JP2000018050A - Outlet steam monitoring system for steam cooling type gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To monitor a temperature change in outlet steam, and to detect something wrong with the cooling object in an early stage, pertaining to this outlet steam monitoring system for a steam cooling type gas turbine. SOLUTION: Steam is supplied to a combustor body 20 by a supply line 3 from a steam supply manifold 1, while the steam recovered from a recovery line 1, is recovered to a steam recovery manifold 5. At each recovery line 4, an outlet steam temperature is detected out of a temperature detector 8, inputting it into a control unit 10, and in this control unit 10, it is compared with the setting temperature, and when the temperature becomes more than the setting temperature, it is so judged as something wrong which is displayed on a display unit 11, while an alarm is emitted by an alarm device 12, and when the temperature is further goes up, flow rate of a flow control valve 15 is throttled, and if it exceeds the upper limit temperature, a shutoff valve 16 is controlled so as to close it. Therefore trouble in a cooling objective part is detectable in its early stages owing to a variation in the outlet steam temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outlet steam monitoring system for a steam-cooled gas turbine, which monitors an outlet temperature of cooling steam so that an abnormality in a combustor or a blade can be detected at an early stage. It is.

[0002]

2. Description of the Related Art In recent years, as many combined plants have been constructed with the high temperature and high efficiency of power plants,
As an effective cooling method for gas turbines, a steam cooling method is being studied instead of an air cooling method, and it has been adopted in actual plants.

[0003] Fig. 3 shows a combustor of a gas turbine employing a steam cooling system, which is an example of a prior art developed by the present applicant, wherein (a) is a configuration diagram, and (b) is a part of a cooling wall surface thereof. And (c) is a cross-sectional view taken along the line AA in (b). In these figures (a), 20 is a combustor body,
Reference numeral 21 denotes a pilot nozzle to which pilot fuel 40 is supplied. Reference numeral 22 denotes a main nozzle, and a plurality of main nozzles are arranged around the pilot nozzle 21 to supply a main fuel 41 to be used for combustion. 23 is a main fuel supply pipe, 24
Is a pilot fuel supply pipe, and fuels 41 and 4 respectively.
0 is supplied.

Numeral 25 denotes a cooling steam supply pipe through which cooling steam 31 is guided, and reference numerals 26 and 27 denote cooling steam recovery pipes.
0,32 is collected and removed.

FIG. 3 (b) is a perspective view showing a part of the wall of the main body 20, in which a number of steam passages 50 are formed inside the wall 20a and provided around the main body 20. . As shown in FIG. 4C, each steam passage 50 is provided with a supply hole 50.
a and the recovery hole 50b, cooling steam is supplied, flows through the inside, cools the wall 20a, and is recovered.

[0006] The steam cooling of the combustor of the gas turbine of the steam cooling system is configured as described above, and the cooling steam 31 is guided from the cooling steam supply pipe 25, and a large number of steams provided in the wall 20 a of the main body 20 are provided. After flowing in the passage 50 and cooling the periphery of the main body 20, it is recovered from the cooling steam recovery pipes 26 and 27.

FIG. 4 shows a stationary blade of a gas turbine employing a steam cooling system, which is also an example developed by the present applicant. In the figure, reference numeral 60 denotes a second stage stationary blade, and reference numeral 70 denotes an adjacent moving blade. 61 is an outer shroud, 62 is an inner shroud, and 63 is a seal tube which penetrates through the inside of the stationary blade 60 and guides sealing air to an inner cavity.
64 is a manifold provided on the blade ring, 65 is a connection pipe for steam supply connected to the manifold 64,
Cooling steam 80 is led. 66 is also a manifold, and 67 is a connecting pipe for steam recovery, which is connected to the manifold 66, passes through the inside of the stationary blade 60, and cools the recovered steam 8 after cooling the blade.
1 is to be collected.

In such a configuration, the cooling steam 8
Numeral 0 is introduced from the manifold 64 to the connecting pipe 65 for steam supply, flows into the stationary blade 60, passes through a steam passage (not shown) provided in communication with the stationary blade 60, and collects steam while cooling the blade. It flows out to the connection pipe 67, is guided from the manifold 66 to the recovery path, returns to the steam system of the steam turbine, and is effectively used.

Although not shown, a steam cooling system is also used for the moving blades. In this case, the cooling steam passes from the rotor end through an axial supply steam passage provided inside the rotor. It is guided from the passage provided in the rotor disk to the inside of the rotor blade, flows through the steam passage communicating similarly in the rotor blade, cools the rotor blade, passes again from the rotor disk through the recovery steam passage in the rotor, and from the rotor end. Collected.

[0010]

As described above, in recent gas turbines, a steam cooling system has begun to be used instead of an air cooling system. However, a combustor burns at a high temperature, and a cooling steam supply system is provided. The system is also complex and it is difficult to monitor the cooling steam temperature. At present, the technology for the structure of the steam supply and steam recovery system in the steam cooling system has been studied and developed considerably, but the technology for monitoring the steam temperature has not yet been established. If the state of the cooling steam temperature can be accurately monitored, the soundness of the target portion to be cooled, that is, the combustor, the stationary blade, and the moving blade can also be confirmed. Therefore, establishment of such a steam temperature monitoring technique is strongly desired. .

Therefore, the present invention measures the temperature of the outlet of the cooling steam of a steam-cooled portion of a combustor or blades in a steam-cooled gas turbine, and the temperature change causes cracks in the target portion and blockage of the steam system. It is an object of the present invention to provide an outlet steam temperature monitoring system capable of detecting an abnormality such as an abnormality at an early stage and performing a safe operation of the gas turbine.

[0012]

The present invention provides the following means for solving the above-mentioned problems.

In a steam-cooled gas turbine for supplying cooling steam to a portion to be cooled, such as a combustor or a blade, and recovering the cooled steam, a temperature detector for detecting an outlet temperature of the cooled steam; The detection signal of the temperature detector is input, compared with a preset set temperature, and when the detected temperature exceeds the set value, an alarm signal, a signal for narrowing the opening of the fuel flow control valve to a predetermined opening or A control device for outputting a signal for closing a shut-off valve; and an outlet steam monitoring system for a steam-cooled gas turbine.

The outlet steam monitoring system of the present invention detects the outlet steam temperature after the temperature detector has cooled the cooling target portion, and this detection signal is input to the control device. The controller sets the outlet steam temperature under normal conditions, the temperature under dangerous conditions, the upper limit temperature at which fuel should be shut off, etc., compares it with the detected temperature, and issues an alarm if the temperature exceeds the set temperature A signal, a signal for reducing the opening of the flow control valve, and a signal for closing the shutoff valve are output according to the respective temperature rise levels.
This allows early detection of abnormalities in the cooling target,
Dangerous situations can be avoided by means of the signals of the control device.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a configuration diagram of an outlet steam temperature monitoring system of a steam-cooled gas turbine according to an embodiment of the present invention, and is an example of monitoring a steam temperature of a combustor.

In FIG. 1, reference numeral 1 denotes a steam supply manifold, and reference numeral 2 denotes a flow control valve, which controls the flow rate of the supplied steam. Reference numeral 3 denotes a supply line, which supplies cooling steam from a steam supply manifold to the cooling steam supply pipes 25 of the plurality of combustor bodies 20. Reference numeral 4 denotes a recovery line and a five-vapor recovery manifold. The recovery line 4 recovers the steam recovered from the cooling steam recovery pipes 26 and 27 of each combustor body 20 to the manifold 5.

Reference numeral 6 denotes a temperature detector, and each combustor body 20
The temperature of the inlet steam flowing through the supply line 3 to the supply line is detected, and those signals are input to the control device 10 through the inlet temperature detection line 7. Numeral 8 denotes a temperature detector, which detects the temperature of the recovered steam from the cooling steam recovery pipes 26 and 27 flowing through each recovery line 4, and inputs those signals to the control device 10 through the outlet temperature detection line 9. I have.

Reference numeral 10 denotes the control device described above, and reference numeral 11 denotes a display device for displaying a result calculated by the control device 10;
Reference numeral 2 denotes an alarm device, which notifies an alarm or the like when it is determined as abnormal as a result of calculation by the control device 10.
Reference numeral 13 denotes a control signal line. A line 13a transmits a signal for controlling the opening of the flow control valve 15 of the fuel system 14, and a line 13b transmits a signal for controlling the opening and closing of the shutoff valve 16.

In the above configuration, the controller 10 detects the inlet steam temperature of each combustor from the temperature detector 6, and further detects the cooling steam recovery pipes 26, 2 of each combustor from the temperature detector 8.
The outlet steam temperature recovered from 7 is detected and input.

The temperature of the supplied steam is about the planned supply temperature, the temperature of the recovered steam is about the planned outlet temperature during normal operation, and the controller 10 first determines that the inlet steam temperature is normal around the planned supply temperature. Check if there is, and monitor the steam outlet temperature. The steam outlet temperature is about the planned outlet temperature during normal times, and the steam passage of the combustor body 20 becomes clogged or cracks occur. If the temperature is abnormal, the temperature rises. Therefore, this state is displayed on the display device 11 and the alarm device 12
Control to generate a warning.

Further, if the temperature rise continues,
The control device 10 outputs a control signal to the control signal line 13b, reduces the opening of the flow control valve 15, controls the load by reducing the fuel in the fuel system, further increases the temperature, increases the upper limit temperature,
For example, when the temperature becomes equal to or higher than the shut-off temperature, a control signal is output to the control signal line 13a to control the shut-off valve 16 to be closed,
Trip the gas turbine.

FIG. 2 is a diagram showing the state described above.
(A) shows the transition of the outlet steam temperature, and (b) shows the change according to the temperature.
(A) in normal operation, (x)
As shown by, the state is around the planned outlet temperature, and (Y₁)
As shown in FIG. ₁Rising in danger
If the temperature is exceeded, the control device 10 causes the combustor body 20 to be dangerous.
The state is determined, and as shown in FIG.₁Output
And the temperature exceeds the dangerous temperature ₁~ T_TwoSignal is continuously output during
To activate the alarm device 11.

Also, this t₁~ T_TwoConstant time between
Then t₁If the temperature rise continues to ', the control device
As shown in FIG._ThreeAnd the fuel system 1
The control is performed so that the opening of the flow control valve 15 of No. 4 is reduced. Change
Then, the temperature rises and (Y_Two), The time t_ThreeIn
When the temperature exceeds the shut-off temperature, the shut-off signal S as shown in FIG.
_TwoAnd shut off the shutoff valve 16 of the fuel system 14 to
Trip the turbine.

In the configuration diagram of FIG. 1, the flow control valve 15, the fuel system 14 is shared by a plurality of
Although the illustration is omitted in an example in which the shutoff valve 16 is commonly controlled, it is needless to say that it is necessary to control each flow control valve and the shutoff valve of the fuel system of each combustor body 20 independently. Detects failures and abnormalities of each combustor,
The fuel flow rate of only the combustor that has detected the abnormality is controlled to close the shutoff valve.

Further, in the above embodiment, the example of steam cooling of the combustor has been described. However, the present invention is not limited to this.
In the case of the moving blade, the temperature can be monitored in the same manner, and the same operation and effect can be obtained.

According to the embodiment described above, the temperature of the outlet steam recovered from the cooling steam recovery pipes 26 and 27 of the combustor body 20 in the recovery line 4 is detected by the temperature detector 8 and When the temperature of the outlet steam exceeds a preset temperature, the alarm is activated by issuing an alarm, and the flow control valve 15 is controlled to control the fuel flow rate. Control or shut-off valve 16
Is closed to shut off the fuel, so that the abnormality of the combustor can be detected early by the change of the outlet steam temperature, and the safe operation of the gas turbine is performed.

[0027]

The outlet steam monitoring system for a steam-cooled gas turbine according to the present invention provides a steam-cooled gas turbine that supplies cooling steam to a portion to be cooled such as a combustor or a blade and collects the cooled steam. A temperature detector for detecting the outlet temperature of the steam after cooling, and a detection signal of the temperature detector is input, compared with a preset set temperature, and an alarm is issued when the detected temperature exceeds the set value. And a control device for outputting a signal, a signal for narrowing the opening of the fuel flow control valve to a predetermined opening, or a signal for closing the shutoff valve. With such a configuration, an abnormality in the cooling target portion is detected early due to a change in the steam outlet temperature after cooling, and a control signal is output from the control device, so that danger can be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an outlet steam monitoring system of a steam-cooled gas turbine according to an embodiment of the present invention.

FIG. 2 shows a relationship between a temperature state and a control signal of an outlet steam monitoring system of a steam-cooled gas turbine according to an embodiment of the present invention, where (a) shows a temperature state and (b) shows a control signal, respectively. .

3A and 3B show a steam-cooled gas turbine combustor according to the prior art, wherein FIG. 3A is a schematic side view, FIG. 3B is a perspective view of a part of a main body wall, and FIG. 3C is A in FIG. -A sectional drawing is shown, respectively.

FIG. 4 is a sectional view of a steam-cooled gas turbine vane according to the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam supply manifold 3 Supply line 4 Recovery line 5 Steam recovery manifold 6,8 Temperature detector 7 Inlet temperature detection line 9 Outlet temperature detection line 10 Control device 11 Display device 12 Alarm device 13 Control signal line 14 Fuel system 15 Flow control valve 16 Shut-off valve 20 Combustor body 25 Cooling steam supply pipe 26, 27 Cooling steam recovery pipe

Claims (1)

[Claims] 1. A steam-cooled gas turbine for supplying cooling steam to a portion to be cooled such as a combustor or a blade and recovering the cooled steam, a temperature detector for detecting an outlet temperature of the cooled steam. And a detection signal of the same temperature detector, and compares it with a preset set temperature. If the detected temperature exceeds the set value, an alarm signal and the opening of the fuel flow control valve are reduced to a predetermined opening. A controller for outputting a signal or a signal for closing a shut-off valve, the outlet steam monitoring system for a steam-cooled gas turbine.