Gas turbine system and extraction control method thereof

Abstract

To stably operate a gas turbine and a turbine which can be driven by air extracted from the gas turbine.SOLUTION: The gas turbine system includes a gas turbine, an extraction line capable of extracting a part of compressed air generated by a compressor of the gas turbine from the gas turbine as extraction air, an exhaust line branching from a middle of the extraction line, an auxiliary turbine capable of being driven by the extraction air flowing through the extraction line, an extraction amount adjustment valve provided in the extraction line and capable of adjusting a flow rate of the extraction air extracted from the gas turbine, an inflow amount adjustment valve provided in the extraction line and capable of adjusting a flow rate of the extraction air flowing into the auxiliary turbine, and an exhaust amount adjustment valve provided in the exhaust line and capable of adjusting a flow rate of the extraction air exhausted from the extraction line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gas turbine system including a gas turbine and a method for controlling bleed air therein. [Background technology]

[0002] A gas turbine includes a compressor that compresses air, a combustor that burns fuel in the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas.

[0003] Patent Document 1 below discloses a technique for reducing the output of a gas turbine. In this technique, when reducing the output of a gas turbine, a portion of the air compressed by the compressor is bled from the gas turbine to reduce the amount of air supplied to the combustor. The high-pressure air bled from the gas turbine is sent to an air expansion turbine via an extraction line. This air expansion turbine is connected to a mechanical load. An extraction line connects the gas turbine and the air expansion turbine. A branch line extending from a low-pressure secondary pressure source is connected to this extraction line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2023 / 0228213 Summary of the Invention [Problem to be solved by the invention]

[0005] It is desirable to be able to operate the gas turbine, and any turbines that can be driven by air extracted from the gas turbine, in a stable manner even when the gas turbine's output is reduced.

[0006] Therefore, an object of the present disclosure is to provide a technology that enables stable operation of a gas turbine and a turbine that can be driven by air extracted from a gas turbine, even when the output of the gas turbine is reduced. [Means for solving the problem]

[0007] One aspect of a gas turbine system for achieving the above object is to provide: a gas turbine having a compressor capable of compressing air, a combustor capable of burning fuel in compressed air compressed by the compressor to generate combustion gas, and a turbine capable of driving the combustion gas; a bleed air line capable of bleeding part of the compressed air generated by the compressor from the gas turbine as bleed air; an exhaust line branching from the bleed air line to discharge part of the bleed air that has flowed into the bleed air line; an auxiliary turbine connected to the bleed air line and driven by the bleed air that has flowed through the bleed air line; a bleed air amount control valve provided in the bleed air line and capable of adjusting the bleed air amount, which is the flow rate of the bleed air bled from the gas turbine; an inflow amount control valve provided in the bleed air line and capable of adjusting the inflow amount, which is the flow rate of the bleed air that flows into the auxiliary turbine; and an exhaust amount control valve provided in the exhaust line and capable of adjusting the exhaust amount, which is the flow rate of the bleed air discharged from the bleed air line.

[0008] In this aspect, by opening the extraction air amount control valve, a portion of the compressed air generated by the compressor is extracted as extraction air from the gas turbine. Therefore, in this aspect, the flow rate of the compressed air flowing into the combustor can be made smaller than the minimum intake air flow rate of the gas turbine. In order to achieve stable combustion of the fuel, fuel is supplied to the combustor in accordance with the flow rate of the compressed air flowing into the combustor. Therefore, in this aspect, the flow rate of the combustion gas flowing from the combustor into the turbine can be made smaller while still achieving stable combustion of the fuel. As a result, in this aspect, even if the externally required output is smaller than the output corresponding to the minimum intake air flow rate of the gas turbine, this required output can be met.

[0009] Furthermore, in this aspect, by adjusting the aperture of the extraction air amount control valve, the aperture of the inflow amount control valve, and the aperture of the exhaust amount control valve, it is possible to maintain a constant extraction air amount, which is the flow rate of extraction air extracted from the gas turbine, while appropriately adjusting the flow rate of the extraction air flowing into the auxiliary turbine. Therefore, in this aspect, the gas turbine and the auxiliary turbine can be operated stably even when the output of the gas turbine is reduced.

[0010] A method for controlling bleed air from a gas turbine system as one aspect for achieving the above object is applied to the following gas turbine system. This gas turbine system includes a gas turbine having a compressor capable of compressing air, a combustor capable of burning fuel in the compressed air compressed by the compressor to generate combustion gas, and a turbine capable of driving the combustion gas; an extraction line capable of extracting a portion of the compressed air generated by the compressor as extraction air from the gas turbine; an exhaust line branching off from the extraction line midway and capable of discharging a portion of the extraction air that has flowed into the extraction line; and an auxiliary turbine connected to the extraction line and capable of driving the extraction air that has flowed through the extraction line. In this method for controlling bleed air for a gas turbine system, a bleed air control process is carried out to adjust an bleed air volume, which is the flow rate of the bleed air bled from the gas turbine, an inflow volume, which is the flow rate of the bleed air flowing into the auxiliary turbine, and an exhaust volume, which is the flow rate of the bleed air exhausted from the bleed air line.

[0011] In this aspect, similar to the gas turbine system of the first aspect, by opening the extraction air amount control valve, it is possible to respond to an externally required output even if the required output is smaller than the output corresponding to the minimum intake air flow rate of the gas turbine.

[0012] Furthermore, in this aspect, by adjusting the aperture of the extraction air amount control valve, the aperture of the inflow amount control valve, and the aperture of the exhaust amount control valve, it is possible to maintain a constant extraction air amount, which is the flow rate of extraction air extracted from the gas turbine, while appropriately adjusting the flow rate of the extraction air flowing into the auxiliary turbine. Therefore, in this aspect as well, the gas turbine and auxiliary turbine can be operated stably even when the output of the gas turbine is reduced. [Effects of the Invention]

[0013] In one aspect of the present disclosure, even when the output of the gas turbine is reduced, the gas turbine and a turbine that can be driven by air extracted from the gas turbine can be operated stably. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a system diagram of a gas turbine system according to an embodiment of the present disclosure. FIG. [Figure 2] 4 is a graph showing a relationship between an actual output of a gas turbine and an IGV opening degree in an embodiment according to the present disclosure. [Figure 3] 3 is a flowchart illustrating the overall operation of a gas turbine system in one embodiment according to the present disclosure. [Figure 4] 4 is a flowchart showing details of a bleed air control process in one embodiment according to the present disclosure. [Figure 5] 10 is a time chart showing changes in the actual output of the gas turbine, the actual output of the auxiliary turbine, the rotation speed of the auxiliary turbine, the opening of the extraction amount control valve, the opening of the exhaust amount control valve, and the opening of the inflow amount control valve during an extraction control process in an embodiment according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of a gas turbine system according to the present disclosure will be described with reference to the drawings.

[0016] "Gas Turbine System Embodiment" Hereinafter, an embodiment of a gas turbine system according to the present disclosure will be described with reference to FIGS.

[0017] 1, the gas turbine system in this embodiment includes a gas turbine 1, a waste heat utilization facility 20 that can utilize the heat of exhaust gas discharged from the gas turbine 1, a gas turbine generator 6 that can generate electricity by driving the gas turbine 1, an air extraction device 30 that can extract part of the air inside the gas turbine 1 to the outside, an auxiliary power generation facility 40, a power system facility 50, and a control device 100. In other words, the gas turbine system in this embodiment is a gas turbine power plant.

[0018] The gas turbine 1 includes a compressor 10 capable of compressing air A, a combustor 15 capable of generating combustion gas by burning fuel F in the compressed air compressed by the compressor 10, a fuel valve 5, a turbine 16 capable of being driven by the high-temperature, high-pressure combustion gas, and an intermediate casing 3.

[0019] The compressor 10 has a compressor rotor 11 that rotates about a rotor axis Ar, a compressor casing 12 that covers the compressor rotor 11, and an intake air amount regulator 13. Here, the direction in which the rotor axis Ar extends is referred to as the axial direction Da, and one side of this axial direction Da is referred to as the axial upstream side Dau, and the other side is referred to as the axial downstream side Dad.

[0020] The compressor rotor 11 has a compressor rotor shaft 11s that extends in the axial direction Da centered on the rotor axis Ar, and a plurality of rotor blade rows 11b fixed to the compressor rotor shaft 11s. The plurality of rotor blade rows 11b are aligned in the axial direction Da. Each of the plurality of rotor blade rows 11b has a plurality of rotor blades aligned in the circumferential direction about the rotor axis Ar. The intake air amount regulator 13 has a plurality of inlet guide vanes (IGVs) 13v that are arranged inside the compressor casing 12 and on the axial upstream side Dau of the plurality of rotor blade rows 11b, and a driver 13d that can change the orientation of each inlet guide vane 13v.

[0021] The turbine 16 is disposed on the axial downstream side Dad of the compressor 10. The turbine 16 has a turbine rotor 17 that rotates about a rotor axis Ar by combustion gas from the combustor 15, and a turbine casing 18 that covers the turbine rotor 17.

[0022] The turbine rotor 17 has a turbine rotor shaft 17s that extends in the axial direction Da centered on the rotor axis Ar, and a plurality of rotor blade rows 17b fixed to the turbine rotor shaft 17s. The plurality of rotor blade rows 17b are aligned in the axial direction Da. Each of the plurality of rotor blade rows 17b has a plurality of rotor blades aligned in the circumferential direction with respect to the rotor axis Ar.

[0023] The turbine rotor 17 and the compressor rotor 11 are connected to each other so as to be rotatable together about the same rotor axis Ar, thereby forming a gas turbine rotor 2. To this gas turbine rotor 2, a rotor of a gas turbine generator 6 is connected.

[0024] The intermediate casing 3 is disposed between the compressor casing 12 and the turbine casing 18 in the axial direction Da, and connects the compressor casing 12 and the turbine casing 18. Compressed air discharged from the compressor 10 flows into the intermediate casing 3. The combustor 15 is fixed to the intermediate casing 3. A fuel line 4 is connected to the combustor 15. The fuel line 4 is provided with the aforementioned fuel valve 5 that adjusts the flow rate of the fuel F flowing through the fuel line 4.

[0025] The waste heat utilization facility 20 includes a heat recovery boiler 21, a chimney 22, a steam turbine 23 that can be driven by steam from the heat recovery boiler 21, a main steam line 24 that can guide the steam generated in the heat recovery boiler 21 to the steam turbine 23, a condenser 25 that can convert the steam exhausted from the steam turbine 23 back into water, a feedwater line 26 that can guide the water in the condenser 25 to the heat recovery boiler 21, and a feedwater pump 27 provided in the feedwater line 26. A driven object that can be rotated by the rotation of the rotor is connected to the rotor of the steam turbine 23. Examples of the driven object include the rotor of the gas turbine generator 6, the rotor of a steam turbine generator independent of the gas turbine generator 6, and the impeller of a pump.

[0026] The heat recovery boiler 21 can generate steam by evaporating water using the heat of exhaust gas, which is combustion gas discharged from the turbine 16. The heat recovery boiler 21 has a duct 21d connected to the turbine casing 18 and a heat transfer tube 21t arranged in the duct 21d. Exhaust gas from the turbine 16 flows through the duct 21d. Liquid water or gaseous water flows through the heat transfer tube 21t. One end of the heat transfer tube 21t forms a water inlet and is connected to the water supply line 26. The other end of the heat transfer tube 21t forms a steam outlet and is connected to the main steam line 24. The chimney 22 is connected to the duct 21d of the heat recovery boiler 21.

[0027] The extraction device 30 includes an extraction line 31 , an exhaust line 32 , an auxiliary turbine 37 , an extraction amount control valve 33 , an inflow amount control valve 34 , and an exhaust amount control valve 35 .

[0028] The extraction line 31 is a line that can extract part of the compressed air generated by the compressor 10 as extraction air from the gas turbine 1. The exhaust line 32 is a line that branches off from the extraction line 31 midway and can exhaust part of the extraction air that has flowed into the extraction line 31.

[0029] The auxiliary turbine 37 has a rotatable auxiliary turbine rotor 38 and an auxiliary turbine casing 39 that covers the auxiliary turbine rotor 38. One end of the extraction line 31 is connected to the intermediate casing 3 of the gas turbine 1. The other end of the extraction line 31 is connected to the auxiliary turbine casing 39. Thus, part of the compressed air that has flowed into the intermediate casing 3 via the extraction line 31 can flow into the auxiliary turbine casing 39 as extraction air. The auxiliary turbine rotor 38 rotates by the extraction air that has flowed into the auxiliary turbine casing 39.

[0030] The extraction air amount control valve 33 is provided in the extraction line 31 at a position closer to the gas turbine 1 than the branching position of the exhaust line 32. The extraction air amount control valve 33 is capable of adjusting the extraction air amount, which is the flow rate of air extracted from the gas turbine 1. The inflow amount control valve 34 is provided in the extraction line 31 at a position closer to the auxiliary turbine 37 than the branching position of the exhaust line 32. The inflow amount control valve 34 is capable of adjusting the inflow amount, which is the flow rate of extracted air flowing into the auxiliary turbine 37. The exhaust amount control valve 35 is provided in the exhaust line 32. The exhaust amount control valve 35 is capable of adjusting the exhaust amount, which is the flow rate of extracted air exhausted from the extraction line 31.

[0031] The auxiliary power generating facility 40 includes a transmission 42 , a clutch 43 , an auxiliary generator 41 , and an electricity storage device 45 .

[0032] The transmission 42 is a reducer having an input shaft, an output shaft, and a reduction mechanism that reduces the rotational speed of the input shaft and transmits it to the output shaft. The input shaft of the transmission 42 is connected to the auxiliary turbine rotor 38. The clutch 43 has an input shaft, an output shaft, and a clutch mechanism provided between the input shaft and the output shaft. The clutch mechanism can change the connection state between the input shaft and the output shaft between a transmission state in which driving force from the input shaft is transmitted to the output shaft and a disconnected state in which driving force from the input shaft is not transmitted to the output shaft. The input shaft of the clutch 43 is connected to the output shaft of the transmission 42. The output shaft of the clutch 43 is connected to the rotor of the auxiliary generator 41. As described above, the rotor of the auxiliary generator 41 is mechanically connected to the auxiliary turbine rotor 38 via the transmission 42 and the clutch 43. Therefore, the auxiliary generator 41 is a generator that can generate electricity by driving the auxiliary turbine 37.

[0033] In this embodiment, the auxiliary generator 41 and the gas turbine generator 6 are both synchronous generators.

[0034] The power storage device 45 has a storage battery 46 and an AC / DC converter 47. The AC / DC converter 47 can convert AC power from an external source into DC power and send it to the storage battery 46, and can also convert DC power from the storage battery 46 into AC power and send it to the outside.

[0035] The power system equipment 50 includes a GT generator dedicated power line 51g, an AT generator dedicated power line 51a, a BESS dedicated power line 51b, an in-plant shared power line 51p, an external connection power line 51c, multiple transformers 53a, 53b, 53c, and 53g, and multiple switches 54a, 54b, 54c, and 54g. The GT generator dedicated power line 51g is electrically connected at one end to the gas turbine generator 6 and at the other end to the in-plant shared power line 51p. The AT generator dedicated power line 51a is electrically connected at one end to the auxiliary generator 41 and at the other end to the in-plant shared power line 51p. The BESS dedicated power line 51b is electrically connected at one end to the power storage device 45 and at the other end to the in-plant shared power line 51p. The external connection power line 51c electrically connects the in-plant shared power line 51p to an external power system 60.

[0036] To compensate for fluctuations in the amount of power generated by power generation facilities that use renewable energy such as solar power and wind power, a power storage device 65 is connected to the external power system 60. This power storage device 65 also has a storage battery 66 and an AC / DC converter 67, similar to the power storage device 45 provided in the gas turbine system (gas turbine power generation plant) of this embodiment.

[0037] A transformer 53g and a switch 54g are provided on the GT generator-dedicated power line 51g. Furthermore, a power meter 55 is connected to the GT generator-dedicated power line 51g to detect the amount of power generated by the gas turbine generator 6, in other words, the actual output PWr of the gas turbine 1. A transformer 53a and a switch 54a are provided on the AT generator-dedicated power line 51a. A transformer 53b and a switch 54b are provided on the BESS-dedicated power line 51b. A transformer 53c and a switch 54c are also provided on the external connection power line 51c. Each of the switches 54a, 54b, 54c, and 54g has a first terminal, a second terminal, and a switching mechanism. The switching mechanism can change the connection state between the first terminal and the second terminal between an ON state in which the first terminal and the second terminal are electrically connected and an OFF state in which the first terminal and the second terminal are not electrically connected. Therefore, for example, the switch 54a provided on the power line 51a dedicated to the AT generator can realize an ON state in which the auxiliary generator 41 is electrically connected to the other power lines 51g, 51b, 51c, and 51p that make up the power system, and an OFF state in which the auxiliary generator 41 is not electrically connected to the other power lines 51g, 51b, 51c, and 51p that make up the power system.

[0038] The control device 100 includes a main controller 101 , a fuel controller 102 , an IGV controller 103 , a bleed controller 104 , and an opening / closing controller 105 .

[0039] The main controller 101 receives various instructions regarding the plant, including the required power PWc required of the gas turbine 1 from the outside, and the actual power PWr detected by the power meter 55, and controls the other controllers.

[0040] The fuel controller 102 receives the required output PWc and the actual output PWr from the main controller 101, determines the opening of the fuel valve 5 according to the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 to this opening. A change in the flow rate of fuel supplied to the combustor 15 is positively correlated with a change in the opening of the fuel valve 5. Furthermore, a change in the opening of the fuel valve 5 is positively correlated with a change in the required output PWc. Therefore, a change in the flow rate of fuel supplied to the combustor 15 is positively correlated with a change in the required output PWc. Therefore, as the required output PWc increases, the flow rate of fuel supplied to the combustor 15 increases, and as the required output PWc decreases, the flow rate of fuel supplied to the combustor 15 decreases.

[0041] The IGV controller 103 receives the actual output PWr from the main controller 101, determines the IGV opening θ according to this actual output PWr, and instructs the intake air regulator 13 of this IGV opening θ. As shown in FIG. 2, when the actual output PWr is between the intermediate output PWmid and the rated output PWrad, changes in the IGV opening θ have a positive correlation with changes in the actual output PWr. Therefore, as the actual output PWr increases, the IGV opening θ also increases, and as the actual output PWr decreases, the IGV opening θ also decreases. When the actual output PWr is the intermediate output PWmid, the IGV opening θ is at its minimum opening θmin, and when the actual output PWr is the rated output PWrad, the IGV opening θ is at its maximum opening θmax. Therefore, it can be said that the intermediate output PWmid is the maximum actual output PWr when the IGV opening θ is at its minimum opening θmin.

[0042] The bleed air controller 104 receives the actual output PWr from the main controller 101, and controls the aperture of the bleed air amount control valve 33, the aperture of the inflow amount control valve 34, and the aperture of the exhaust amount control valve 35 depending on whether or not this actual output PWr satisfies the bleed air condition. Here, the bleed air condition is that the actual output PWr detected by the power meter 55 is equal to or less than a predetermined bleed air output PWbl. Here, the bleed air output PWbl is a pressure less than the aforementioned intermediate output PWmid, as shown in FIG. 2. When the bleed air controller 104 determines that the actual output PWr detected by the power meter 55 satisfies the bleed air condition, in other words, that the actual output PWr is equal to or less than the bleed air output PWbl, the bleed air controller 104 starts controlling the aperture of the bleed air amount control valve 33, the aperture of the inflow amount control valve 34, and the aperture of the exhaust amount control valve 35.

[0043] The switching controller 105 controls the switches 54a, 54b, 54c, and 54g. When an emergency that is inconvenient for the gas turbine system (gas turbine power plant) occurs, the switching controller 105 instructs the switches 54a, 54b, 54c, and 54g corresponding to the emergency to be turned off. Furthermore, the switching controller 105 instructs the switch 54b provided on the BESS-dedicated power line 51b to be turned on or off depending on whether the extraction air amount control valve 33 is open or closed and on the discharge condition described below. The switching controller 105 instructs the switch 54b to be turned on when the discharge condition is met and the extraction air amount control valve 33 is open. Furthermore, the switching controller 105 instructs the switch 54b to be turned off when the discharge condition is not met and the extraction air amount control valve 33 is not open.

[0044] Next, the operation of the gas turbine system will be described with reference to the flowchart shown in FIG.

[0045] First, the main controller 101 determines whether to execute main power generation, which involves driving the gas turbine 1 and causing the gas turbine generator 6 to generate electricity (main power generation execution determination step S1). When the main controller 101 determines to execute main power generation, it instructs the fuel controller 102 and the IGV controller 103 to execute the main power generation step S2.

[0046] This main power generation process S2 includes a fuel control process S2a in which the fuel controller 102 controls the fuel flow rate, and an IGV control process S2b in which the IGV controller 103 controls the intake air flow rate of the gas turbine 1.

[0047] In the fuel control process S2a, the fuel controller 102 receives the required output PWc from the outside and the actual output PWr detected by the power meter 55. The fuel controller 102 determines the opening degree of the fuel valve 5 according to the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 to determine the opening degree. Therefore, as described above, the flow rate of fuel supplied to the combustor 15 basically has a value that has a positive correlation with the required output PWc. When the required output PWc is equal to or less than the rated output PWrad, fuel commensurate with the required output PWc is supplied to the combustor 15. However, when the required output PWc is greater than the rated output PWrad, fuel commensurate with the required output PWc is not supplied to the combustor 15, but fuel commensurate with the rated output PWrad is supplied to the combustor 15, from the viewpoint of protecting the combustor 15 and the turbine 16. Therefore, the output of the gas turbine 1 basically does not exceed the rated output PWrad.

[0048] In the IGV control step S2b, the IGV controller 103 receives the actual output PWr detected by the power meter 55. The IGV controller 103 determines the IGV opening θ according to the actual output PWr and notifies the intake air regulator 13 of the IGV opening θ (IGV control step S2b). In this case, as described above with reference to FIG. 2, the IGV opening θ assumes a value that has a positive correlation with the actual output PWr. However, when the actual output PWr is equal to or less than the intermediate output PWmid, the IGV opening θ is maintained at the minimum opening θmin, and when the actual output PWr is equal to the rated output PWrad, the IGV opening θ is maintained at the maximum opening θmax. Therefore, when the actual output PWr is equal to or less than the intermediate output PWmid, the intake air flow rate of the gas turbine 1 is maintained at the minimum flow rate, and when the actual output PWr is equal to the rated output PWrad, the intake air flow rate of the gas turbine 1 is maintained at the maximum flow rate.

[0049] By executing the fuel control process S2a and the IGV control process S2b described above, the gas turbine 1 is driven and the gas turbine generator 6 generates electricity.

[0050] If the externally required output PWc is equal to or less than the rated output PWrad and greater than the extraction steam output PWbl, the extraction steam amount control valve 33 is closed, the inflow amount control valve 34 is closed, and the exhaust amount control valve 35 is closed. Furthermore, in this case, a switch 54g provided on the GT generator-dedicated power line 51g is in the ON state, a switch 54a provided on the AT generator-dedicated power line 51a is in the OFF state, and a switch 54c provided on the external connection power line 51c is in the ON state. In this case, the gas turbine generator 6 supplies an actual output PWr corresponding to the required output PWc to the external power system 60. Furthermore, because the extraction steam amount control valve 33 is closed, compressed air in the intermediate casing 3 is not supplied to the auxiliary turbine 37 via the extraction steam line 31, and the auxiliary turbine 37 is not driven. Furthermore, because the switch 54b provided on the BESS-dedicated power line 51b is in the OFF state, no power is input or output to or from the power storage device 45. That is, the power storage device 45 is not charged with power and is not discharged.

[0051] The bleed air controller 104 determines whether or not the bleed condition for bleeding a portion of the compressed air in the intermediate casing 3 as bleed air is satisfied (bleed air condition determination step S3). As described above, the bleed air condition is that the actual output PWr detected by the power meter 55 is equal to or less than the bleed air output PWbl. If the bleed air controller 104 determines that the bleed air condition is satisfied, it executes the bleed air control step S4. In this bleed air control step S4, the bleed air controller 104 controls the aperture of the bleed air amount adjustment valve 33, the aperture of the inflow amount adjustment valve 34, and the aperture of the exhaust amount adjustment valve 35, so that a portion of the compressed air in the intermediate casing 3 is bled as bleed air. This bleed air control step S4 is continuously executed until the bleed air cancellation step S9, which will be described later, is executed. The bleed air control step S4 will be described in detail later.

[0052] When the bleed air control step S4 is started, bleed air is supplied to the auxiliary turbine 37, and the auxiliary turbine 37 starts to be driven by the inflow of this bleed air.

[0053] When the auxiliary turbine 37 starts to operate, the switching controller 105 determines whether a parallel connection condition for the auxiliary generator 41 is satisfied (parallel connection condition determination step S5). This parallel connection condition is whether the rotation speed of the auxiliary generator 41 has become equal to a predetermined rated rotation speed. Note that "the rotation speed of the auxiliary generator 41 is equal to the rated rotation speed" not only means that the rotation speed of the auxiliary generator 41 is exactly equal to the rated rotation speed, but also includes a case where the rotation speed of the auxiliary generator 41 is within a range of, for example, ±3% of the rated rotation speed. When the switching controller 105 determines that the parallel connection condition is satisfied, in other words, that the rotation speed of the auxiliary generator 41 has become equal to the predetermined rated rotation speed, the switching controller 105 turns on the switch 54a provided on the AT generator-dedicated power line 51a. In other words, the parallel connection step S6 is executed.

[0054] When the switching controller 105 turns on the switch 54a provided on the AT generator dedicated power line 51a, it also turns on the switch 54b provided on the BESS dedicated power line 51b. As a result, the auxiliary generator 41 and the power storage device 45 are electrically connected, and the power generated by the auxiliary generator 41 is charged to the power storage device 45 (charging step S8).

[0055] If the switching controller 105 determines that the parallel-in condition is no longer satisfied during the parallel-in step S6, it turns off the switch 54a provided on the AT generator dedicated power line 51a. In other words, the parallel-out step S7 is executed. As a result, power is no longer supplied from the auxiliary generator 41 to the outside.

[0056] When the switching controller 105 turns off the switch 54a provided on the AT generator dedicated power line 51a, it also turns off the switch 54b provided on the BESS dedicated power line 51b.

[0057] It is assumed that the extraction control process S4 is not executed even when the actual output PWr is equal to or less than the extraction output PWbl. In this case, the flow rate of fuel supplied to the combustor 15 has a value that is positively correlated with the required output PWc, while the flow rate of air drawn into the compressor 10 is maintained at the flow rate when the actual output PWr is the intermediate output PWmid. Therefore, the fuel-air ratio, which is the ratio of the fuel flow rate to the air flow rate in the combustor 15, becomes smaller than when the actual output PWr is the intermediate output PWmid. When the fuel-air ratio decreases, the temperature of the combustion gas flowing from the combustor 15 into the turbine 16 decreases, and the temperature of the steam generated in the heat recovery boiler 21 decreases. As a result, the output efficiency of the exhaust heat utilization equipment 20 decreases. Furthermore, when the fuel-air ratio decreases, the combustibility of the fuel deteriorates, and in the worst case, a misfire may occur.

[0058] To reiterate, when the required output PWc becomes equal to or less than the bleed steam output PWbl, the bleed steam control step S4 is executed, and part of the compressed air in the intermediate casing 3 is bled as bleed air. As a result, the flow rate of the compressed air flowing into the combustor 15 becomes less than the minimum intake flow rate of the gas turbine 1, and fuel according to the required output PWc is supplied to the combustor 15, thereby enabling stable combustion of the fuel without excessively reducing the temperature of the combustion gas. That is, in this embodiment, the actual output PWr of the gas turbine 1 can be made equal to or less than the bleed steam output PWbl, which is less than the intermediate output PWmid, while maintaining stable operation of the gas turbine 1.

[0059] If the bleed air controller 104 determines in the bleed air condition determination step S3 that the bleed air conditions are not satisfied, the bleed air controller 104 closes the bleed air amount control valve 33, closes the inflow amount control valve 34, and closes the exhaust amount control valve 35 (bleed air stop step S9). As a result, part of the compressed air in the intermediate casing 3 is no longer bled as bleed air, and bleed air no longer flows into the auxiliary turbine 37.

[0060] Furthermore, if the extraction controller 104 determines in the extraction condition determination step S3 that the extraction condition is not satisfied, the switching controller 105 determines whether or not the discharge condition is satisfied (discharge condition determination step S10). Here, the discharge condition means that the required output PWc is equal to or greater than a discharge output PWdis that is greater than the rated output PWrad of the gas turbine 1, and that the amount of change in the required output PWc per unit time is greater than a predetermined value. If the switching controller 105 determines that the discharge condition is satisfied, it instructs the switch 54b provided on the BESS dedicated power line 51b to be turned on. As a result, the switch 54b is turned on, and the power stored in the power storage device 45 is discharged (discharge step S11).

[0061] If the switching controller 105 determines in the discharge condition determination step S10 that the discharge conditions are not met, it turns off the switch 54b provided on the BESS dedicated power line 51b, and the power stored in the storage device 45 is no longer discharged (discharge stop step S12).

[0062] Next, the details of the bleed control step S4 will be described in detail with reference to the flowchart shown in FIG.

[0063] As described above with reference to Fig. 3, when the bleeding controller 104 determines in the bleeding condition determination step S3 that the bleeding conditions for bleeding part of the compressed air in the intermediate casing 3 as bleed air are satisfied, the bleeding controller 104 executes the bleeding start step S41. In this bleeding start step S41, the bleeding controller 104 controls the aperture of the bleeding air amount control valve 33 and the aperture of the exhaust amount control valve 35 so that the bleeding amount gradually increases and the exhaust amount gradually increases as the bleeding amount increases, as shown in Fig. 5. By executing this bleeding start step S41, part of the compressed air in the intermediate casing 3 is bled as bleed air, and all of this bleed air is exhausted from the exhaust line 32. As a result, the actual power output PWr of the gas turbine 1 becomes equal to or less than the bleed power PWbl that is less than the intermediate power PWmid.

[0064] When the opening degree of the bleed air amount control valve 33 reaches a predetermined opening degree, for example, fully open, and the opening degree of the exhaust amount control valve 35 reaches a predetermined opening degree, for example, fully open, this bleed start step S41 ends.

[0065] When the extraction start step S41 is completed, the extraction controller 104 executes an extraction air amount constant control step S42. In this extraction air amount constant control step S42, the extraction controller 104 controls the aperture of the extraction air amount adjustment valve 33 so as to maintain the extraction air amount constant, as shown in Fig. 5. In this case, the aperture of the extraction air amount adjustment valve 33 is maintained at the aperture at the end of the extraction start step S41, for example, fully open. As a result, the actual output of the gas turbine 1 is maintained at the output at the end of the extraction start step S41, that is, an output equal to or less than the extraction air output PWbl which is less than the intermediate output PWmid.

[0066] When the extraction start step S41 is completed, the extraction controller 104 further executes an inflow amount increasing step S43 in parallel with the extraction amount constant control step S42, as shown in Fig. 5. In this inflow amount increasing step S43, the extraction controller 104 controls the opening degree of the exhaust amount control valve 35 and the opening degree of the inflow amount control valve 34 so that the exhaust amount gradually decreases and the inflow amount gradually increases as the exhaust amount decreases, as shown in Fig. 5.

[0067] By executing this inflow amount increasing step S43, the flow rate of the bleed air flowing into the auxiliary turbine 37 gradually increases, and the rotation speed of the auxiliary turbine 37 and the rotation speed of the auxiliary generator 41 gradually increase, as shown in Fig. 5. When the rotation speed of the auxiliary generator 41 becomes equal to the predetermined rated rotation speed, the paralleling step S6 is executed as described above with reference to Fig. 3, and the power generated by the auxiliary generator 41 is charged to the power storage device 45.

[0068] If the inflow amount increasing step S43 continues to be executed even after the parallel introduction step S6 has been executed, the actual output of the auxiliary turbine 37, in other words, the actual output of the auxiliary generator 41, becomes the rated output.

[0069] When the actual output of the auxiliary generator 41 becomes the rated output, the extraction controller 104 executes an inflow rate constant control step S44 in parallel with the extraction rate constant control step S42. In this inflow rate constant control step S44, the extraction controller 104 controls the aperture of the inflow rate control valve 34 and the aperture of the exhaust rate control valve 35 so as to maintain the inflow rate constant, as shown in Fig. 5. In this case, the aperture of the inflow rate control valve 34 is maintained at the aperture when the actual output of the auxiliary generator 41 became the rated output, for example, fully open. In addition, the aperture of the exhaust rate control valve 35 is maintained at the aperture when the actual output of the auxiliary generator 41 became the rated output, for example, fully closed.

[0070] By executing this constant inflow control step S44, the actual output of the auxiliary generator 41 is maintained at the rated output.

[0071] During execution of this inflow rate constant control step S44, if the bleeding condition determination step S3 determines that the bleeding conditions for bleeding part of the compressed air in the intermediate casing 3 as bleed air are not satisfied, as described above with reference to Fig. 3, the bleeding controller 104 executes the inflow rate decreasing step S45 in parallel with the bleeding rate constant control step S42. In this inflow rate decreasing step S45, the bleeding controller 104 controls the aperture of the exhaust rate control valve 35 and the aperture of the inflow rate control valve 34 so that the exhaust rate gradually increases and the inflow rate gradually decreases as the exhaust rate increases, as shown in Fig. 5.

[0072] By executing this inflow amount reducing step S45, the flow rate of the bleed air flowing into the auxiliary turbine 37 is reduced, and the actual output of the auxiliary turbine 37, in other words, the actual output of the auxiliary generator 41, gradually decreases. Then, when the actual output of the auxiliary generator 41 decreases to a predetermined output, the parallel-off step S7 is executed as described above with reference to Fig. 3, and the auxiliary generator 41 stops generating electricity.

[0073] When the opening of the inflow amount adjustment valve 34 becomes, for example, fully closed and the opening of the exhaust amount adjustment valve 35 becomes, for example, fully open, the inflow amount becomes substantially zero, and the inflow amount reduction step S45 and the constant bleed air amount control step S42 are completed.

[0074] When the inflow amount reducing step S45 and the extraction air amount constant control step S42 are completed, the extraction air controller 104 executes the extraction air termination step S46. In this extraction air termination step S46, as shown in FIG. 5, the extraction air controller 104 controls the aperture of the extraction air amount control valve 33 and the aperture of the exhaust air amount control valve 35 so that the extraction air amount gradually decreases and the exhaust air amount gradually decreases in accordance with the decrease in the extraction air amount. By executing this extraction air termination step S46, a portion of the compressed air in the intermediate casing 3 is no longer extracted as extraction air. As a result, the actual output PWr of the gas turbine 1 becomes larger than the extraction air output PWbl. It should be noted that the extraction air termination step S9 described above with reference to FIG. 3 is a step that includes the inflow amount reducing step S45 and the extraction air termination step S46 described above.

[0075] As described above, in this embodiment, by opening the extraction air amount control valve 33, a portion of the compressed air generated by the compressor 10 is extracted as extraction air from the gas turbine 1. Therefore, in this embodiment, the flow rate of the compressed air flowing into the combustor 15 can be made smaller than the minimum intake air flow rate of the gas turbine 1. To ensure stable combustion of the fuel, fuel is supplied to the combustor 15 according to the flow rate of the compressed air flowing into the combustor 15. Therefore, in this embodiment, the flow rate of the combustion gas flowing from the combustor 15 into the turbine can be reduced while maintaining the temperature of the combustion gas, while ensuring stable combustion of the fuel. As a result, in this embodiment, even if the externally required output is smaller than the output corresponding to the minimum intake air flow rate of the gas turbine 1, this required output can be met.

[0076] Furthermore, in this embodiment, by adjusting the opening degree of the extraction air amount control valve 33, the opening degree of the inflow amount control valve 34, and the opening degree of the exhaust amount control valve 35, it is possible to appropriately adjust the flow rate of the extraction air flowing into the auxiliary turbine 37 while maintaining a constant extraction air amount, which is the flow rate of the extraction air extracted from the gas turbine 1. Therefore, in this mode, the gas turbine 1 and the auxiliary turbine 37 can be operated stably even when the output of the gas turbine 1 is reduced.

[0077] In the gas turbine 1 in which air is extracted while operating at partial load, the flow rate of compressed air and the flow rate of fuel flowing into the combustor 15 are both small, and therefore fluctuations in these flow rates have a significant effect on the combustion state. As mentioned above, in this embodiment, the amount of extracted air can be maintained constant, so that the gas turbine 1 can be operated stably while suppressing changes in the combustion state in the combustor 15, even while extracting compressed air from the gas turbine 1.

[0078] Moreover, in this embodiment, whether the inflow rate, which is the flow rate of bleed air flowing into the auxiliary turbine 37, is increased or whether the inflow rate is decreased, the bleed air rate, which is the flow rate of bleed air bled from the gas turbine 1, can be maintained constant. Moreover, in this embodiment, whether the bleed air rate, which is the flow rate of bleed air bled from the gas turbine 1, is increased or whether the bleed air rate is decreased, the inflow rate, which is the flow rate of bleed air flowing into the auxiliary turbine 37, can be maintained constant (for example, inflow rate 0).

[0079] Furthermore, in this embodiment, the inflow rate is maintained constant during the time period in which the extraction rate is maintained constant, so that the gas turbine 1 and the auxiliary turbine 37 can be operated stably.

[0080] In this embodiment, "constant extraction air volume" means that the fluctuation range of the extraction air volume is within ±10% of the maximum extraction air volume. Also, "constant inflow volume" means that the fluctuation range of the inflow volume is within ±10% of the maximum inflow volume. If the maximum extraction air volume is 10% of the intake air volume of the gas turbine 1, then "constant extraction air volume" means that the fluctuation range of the extraction air volume is within ±1% of the intake air volume of the gas turbine 1.

[0081] "Variations" The gas turbine system in the above embodiment includes the exhaust heat utilization facility 20. However, the gas turbine system does not necessarily have to include the exhaust heat utilization facility 20. Furthermore, the gas turbine system in the above embodiment includes the power storage device 45. However, the gas turbine system does not necessarily have to include the power storage device 45.

[0082] The gas turbine system in the above embodiment is a gas turbine power plant equipped with a generator. However, the gas turbine system does not have to be a gas turbine power plant. For example, the gas turbine 1 in the gas turbine system may be a drive source for a mobile object, and the auxiliary turbine 37 may be a drive source for a mechanical load equipped in the mobile object.

[0083] The control device 100 in the above embodiment has the bleed air controller 104. However, this bleed air controller 104 may be omitted. In this case, an operator or the like will adjust the opening degree of the bleed air amount control valve 33, the opening degree of the inflow amount control valve 34, and the opening degree of the exhaust amount control valve 35, respectively.

[0084] In the above-described embodiment, the bleed air amount control valve 33, the inflow amount control valve 34, and the exhaust amount control valve 35 are independent valves. However, any two or all of the bleed air amount control valve 33, the inflow amount control valve 34, and the exhaust amount control valve 35 may be configured as a single three-way valve.

[0085] Furthermore, the present disclosure is not limited to the embodiments and modifications described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents.

[0086] "Addendum" The gas turbine systems in the above-described embodiments and modifications can be understood, for example, as follows. (1) A gas turbine system according to a first aspect includes: The gas turbine 1 has a compressor 10 capable of compressing air, a combustor 15 capable of burning fuel in compressed air that is air compressed by the compressor 10 to generate combustion gas, and a turbine 16 that can be driven by the combustion gas, an extraction line 31 that can extract part of the compressed air generated by the compressor 10 as extraction air from the gas turbine 1, an exhaust line 32 that branches off from the extraction line 31 midway and can exhaust part of the extraction air that has flowed into the extraction line 31, and an exhaust line 32 that is connected to the extraction line 31 and is capable of exhausting part of the extraction air that has flowed into the extraction line 31. The gas turbine is provided with an auxiliary turbine 37 that can be driven by the bleed air that has flowed through the bleed line 31, an bleed air volume control valve 33 that is provided in the bleed line 31 and that can adjust the bleed air volume, which is the flow rate of the bleed air that is bled from the gas turbine 1, an inflow volume control valve 34 that is provided in the bleed line 31 and that can adjust the inflow volume, which is the flow rate of the bleed air that flows into the auxiliary turbine 37, and an exhaust volume control valve 35 that is provided in the exhaust line 32 and that can adjust the exhaust volume, which is the flow rate of the bleed air that is exhausted from the bleed line 31.

[0087] In this embodiment, by opening the extraction air amount control valve 33, a portion of the compressed air generated by the compressor 10 is extracted as extraction air from the gas turbine 1. Therefore, in this embodiment, the flow rate of the compressed air flowing into the combustor 15 can be made smaller than the minimum intake air flow rate of the gas turbine 1. To ensure stable combustion of the fuel, fuel is supplied to the combustor 15 in accordance with the flow rate of the compressed air flowing into the combustor 15. Therefore, in this embodiment, the flow rate of the combustion gas flowing into the turbine from the combustor 15 can be made smaller while still ensuring stable combustion of the fuel. As a result, in this embodiment, even if the externally required output is smaller than the output corresponding to the minimum intake air flow rate of the gas turbine 1, this required output can be met.

[0088] Furthermore, in this embodiment, by adjusting the opening of the extraction air amount control valve 33, the opening of the inflow amount control valve 34, and the opening of the exhaust amount control valve 35, it is possible to appropriately adjust the flow rate of the extraction air flowing into the auxiliary turbine 37 while maintaining a constant extraction air amount, which is the flow rate of the extraction air extracted from the gas turbine 1. Therefore, in this embodiment, the gas turbine 1 and the auxiliary turbine 37 can be operated stably even when the output of the gas turbine 1 is reduced.

[0089] (2) In a second aspect, the gas turbine system comprises: The gas turbine system according to the first aspect further comprises a control device 100 that controls the opening degree of the extraction amount control valve 33, the opening degree of the inflow amount control valve 34, and the opening degree of the exhaust amount control valve 35, respectively.

[0090] In this embodiment, the gas turbine 1 and the auxiliary turbine 37 can be stably operated without requiring much effort from the workers.

[0091] (3) A gas turbine system according to a third aspect includes: In the gas turbine system according to the second aspect, the control device 100 executes an inflow rate increasing step S43 and an inflow rate decreasing step S45. In the inflow rate increasing step S43, the control device 100 controls the aperture of the exhaust rate control valve 35 and the aperture of the inflow rate control valve 34 so that the exhaust rate gradually decreases and the inflow rate gradually increases as the exhaust rate decreases. In the inflow rate decreasing step S45, the control device 100 controls the aperture of the exhaust rate control valve 35 and the aperture of the inflow rate control valve 34 so that the exhaust rate gradually increases and the inflow rate gradually decreases as the exhaust rate increases.

[0092] In this embodiment, even when the inflow rate, which is the flow rate of the bleed air flowing into the auxiliary turbine 37, is increased or decreased, the bleed rate, which is the flow rate of the bleed air bled from the gas turbine 1, can be maintained constant.

[0093] (4) A gas turbine system according to a fourth aspect includes: In the gas turbine system according to the third aspect, the control device 100 executes an extraction air amount constant control step S42 and an inflow amount constant control step S44. In the extraction air amount constant control step S42, the control device 100 controls the aperture of the extraction air amount control valve 33 so that the extraction air amount is maintained constant. In the inflow amount constant control step S44, the control device 100 controls the aperture of the inflow amount control valve 34 and the aperture of the exhaust amount control valve 35 so that the inflow amount is maintained constant during a time period in which the extraction air amount is maintained constant by executing the extraction air amount constant control step S42.

[0094] In this embodiment, the inflow rate is maintained constant during the time period in which the extraction rate is maintained constant, so that the gas turbine 1 and the auxiliary turbine 37 can be operated stably.

[0095] (5) A gas turbine system according to a fifth aspect includes: In the gas turbine system according to the fourth aspect, the control device 100 executes a bleeding start step S41 before the bleeding air amount constant control step S42, and executes a bleeding end step S46 after the bleeding air amount constant control step S42. In the bleeding start step S41, the control device 100 controls the aperture of the bleeding air amount control valve 33 and the aperture of the exhaust air amount control valve 35 so that the bleeding air amount gradually increases and the exhaust air amount gradually increases as the bleeding air amount increases. In the bleeding end step S46, the control device 100 controls the aperture of the bleeding air amount control valve 33 and the aperture of the exhaust air amount control valve 35 so that the bleeding air amount gradually decreases and the exhaust air amount gradually decreases as the bleeding air amount decreases.

[0096] In this embodiment, whether the extraction amount, which is the flow rate of the extracted air extracted from the gas turbine 1, is increased or whether this extraction amount is decreased, the inflow amount, which is the flow rate of the extracted air flowing into the auxiliary turbine 37, can be maintained constant (for example, the inflow amount is 0).

[0097] (6) A gas turbine system according to a sixth aspect includes: In the gas turbine system according to the fifth aspect, the control device 100 executes the inflow amount increasing step S43 after the extraction start step S41 and before the extraction amount constant control step S42, and executes the inflow amount decreasing step S45 after the extraction amount constant control step S42 and before the extraction amount ending step S46.

[0098] (7) A gas turbine system according to a seventh aspect includes: In the gas turbine system according to the fifth or sixth aspect, the control device 100 executes the extraction start step S41 when the output of the gas turbine 1 becomes equal to or less than an extraction output PWbl that is smaller than the rated output PWrad of the gas turbine 1.

[0099] In this embodiment, the extraction start step S41 is executed, in which the output of the gas turbine 1 becomes equal to or less than the extraction output PWbl, which is smaller than the rated output PWrad of the gas turbine 1, so that the flow rate of the compressed air flowing into the combustor 15 can be reduced.

[0100] (8) In an eighth aspect, the gas turbine system comprises: The gas turbine system according to any one of the third to seventh aspects includes an auxiliary generator 41 capable of generating electricity by driving the auxiliary turbine 37, and a switch 54a capable of disconnecting the electrical connection between the auxiliary generator 41 and an electric power grid. The control device 100 includes a switching controller 105 that instructs the switch 54a to operate. When the rotation speed of the auxiliary generator 41 becomes equal to a predetermined rated rotation speed during the inflow amount increasing step S43, the switching controller 105 instructs the switch 54a to electrically connect the auxiliary generator 41 to the electric power grid, and when the actual output of the auxiliary generator 41 decreases to a predetermined output during the inflow amount decreasing step S45, the switching controller 105 instructs the switch 54a to disconnect the electrical connection between the auxiliary generator 41 and the electric power grid.

[0101] The bleed air control method for the gas turbine system in the above-described embodiment and modified example can be understood as follows, for example. (9) The bleed control method for a gas turbine system according to the ninth aspect is applied to the following gas turbine system. This gas turbine system includes a gas turbine 1 having a compressor 10 capable of compressing air, a combustor 15 capable of burning fuel in the compressed air compressed by the compressor 10 to generate combustion gas, and a turbine 16 capable of driving the combustion gas, an extraction line 31 capable of extracting a portion of the compressed air generated by the compressor 10 as extraction air from the gas turbine 1, an exhaust line 32 branching off from the extraction line 31 midway and capable of discharging a portion of the extraction air that has flowed into the extraction line 31, and an auxiliary turbine 37 connected to the extraction line 31 and capable of driving the extraction air that has flowed through the extraction line 31. In this method for controlling bleed air for a gas turbine system, a bleed air control step S4 is executed in which an bleed air volume, which is the flow rate of the bleed air bled from the gas turbine 1, an inflow volume, which is the flow rate of the bleed air flowing into the auxiliary turbine 37, and an exhaust volume, which is the flow rate of the bleed air exhausted from the bleed air line 31, are adjusted.

[0102] In this aspect, similar to the gas turbine system in the first aspect, by opening the extraction air amount control valve 33, it is possible to respond to the required output from the outside even if the required output is smaller than the output corresponding to the minimum intake air flow rate of the gas turbine 1.

[0103] Furthermore, in this embodiment, by adjusting the opening degree of the extraction air amount control valve 33, the opening degree of the inflow amount control valve 34, and the opening degree of the exhaust amount control valve 35, it is possible to appropriately adjust the flow rate of the extraction air flowing into the auxiliary turbine 37 while maintaining a constant extraction air amount, which is the flow rate of the extraction air extracted from the gas turbine 1. Therefore, in this embodiment as well, the gas turbine 1 and the auxiliary turbine 37 can be operated stably even when the output of the gas turbine 1 is reduced.

[0104] (10) A method for controlling bleed air in a gas turbine system according to a tenth aspect includes the steps of: In the ninth aspect of the bleeding control method for a gas turbine system, the bleeding control step S4 includes an inflow rate increasing step S43 and an inflow rate decreasing step S45. In the inflow rate increasing step S43, the exhaust rate and the inflow rate are controlled so that the exhaust rate gradually decreases and the inflow rate gradually increases as the exhaust rate decreases. In the inflow rate decreasing step S45, the exhaust rate and the inflow rate are controlled so that the exhaust rate gradually increases and the inflow rate gradually decreases as the exhaust rate increases.

[0105] In this aspect, similarly to the gas turbine system of the third aspect, the extraction rate, which is the flow rate of the extraction air extracted from the gas turbine 1, can be maintained constant whether the inflow rate, which is the flow rate of the extraction air flowing into the auxiliary turbine 37, is increased or whether the inflow rate is decreased.

[0106] (11) An eleventh aspect of a method for controlling bleed air in a gas turbine system includes: In the bleed air control method for a gas turbine system according to the tenth aspect, the bleed air control step S4 executes a constant bleed air amount control step S42 and a constant inflow amount control step S44. In the constant bleed air amount control step S42, the bleed air amount is controlled so that the bleed air amount is maintained constant. In the constant inflow amount control step S44, the exhaust amount and the inflow amount are controlled so that the inflow amount is maintained constant during a time period in which the bleed air amount is maintained constant by execution of the constant bleed air amount control step S42.

[0107] In this embodiment, similar to the gas turbine system of the fourth embodiment, the inflow rate is maintained constant during the time period in which the extraction rate is maintained constant, so that the gas turbine 1 and the auxiliary turbine 37 can be operated stably.

[0108] (12) A twelfth aspect of a method for controlling bleed air in a gas turbine system includes: In the eleventh aspect of the method for controlling bleeding of a gas turbine system, the bleeding control step S4 includes a bleeding start step S41 executed before the bleeding amount constant control step S42, and a bleeding end step S46 executed after the bleeding amount constant control step S42. In the bleeding start step S41, the bleeding amount and the exhaust amount are controlled so that the bleeding amount gradually increases and the exhaust amount gradually increases as the bleeding amount increases. In the bleeding end step S46, the bleeding amount and the exhaust amount are controlled so that the bleeding amount gradually decreases and the exhaust amount gradually decreases as the bleeding amount decreases.

[0109] In this aspect, similarly to the gas turbine system of the fifth aspect, the inflow rate, which is the flow rate of the bleed air flowing into the auxiliary turbine 37, can be maintained constant (for example, the inflow rate is 0), whether the bleed rate, which is the flow rate of the bleed air bled from the gas turbine 1, is increased or whether the bleed rate is decreased.

[0110] (13) A method for controlling bleed air in a gas turbine system according to a thirteenth aspect includes the steps of: In the twelfth aspect of the method for controlling bleeding of a gas turbine system, the inflow rate increasing step S43 is executed after the bleeding start step S41 and before the bleeding rate constant control step S42. The inflow rate decreasing step S45 is executed after the bleeding rate constant control step S42 and before the bleeding rate termination step S46.

[0111] (14) A method for controlling bleed air in a gas turbine system according to a fourteenth aspect includes the steps of: In the method for controlling extraction of a gas turbine system according to the twelfth or thirteenth aspect, when the output of the gas turbine 1 becomes equal to or less than an extraction output PWbl that is smaller than the rated output PWrad of the gas turbine 1, the extraction start step S41 is executed.

[0112] (15) A method for controlling bleed air in a gas turbine system according to a fifteenth aspect includes the steps of: In the method for controlling bleeding of a gas turbine system according to any one of the tenth to fourteenth aspects, the gas turbine system includes an auxiliary generator 41 capable of generating electricity by driving the auxiliary turbine 37, and a switch 54a capable of interrupting electrical connection between the auxiliary generator 41 and an electric power grid. In this gas turbine system bleeding control method, when the rotation speed of the auxiliary generator 41 becomes equal to a predetermined rated rotation speed during the inflow amount increasing step S43, a parallel-in step S6 is executed to instruct the switch 54a to electrically connect the auxiliary generator 41 to the power grid, and when the actual output of the auxiliary generator 41 decreases to a predetermined output during the inflow amount decreasing step S45, a parallel-out step S7 is executed to instruct the switch 54a to cut off the electrical connection between the auxiliary generator 41 and the power grid. [Explanation of symbols]

[0113] 1: Gas turbine 1 2: Gas turbine rotor 3: Intermediate casing 4: Fuel line 5: Fuel valve 6: Gas turbine generator 10: Compressor 11: Compressor rotor 11s: Compressor rotor shaft 11b: Moving blade row 12: Compressor casing 13: Intake volume regulator 13v: Inlet guide vane (IGV) 13d: Drive unit 15: Combustor 16: Turbine 17: Turbine rotor 17s: Turbine rotor shaft 17b: Moving blade row 18: Turbine casing 20: Waste heat utilization equipment 21: Waste heat recovery boiler 21d: Duct 21t: Heat transfer tube 22: Chimney 23: Steam turbine 24: Main steam line 25: Condenser 26: Water supply line 27: Water supply pump 30: Air extraction device 31: Bleed line 32: Exhaust line 33: Bleed air volume control valve 34: Inflow control valve 35: Exhaust volume control valve 37: Auxiliary turbine 38: Auxiliary turbine rotor 39: Auxiliary turbine casing 40: Auxiliary power generation equipment 41: Auxiliary generator 42: Transmission 43: Clutch 45: Power storage device 46: Storage battery 47: AC / DC converter 50: Power system equipment 51g: Dedicated power line for GT generator 51a: Dedicated power line for automatic generators 51b: BESS dedicated power line 51p: Shared power lines within the plant 51c: External power line 53a, 53b, 53c, 53g: Transformers 54a, 54b, 54c, 54g: Switch 55: Output meter 60: External power system 65: Power storage device 66: Storage battery 67: AC / DC converter 100: Control device 101: Main controller 102: Fuel controller 103:IGV controller 104: Bleed air controller 105: Opening and closing controller A: Air F:Fuel PWr: Actual output PWc: Request output PWrad: Rated power PWmid: Medium output PWbl: Extraction power Ar: rotor axis Da: Axial direction Dau: Axis upstream side Dad: Downstream of the axis

Claims

1. a gas turbine including a compressor capable of compressing air, a combustor capable of burning fuel in the compressed air compressed by the compressor to generate combustion gas, and a turbine capable of being driven by the combustion gas; an extraction line that allows a portion of the compressed air generated by the compressor to be extracted from the gas turbine as extraction air; an exhaust line branching from the bleed line and capable of exhausting a portion of the bleed air that has flowed into the bleed line; an auxiliary turbine connected to the extraction line and capable of being driven by the extraction air flowing through the extraction line; an extraction air amount control valve provided in the extraction line and capable of adjusting an extraction air amount, which is a flow rate of the extraction air extracted from the gas turbine; an inflow control valve provided in the extraction line and capable of adjusting an inflow rate, which is a flow rate of the extraction air flowing into the auxiliary turbine; an exhaust amount control valve provided in the exhaust line and capable of adjusting an exhaust amount, which is a flow rate of the bleed air discharged from the bleed line; A gas turbine system comprising:

2. 2. The gas turbine system according to claim 1, a control device that controls the opening degree of the bleed air amount control valve, the opening degree of the inflow amount control valve, and the opening degree of the exhaust amount control valve, Gas turbine systems.

3. 3. The gas turbine system according to claim 2, The control device executes an inflow amount increasing step and an inflow amount decreasing step, In the inflow rate increasing step, the control device controls the aperture of the exhaust rate control valve and the aperture of the inflow rate control valve so that the exhaust rate gradually decreases and the inflow rate gradually increases in accordance with the decrease in the exhaust rate, In the inflow amount reducing step, the control device controls the aperture of the exhaust amount control valve and the aperture of the inflow amount control valve so that the exhaust amount gradually increases and the inflow amount gradually decreases as the exhaust amount increases. Gas turbine systems.

4. 4. The gas turbine system according to claim 3, the control device executes a constant extraction air amount control step and a constant inflow amount control step, In the bleed air amount constant control step, the control device controls the opening degree of the bleed air amount adjustment valve so that the bleed air amount is maintained constant, In the inflow amount constant control step, the control device controls the opening degree of the inflow amount control valve and the opening degree of the exhaust amount control valve so that the inflow amount is maintained constant during a time period in which the bleed air amount is maintained constant by executing the bleed air amount constant control step. Gas turbine systems.

5. 5. The gas turbine system according to claim 4, the control device executes a bleeding start step before the bleeding amount constant control step, and executes a bleeding end step after the bleeding amount constant control step, In the bleeding start step, the control device controls the opening degree of the bleeding air amount control valve and the opening degree of the exhaust amount control valve so that the bleeding air amount gradually increases and the exhaust amount gradually increases in accordance with the increase in the bleeding air amount, In the bleeding termination step, the control device controls the opening degree of the bleeding air amount control valve and the opening degree of the exhaust amount control valve so that the bleeding air amount gradually decreases and the exhaust amount gradually decreases in accordance with the decrease in the bleeding air amount. Gas turbine systems.

6. 6. The gas turbine system according to claim 5, the control device executes the inflow amount increasing step after the extraction start step and before the extraction amount constant control step, and executes the inflow amount decreasing step after the extraction amount constant control step and before the extraction amount ending step. Gas turbine systems.

7. 6. The gas turbine system according to claim 5, the control device executes the extraction start step when the output of the gas turbine becomes equal to or less than an extraction output that is smaller than a rated output of the gas turbine. Gas turbine systems.

8. 8. The gas turbine system according to claim 3, an auxiliary generator capable of generating electricity by driving the auxiliary turbine; a switch capable of interrupting an electrical connection between the auxiliary generator and a power grid; Equipped with the control device has a switching controller that instructs the operation of the switch, The switching controller instructs the switch to electrically connect the auxiliary generator to the power grid when the rotational speed of the auxiliary generator becomes equal to a predetermined rated rotational speed during the inflow amount increasing step, and instructs the switch to disconnect the electrical connection between the auxiliary generator and the power grid when the actual output of the auxiliary generator decreases to a predetermined output during the inflow amount decreasing step. Gas turbine systems.

9. a gas turbine including a compressor capable of compressing air, a combustor capable of burning fuel in the compressed air compressed by the compressor to generate combustion gas, and a turbine capable of being driven by the combustion gas; an extraction line that allows a portion of the compressed air generated by the compressor to be extracted from the gas turbine as extraction air; an exhaust line branching from the bleed line and capable of exhausting a portion of the bleed air that has flowed into the bleed line; an auxiliary turbine connected to the extraction line and capable of being driven by the extraction air flowing through the extraction line; A method for controlling bleed air in a gas turbine system comprising: a bleed air control step of adjusting an bleed air amount, which is the flow rate of the bleed air bled from the gas turbine, adjusting an inflow amount, which is the flow rate of the bleed air flowing into the auxiliary turbine, and adjusting an exhaust amount, which is the flow rate of the bleed air exhausted from the bleed air line; A method for controlling bleed air in a gas turbine system comprising:

10. 10. The method for controlling bleed air in a gas turbine system according to claim 9, the bleed air control step includes an inflow amount increasing step and an inflow amount decreasing step, In the inflow amount increasing step, the exhaust amount and the inflow amount are controlled so that the exhaust amount is gradually decreased and the inflow amount is gradually increased in accordance with the decrease in the exhaust amount; In the inflow amount decreasing step, the exhaust amount and the inflow amount are controlled so that the exhaust amount gradually increases and the inflow amount gradually decreases as the exhaust amount increases. A method for controlling bleed air in a gas turbine system.

11. The method for controlling bleed air in a gas turbine system according to claim 10, the bleed air control step includes a constant bleed air amount control step and a constant inflow amount control step; In the bleed air amount constant control step, the bleed air amount is controlled so as to be maintained constant; In the inflow amount constant control step, the exhaust amount and the inflow amount are controlled so that the inflow amount is maintained constant during a time period in which the bleed air amount is maintained constant by executing the bleed air amount constant control step. A method for controlling bleed air in a gas turbine system.

12. The method for controlling bleed air in a gas turbine system according to claim 11, The bleed air control step includes: a bleed start step executed before the bleed air amount constant control step, and a bleed end step executed after the bleed air amount constant control step, In the bleed start step, the bleed air amount and the exhaust amount are controlled so that the bleed air amount gradually increases and the exhaust amount gradually increases in accordance with the increase in the bleed air amount; In the bleed air termination step, the bleed air amount and the exhaust amount are controlled so that the bleed air amount is gradually reduced and the exhaust amount is gradually reduced in accordance with the reduction in the bleed air amount. A method for controlling bleed air in a gas turbine system.

13. 13. The method for controlling bleed air in a gas turbine system according to claim 12, the inflow amount increasing step is performed after the extraction start step and before the extraction amount constant control step, the inflow amount reducing step is performed after the extraction amount constant control step and before the extraction end step. A method for controlling bleed air in a gas turbine system.

14. 13. The method for controlling bleed air in a gas turbine system according to claim 12, When the output of the gas turbine becomes equal to or less than an extraction output that is smaller than a rated output of the gas turbine, the extraction starting step is executed. A method for controlling bleed air in a gas turbine system.

15. The method for controlling bleed air in a gas turbine system according to any one of claims 10 to 14, The gas turbine system includes: an auxiliary generator capable of generating electricity by driving the auxiliary turbine; a switch capable of interrupting an electrical connection between the auxiliary generator and a power grid; Equipped with a parallel connection step of instructing the switch to electrically connect the auxiliary generator to the power grid when the rotational speed of the auxiliary generator becomes equal to a predetermined rated rotational speed during the inflow amount increasing step; a parallel-off process of instructing the switch to disconnect the electrical connection between the auxiliary generator and the power grid when the actual output of the auxiliary generator decreases to a predetermined output during the inflow amount reduction process; To execute A method for controlling bleed air in a gas turbine system.

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