JPH07189740A - Gas turbine cooling system - Google Patents

Abstract

PURPOSE:To provide a cooling system and the operating method thereof required to smooth the start-stop of a gas turbine in the case of abnormality being generated to a cooling air system in a closed air-cooled gas turbine system. CONSTITUTION:A cooling air cutoff valve 16 is installed at a cooling air supply pipe 20 installed between the outlet of a boost compressor 1 and a gas turbine cooling part 4 so as to supply cooling air, and a cooling air exhaust pipe is installed between the cutoff valve 16 and the gas turbine cooling part 4. This constitution can provide a cooling system and a method of operating this cooling system for supplying cooling air required for the gas turbine cooling part 4 in the case of abnormality being generated to a cooling system in a closed air-cooled gas turbine system and at the start-stop time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for cooling a high temperature part of a gas turbine, and more particularly to a system suitable for coping with abnormal conditions of a closed air cooling system using air.

[0002]

2. Description of the Related Art The air at the outlet of a compressor is extracted to cool a high temperature part of a gas turbine, especially for cooling a blade, the pressure is boosted by a boost compressor and supplied to a gas turbine cooling part, and the cooled cooling air is supplied to a combustor or turbine. The closed air cooling for returning is described in JP-A-54-82518 (gas turbine device). Further, JP-A-59-5835 and JP-A-5-86901 also disclose a technique relating to cooling air.

[0003]

In an ordinary air-cooled gas turbine, cooling air is extracted from a compressor and supplied to a gas turbine cooling section, and the cooling air after cooling the gas turbine is discharged into the gas turbine. The pressure of the cooling air discharge part in the gas turbine is always lower than the pressure of the discharged cooling air, even considering the pressure of the compressor extraction part that is the source of the cooling air and the pressure loss of the cooling air passage. Therefore, regardless of the operating state of the gas turbine, the cooling air is always supplied to the gas turbine cooling unit, and the cooling air does not flow and the gas turbine is not damaged.

On the other hand, in the air closed cooling gas turbine which is the object of the present invention, the cooling air extracted from the outlet of the gas turbine compressor is supplied to the gas turbine cooling section, and the cooling air after cooling the gas turbine is compressed by the gas turbine. Between the machine and the gas turbine combustor. In this method, it is necessary to install a boost compressor that boosts the pressure in the cooling system in order to compensate for pressure loss in the cooling system, and if an abnormality occurs in the boost compressor system, etc., cooling air will be supplied to the gas turbine cooling unit. It could be out of supply and damage the gas turbine.

Further, the inlet pressure of the boost compressor for boosting the cooling air is linked with the outlet pressure of the gas turbine compressor. Therefore, to operate the boost compressor from the stopped state of the gas turbine to the 100% load state, approximately 1 ata is required.
A boost compressor that can be applied to changes in the inlet pressure in the range of (when the gas turbine is stopped) to approximately 16 ata (an example of the current gas turbine 100% load) is required, and the characteristics of the boost compressor are required for the gas turbine cooling section. It is necessary to satisfy the specifications of various cooling air. Generally, there are few compressors that can operate efficiently in such a wide range.

An object of the present invention is to provide a cooling system and a method of operating the cooling system, which are required in the case where an abnormality occurs in a cooling air system in a closed air cooling gas turbine system and to smoothly start and stop the gas turbine. Especially.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to install a valve for shutting off cooling air in a pipe line between a boost compressor for boosting the gas turbine cooling air and a gas turbine cooling section requiring the cooling air. Further, it is achieved by installing a cooling air discharge pipe equipped with a valve in a pipe line between the valve and the gas turbine cooling unit.

Therefore, in the air-closed gas turbine cooling system of the present invention, the air extracted from the compressor is boosted by the boost compressor to be used for cooling the high temperature part of the turbine.
A device for returning the cooling air after cooling the high temperature part to the combustor inlet, and a valve for shutting off the cooling air between the boost compressor and the turbine cooling part, and between the shutoff valve and the turbine cooling part. It is characterized in that a valve is provided and a cooling air discharge pipe is provided for flowing cooling air to the outside.

Further, according to the present invention, the air extracted from the compressor is boosted by the boost compressor and used for cooling the high temperature part of the turbine, and the cooling air after cooling the high temperature part is returned to the combustor inlet. It is characterized in that the pressure of the cooling air supply part to the high temperature part of the turbine is reduced below the combustor inlet pressure.

Further, the gas turbine cooling system of the present invention is
It is characterized in that the air extracted from the compressor is used for cooling the high temperature part of the turbine, and a cooling air discharge pipe is provided for flowing the cooling air after cooling the high temperature part to the outside.

It is also preferable to use the compressor outlet pressure and the pressures of the boost compressor and the cooling cutoff valve pipe as control signals for the cooling air cutoff valve and the valve on the cooling air discharge pipe.

Further, according to the present invention, the air extracted from the compressor is boosted by the boost compressor to be used for cooling the high temperature part of the turbine, and the cooling air after cooling the high temperature part is returned to the combustor inlet. , A cooling air control valve is installed in the cooling air supply pipe between the boost compressor and the turbine cooling part and the cooling air return pipe between the turbine cooling part and the combustor inlet, and this control valve connects the cooling air supply pipe to the turbine cooling part inlet. A mode in which the turbine cooling section outlet channel is connected to the cooling channel and the turbine cooling section inlet channel is connected to the cooling air return tube, and the turbine cooling section outlet channel is connected to the outside. It is characterized by having.

Further, it is desirable to connect the cooling air control valve to the pressure introducing pipe from the cooling air return pipe and the cooling air supply pipe, respectively.

Further, the gas turbine cooling system of the present invention is
It is characterized in that the cooled air is mixed with the compressor inlet air through a cooling air discharge pipe.

An intercooler is preferably installed between the compressor and the boost compressor.

Further, the present invention is characterized in that a cooling air tank is installed between the boost compressor and the shutoff valve.

Further, according to the present invention, in the gas turbine first-stage vane for air cooling the inside, a part of the cooling air passage is opened to the space between the compressor and the combustor, and the other part is cooled. It is characterized in that it is connected to a pipe line that flows to the outside.

[0018]

When the closed air cooling system is operating normally, the cooling air boosted by the boost compressor is supplied to the gas turbine cooling section through the pipe line at the outlet of the boost compressor. Then, the cooling air that has cooled the gas turbine cooling unit is returned to the combustor inlet.

If some abnormality occurs in the air cooling system, for example, the boost compressor, and the pressure of the cooling air cannot be maintained in the normal range, it is provided in the pipe line between the boost compressor and the gas turbine cooling section. The valve for shutting off the cooling air is closed, and the valve for the cooling air discharge pipe connected to the pipe between the valve and the gas turbine cooling section is opened. By closing the cooling air cutoff valve and opening the cooling air discharge pipe, the pressure of the cooling air supply pipe of the gas turbine cooling unit is lowered. The cooling air flowing from the gas turbine cooling part to the combustor inlet due to the decrease in the pressure of the cooling air supply pipe flows backward and flows from the combustor inlet to the gas turbine cooling part, and passes through the cooling air supply pipe and the cooling air discharge pipe. Is discharged from the outside. here,
The outside may be a place other than the cooling air system and a pressure lower than that of the combustor inlet.

If the outlet of the cooling air discharge pipe is opened to the atmosphere, the pressure difference for flowing the cooling air can be made large. Therefore, there is no problem in increasing the pressure loss that occurs when the cooling air flows backward, and the amount of cooling air is higher than usual. Since a large amount can be flowed, it is possible to compensate for the deterioration of the cooling performance when the gas turbine cooling unit flows backward. Further, if necessary, it is possible to adjust the flow rate by inserting resistance in the cooling air discharge pipe to change the pressure difference for flowing the cooling air.

Further, at the time of starting the gas turbine, the valve for shutting off the cooling air provided in the pipeline between the boost compressor and the gas turbine cooling section is closed, and the cooling connected to the pipeline between this valve and the gas turbine cooling section. Open the valve on the air exhaust pipe. As a result, the cooling air flows from the combustor inlet to the gas turbine cooling section, and the gas turbine cooling section is cooled. Thereafter, the cooling air passes through the cooling air supply pipe and is discharged from the cooling air discharge pipe. When the boost compressor is started and the flow rate and pressure that can be supplied to the gas turbine cooling section are obtained, the valve installed in the cooling air discharge pipe is closed and the cooling air cutoff valve is opened to exit the boost compressor. The cooling air is supplied to the gas turbine cooling unit through the cooling air supply pipe, and is operated in a normal Coulosed cooling system.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The gas turbine system comprises an air compressor 1, a combustor 2, a gas turbine 3 and a gas turbine generator 5. A gas turbine compressor intake pipe 6 is connected to the inlet of the gas turbine compressor 1, and a gas turbine compressor outlet pipe 7 and a cooling air extraction pipe 20 are connected to the outlet thereof. A fuel supply pipe 9 is connected to the combustor 2, and a gas turbine exhaust pipe 8 is connected to the gas turbine 3. A gas turbine cooling unit 4 is installed inside the gas turbine 3.

The cooling air pipelines are a cooling air extraction pipe 20 and a cooling air extraction pipe 2 connected to the outlet of the gas turbine compressor 1.
0, a cooling air boost compressor 12, a cooling air supply pipe 22 connected from the cooling air boost compressor 12 to the gas turbine cooling unit 4 in the gas turbine 3, and a gas turbine cooling unit 4 outlet pipe from the gas turbine cooling unit 4. 7, a cooling air return pipe 10 connected to the cooling air extraction pipe 20
The cooling air intercooler 11 provided with the intercooler cooling water 23 is installed above, and the cooling air tank 15 and the cooling air cutoff valve 16 are installed above the cooling air supply pipe 22.
The cooling air boost compressor 12 is connected to a boost compressor drive motor 13.

A boost compressor bypass valve 14 is provided between the outlet of the cooling air boost compressor 12 and the cooling air tank 15 and between the outlet of the gas turbine compressor 1 and the cooling air intercooler 11.
A boost compressor bypass 21 is installed. A cooling air blow pipe 19 having a boost compressor blow valve 17 is connected to the cooling air tank 15.

Further, a cooling air exhaust pipe 24 having a cooling air exhaust valve 18 is connected between the cooling air cutoff valve 16 installed in the cooling air supply pipe 22 and the gas turbine cooling section 4.

A compressor outlet pressure detector 26 is provided at the gas turbine compressor outlet pipe 7, and a cooling air pressure detector 25 is provided between the cooling air boost compressor 12 and the cooling air cutoff valve 16 of the cooling air supply pipe 22. Installed, compressor outlet pressure detector 2
6 and the cooling air pressure detector 25 are respectively connected to the valve control device 29 with signal cables.

The cooling air cutoff valve 16 has a cooling air cutoff valve drive device 27, the boost compressor blowoff valve 17 has a boost compressor blowoff valve drive device 28, and the cooling air discharge valve 18 has a cooling air cutoff valve drive device. 27 is provided, and a signal cable is connected to the valve control device 29 from each.

The operation of the present embodiment during steady operation will be described below.

The air that has entered the gas turbine compressor 1 through the gas turbine compressor intake pipe 6 is the gas turbine compressor 1
It is pressurized inside and becomes high-pressure and high-temperature air, which is supplied to the combustor 2 through the gas turbine compressor outlet pipe 7. In the combustor 2, the fuel supplied from the fuel supply pipe 9 is burned to burn at high temperature. It becomes gas and flows into the gas turbine 3, expands, generates power, and is discharged from the gas turbine exhaust pipe 8 to the outside. The gas turbine 3 drives the air compressor 1 and the gas turbine generator 5.

The cooling air flows from the outlet of the gas turbine compressor 1 through the cooling air extraction pipe 20 and the cooling air intercooler 1
1 and is cooled by the intercooler cooling water 23. The cooling air intercooler 11 can reduce the air temperature at the compressor outlet, reduce the cooling air amount by lowering the cooling air temperature, and reduce the boost compressor compression power by lowering the boost compressor inlet air temperature. Have an effect. The cooling air that has exited the cooling air intercooler 11 enters the cooling air boost compressor 12 and is boosted to a pressure at which it can be supplied to the gas turbine cooling unit 4. The cooling air boost compressor 12 is driven by a boost compressor drive motor 13. An electric motor is generally used as the drive source of the cooling air boost compressor 12, and although the configuration and operation are simple, there is a drawback that the rotation speed control is difficult and the operating range of the boost compressor cannot be widened. Also, it is conceivable that the drive source is a steam turbine or the like capable of controlling the rotation speed,
It is not common because many accessories are attached.

Due to the characteristics of the cooling air boost compressor 12, the boost compressor bypass 21 has a cooling air flow rate required for the gas turbine cooling section 4 and the boost compressor bypass 2.
1 is used to open the boost compressor bypass valve 14 when the flow rate that can operate does not match, and is used to recycle air to the boost compressor bypass 21 from the cooling air boost compressor 12 outlet to the intercooler cooling water 23 inlet, From the viewpoint of efficiency, it is desirable not to use in a steady state.

Cooling air boost The cooling air leaving the compressor 12 is sent to a cooling air tank 15. Cooling air tank 1
5 is not necessarily required, but the gas turbine cooling unit 4
To stabilize the supply pressure of the cooling air, and to suppress the rate of decrease of the cooling air supply pressure in the event of an abnormality.

In the steady state, the cooling air cutoff valve 16 provided in the cooling air supply pipe 22 is opened, so that the cooling air flows through the cooling air cutoff valve 16 through the cooling air supply pipe 22 and the gas of the gas turbine 3 is discharged. After being supplied to the turbine cooling unit 4 and cooling the gas turbine cooling unit 4, the gas is discharged to the gas turbine compressor outlet pipe 7 through the cooling air return pipe 10.

In the cooling air intercooler 11, when the equipment of the cooling system becomes abnormal, for example, the drive power of the boost compressor drive motor 13 is lost, or the hydraulic system of the cooling air boost compressor 12 fails. When a leak of the cooling water occurs, it is necessary to stop the cooling air boost compressor 12. In this case, the cooling air supply pipe 22
The upper cooling air cutoff valve 16 is closed and the boost compressor blowoff valve 17 and the cooling air discharge valve 18 are opened. The cooling air flowing through the cooling air supply pipe 22 from the cooling air cutoff valve 16, the gas turbine cooling unit 4, the cooling air return pipe 10 to the gas turbine compressor outlet pipe 7 closes the cooling air cutoff valve 16 and discharges the cooling air. By opening the valve 18, the pressure between the cooling air cutoff valve 16 and the gas turbine cooling unit 4 decreases, and the air at the outlet of the gas turbine compressor 1 passes through the cooling air return pipe 10 to cool the gas turbine cooling unit 4. Then, it flows through the cooling air discharge valve 18 and the cooling air discharge pipe 24 and is discharged to the outside. Therefore, the flow of cooling air is secured in the gas turbine cooling unit 4 and the rise in temperature causes the gas turbine cooling unit 4 to cool.
Can be prevented from being damaged. In general, the gas turbine cooling unit 4, especially the cooling flow path in the blade, is devised to improve the cooling efficiency, and if the flow of the cooling air is reversed, the cooling performance is not as high as in the case of a normal flow, The pressure difference between the pressure of the gas turbine compressor outlet pipe 7 and the outlet of the cooling air discharge pipe 24 can be made large. Therefore, the flow rate of the cooling air can be easily increased, so that the flow rate sufficient to cool the gas turbine cooling unit 4 can be supplied. It is also possible to design a cooling flow path for both forward and backward flows and deal with it at the expense of some cooling performance.

According to this embodiment, the gas turbine cooling section 4 can be easily cooled in the following manner even when the gas turbine is started and stopped. When starting the gas turbine, the cooling air cutoff valve 16 is closed and the cooling air discharge valve 18 is opened. When the gas turbine is started by the starter (not shown in this embodiment) and the rotation speed increases, the air pressurized by the compressor passes through the gas turbine compressor outlet pipe 7 and the cooling air return pipe 10. It flows into the gas turbine cooling unit 4, cools the gas turbine cooling unit 4, and flows to the outside through the cooling air discharge valve 18 and the cooling air discharge pipe 24. When the pressure at the outlet of the gas turbine compressor 1 reaches the operable range of the cooling air boost compressor 12, the cooling air boost compressor 12 is activated and boosted while controlling the recycling flow rate by the boost compressor bypass valve 14. The air flows through the cooling air tank 15, the boost compressor blowoff valve 17, and the cooling air blowoff pipe 19 and is discharged to the outside. The pressure of the cooling air tank 15 is the gas turbine cooling unit 4
Cooling air shutoff valve 16
And the boost compressor blow-off valve 17 and the cooling air discharge valve 18 are closed. As a result, the cooling air flows from the cooling air tank 15 through the cooling air cutoff valve 16 and the cooling air supply pipe 22 to the gas turbine cooling unit 4, and the cooling air return pipe 1
A steady-state cooling flow path that flows through 0 to the gas turbine compressor outlet pipe 7 is secured.

Similarly, when the gas turbine is stopped, the cooling air is shut off from the gas turbine compressor outlet pipe 7 by closing the cooling air shutoff valve 16 and opening the cooling air discharge pipe 24 and the boost compressor blowoff valve 17. Flowing through the air return pipe 10 to the gas turbine cooling unit 4, the cooling air exhaust valve 18,
It is discharged from the cooling air discharge pipe 24 to the outside. The cooling air boost compressor 12 stops while discharging air from the boost compressor blowoff valve 17 and the cooling air blowoff pipe 19 to the outside.

As described above, according to this embodiment, there is an effect that the cooling section cooling air flow rate at the time of starting and stopping can be supplied.

Further, according to this embodiment, air is extracted from the compressor at the time of start-up, the gas turbine cooling part 4 is made to flow, and the air is discharged to the outside through the cooling air discharge valve 18 and the cooling air discharge pipe 24. At times, the amount of air flowing into the combustor 2 can be reduced. Therefore, in the combustor (air / fuel)
The effect of stabilizing the combustion in the combustor can be achieved by reducing the change in the ratio.

FIG. 2 shows an embodiment relating to the control of each valve which realizes the implementation shown in FIG. 1, and the valve control device 29 shown in FIG.
3 shows an example of the inside. Although the boost compressor bypass valve 14 is also shown as a valve in the embodiment of FIG. 1, the operation of the cooling air cutoff valve 16, the boost compressor blowoff valve 17, and the cooling air discharge valve 18 related to the present invention is targeted here. I am trying.

The signal a from the cooling air pressure detector 25 and the signal b from the compressor outlet pressure detector 26 are input to the valve control device 29, which outputs a control signal to the drive device of each valve.

When the deviation between the signal a and the signal b and the signal b enter the function generator and the deviation is larger than the preset value Ps1 and the signal b is larger than the preset value Ps2, the cooling air cutoff valve 16 is turned on. A control signal that opens and closes the boost compressor blowoff valve 17 and the cooling air discharge valve 18 is output.
Under other conditions, the cooling air cutoff valve 16 is closed, and the boost compressor blowoff valve 17 and the cooling air discharge valve 18 are open control signals. The deviation between the signal a and the signal b is the set value Ps.
A value greater than 1 means that the cooling air boost compressor 12 system is operating normally, and a signal b greater than the set value Ps2 indicates that the gas turbine system is supplying cooling air from the boost compressor. This indicates that the operation status is acceptable.

Although not shown in the present embodiment, it goes without saying that the valve control device 29 informs the valve control device 29 of other supplemental signals indicating abnormalities of the cooling air boosting system, such as the cooling air intercooler 11 outlet air temperature and the cooling air. The boost compressor 12 lubricating oil temperature, the gas turbine cooling unit 4 outlet air temperature, the gas turbine 3 outlet temperature, the fuel flow rate, etc. can be input as necessary.

According to this embodiment, the cooling air cutoff valve 16,
The boost compressor blowoff valve 17 and the cooling air discharge valve 18 can be easily controlled.

Further, if the signal is not normally input, the cooling air cutoff valve 16 is closed, and the boost compressor blowoff valve 17 and the cooling air discharge valve 18 are opened, so that the valve control device 29 can cope with a failure in the system. There is an effect that can be done.

FIG. 3 and FIG. 4 show another embodiment of the present invention.

The embodiment of FIGS. 3 and 4 differs from the embodiment of FIG. 1 in that the cooling air cutoff valve 1 is provided on the cooling air supply pipe 22.
A cooling air control valve 32 is installed in place of 6, and the cooling air control valve 32 is connected to a cooling air supply pipe 22, a cooling air return pipe 10 and a cooling air discharge pipe 24. A cooling air control valve drive device 33 is connected to the cooling air control valve 32, and a valve control device 29 is connected to the cooling air control valve drive device 33.
The signal cable from is connected.

The structure of the gas turbine cooling section 31 in the gas turbine 3 is such that the flow of cooling air flows in only one direction. The cooling air control valve 32 in FIG. 3 shows the position in the normal state, and the cooling air control valve 32 in FIG. 4 shows the position when the cooling system is abnormal and when it is started and stopped. In FIG. 3, the cooling air leaving the cooling air boost compressor 12 passes through the cooling air supply pipe 22 and enters the gas turbine cooling section 31 from the cooling air control valve 32. The air that has cooled the gas turbine cooling section 31 is cooled again. Air control valve 3
2 and flows through the cooling air return pipe 10 to the gas turbine compressor outlet pipe 7.

At the time of abnormality, start-up and stop, the cooling air control valve 32 is switched as shown in FIG.
Flowing through the boost compressor blow valve 17 of the cooling air blow pipe 19 to the outside, and the air from the gas turbine compressor outlet pipe 7 flows through the cooling air return pipe 10 and enters the cooling air control valve 32 to enter the gas. Switching to the inlet of the turbine cooling unit 31, the cooling air leaving the gas turbine cooling unit 31 flows again to the cooling air control valve 32 and is discharged from the cooling air discharge pipe 24 to the outside.

In this way, according to this embodiment, the flow of the cooling air flowing through the gas turbine cooling section 31 is not changed, so that the cooling structure of the gas turbine cooling section 31 is highly efficient depending on the flow. At the same time as it has an effect, it does not stop the cooling air at the moment of switching the flow, so
This has the effect of increasing reliability.

Another embodiment of the present invention is shown in FIG.

The embodiment of FIG. 5 differs from the embodiments of FIGS. 3 and 4 in that a cooling air supply pipe 22 and a cooling air return pipe 10 are provided.
The pressure of the gas turbine compressor outlet pipe 7 and the pressure of the cooling air boost compressor 12 outlet are used as the operating force of the cooling air control valve 50 installed at.

The cooling air control valve 50 has a cooling air control valve actuating portion 51 installed therein, and one end of the cooling air control valve 50 is connected to a compressor pressure introduction pipe 52 communicating with the cooling air return pipe 10 and the other end. A cooling air pressure introducing pipe 53 communicating with the cooling air supply pipe 22 between the cooling air boost compressor 12 and the cooling air control valve 50 is connected to one end thereof.

FIG. 5 shows the flow of cooling air in a normal state. When the pressure between the cooling air boost compressor 12 and the cooling air control valve 50 becomes larger than the pressure in the cooling air return pipe 10, the cooling air control valve actuating portion 51 moves to the left to maintain the normal air flow.

When the pressure of the cooling air decreases due to an abnormality in the boost compressor or the like, the pressure of the cooling air return pipe 10 increases and the cooling air control valve operating portion 51 is moved to the right, so that the cooling air is discharged from the gas turbine compressor outlet pipe. 7 to cooling air return pipe 1
After passing through 0, the gas flows through the cooling air control valve 50, cools the gas turbine cooling section 31, and is discharged from the cooling air discharge pipe 24.

According to this embodiment, the cooling air control valve 50
Since the driving force of C is obtained directly from the supply pressure difference of the cooling air, the risk of failure in the process of pressure detection, signal conversion, control, etc. can be avoided, and a highly reliable cooling system can be provided.

Although the cooling air control valve is shown in the form of a cylinder in the embodiments of FIGS. 3, 4 and 5, the present invention does not depend on the shape of the cooling air control valve, and a valve having a flow path switching function is provided. It will be obvious that it is applicable.

Another embodiment of the present invention is shown in FIG.

The embodiment shown in FIG. 6 is different from the embodiment shown in FIG. 1 in that the cooling air discharge pipe 60 for arranging the cooling air discharge valve 18 branched from the cooling air supply pipe 22 is connected to the gas turbine compressor intake air. It is a point made into the tube 6.

Since the cooling air bypasses the combustor 2, the air flow rate to the combustor 2 is reduced, and at the same time, the hot air compressed from the gas turbine compressor outlet pipe 7 through the cooling air discharge pipe 60 is compressed by the gas turbine. It is guided to the machine intake pipe 6 and mixed with intake air. Therefore, the inlet temperature of the gas turbine compressor 1 rises, and the volumetric flow rate at the compressor inlet is almost constant in view of the characteristics of the compressor, so that the compressor inlet weight flow rate decreases.
Therefore, it is possible to further reduce the change in the (air / fuel) ratio of the combustor at the time of start-up and at the time of partial load, and it is possible to provide a combustor capable of stable combustion.

Another embodiment of the present invention is shown in FIG. This embodiment shows a specific structure around the combustor 2 in the embodiment of FIG.

A gas turbine compressor outlet pipe 7 is connected to the outlet of the gas turbine compressor 1 and continues to the combustor 2. Inside the combustor 2, a combustor liner 73, a combustor chamber 74, a transition piece 75, etc. are installed. And continues to the gas turbine 3. The gas turbine 3 is composed of a gas turbine first stage vane 70 connected to a transition piece 75, a moving vane following it, and each stage. The fuel supply pipe 9 is connected to the combustor liner 73 of the combustor 2, and the cooling air extraction pipe 20 is connected to the combustor chamber 74. One end of the gas turbine first stage vane 70 is connected to the cooling air supply chamber 71 separated from the combustor chamber 74 by the cooling air supply wall 72, and the other end is connected to the combustor chamber 74. Cooling air supply chamber 7
1, a cooling air supply pipe 22 is connected, and a cooling air discharge pipe 24 is connected to the cooling air supply pipe 22.

In the steady state, the air A flowing out of the gas turbine compressor 1 and flowing through the gas turbine compressor outlet pipe 7 flows into the combustor chamber 74, and most of the air (B) enters the combustor liner 73 and the fuel is discharged. The fuel from the supply pipe 9 is burned to become combustion gas (C), (D), (E), and then enters the gas turbine 3 and flows like (F). The cooling air for cooling the turbine cooling section flows from the combustor chamber 74 into the cooling air extraction pipe 20 (G) and flows into the boosting system (H). The cooling air (I) whose pressure has been boosted outside flows into the cooling air supply chamber 71 through the cooling air supply pipe 22 and flows into the gas turbine first-stage stationary blade 70 that is the gas turbine cooling unit (J). The cooling air (K) that has cooled the first turbine vane 70 of the gas turbine flows into the combustor chamber 74 and is used as combustion air.

When the external booster system is not operating, the extraction (G) to the cooling air extraction pipe 20 is shut off and the combustor chamber 74
The air inside flows into the gas turbine first-stage vanes 70 to cool the gas turbine first-stage vanes 70, enters the cooling air supply chamber 71, and is discharged from the cooling air supply pipe 22 to the outside through the cooling air discharge pipe 24.

By opening one end of the cooling passage of the gas turbine first stage vane 70 to the combustor chamber 74 as in the present embodiment, the cooling air return pipe 10 shown in FIG. 1 is substantially eliminated and the structure is simplified. effective. In addition, a plurality of gas turbine first stages are provided at the other end of the gas turbine first stage vane 70.
By providing the cooling air supply chamber 71 common to the stage vanes 70, the supply air pressure becomes uniform, so that the flow rate to each gas turbine first stage vane 70 can be made uniform.

[0066]

According to the present invention, the cooling system for supplying the cooling air required to the gas turbine cooling unit in the closed cooling gas turbine system when the cooling system has an abnormality and at the time of starting and stopping and the operation thereof. Can provide the law.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing an embodiment of the present invention.

FIG. 4 is a diagram showing an embodiment of the present invention.

FIG. 5 is a diagram showing an embodiment of the present invention.

FIG. 6 is a diagram showing an embodiment of the present invention.

FIG. 7 is a diagram showing an embodiment of the present invention.

[Explanation of symbols]

3 ... Gas turbine, 4 ... Gas turbine cooling part, 7 ... Gas turbine compressor outlet pipe, 10 ... Cooling air return pipe, 12 ...
Cooling air boost compressor, 16 ... Cooling air cutoff valve, 17
… Boost compressor blow valve, 18… Cooling air exhaust valve, 19
... Cooling air blow pipe, 20 ... Cooling air extraction pipe, 22 ... Cooling air supply pipe, 24 ... Cooling air discharge pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Kiyoki No. 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. Inside the Mechanical Research Laboratory (72) Inventor Takashi Ikeguchi 502 Kintatecho, Tsuchiura City, Ibaraki Prefecture

Claims (10)

[Claims] 1. An air-closed gas turbine cooling system in which air extracted from a compressor is boosted by a boost compressor to be used for cooling a high temperature part of a turbine and cooling air after cooling the high temperature part is returned to a combustor inlet. A valve for shutting off the cooling air between the boost compressor and the turbine cooling section, and a valve between the shutoff valve and the turbine cooling section, and a cooling air discharge pipe for flowing the cooling air to the outside are provided. Gas turbine cooling system characterized by. 2. An air-closed gas turbine cooling system in which air extracted from a compressor is boosted by a boost compressor to be used for cooling a high temperature part of a turbine, and cooling air after cooling the high temperature part is returned to a combustor inlet. A gas turbine cooling system, characterized in that the pressure of a cooling air supply section to the turbine high temperature section is reduced to a combustor inlet pressure or lower. 3. A gas turbine cooling system characterized in that air extracted from a compressor is used for cooling a high temperature part of a turbine, and a cooling air discharge pipe is provided for flowing the cooling air after cooling the high temperature part to the outside. 4. The gas according to claim 1, wherein the compressor outlet pressure and the pressure of the boost compressor and the cooling cutoff valve pipe are used as control signals for the cooling air cutoff valve and the valve on the cooling air discharge pipe. Turbine cooling system. 5. A booster in an air-closed gas turbine cooling system, wherein air extracted from a compressor is boosted by a boost compressor and used for cooling a high temperature part of a turbine, and cooling air after cooling the high temperature part is returned to a combustor inlet. A cooling air control valve is installed on the cooling air supply pipe between the compressor and the turbine cooling unit and on the cooling air return pipe between the turbine cooling unit and the combustor inlet, and this control valve connects the cooling air supply pipe to the turbine cooling unit inlet passage. And the turbine cooling section outlet flow path is connected to the cooling air return pipe, and the turbine cooling section inlet flow path is connected to the cooling air return pipe and the turbine cooling section outlet flow path is connected to the outside. A gas turbine cooling system characterized in that 6. The gas turbine cooling system according to claim 5, wherein the cooling air control valve is connected to a pressure introduction pipe from each of the cooling air return pipe and the cooling air supply pipe. 7. The gas turbine cooling system according to claim 3, wherein the cooled air is mixed with the compressor inlet air through a cooling air discharge pipe. 8. The gas turbine cooling system according to claim 1, wherein an intercooler is installed between the compressor and the boost compressor. 9. The gas turbine cooling system according to claim 1, wherein a cooling air tank is installed between the boost compressor and the shutoff valve. 10. A pipe line in which a part of a cooling air passage of a gas turbine first stage vane for air cooling the inside thereof is opened to a space between a compressor and a combustor, and another part of the cooling air flows to the outside. A gas turbine cooling system characterized by being connected to.