is 5 to 50
Since the k9/Cli·g1 temperature is relatively low at 200 to 300°C, warming up is not required.

An object of the present invention is to provide a warm-up device for a BFP turbine that can automatically and reliably warm up a high-pressure steam introduction section when high-pressure steam as main steam is introduced into the BFP turbine.

The present invention is characterized in that, in a steam turbine for driving a boiler feed water pump of power generation turbine equipment, a measuring device for measuring the inner wall metal temperature of a high-pressure steam introduction section, and a comparator for comparing the temperature measured by the measuring device and a target value are provided. and opening and closing the high pressure emergency stop valve intermittently at set time intervals while the high pressure steam heating valve is closed, and interlockingly opening and closing the drain discharge valve intermittently, The system is equipped with an operation circuit that repeats this operation until the measured temperature reaches the target value, and this configuration ensures that the high-pressure steam introduction section is automatically and reliably heated when high-pressure steam is introduced into the BFP turbine. This provides a warm-up device for a BFP turbine that can be used to warm up a BFP turbine.

The present invention will be explained below based on the drawings. Fig. 1 and Fig. 2 show one embodiment of the present invention.As shown in Fig. 1, the BFP turbine of power generation turbine equipment has a low-pressure steam system, a high-pressure steam system, and low- and high-pressure steam control valves. It has a drive device.

The drive device for the low and high pressure steam control valves is mounted on bearings 1 and 2. A supported rotating shaft 3, cams 4, 5 fixed thereto, leggies 6, 7 separately hinged to supports 10, 11 mounted on the upper half compartment 16, an end of each lever 6, 7. The cam follower 8, 9 is attached to the cam follower 8, 9 and is brought into contact with the cam 4, 5 separately.

The low pressure steam control valve 15 is connected to the lever 6 via the valve stem 13.
The high pressure steam control valve 77 is connected to the lever 7 via a valve stem 73. The low pressure steam system includes a low pressure steam control valve 15, a low pressure/steam emergency stop valve 27, and a control device thereof.

The low-pressure steam control valve 15 is provided in a chest 17 formed on the upper half compartment 16 side, and the chest 17 and the ball 1
8, and is inserted in the closing direction by a compression spring 12.

The opening/closing operation and valve opening of the low-pressure steam control valve 15 are determined by a drive device for the low- and high-pressure steam control valves, and the drive device receives a valve-opening signal (not shown) from the boiler water supply system. ), the rotating shaft 3 and cam 4 are rotated, and the valve stem 13 is moved in the axial direction via the cam follower 8 and lever 6, so that the low pressure steam control valve 15 is opened/closed and the valve opening is adjusted. It's getting old.

The low-pressure emergency stop valve 27 is provided within the valve chamber 25 and is disposed corresponding to a valve seat formed on a passage connecting the valve chamber 25 and the steam chamber 28.

A strainer 26 is provided in the valve chamber 25 surrounding the low-pressure emergency stop valve 27. Said low pressure emergency stop valve 2
The steam chamber 28 of No. 7 and the chest 17 of the low pressure steam control valve 15 are connected by a steam pipe 83.

The control device for the emergency stop valve includes a set of oil passages 33 and 31 provided in the housing 32, an oil passage 34, and a pilot valve 35.
and a set of compression springs 41 for returning the same, an oil passage 36, a pilot valve 37, and an oil hole 4 penetrated into the pilot valve 37.
3, a set of compression spring 42 for returning the pilot valve, and oil passage 38
, an oil passage 44, an oil passage 31 connecting the oil passages 30 and 44, an oil chamber 85, a piston 40 provided in the oil chamber 85, and a compression spring 39 for returning the piston.

The low pressure emergency stop valve 27 is connected to the piston 40 via a valve stem 29.

When pilot pressure is supplied to the oil passage 34 side of the low pressure emergency stop valve 27 from the open state shown in FIG. 1, and the bypass valve 35 is switched to open the oil passages 44 and 31,
Pressure oil in the oil chamber 85 is discharged through the valve chamber of the pilot valve 35 and the oil passages 31, 30, and 33, and the piston 40 is pushed toward the return side by the compression spring 39, and the piston 40 is pushed toward the return side by the compression spring 39. Closed via.

Further, after the pilot valve 35 is switched from the closed state to the oil passages 44 and 31 closing, the low pressure emergency stop valve 27 is supplied with pressure oil to the oil passage 36, and the pressure oil causes the pilot valve 3
7 is first moved to the oil passage 44 side, the oil passages 38 and 44 are directly connected, the oil hole 43 of the pilot valve 37 and the oil passage 44 are directly connected, and then the oil chamber 85 is opened through the oil hole 43 and the oil passage 44.
When pressure oil is fed into the piston 40, the compression spring 39
It is configured so that it is pushed toward the forward side against the pressure and opened to the state shown in FIG. 1 via the valve stem 29.

The low-pressure emergency stop valve 27 is set to either fully open or fully closed, and is not set to an intermediate opening. When the low-pressure steam control valve 15 and the low-pressure emergency stop valve 27 are opened, the low-pressure steam flows through the strainer 26 of the low-pressure emergency stop valve 27, the steam chamber 28, the steam pipe 83 connecting both valves, and the low-pressure steam control valve 15. The flow rate is adjusted by the low-pressure steam regulating valve 15, and the steam is injected from the nozzle 23 through the ball 18 toward the rotor blades 21, and the rotor 19 is rotated via the disk 20.

The high pressure steam system includes a low pressure emergency stop valve 51, a control device for the high pressure emergency stop valve, an operating circuit for the control device, a high pressure steam control valve 77, and a drain system for the high pressure steam control valve. There is.

The high pressure emergency stop valve 51 and the high pressure steam control valve 77 are:
In this embodiment, a single housing 72 is provided.

The high-pressure emergency stop valve 51 is provided in the valve chamber 49 in a chamber in which the steam chamber formed in one half of the housing 72 communicates with the valve chamber 49, and is a valve formed between the valve chamber 49 and the steam passage 50. They are arranged corresponding to the seats.

A steam inlet 47 is provided in the valve chamber 49, and steam flows through the steam chamber, and a strainer 4 is provided in the steam chamber.
8 is provided.

The control device for the high-pressure emergency stop valve includes a set of oil passages 54 and 55 provided in the housing 65, a set of an oil passage 57, a pilot valve 56, and a compression spring 64 for returning the pilot valve, and an oil passage 5.
8, a pilot valve 59, an oil hole 60 penetrated inside the pilot valve 59, and a compression spring 62 for returning the pilot valve.
, an oil passage 61, an oil passage 63, an oil passage 53 connecting the oil passages 54 and 63, an oil chamber 87, a piston 66 provided in the oil chamber 87, and a compression spring 67 for returning the piston. There is.

The high pressure emergency stop valve 51 has a valve stem 52 and a lever joint 45.
and is connected to the piston 66 via the valve stem 46.

A lever 70 is attached to the valve rod 52 directly connected to the piston 66.
is attached, and limit switches 68 and 69 are arranged within the movement range of the bar 70. The limit switch 69 and the bar 70 detect the opening of the high pressure emergency stop valve, and the other limit switch 68 and the bar 70 detect the opening of the high pressure emergency stop valve. The closure of the high-pressure emergency stop valve is now detected.

Trip and reset oil pressures are introduced into the oil passage 58 via an oil pipe 84.

Further, an electromagnetic three-way valve 89 is connected to the oil passage 57 via an oil pipe 90, and the oil pipe 91, the electromagnetic three-way valve 89, and the oil pipe 9
Pilot pressure is introduced through 0.

The high-pressure emergency stop valve 51 is supplied with pilot pressure from the open state shown in FIG. The pressure oil in the chamber 87 is discharged through the oil passage 63, the valve chamber of the pilot valve 56, and the oil passages 53, 54, and 55, and the piston 66 is pushed toward the return side by the compression spring 67, causing the valve stem 52 and the lever to It is closed through a joint 45 and a valve stem 46.

Further, the high pressure emergency stop valve 51 is switched from the closed state to the oil passages 63, 53 of the pilot valve 56, and the oil piping 8
When pressure oil is supplied to the oil passage 58 through 4, the pilot valve 59 is moved to the oil passage 63 side, and the oil passages 61, 63 are
The gap between the oil hole 60 in the pilot valve and the oil passage 6 is closed.
3 are directly connected, and then the pressure oil is supplied to the oil hole 60 and the oil passage 63.
) flows into the oil chamber 87, and the pressure oil causes the piston 66
is pushed toward the forward side against the compression spring 67, and the valve stem 52,
It is set to the open state shown in FIG. 1 via the lever joint 45 and valve stem 46.

The high-pressure emergency stop valve 51 is also selectively set to either fully open or completely closed.

On the other hand, the high-pressure steam control valve 77 is provided in a chest 76 formed in the housing 72, and is disposed corresponding to a valve seat formed on a passage connecting the chest 76 and the steam chamber 71. It is pushed in the closing direction by a compression spring 14 provided on the upper side. Furthermore, high pressure steam control valve 77
is connected to the lever 7 of the drive device for the low and high pressure steam control valves via the valve stem 73, and the drive device determines the opening/closing operation and the valve opening degree. When actuated by a valve opening signal (not shown) from the system, the rotating shaft 3 and the cam 5 are rotated, the lever 7 is moved via the force follower 9, and the valve stem 73 connected to the lever 7 is moved to the shaft. The high pressure steam regulating valve 77 is opened/closed and the valve opening degree is adjusted.

The drive device operates the cams 4 and 5 so that the high pressure steam control valve 77 starts to open after the low pressure steam control valve 15 is fully closed.
The shape of is determined.

A bar 74 is attached to the valve stem 73 of the high pressure steam control valve, and a limit switch 75 is installed within the movement range of the bar 74.
is provided, and the bar 74 and the limit switch 7
5, it is possible to detect the closing of the high pressure steam control valve.

The steam chamber 71 of the high-pressure steam control valve 77 is connected to the ball 24 formed in the upper half casing 22 via a steam pipe 79.

When the high-pressure emergency stop valve 51 and the high-pressure steam control valve 77 are opened, high-pressure steam flows from the steam pipe 86 to the steam inlet 47, the strainer 48, the valve chamber 49 of the high-pressure emergency stop valve 51, and the steam passage 50 connecting both valves. , CHEST 7 of high pressure steam control valve 77
6, the flow rate is adjusted by the high pressure steam control valve 77, and then sent to the ball 24 through the steam chamber 91 of the high pressure steam control valve 77 and the steam pipe 79, and is injected from the nozzle 23 toward the moving blade 21, The roller 19 is rotated via the disk 20.

The drain system of the chest of the high-pressure steam control valve includes a drain hole 7.8 formed at the bottom of the chest 76, a steam pipe 80 connected to the drain hole 7.8, a valve 81, and an automatic valve 82 that is a drain discharge valve. configured, Chest 7 when the turbine starts
The drain and warm-up steam generated inside the tank 6 can be discharged.

!
A bar 94 is attached to the valve shaft of the automatic valve 82, and a limit switch 93 is provided within the movement range of the bar 94, so that the limit switches 93 and 94 detect that the automatic valve 82 is closed. It's summery.
zThe operation circuit of the control device for the low pressure emergency stop valve is a warm-up button (not shown) in the illustrated embodiment.
, the limit switches 68 and 69 provided near the valve stem 52 of the high-pressure emergency stop valve 51, and the high-pressure steam control valve 77.
A limit switch 75 provided near the valve stem 73,
The limit switch 9 provided near the automatic valve 82
3. A thermocouple 88 provided on the chest 76 side of the high-pressure steam control valve 77, which is a high-pressure steam introduction part in the housing 72, and which indicates the temperature of the inner wall metal of the chest 76;
It has a comparator (not shown) that compares the temperature indicated by the 88 with a target value. The operation circuit is such that the high pressure emergency stop valve 51 is open, the high pressure steam control valve 77 and the automatic valve 82 are fully open, the high pressure emergency stop valve 51 is opened from the limit switch 69, and the limit switches 75 and 9 are in the open state.
3 high pressure steam control valve 77 and drain system automatic valve 82
In response to the detection signal that both are fully closed, the electromagnetic three-way valve 89 is energized to open to supply pilot pressure to the high-pressure emergency stop valve control device, and the high-pressure emergency stop valve 51 is accordingly closed. Chest 7 of high pressure steam control valve 77 from time point
6 is warmed up, and after warming up for a set time, the automatic valve 82 is fully opened, and after the set time has elapsed, the automatic valve 82 is fully closed again, and a detection signal from the limit switch 93 that the automatic valve 82 is fully closed is generated. , the electromagnetic three-way valve 89 is demagnetized by a signal indicating that the temperature indicated by the thermocouple 88 has not reached the target value set in the comparator, and the high-pressure emergency stop valve 51 is thereby opened.
Warming up steam is supplied to the chest 76 again, the above sequence of operations is repeated, and the electromagnetic three-way valve 89 is demagnetized by a signal indicating that the temperature indicated by the thermocouple 88 has reached the target value.
From then on, the high-pressure emergency stop valve 51 is kept open.

In the BFP turbine of the steam turbine equipment for power generation having the above-mentioned configuration, the present invention provides high-pressure steam introduction by cooperation of the high-pressure emergency stop valve 51, its control device, the drain system of the chest of the high-pressure steam control valve, and the operation circuit of the control device. It is characterized by warming up the parts. As mentioned above, only the high-pressure steam system requires warming up, and there is no need to consider the low-pressure steam system. Also, in the high-pressure steam system, the chest 76 that is directly exposed to high-temperature, high-pressure main steam is to be warmed up. The high-pressure emergency stop valve 51 has the following functions:
It is set only in two positions, fully open or completely open, and no intermediate opening is provided that would throttle the incoming steam during normal operation.

That is, since there is no steam throttling phenomenon, the pressure and temperature of steam at the chest 76 downstream of the high-pressure emergency stop valve 51 are almost the same as the conditions at the upstream side. On the other hand, the high-pressure steam control valve 77 has a throttling action that controls the flow rate of steam, and therefore the pressure and temperature of the steam in the steam chamber 71, steam piping 79, and bowl 24 are reduced.

Therefore, the thermal stress on the downstream side of the high pressure steam comparator 77 is reduced,
No warm-up is required, and even if warm-up is required, it is impossible because the warm-up steam will rotate the rotor 19. Next, the operation of the present invention will be explained. When the turbine is reset from the fully closed state of the high-pressure emergency stop valve 51 and the high-pressure steam control valve 77 prior to warming up of the high-pressure steam introduction section CHEST 76, the oil piping 84 of the high-pressure emergency stop valve control device is reset. Hydraulic pressure, that is, pressure oil is supplied, and the pressure oil flows into the oil chamber 87 through the oil passage 58, the oil hole 60 provided inside the pilot valve 9, and the oil passage 63, and the piston 66 is pushed toward the forward side. and the high pressure emergency stop valve 51 is opened.

At this point, the electromagnetic three-way valve 89 is demagnetized, and the electromagnetic three-way valve 89 is demagnetized.
The control hydraulic pressure supplied to the 9 side is released from the oil pipes 91 and 92.

When the high-pressure emergency stop valve 51 is open and the high-pressure steam control valve 77 is closed, the steam inlet 47, strainer 48, and valve chamber 4
9. Warm-up steam (10~20k9/Cfi・Gll5O~20
0° C.) and stays in the chest 76.

Then, when the warm-up button of the operation circuit is pressed, the electromagnetic three-way valve 89 is excited by the detection signal from the limit switches 75 and 93 that the high-pressure steam control valve 77 and the automatic valve 82 of the CHEST drain system are fully closed.

As a result, the oil pipes 91 and 92 are communicated, and control oil pressure, that is, pilot pressure is supplied to the oil path 57 of the control device.
The movement of the pilot valve 56 opens the oil passages 63, 53, and the pressure oil in the oil chamber 87 flows through the oil passages 63, 53, 54, and 55.
The piston 66 is pushed to the return side by the compression spring 67, the high pressure emergency stop valve 51 is closed, and the limit switch 68 detects that the high pressure emergency stop valve 51 is closed.

The high-pressure emergency stop valve 51 is maintained in a fully closed state for a set period of time, such as about 1 hour.

During this time, the chest 76 is warmed up by the warm-up steam sealed in the chest 76. After the set time has elapsed, the automatic valve 82 of the drain system is fully opened, and the warm-up steam in the chest 76 is discharged from the drain hole 78 provided at the bottom of the chest 76 through the drain system. The automatic valve 82 has approximately 1
After being fully opened for the set time, it will be fully closed again. In this embodiment, the automatic valve 82, which is a drain discharge valve, is operated as described above.
It is configured to be interlocked with the high pressure emergency stop valve 51. While the chest 76 is being warmed up, a comparator compares the temperature indicating the inner wall metal temperature of the chest 76 by the thermocouple 88, that is, the measured temperature, with a target value.

Then, the electromagnetic three-way valve 89 is demagnetized again by the detection signal from the limit switch 93 that the automatic valve 82 is fully closed and the signal from the comparator indicating that the measured temperature has not reached the target value, and the pilot valve 56 of the control device is demagnetized again. The pilot pressure is cut off, the pilot valve 56 moves, and the space between the oil passages 53 and 63 is closed. As a result, the piston 66 is pushed to the forward side by the pressure oil supplied to the oil chamber 87 of the control device again, the high pressure emergency stop valve 51 is opened, the warm-up steam is introduced into the chest 76 again, and the limit switch 69, it is detected that the high pressure emergency stop valve 51 is open. The above actions are Chest 7
The operation is repeated until the inner wall metal temperature of No. 6 reaches the target value, and the high-pressure emergency stop valve 51 is normally opened in response to a signal indicating that the temperature measured by the thermocouple 88 has reached the target value. This is performed according to the sequential operations shown in the figure. The present invention has the above-described structure and operation, and includes a high-pressure emergency stop valve, a control device for opening and closing the same, a high-pressure steam control valve, a drain system for the chest, and an operation circuit of the control device. This has the effect of automatically and reliably warming up the high-pressure steam introduction section.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention, and FIG. 2 is an interlock diagram of the present invention. 1-9...Members constituting a drive device for low and high pressure steam control valves, 15...Low pressure steam control valves, 27.
...Low pressure emergency stop valve, 29-40...
A member constituting a control device for a low-pressure emergency stop valve, 51...
...High pressure emergency stop valve, 52-67... Member constituting the control device for the high pressure emergency stop valve, 87...
...Same oil chamber, 89...Same electromagnetic 3-way valve, 76.
・・・・・・・・・High pressure steam control valve CHEST, 77...
...High pressure steam control valve, 80...Steam pipe, 8
1... Valve, 82... Automatic valve serving as a drain discharge valve, 88... Thermocouple constituting the operating circuit, 68, 69, 75, 93...・Same limit switch.

Claims (1)

[Claims] 1. It has a low pressure steam system, a high pressure steam system, and a drive device for low and high pressure steam control valves, and the high pressure steam system has a high pressure emergency stop valve, a control device for controlling the opening and closing of the high pressure emergency stop valve, and a high pressure steam control device for controlling the opening and closing of the high pressure emergency stop valve. In a steam turbine for driving a boiler feed water pump of steam turbine equipment for power generation, which is configured with a drain system having a valve and a drain discharge valve of the chest, a measuring device for measuring the temperature of an inner wall metal of a high pressure steam introduction part; a comparator that compares the temperature measured by the measuring device with a target value, and intermittently opens and closes the high pressure emergency stop valve at set time intervals while the high pressure steam control valve is closed; The control circuit is provided with an operation circuit that intermittently opens and closes a drain discharge valve in conjunction with the high-pressure steam introduction section to warm up the high-pressure steam introduction section and discharge the drain, and repeatedly performs this operation until the measured temperature reaches the target value. A warm-up device for a steam turbine for driving a boiler feed water pump, characterized in that: