JP2017145701A - Gas turbine control device, gas turbine control method, and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine control device, a gas turbine control method, and a gas turbine capable of performing an appropriate control in response to a scale of risk of over-speed of the gas turbine while establishing both reduction in risk of over-speed and a prevention of flame failure at the time of load blockage.SOLUTION: A gas turbine control device comprising a compressor for generating compressed air, a combustor for igniting fuel under application of compressed air to generate combustion gas, a turbine constituted to be driven with combustion gas and a regulating valve for regulating a flow rate of extraction steam extracted from the compressor is constituted in such a way that the regulating valve is opened when the load of the gas turbine is blocked and an opening of the regulating valve is controlled on the basis of an index having correlation with an output of the gas turbine just before the time of load blockage of the gas turbine.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a control apparatus and control method for a gas turbine, and a gas turbine.

  Generally, in a gas turbine, there is a case where an operation (load interruption) for separating a load is performed during a load operation. When the load is interrupted, control is required so that no misfire occurs in the combustor after the load is interrupted, and the turbine speed does not become excessive.

  For example, Patent Document 1 discloses a fuel command value (minimum value for realizing a target fuel / air ratio obtained from combustion maintenance limit information indicating a limit balance between a pilot ratio and a fuel / air ratio that can maintain combustion stability. It is disclosed that the fuel valve opening is determined based on a high value of the fuel flow rate command and the minimum fuel command.

  Further, in Patent Document 2, when the load of the gas turbine is shut off, the extraction valve for extracting compressed air from the compressor is controlled to be fully opened, and the inlet guide vanes of the compressor have an intermediate opening degree. It is described that the wing is controlled to the closed side.

JP 2011-85105 A JP 2010-216441 A

  However, the control of the gas turbine described in Patent Document 1 determines the fuel valve opening based on the minimum fuel flow rate necessary for maintaining stable combustibility. In some cases, it is difficult to achieve both reduction in the risk of overspeed and prevention of misfire.

  Further, in the gas turbine described in Patent Document 2, when the load is shut off, the extraction valve for extracting compressed air from the compressor is controlled to be fully opened regardless of the risk of over-rotation of the gas turbine. Yes. For this reason, the air is extracted more than necessary to prevent over-rotation. For example, when compressed air is used to cool the gas turbine hot section, the gas turbine hot section is not cooled. It may be enough.

  In view of the above-described circumstances, at least some embodiments of the present invention are suitable according to the magnitude of the risk of over-rotation of the gas turbine while simultaneously reducing the risk of over-rotation and preventing misfire at the time of load interruption. It is an object of the present invention to provide a gas turbine control device and control method, and a gas turbine capable of performing simple control.

(1) A gas turbine control device according to at least some embodiments of the present invention includes:
A compressor for generating compressed air; a combustor for generating combustion gas by burning fuel using the compressed air; a turbine configured to be driven by the combustion gas; and the compression A control valve for adjusting the flow rate of the extraction air extracted from the machine, and a control device for the gas turbine,
When the load of the gas turbine is cut off, the adjustment valve is opened, and the opening of the adjustment valve is controlled based on an index correlated with the output of the gas turbine immediately before the load cut off of the gas turbine. .

According to the configuration of (1) above, the flow rate of the compressed air supplied to the combustor decreases because the flow rate of the extracted air from the compressor increases by opening the regulating valve when the load of the gas turbine is shut off. Thereby, the fuel-air ratio in a combustor becomes high, and misfire in a combustor can be prevented, suppressing an overspeed. The fuel / air ratio is the ratio of fuel to compressed air supplied to the combustor.
By the way, the larger the gas turbine output immediately before the load is interrupted, the greater the risk that the gas turbine will over-rotate when the load is interrupted. In this regard, in the configuration of (1) above, since the opening degree of the regulating valve is controlled based on an index that correlates with the gas turbine output immediately before the load interruption of the gas turbine, the risk of over-rotation of the gas turbine is reduced. The opening degree of the regulating valve can be appropriately controlled according to the size.

(2) In some embodiments, in the configuration of (1) above,
The load opening of the gas turbine is configured to increase the opening of the regulating valve as the index increases.

For example, when the gas turbine is operated at a high output before the load is cut off, the increase in the number of revolutions at the time of load cut is large, and the risk of overspeeding is increased. In this case, according to the configuration of (2) above, the adjustment valve is opened with a relatively large opening so as to cope with a significant increase in the rotational speed, and the amount of extraction from the compressor increases. Therefore, it is possible to significantly reduce the fuel flow rate as compared with the load operation while maintaining a fuel-air ratio that does not cause misfire. Thereby, the energy of the combustion gas produced | generated with a combustor and flowing into a turbine can be reduced significantly, and the excessive rotation after load interruption can be prevented reliably.
On the other hand, when the gas turbine is operated at a low output before the load is cut off, the increase in the number of revolutions at the time of load cut is small, and the risk of overspeed is small. In this case, since the increase range of the rotation speed is small, the adjustment valve is opened with a relatively small opening, and the amount of bleed from the compressor is small. As a result, it is possible to prevent over-rotation after load interruption while avoiding a sudden change in the operating state of the gas turbine.

(3) In some embodiments, in the above configuration (1) or (2),
The index is the output of the gas turbine immediately before the load interruption of the gas turbine or the opening degree of the inlet guide blade of the compressor immediately before the load interruption of the gas turbine.

  According to the configuration of the above (3), the value of the output of the gas turbine itself or the opening degree of the inlet guide vane correlated with the output of the gas turbine is used as an index, so that it corresponds to the magnitude of the overspeed risk. It is possible to accurately control the opening degree of the regulating valve.

(4) In some embodiments, in any one of the above configurations (1) to (3),
A valve opening calculation unit that calculates the opening of the adjustment valve according to the index when the load of the gas turbine is interrupted;
A valve opening degree correction unit configured to correct the opening degree calculated by the valve opening degree calculation unit by an atmospheric temperature.

  Normally, since the mass flow rate of air flowing into the compressor changes depending on the atmospheric temperature, the atmospheric temperature is corrected by correcting the opening calculated by the valve opening calculation unit with the atmospheric temperature as in the configuration of (4) above. Regardless of this, the extraction air having a desired mass flow rate corresponding to the risk of over-rotation can be discharged from the compressor.

(5) In some embodiments, in any one of the above configurations (1) to (4),
The minimum opening degree is selected from the required opening degree of the regulating valve corresponding to the temperature measurement value of the high temperature part of the gas turbine and the opening degree of the regulating valve determined based on the index. The minimum opening selection unit is further provided.

  According to the configuration of (5) above, after ensuring the air flow rate necessary for cooling the high temperature part (for example, cooling of the turbine blades), which is one of the most prioritized matters in the operation of the gas turbine, Misfire can be suppressed.

(6) In some embodiments, in any one of the above configurations (1) to (5),
The regulating valve is a circulation valve provided in a circulation line for returning the extracted air to the intake side of the compressor, or at least for adjusting a supply amount of the extracted air from the compressor to the turbine It is at least one of one bleed valve.

(7) In some embodiments, in any one of the configurations (1) to (6) above,
Each of the plurality of regulating valves is configured to control the opening / closing timing and the opening degree independently of the other regulating valves.

  According to the configuration of the above (7), when a plurality of regulating valves are provided, the opening / closing timing and the opening degree of each regulating valve are controlled independently of the other regulating valves. The influence on the operation of the gas turbine due to the response can be minimized.

(8) A gas turbine according to at least some embodiments of the present invention includes:
A compressor for generating compressed air;
A combustor for combusting fuel using the compressed air to generate combustion gas;
A turbine configured to be driven by the combustion gas;
An adjustment valve for adjusting the flow rate of the extracted air extracted from the compressor;
The control device according to any one of (1) to (7), configured to control an opening degree of the regulating valve;
Is provided.

  According to the configuration of (8) above, misfire in the combustor can be prevented while suppressing overspeed, and the opening degree of the regulating valve is appropriately controlled according to the risk of overspeed of the gas turbine. Since the control apparatus which can be provided is provided, a reliable gas turbine can be provided.

(9) A gas turbine control method according to at least some embodiments of the present invention includes:
A compressor for generating compressed air; a combustor for generating combustion gas by burning fuel using the compressed air; a turbine configured to be driven by the combustion gas; and the compression A control method for a gas turbine comprising: an adjustment valve for adjusting a flow rate of the extraction air extracted from the machine,
When the load of the gas turbine is cut off, the adjustment valve is opened, and the opening degree of the adjustment valve is controlled based on an index correlated with the output of the gas turbine immediately before the load cut off of the gas turbine.

According to the above method (9), the flow rate of the compressed air supplied to the combustor is reduced because the flow rate of the extracted air from the compressor is increased by opening the regulating valve when the load of the gas turbine is shut off. Thereby, the fuel-air ratio in a combustor becomes high, and misfire in a combustor can be prevented, suppressing an overspeed.
In addition, since the opening of the regulator valve is controlled based on an index that correlates with the gas turbine output immediately before the load interruption of the gas turbine, the regulator valve is opened according to the risk of over-rotation of the gas turbine. The degree control can be performed appropriately.

(10) In some embodiments, in the method of (9) above,
When the load of the gas turbine is cut off, the opening degree of the regulating valve is increased as the index increases.

  According to the above method (10), when the index correlated with the output of the gas turbine is large, the energy of the combustion gas generated in the combustor and flowing into the turbine is reduced by opening the regulating valve at a relatively large opening. It can be greatly reduced, and over-rotation after load interruption can be reliably prevented. On the other hand, when the index correlated with the output of the gas turbine is small, the regulating valve is opened with a relatively small opening, so that overspeed after shutting off the load is avoided while avoiding a sudden change in the operating state of the gas turbine. Can be prevented.

(11) In some embodiments, in the above method (9) or (10),
The index is the output of the gas turbine immediately before the load interruption of the gas turbine or the opening degree of the inlet guide blade of the compressor immediately before the load interruption of the gas turbine.

  According to the above method (11), the value of the output of the gas turbine itself or the opening degree of the inlet guide vane correlated with the output of the gas turbine is used as an index, so that the degree of over-rotation risk is met. It is possible to accurately control the opening degree of the regulating valve.

(12) In some embodiments, in any one of the above methods (9) to (11),
Calculating the opening of the regulating valve according to the index when the gas turbine is shut off from the load;
Correcting the opening of the regulating valve calculated in the step of calculating the opening by the atmospheric temperature;
Is provided.

  According to the method of (12) above, by correcting the opening calculated based on the index correlated with the gas turbine output by the atmospheric temperature, the desired mass corresponding to the over-rotation risk regardless of the atmospheric temperature. A flow of extracted air can be discharged from the compressor.

(13) In some embodiments, in any one of the above methods (9) to (12),
Selecting a minimum opening among the required opening of the regulating valve corresponding to the temperature measurement value of the high temperature portion of the gas turbine and the opening of the regulating valve determined based on the index.

  According to the method of (13) above, after ensuring the air flow rate necessary for cooling the high temperature part (for example, cooling of the turbine blades), which is one of the most priorities in the operation of the gas turbine, Misfire can be suppressed.

(14) In some embodiments, in any one of the above methods (9) to (13),
The regulating valve is a circulation valve provided in a circulation line for returning the extracted air to the intake side of the compressor, or at least for adjusting a supply amount of the extracted air from the compressor to the turbine It is at least one of one bleed valve.

(15) In some embodiments, in any one of the methods (9) to (14),
The opening / closing timing and the opening degree of each of the plurality of regulating valves are controlled independently of the other regulating valves.

  According to the above method (15), when a plurality of regulating valves are provided, the opening / closing timing and opening degree of each regulating valve are controlled independently of the other regulating valves. The influence on the operation of the gas turbine due to the response can be minimized.

According to at least some embodiments of the present invention, the flow rate of the compressed air supplied to the combustor is increased because the flow rate of the bleed air from the compressor is increased by opening the regulating valve when the load of the gas turbine is shut off. Decrease. Thereby, the fuel-air ratio in a combustor becomes high, and misfire in a combustor can be prevented, suppressing an overspeed.
In addition, since the opening of the regulator valve is controlled based on an index that correlates with the gas turbine output immediately before the load interruption of the gas turbine, the regulator valve is opened according to the risk of over-rotation of the gas turbine. The degree control can be performed appropriately.

It is a figure showing a schematic structure of a gas turbine concerning one embodiment. It is a block diagram of the control apparatus of the gas turbine which concerns on one Embodiment. It is a block diagram which shows the basic control of the regulating valve in one Embodiment. It is a figure which shows the correlation with a gas turbine output and an adjustment valve opening degree. It is a block diagram which shows the basic control of the regulating valve in the modification of one Embodiment. It is a figure which shows the correlation with an IGV opening and an adjustment valve opening. It is a block diagram which shows control of the regulating valve in other embodiment. It is a block diagram which shows control of the regulating valve in other embodiment. It is a figure for demonstrating the opening / closing timing and opening degree of each adjustment valve.

  Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.

  First, the overall configuration of the gas turbine 1 according to some embodiments will be described with reference to FIG. Here, FIG. 1 is a diagram illustrating a schematic configuration of a gas turbine 1 according to an embodiment.

A gas turbine 1 according to some embodiments includes a compressor 3 for generating compressed air, a combustor 4 for generating fuel gas by burning fuel using the compressed air, and driven by the combustion gas. A turbine 5 configured to be configured.
The gas turbine 1 further includes an adjustment valve 10 that adjusts the flow rate of the extracted air extracted from the compressor 3.

In the gas turbine 1, the air taken into the compressor 3 is compressed by passing through the inlet guide blades 2, the plurality of stationary blades and the moving blades provided in the compressor casing, thereby causing high-temperature and high-pressure air (compression Air).
The combustor 4 is supplied with fuel and high-temperature and high-pressure air from the compressor 3. In the combustor 4, combustion gas is generated by mixing and burning fuel and air in the combustor cabin. During partial load operation or full load operation of the gas turbine 1, the flow rate of the fuel supplied to the combustor 4 is determined by the operation state of the gas turbine 1, the load, and the like. For example, the fuel flow rate is determined based on at least one of the load of the gas turbine 1, the rotational speed (rotational speed), and the combustion gas temperature.
The combustion gas from the combustor 4 is introduced into the turbine 5. The combustion gas passes through a plurality of stationary blades and moving blades arranged in the turbine casing, so that a rotor provided so as to penetrate the turbine casing and the compressor casing is rotated. When the gas turbine 1 is used for power generation, power is generated by a generator (not shown) connected to the rotor by rotation of the rotor.
An exhaust duct 6 communicating with the turbine casing is connected to the downstream side of the turbine 5. The exhaust gas after driving the turbine 5 is discharged to the outside through the exhaust duct 6.

  The gas turbine 1 further includes at least one extraction line 20 (20a to 20c) for extracting air from the compressor 3 and an adjusting valve 10 for adjusting the flow rate of the extracted air extracted from the compressor 3. Yes.

  The extraction line 20 is connected to the cooling line 21 (21a to 21c). The cooling line 21 is disposed so as to guide at least part of the extracted air from the compressor 3 to the turbine 5 as cooling air via the extraction line 20. The cooling line 21 is provided with orifices 22 (22a to 22c).

In addition, the extraction line 20 is connected to at least one of the circulation line 23 or the exhaust lines 24 (24a to 24c).
The circulation line 23 is disposed so as to return at least a part of the extracted air from the compressor 3 to the inlet side of the compressor 3.
The exhaust line 24 is arranged to guide at least a part of the air extracted from the compressor 3 to the downstream side of the turbine 5, that is, the exhaust duct 6 in FIG.

The regulating valve 10 includes at least one of the circulation valve 11 provided in the circulation line 23 or the extraction valve 12 (12a to 12c) provided in the exhaust line 24.
The circulation valve 11 is configured to adjust the circulation amount of the extracted air that is returned to the inlet side of the compressor 3 through the circulation line 23.
The extraction valve 12 adjusts the flow rate of the cooling air supplied to the turbine 5 by adjusting the differential pressure across the orifice 22 by adjusting the pressure of the extraction line 10.
The circulation valve 11 or the extraction valve 12 can also be used as an adjustment valve 10 for adjusting the extraction flow rate from the compressor 3 when the load of the gas turbine 1 is interrupted. During the load operation of the gas turbine 1, the circulation valve 11 and the bleed valve 12 (12 a to 12 c) are normally closed, and a predetermined amount of cooling air is sent to the turbine 5 via the orifice 22. Yes. When changing the flow rate of the cooling air, the differential pressure across the orifice 22 on the cooling line 21 is changed and supplied to the turbine 5 by controlling the opening of at least one of the circulation valve 11 or the extraction valve 12. The flow rate of cooling air is adjusted.

In the embodiment shown in FIG. 1, the bleed line 20 includes a high pressure bleed line 20 a that bleeds from the high pressure stage (exit side) of the compressor 3 and an intermediate pressure bleed line 20 b that bleeds from the medium pressure stage (intermediate) of the compressor 3. And a low-pressure extraction line 20c that extracts air from the low-pressure stage (inlet side) of the compressor 3.
The cooling line 21 is connected to the high pressure bleed line 20 a and is connected to the high pressure cooling line 21 a that introduces air into the high pressure stage (inlet side) of the turbine 5 and the medium pressure bleed line 20 b. An intermediate pressure cooling line 21b that introduces air into the (middle) and a low pressure cooling line 21c that is connected to the low pressure extraction line 20c and that introduces air into the low pressure stage (outlet side) of the turbine 5 is included. Each of these cooling lines 21a to 21c is provided with a high-pressure orifice 22a, a medium-pressure orifice 22b, and a low-pressure orifice 22c.
The circulation line 23 is connected to all of the high pressure bleed line 20a, the medium pressure bleed line 20b, and the low pressure bleed line 20c.
The exhaust line 24 includes a high-pressure exhaust line 24a connected to the high-pressure extraction line 20a and the high-pressure cooling line 21a, an intermediate-pressure exhaust line 24b connected to the intermediate-pressure extraction line 20b and the intermediate-pressure cooling line 21b, and a low-pressure extraction line 20c. And a low-pressure exhaust line 24c connected to the low-pressure cooling line 21c. In this case, a high pressure bleed valve 12a, an intermediate pressure bleed valve 12b, and a low pressure bleed valve 12c are provided in each of the high pressure exhaust line 24a, the intermediate pressure exhaust line 24b, and the low pressure exhaust line 24c.

  In the gas turbine 1 as described above, an operation (load interruption) for separating the load may be performed during the load operation. In this case, after the load is interrupted, if the misfire does not occur in the combustor 4 and the rotation speed of the gas turbine 1 is equal to or less than the overspeed trip specified value (for example, 110%), it can be considered that the load is interrupted appropriately.

  However, there is a trade-off relationship between prevention of misfire after load interruption and risk reduction of overspeed, and it may be difficult to achieve both. In the general gas turbine 1, when the load is cut off, for example, the fuel to the combustor 4 is throttled to suppress the increase in the rotational speed. That is, in the combustor 4, the fuel flow rate is set such that the rotational speed of the gas turbine 1 is maintained within the set range even in no-load operation. However, depending on the gas turbine 1, when the fuel flow rate is set so as to suppress over-rotation, the fuel / air ratio becomes too large, and the gas turbine 1 may stop due to misfire of the combustor 4. . The fuel / air ratio is the ratio of fuel to compressed air supplied to the combustor 4. Normally, the air flow rate supplied to the combustor 4 is determined by the rotational speed and the opening degree of the inlet guide vane 2 (IGV opening degree), but the compressor 3 is coaxial with the turbine 5, and the air flow rate at the rotational speed. It is difficult to operate. On the other hand, the IGV opening is normally controlled to be fully closed when the load is interrupted, but the air that has already been compressed after passing through the inlet guide vanes 2 is thrown into the combustor 4. Therefore, it is difficult to increase the fuel-air ratio without increasing the fuel flow rate of the combustor 4.

Therefore, in the following embodiment, control that can both reduce the risk of over-rotation and prevent misfire at the time of load interruption, and can perform appropriate control according to the magnitude of the over-rotation risk of the gas turbine 1. The device 30 will be described.
FIG. 2 is a configuration diagram of the control device 30 of the gas turbine 1 according to an embodiment.
In the following description, each part of the gas turbine 1 is denoted by the reference numerals shown in FIG.

As illustrated in FIG. 2, the control device 30 according to some embodiments mainly controls the opening degree of the regulating valve 10 of the gas turbine 1. When the load of the gas turbine 1 is interrupted, the regulating valve 10 is controlled. And the opening degree of the regulating valve 10 is controlled based on an index correlated with the output of the gas turbine 1 immediately before the load interruption of the gas turbine 1 (hereinafter referred to as an output index).
The control device 30 may be configured to increase the opening of the regulating valve 10 as the output index increases when the load of the gas turbine 1 is interrupted.
As the output index, the gas turbine output immediately before the load interruption of the gas turbine 1 or the opening degree of the inlet guide blade 2 of the compressor 3 immediately before the load interruption of the gas turbine 1 may be used.

According to the above configuration, the flow rate of the compressed air supplied to the combustor 4 decreases because the flow rate of the extracted air from the compressor 3 increases by opening the adjustment valve 10 when the load of the gas turbine 1 is shut off. Thereby, the fuel-air ratio in the combustor 4 can be increased without increasing the amount of fuel input to the combustor 4, and misfire in the combustor 4 can be prevented while suppressing over-rotation.
By the way, the larger the gas turbine output just before the load is interrupted, the greater the risk that the gas turbine 1 will over-rotate when the load is interrupted. In this regard, in the above configuration, since the opening degree of the regulating valve 10 is controlled based on the output index immediately before the load interruption of the gas turbine 1, the regulating valve is adjusted according to the risk of over-rotation of the gas turbine 1. 10 opening degree control can be performed appropriately.

For example, when the gas turbine 1 is operated at a high output before the load is cut off, the increase in the number of rotations at the time of load cut is large, and the risk of overspeeding is increased. In this case, according to the above configuration, the regulating valve 10 is opened with a relatively large opening so as to cope with a significant increase in the rotational speed, and the amount of air extracted from the compressor 3 increases. Therefore, it is possible to significantly reduce the fuel flow rate as compared with the load operation while maintaining a fuel-air ratio that does not cause misfire. Thereby, the energy of the combustion gas produced | generated by the combustor 4 and flowing into a turbine can be reduced significantly, and the excessive rotation after load interruption can be prevented reliably.
On the other hand, when the gas turbine 1 is operated at a low output before the load is cut off, the increase in the number of revolutions at the time of load cut is small, and the risk of overspeed is small. In this case, since the speed increase is small, the regulating valve 10 is opened with a relatively small opening, and the amount of air extracted from the compressor 3 is small. As a result, it is possible to prevent over-rotation after load interruption while avoiding a sudden change in the operating state of the gas turbine 1.

In the embodiment described above, the control device 30 sets the opening of the regulating valve 10 to the opening before the load is interrupted (for example, fully closed) after a set time (for example, several seconds to several tens of seconds) has elapsed since the load is interrupted. It is good also as a structure controlled to return (refer FIG. 7). In this case, the set time may correspond to a time zone immediately after the load is interrupted with a high risk of overspeed and misfire. For example, the set time can be set from a result of a simulation or a combustor unit test.
In this way, control is performed to open the regulating valve 10 during the time period immediately after the load is shut off where there is a high risk of overspeed and misfire. When the risk decreases, the opening degree of the regulating valve 10 is returned. Thereby, the stable operation of the gas turbine 1 after load interruption becomes possible. For example, even if the cooling air is reduced by opening the regulating valve 10 immediately after the load is cut off, returning the opening degree of the regulating valve 10 after the set time has elapsed will affect the cooling of the turbine 5. Can be suppressed.

Here, a specific configuration of the control device 30 will be described with reference to FIGS.
As illustrated in FIG. 2, the control device 30 according to some embodiments includes a valve opening calculation unit 31 for calculating the opening of the regulating valve 10 and a valve opening for generating a valve opening command. Degree command output unit 34.
The control device 30 may further include at least one of a valve opening correction unit 32 or a minimum opening selection unit 33.

The valve opening calculation unit 31 is configured to calculate the opening of the adjustment valve 10 according to the output index immediately before the load interruption when the load of the gas turbine 1 is interrupted.
The valve opening command output unit 34 is configured to generate a valve opening command based on the opening of the adjustment valve 10 calculated by the valve opening calculation unit 31 and to output the valve opening command to the adjustment valve 10. Is done.

FIG. 3A is a block diagram showing basic control of the regulating valve 10 in one embodiment. FIG. 3B is a diagram showing a correlation between the gas turbine output and the adjustment valve opening. These figures are related to control when the gas turbine output immediately before the load interruption of the gas turbine 1 is used as an output index.
In the embodiment shown in FIG. 3A, the valve opening calculation unit 31 (see FIG. 2) includes a switch 311, a function calculator 312, and a switch 313.
The switch 311 receives the current value of the gas turbine output and the previous value of the gas turbine output. When the switch 311 does not detect the load cutoff signal, the current value of the gas turbine output is input again to the switch 311 as the previous value. On the other hand, when the switch 311 detects the load cutoff signal, the previous value of the gas turbine output is input to the function calculator 312.
The function calculator 312 calculates the opening of the regulating valve 10 from the previous value of the gas turbine output based on the correlation between the gas turbine output and the regulating valve opening as shown in FIG. 3B.
The opening of the regulating valve 10 calculated by the function calculator 312 is input to the switch 313. When the switch 313 does not detect the load cutoff signal, the switch 313 outputs a valve opening command for setting the opening degree to zero. When the switch 313 detects a load cutoff signal, the opening degree of the regulating valve 10 calculated by the function calculator 312 is output, and the valve opening degree command output unit 34 (see FIG. 2) based on this opening degree. A valve opening command is generated.

According to the above configuration, since the opening degree of the regulating valve 10 is determined based on the previous value of the gas turbine output, the opening degree control of the regulating valve 10 is controlled according to the risk of over-rotation of the gas turbine. Can be done appropriately.
Further, by using the value of the output itself of the gas turbine 1 as an index, the opening degree control of the regulating valve 10 according to the magnitude of the over-rotation risk can be accurately performed.
In addition, when the turbine 5 of the gas turbine 1 is configured to drive the generator, the generator output may be used as the gas turbine output.

FIG. 4A is a block diagram showing basic control of the regulating valve 10 in a modification of the embodiment. FIG. 4B is a diagram illustrating a correlation between the IGV opening and the adjustment valve opening. These drawings are diagrams related to control when the opening degree (IGV opening degree) of the inlet guide vane 2 of the compressor 3 immediately before the load interruption of the gas turbine 1 is used as an output index.
The switch 311 receives the current value of the IGV opening and the previous value of the IGV opening. When the switch 311 does not detect the load cutoff signal, the current value of the IGV opening is input again to the switch 311 as the previous value. On the other hand, when the switch 311 detects the load cutoff signal, the previous value of the IGV opening is input to the function calculator 312.
The function calculator 312 calculates the opening of the adjustment valve 10 from the previous value of the IGV opening based on the correlation between the IGV opening and the adjustment valve opening as shown in FIG. 4B.
The opening of the regulating valve 10 calculated by the function calculator 312 is input to the switch 313. When the switch 313 does not detect the load cutoff signal, the switch 313 outputs a valve opening command for setting the opening degree to zero. When the switch 313 detects a load cutoff signal, the opening degree of the regulating valve 10 calculated by the function calculator 312 is output, and the valve opening degree command output unit 34 (see FIG. 2) based on this opening degree. A valve opening command is generated.

According to the above configuration, since the opening degree of the regulating valve 10 is determined based on the previous value of the IGV opening degree, the opening degree control of the regulating valve 10 is controlled according to the risk of over-rotation of the gas turbine. Can be done appropriately.
Moreover, the opening degree control of the regulating valve 10 according to the magnitude of the over-rotation risk can be accurately performed by using the IGV opening degree correlated with the turbine output as the output index.

  FIG. 5 is a block diagram showing the control of the regulating valve 10 in another embodiment. In addition to the basic control of FIGS. 3A and 4A, a calculation by the valve opening correction unit 32 (see FIG. 2) is added. Control. In FIG. 5, the control of the valve opening calculation unit 31 (see FIG. 2) is the same as that in FIGS.

As shown in FIG. 2, the valve opening correction unit 32 is configured to correct the opening of the adjustment valve 10 calculated by the valve opening calculation unit 31 with the atmospheric temperature.
In the embodiment illustrated in FIG. 5, the valve opening correction unit 32 includes a function calculator 321 and a multiplier 322.
An atmospheric temperature is input to the function calculator 321. Then, the function calculator 321 calculates a correction coefficient from the atmospheric temperature based on the correlation between the atmospheric temperature and the correction coefficient of the opening degree of the regulating valve 10. Usually, the mass flow rate of air flowing into the compressor 3 varies depending on the atmospheric temperature. For this reason, the function calculator 321 calculates a correction coefficient for the opening degree of the regulating valve 10 so as to absorb the variation of the mass flow rate due to the atmospheric temperature, for example, using a state equation.
When the load control command is detected, the multiplier 322 multiplies the opening degree of the regulating valve 10 input from the switch 312 described above by the correction coefficient input from the function calculator 321, and is corrected by the atmospheric temperature. The opening degree of the regulating valve 10 is output. Based on the corrected opening of the regulating valve 10, a valve opening command is generated in the valve opening command output unit 34 (see FIG. 2).

  According to the above configuration, by correcting the opening calculated by the valve opening calculation unit 31 with the atmospheric temperature, the bleed air having a desired mass flow rate corresponding to the over-rotation risk is supplied to the compressor 3 regardless of the atmospheric temperature. Can be discharged from. Thereby, even in a gas turbine plant having a large atmospheric temperature difference throughout the year, it is not necessary to change the specification of the opening degree setting of the regulating valve 10, and the opening degree control of the regulating valve 10 can be appropriately performed.

  FIG. 6 is a block diagram showing the control of the regulating valve 10 in still another embodiment. In addition to the basic control in FIGS. 3A and 4A, a calculation by the minimum opening selector 33 (see FIG. 2) is added. Control is shown. In FIG. 6, the control of the valve opening calculation unit 31 (see FIG. 2) is the same as that in FIGS.

As shown in FIG. 2, the minimum opening selection unit 33 opens the adjustment valve 10 determined based on the required opening of the adjustment valve 10 corresponding to the temperature measurement value of the high temperature part of the gas turbine 1 and the output index. The minimum opening degree is selected from the degrees.
In the embodiment shown in FIG. 6, the minimum opening selector 33 has a function calculator 331 and a comparator 332.
The function calculator 331 receives a temperature measurement value of the high temperature portion of the gas turbine 1. The high temperature part here is a part to be cooled of the gas turbine 1 cooled by the bleed air from the compressor 3, and particularly a part to be cooled that should be prioritized over ensuring the fuel-air ratio at the time of load interruption. There may be. For example, the high temperature part is a turbine blade. In this case, the temperature measurement value of the high temperature part may be a temperature correlated with the blade temperature of the turbine 5. Examples of the temperature having a correlation with the blade temperature include a disk cavity temperature, a blade path temperature, and an exhaust gas temperature. Then, the function calculator 331 calculates the required opening of the regulating valve 10 corresponding to the temperature measurement value of the high temperature part, that is, the required opening of the regulating valve 10 capable of supplying the cooling air required for cooling the high temperature part. To do.
When the load control command is detected, the comparator 332 compares the opening degree of the adjusting valve 10 input from the switch 312 described above with the required opening degree of the adjusting valve 10 input from the function calculator 331, and The smallest opening is output. In the comparator 332, the corrected opening degree output from the multiplier 322 shown in FIG. 5 may be input instead of the opening degree input from the switch 312.

  According to the above configuration, the air flow necessary for cooling the high temperature part (for example, cooling of the turbine blades), which is one of the most prioritized matters in the operation of the gas turbine 1, is secured, and the risk of overspeed and misfire. Can be reduced.

In the embodiment described above, the adjustment valve 10 whose opening degree is controlled may be the circulation valve 11 already described in FIG. 1 or at least one of the at least one extraction valves 12a to 12c.
In a typical gas turbine plant, for example, a circulation valve 10 for adjusting the return amount of the extracted air to the suction side of the compressor 3 in order to prevent a surge of the compressor 3, Some of them are provided with extraction valves 12a to 12c for adjusting the amount of extraction for cooling.
Therefore, by using the circulation valve 11 and the bleed valves 12a to 12c that are typically provided in the gas turbine plant as the regulating valve 10 used to achieve both over-rotation prevention and misfire prevention at the time of load interruption, The configuration of the above-described embodiment can be easily applied to an existing gas turbine plant.

FIG. 7 is a diagram for explaining the opening / closing timing and the opening degree of each regulating valve 10.
With reference to FIG.1 and FIG.7, the control apparatus 30 which concerns on one Embodiment is comprised so that the opening / closing timing and opening degree of each of the some regulating valve 10 may be controlled independently of the other regulating valve 10. FIG. May be.
As shown in FIG. 1, when a circulation valve 11 and a plurality of extraction valves 12 a to 12 c are used as the regulating valve 10, a valve opening determination criterion is individually provided, and the opening / closing timing and opening of each valve can be controlled. To do. For example, as shown in FIG. 7, the cooling requirement is more severe in the high pressure system, so that the opening time of the high pressure extraction valve 12a may be shortened and the flow rate of the cooling air may be increased. Alternatively, the intermediate pressure bleed valve 12b may be opened at the timing when the high pressure bleed valve 12a is closed, and then the low pressure bleed valve 12c may be opened. Further, the circulation valve 11, the high pressure bleed valve 12a, and the intermediate pressure bleed valve 12b may be closed after a predetermined time has elapsed, and the low pressure bleed valve 12c may be kept open.

  According to the above configuration, when a plurality of regulating valves 10 are provided, the opening / closing timing and the opening degree of each regulating valve 10 are controlled independently from the other regulating valves 10. The influence of the response on the operation of the gas turbine 1 can be minimized.

As illustrated in FIG. 1, a gas turbine 1 according to some embodiments includes a compressor 3, a combustor 4, a turbine 5, and a regulating valve 10 (for example, a circulation valve 11 or extraction valves 12 a to 12 c). And the control device 30 described in any of the above-described embodiments.
With this configuration, misfire in the combustor 4 can be prevented while suppressing overspeed, and the opening control of the regulating valve 10 can be appropriately performed according to the risk of overspeed of the gas turbine 1. Since the control apparatus 30 is provided, the gas turbine 1 with high reliability can be provided.

Next, a method for controlling the gas turbine 1 according to some embodiments will be described with reference to FIG. Note that the configuration of the gas turbine 1 is the same as the configuration described above, and is omitted.
In the control method of the gas turbine 1 according to some embodiments, when the load of the gas turbine 1 is cut off, the adjustment valve 10 is opened, and the opening degree of the adjustment valve 10 is set based on the output index immediately before the load interruption of the gas turbine 1. Control.
In this method, when the load of the gas turbine 1 is interrupted, the opening degree of the regulating valve 10 may be increased as the output index increases.

According to the above method, the fuel-air ratio in the combustor 4 can be increased without increasing the amount of fuel input to the combustor 4 by opening the regulating valve 10 when the load of the gas turbine 1 is shut off, and the overspeed It is possible to prevent misfire in the combustor 4 while suppressing the above.
Further, by controlling the opening degree of the regulating valve 10 based on the output index immediately before the load interruption of the gas turbine 1, the opening degree control of the regulating valve 10 is appropriately performed according to the risk of over-rotation of the gas turbine 1. It can be carried out.

The control method of the gas turbine 1 which concerns on one Embodiment is the adjustment valve calculated by the step which calculates the opening degree of the adjustment valve 10 according to an output parameter | index at the time of load interruption of the gas turbine 1, and the step which calculates an opening degree And a step of correcting the opening degree of 10 by the atmospheric temperature.
According to this method, the opening calculated in accordance with the output index is corrected by the atmospheric temperature, so that the extraction air having a desired mass flow rate corresponding to the over-rotation risk is discharged from the compressor 3 regardless of the atmospheric temperature. can do.

The control method of the gas turbine 1 which concerns on other embodiment is the opening degree of the regulating valve 10 determined based on the required opening degree of the regulating valve 10 corresponding to the temperature measurement value of the high temperature part of the gas turbine 1, and the output index. And a step of selecting a minimum opening degree.
According to this method, the air flow rate necessary for cooling the high temperature part (for example, cooling of the turbine blades), which is one of the most prioritized matters in the operation of the gas turbine 1, is secured, and the risk of over-rotation and misfire. Can be reduced.

In any of the above-described embodiments, the opening / closing timing and the opening degree of each of the plurality of regulating valves 10 may be controlled independently of the other regulating valves 10.
According to this method, when a plurality of regulating valves 10 are provided, the opening / closing timing and the opening degree of each regulating valve 10 are controlled independently of the other regulating valves 10. The influence of the response on the operation of the gas turbine 1 can be minimized.

As described above, according to at least some embodiments of the present invention, the flow rate of the bleed air from the compressor 3 is increased by opening the regulating valve 10 when the load of the gas turbine 1 is shut off. The flow rate of the compressed air supplied to is reduced. Thereby, the fuel-air ratio in the combustor 4 becomes high, and misfire in the combustor 4 can be prevented while suppressing excessive rotation.
Moreover, since the opening degree of the regulating valve 10 is controlled based on an index correlated with the gas turbine output immediately before the load interruption of the gas turbine 1, the adjustment is made according to the magnitude of the risk of over-rotation of the gas turbine 1. The opening degree control of the valve 10 can be appropriately performed.

The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.
For example, in the above-described embodiment, the gas turbine 1 used for power generation in a power generation gas turbine plant or the like has been specifically described. However, the use of the gas turbine 1 is not limited to this, and may be applied to other plants. It may be applied or it may be operated by a gas turbine alone.

For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expression “comprising”, “including”, or “having” one constituent element is not an exclusive expression that excludes the presence of the other constituent elements.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Inlet guide vane 3 Compressor 4 Combustor 5 Turbine 6 Exhaust gas duct 10 Regulating valve 11 Circulation valve 12 Extraction valve 12a High pressure extraction valve 12b Medium pressure extraction valve 12c Low pressure extraction valve 20 Extraction line 20a High pressure extraction line 20b Medium pressure Extraction line 20c Low pressure extraction line 21 Cooling line 21a High pressure cooling line 21b Medium pressure cooling line 21c Low pressure cooling line 22 (22a-22c) Orifice 23 Circulation line 24 Exhaust line 24a High pressure exhaust line 24b Medium pressure exhaust line 24c Low pressure exhaust line 30 Control Device 31 Valve opening calculation unit 32 Valve opening correction unit 33 Minimum opening selection unit 34 Valve opening command output unit

Claims (15)

A compressor for generating compressed air; a combustor for generating combustion gas by burning fuel using the compressed air; a turbine configured to be driven by the combustion gas; and the compression A control valve for adjusting the flow rate of the extraction air extracted from the machine, and a control device for the gas turbine,
When the load of the gas turbine is cut off, the adjustment valve is opened, and the opening degree of the adjustment valve is controlled based on an index correlated with the output of the gas turbine immediately before the load cut off of the gas turbine. A control device for a gas turbine.   2. The gas turbine control device according to claim 1, wherein when the load of the gas turbine is interrupted, the opening degree of the regulating valve is increased as the index increases.   3. The index is an output of the gas turbine immediately before a load interruption of the gas turbine or an opening degree of an inlet guide blade of the compressor immediately before the load interruption of the gas turbine. The control apparatus of the gas turbine described in 2. A valve opening calculation unit that calculates the opening of the adjustment valve according to the index when the load of the gas turbine is interrupted;
The valve opening degree correction | amendment part comprised so that the said opening degree calculated by the said valve opening degree calculation part was correct | amended by atmospheric temperature, It is provided with any one of Claim 1 thru | or 3 characterized by the above-mentioned. Gas turbine control device.   The minimum opening degree is selected from the required opening degree of the regulating valve corresponding to the temperature measurement value of the high temperature part of the gas turbine and the opening degree of the regulating valve determined based on the index. The gas turbine control device according to any one of claims 1 to 4, further comprising a minimum opening selection unit.   The regulating valve is a circulation valve provided in a circulation line for returning the extracted air to the intake side of the compressor, or at least for adjusting a supply amount of the extracted air from the compressor to the turbine The control device for a gas turbine according to any one of claims 1 to 5, wherein the control device is at least one of a single bleed valve.   The gas turbine according to any one of claims 1 to 6, wherein each of the plurality of regulating valves is configured to control the opening / closing timing and the opening degree independently of other regulating valves. Control device. A compressor for generating compressed air;
A combustor for combusting fuel using the compressed air to generate combustion gas;
A turbine configured to be driven by the combustion gas;
An adjustment valve for adjusting the flow rate of the extracted air extracted from the compressor;
The control device according to any one of claims 1 to 7, which is configured to control an opening degree of the regulating valve;
A gas turbine comprising: A compressor for generating compressed air; a combustor for generating combustion gas by burning fuel using the compressed air; a turbine configured to be driven by the combustion gas; and the compression A control method for a gas turbine comprising: an adjustment valve for adjusting a flow rate of the extraction air extracted from the machine,
When the load of the gas turbine is cut off, the adjustment valve is opened, and the opening of the adjustment valve is controlled based on an index correlated with the output of the gas turbine immediately before the load interruption of the gas turbine. Gas turbine control method.   The gas turbine control method according to claim 9, wherein when the load of the gas turbine is interrupted, the opening degree of the regulating valve is increased as the index increases.   The index is an output of the gas turbine immediately before a load interruption of the gas turbine or an opening degree of an inlet guide blade of the compressor immediately before the load interruption of the gas turbine. The control method of the gas turbine as described in Claim 1. Calculating the opening of the regulating valve according to the index when the gas turbine is shut off from the load;
Correcting the opening of the regulating valve calculated in the step of calculating the opening by the atmospheric temperature;
The method for controlling a gas turbine according to any one of claims 9 to 11, further comprising:   Selecting a minimum opening among the required opening of the regulating valve corresponding to the temperature measurement value of the high temperature part of the gas turbine and the opening of the regulating valve determined based on the index. The method for controlling a gas turbine according to any one of claims 9 to 12, wherein:   The regulating valve is a circulation valve provided in a circulation line for returning the extracted air to the intake side of the compressor, or at least for adjusting a supply amount of the extracted air from the compressor to the turbine The gas turbine control method according to any one of claims 9 to 13, wherein the control method is at least one of one bleed valve.   The method for controlling a gas turbine according to any one of claims 9 to 14, wherein the opening / closing timing and the opening degree of each of the plurality of regulating valves are controlled independently of the other regulating valves.

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