Control device, fuel supply facility of gas turbine, control method and program

Abstract

To provide a technology for recovering fuel remaining in a nozzle, etc., of a combustor of a gas turbine.SOLUTION: A control device includes means for performing reverse blow control, which, starting from a point when a rotation speed of a gas turbine reaches a predetermined low speed lower than a rated rotation speed after the gas turbine has stopped operating, causes air in a combustor to flow back through a nozzle provided in the combustor into a fuel supply system associated with the nozzle, and guides the air into a fuel recovery system, which is connected to the fuel supply system and recovers fuel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a fuel supply system for a gas turbine, a control method, and a program. [Background technology]

[0002] Patent Document 1 discloses a method for purging oil remaining in the nozzle of a combustor of a gas turbine that can switch between oil and gas fuel and has three fuel supply systems (main A, main B, and pilot) by flowing water or air into each of the main A, main B, and pilot systems immediately after switching the fuel from oil to gas. This purging method prevents the oil fuel in the nozzle, which is kept at a high temperature, from coking and solidifying, causing the nozzle to clog, by burning gas fuel while the oil fuel remains. However, this method results in the unused fuel in the nozzle being discharged, resulting in waste. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-59427 Summary of the Invention [Problem to be solved by the invention]

[0004] A technology is provided for recovering fuel remaining in the nozzle of a gas turbine combustor, etc.

[0005] The present disclosure provides a control device, a fuel supply system for a gas turbine, a control method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The control device according to the present disclosure includes means for performing reverse blow control, which, starting from the point at which the rotation speed of the gas turbine reaches a predetermined low speed that is lower than the rated rotation speed after the gas turbine has stopped operating, causes air from the combustor to flow backward through a fuel supply system associated with the nozzle, via a nozzle provided in the combustor, and directs the air to a fuel recovery system connected to the fuel supply system for recovering fuel.

[0007] A fuel supply system for a gas turbine according to the present disclosure includes a combustor of the gas turbine, a fuel supply system that supplies fuel to the combustor, a fuel recovery system that is connected to the fuel supply system and recovers the fuel, a drain valve provided in the fuel recovery system, and the above-described control device.

[0008] The control method according to the present disclosure, after the gas turbine has stopped operating, starts when the rotation speed of the gas turbine reaches a predetermined low rotation speed that is lower than the rated rotation speed, and controls the air in the combustor to flow backward through a nozzle provided in the combustor and a fuel supply system associated with the nozzle, and to guide the air to a fuel recovery system connected to the fuel supply system for recovering fuel.

[0009] The program according to the present disclosure causes a computer to function as a means for performing reverse blow control, which, starting from the point when the rotation speed of the gas turbine reaches a predetermined low speed that is lower than the rated rotation speed after the gas turbine has stopped operating, causes air from the combustor to flow backward through a nozzle provided in the combustor and a fuel supply system associated with the nozzle, and also directs the air to a fuel recovery system connected to the fuel supply system for recovering fuel. [Effects of the Invention]

[0010] According to the control device, gas turbine fuel supply equipment, control method, and program of the present disclosure, it is possible to recover fuel remaining in the nozzle of the combustor of the gas turbine, etc. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a fuel supply system of a gas turbine according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a control device according to an embodiment. [Figure 3] 4 is a timing chart showing an example of control according to the embodiment. [Figure 4] 4 is a flowchart illustrating an example of control according to the embodiment. [Figure 5] FIG. 2 illustrates an example of a hardware configuration of a control device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Embodiment> Hereinafter, the reverse blow control and purge control according to this embodiment will be described with reference to the drawings. (System Configuration) FIG. 1 is a schematic diagram of a supply system for fuel and the like according to an embodiment. A combustor 400 of a gas turbine is provided with nozzles 133, 134, 233, 234, 333, 334, and the like. The nozzles 133 and 134 are nozzles of a pilot system, the nozzles 233 and 234 are nozzles of a main A system, and the nozzles 333 and 334 are nozzles of a main B system. For example, in an actual combustor, a pilot nozzle is provided near the center of a cylindrical cross section of the combustor, and a predetermined number of main A nozzles and a predetermined number of main B nozzles are arranged on the outer periphery of the pilot nozzle. FIG. 1 schematically illustrates nozzles 133 and 134 corresponding to the pilot nozzle, nozzles 233 and 234 corresponding to the main A nozzle, and nozzles 333 and 334 corresponding to the main B nozzle. A control device 10 controls the opening and closing of valves of each system, as described below, to perform reverse blow control for recovering fuel remaining in the nozzle 333 and the like and purge control for discharging the remaining fuel.

[0013] A fuel supply system 100 that supplies fuel oil is provided upstream of the pilot nozzles 133 and 134. The fuel supply system 100 is provided with a valve 101 that adjusts the flow rate of fuel, and the fuel evenly distributed by the flow distributor 130 is supplied to the pilot nozzles 133 and 134 through fuel supply systems 131 and 132. An air supply system 110 is connected to the fuel supply system 100 upstream of the flow distributor 130. The air supply system 110 is provided with a valve 111. When purging fuel remaining in the pilot nozzles 133 and 134 after shutting down the gas turbine, high-pressure air is supplied through the air supply system 110. Furthermore, a fuel recovery system 120 that guides fuel (oil) to a drain tank (not shown) for fuel recovery is connected to the fuel supply system 100 upstream of the flow distributor 130, and a drain valve 121 is provided in the fuel recovery system 120. After the gas turbine is shut down, the drain valve 121 is opened by reverse blow control, and the fuel remaining in the fuel supply systems 131 and 132 and the nozzles 133 and 134 is collected in the drain tank and reused.

[0014] A fuel supply system 200 that supplies fuel oil is provided upstream of the main A nozzles 233 and 234. The fuel supply system 200 is provided with a valve 201 that adjusts the flow rate of fuel, and the fuel evenly distributed by a flow distributor 230 is supplied to the main A nozzles 233 and 234 through fuel supply systems 231 and 232. Downstream of the flow distributor 230, a purge system 241 is connected to the fuel supply system 231, and a purge system 242 is connected to the fuel supply system 232. A valve 243 is provided in the purge systems 241 and 242. The purge systems 241 and 242 are connected to a purge system 240 on the upstream side, and water or high-pressure air is supplied to the purge systems 241 and 242 through the purge system 240. The purge system 240 is connected to a water supply system 210 and a high-pressure air supply system 220 on the upstream side. The water supply system 210 is provided with a valve 211, and the high-pressure air supply system 220 is provided with a valve 221. After the gas turbine is shut down, when the valve 211 is opened with the valve 221 closed, water for fuel purging is supplied from the water supply system 210 to the purge system 240. Similarly, after the gas turbine is shut down, when the valve 221 is opened with the valve 211 closed, high-pressure air for fuel purging is supplied from the high-pressure air supply system 220 to the purge system 240. Furthermore, a fuel recovery system 244 for guiding fuel (oil) to a drain tank (not shown) is connected to the purge system 240, and a drain valve 245 is provided in the fuel recovery system 244. When the drain valve 245 is opened by reverse blow control, the fuel remaining in the fuel supply systems 231 and 232 and the main A nozzles 233 and 234 is recovered into the drain tank and reused. In addition, a waste system 246 for guiding fuel (oil) to a drain pit (not shown) is connected to the purge system 240, and the waste system 246 is provided with a vent valve 247. When the valve 247 is opened, the fuel is guided to the drain pit. The oil collected in the drain pit is discarded.

[0015] A fuel supply system 300 that supplies fuel oil is provided upstream of the main B nozzles 333 and 334. The fuel supply system 300 is provided with a valve 301 that adjusts the fuel flow rate, and the fuel evenly distributed by a flow distributor 330 is supplied to the main B nozzles 333 and 334 through fuel supply systems 331 and 332. Downstream of the flow distributor 330, a purge system 341 is connected to the fuel supply system 331, and a purge system 342 is connected to the fuel supply system 332. The purge systems 341 and 342 are connected to a purge system 340 on their upstream sides, and water or high-pressure air is supplied to the purge systems 341 and 342 through the purge system 340. The purge system 340 is connected upstream to a water supply system 310 and a high-pressure air supply system 320. The water supply system 310 is provided with a valve 311, and the high-pressure air supply system 320 is provided with a valve 321. When the gas turbine is shut down (before being shut down), if valve 311 is opened with valve 321 closed, water for fuel purging is supplied from water supply system 310 to purge system 340. Similarly, when the gas turbine is shut down (before being shut down), if valve 321 is opened with valve 311 closed, high-pressure air for fuel purging is supplied from high-pressure air supply system 320 to purge system 340. Purge systems 341 and 342 are provided with valve 343. Furthermore, purge system 340 is connected to fuel recovery system 344 for guiding fuel (oil) to a drain tank (not shown), and fuel recovery system 344 is provided with drain valve 345. When drain valve 345 is opened by reverse blow control, fuel remaining in fuel supply systems 331 and 332 and nozzles 333 and 334 is recovered to the drain tank and reused. In addition, a waste system 346 for guiding fuel (oil) to a drain pit (not shown) is connected to the purge system 340, and a vent valve 347 is provided in the exhaust system 346. When the valve 347 is opened, the fuel is guided to the drain pit. The oil collected in the drain pit is discarded.

[0016] In the gas turbine according to this embodiment, fuel is supplied to the pilot system and the main A system until the gas turbine is shut down, but the supply of fuel to the main B system is stopped when the gas turbine is shut down. In other words, when the gas turbine is shut down, the supply of fuel to the main B system is first stopped, and then the amount of fuel supplied to the pilot system and the main A system is reduced to shut down the gas turbine. At that time, when the supply of fuel to the main B system is stopped, the fuel in the main B system is purged. Therefore, the fuel in the main B system is purged before the gas turbine is shut down.

[0017] Furthermore, in this embodiment, after the operation of the gas turbine is stopped (after the supply of fuel to the pilot system and the main A system is stopped), reverse blow control is performed starting from the point where the rotation speed of the gas turbine drops to a predetermined value. Specifically, valves 121, 243, 245, 343, and 345 in Fig. 1 are opened, and other valves 101, 111, 201, 211, 221, 247, 311, 321, and 347 are closed. Then, high-pressure air flows from a casing (not shown) into the combustor 400 due to a pressure difference, and the high-pressure air flows from the tips of the pilot nozzles 133 and 134 into the fuel supply systems 131 and 132, then flows back upstream, and is recovered into the drain tank via the fuel recovery system 120. Similarly, high-pressure air flows in from the tips of the main A nozzles 233 and 234, flows backward through the fuel supply systems 231 and 232, and is collected in a drain tank through the purge systems 241 and 242 and the fuel recovery system 244. In the main B system, high-pressure air flows from the tips of the main B nozzles 333 and 334 into the fuel supply systems 331 and 332, flows backward upstream, and is collected in a drain tank through the purge systems 341 and 342 and the fuel recovery system 344. The combustor 400 is attached to a casing (not shown) downstream of a compressor (not shown), and has an air intake port that communicates with the casing. When the valves 121, 243, 245, 343, and 345 are opened, the high-pressure air in the casing flows into the combustor 400 from the air intake port and flows backward through the fuel supply system 131, etc., through the tips of the nozzles 133, etc.

[0018] Furthermore, as described above, purge control is performed on the main B system before shutting down, i.e., before blow control. For example, after fuel supply to the main B system is stopped, valve 311 is opened to allow water to flow, and then valve 311 is closed and valve 321 is opened to allow high-pressure air to flow and purge remaining fuel from the tips of nozzles 333 and 334. After purging with high-pressure air, valve 321 is closed again. This causes the high-pressure air used for purging to accumulate in purge system 340. If blow control is performed in this state (i.e., valves 343 and 345 are opened), the high-pressure air accumulated in purge system 340 will be sprayed into the drain tank, causing the fuel collected in the drain tank to spill over. Therefore, in this embodiment, after purge control of the main B system, vent valve 347 is opened to depressurize this system, and control is performed to discard the high-pressure air accumulated in purge system 340. This prevents the fuel collected in the drain tank from boiling over.

[0019] (Control device configuration) Next, the functions of the control device 10 will be described with reference to Fig. 2. As shown in Fig. 2, the control device 10 includes a signal acquisition unit 11 and a control unit 12.

[0020] The signal acquisition unit 11 acquires a signal instructing the shutdown of the gas turbine, a signal instructing the shutdown of the main B system, a signal including the rotation speed of the gas turbine, etc. With regard to the signals instructing the shutdown of the gas turbine or the main B system, the signal related to the operation may be acquired when an operator inputs an operation to instruct the same into the control device 10, or the signal may be acquired from a higher-level control device or the like. With regard to the rotation speed of the gas turbine, a signal including a measurement result is acquired from a sensor or the like that measures the rotation speed of the gas turbine.

[0021] The control unit 12 controls the valve 101 and the like shown in Fig. 1. The control unit 12 includes a main B system purge control unit 13, a depressurization control unit 14, and a reverse blow control unit 15.

[0022] The main B system purge control unit 13 performs purge control of the main B system. Specifically, when the signal acquisition unit 11 acquires a signal instructing the main B system to be stopped, the main B system purge control unit 13 keeps valve 321 closed and opens valves 311 and 343 for a predetermined time to perform a water purge in which water is supplied to fuel supply systems 331 and 332 through water supply system 310 and purge systems 340, 341, and 342. After the water purge is completed, the main B system purge control unit 13 closes valve 311 and opens valves 321 and 343 for a predetermined time to perform an air purge in which high-pressure air is supplied to fuel supply systems 331 and 332 through high-pressure air supply system 320 and purge systems 340, 341, and 342.

[0023] After the main B system purge control unit 13 completes the air purge, the depressurization control unit 14 performs depressurization control by opening the vent valve 347 for a predetermined time.

[0024] The reverse blow control unit 15 performs reverse blow control, using high-pressure air present in the casing to reversely flow and recover fuel remaining in each nozzle 133, the fuel supply system 131, etc. Specifically, the reverse blow control unit 15 monitors the gas turbine rotation speed acquired by the signal acquisition unit 11, and opens the valves 121, 243, 245, 343, and 345 for a predetermined time period starting from when the rotation speed reaches a predetermined value. For example, the predetermined rotation speed is approximately 1700 to 1800 rpm for a gas turbine operating at a rated speed of 3600 rpm. This rotation speed is an example and is not limited to this. It is arbitrarily set depending on the specifications of the combustor, etc. Because excessively high-pressure air can cause problems if it flows backward, after the gas turbine stops operating, the reverse blow control unit 15 waits until the rotation speed drops to a predetermined value. Then, when the gas turbine rotation speed drops to the predetermined value and a predetermined time has elapsed, the reverse blow control unit 15 opens the valves 121, etc. The predetermined time period is, for example, approximately 0 to 10 seconds.

[0025] (Timing chart) FIG. 3 shows a timing chart of the purge control and reverse blow control of the main B system. When the signal acquisition unit 11 receives a signal instructing the main B system to stop at time T0, the main B system purge control unit 13 starts a water purge a few seconds later at time T1. The main B system purge control unit 13 continues the water purge for a few minutes and ends the water purge at time T2. Next, the main B system purge control unit 13 starts an air purge at time T3, a dozen seconds after the water purge ends, and continues this for a few minutes before ending the air purge at time T4. Next, the depressurization control unit 14 starts depressurization of the main B system (purge system 340) at time T5, a few seconds after the air purge ends, and continues this for about 10 seconds before ending the depressurization control at time T6.

[0026] When the supply of fuel to the main B system is stopped and the purge control and depressurization control are completed, an instruction to stop the gas turbine is issued. This causes the gas turbine rotation speed to gradually decrease. When the gas turbine rotation speed decreases to a predetermined value X1 rpm at time T7, the reverse blow control unit 15 starts reverse blow control for the pilot system, main A system, and main B system at time T8, a predetermined time after that. The reverse blow control unit 15 continues the reverse blow control for several minutes and ends the reverse blow control at time T9. Note that the time for each control and the time between controls illustrated in Figure 3 are merely examples and are not limited to those described above. For example, depressurization control may be performed immediately before reverse blow control.

[0027] (operation) FIG. 4 shows a flowchart of the purge control and reverse blow control of the main B system. 4, it is assumed that the gas turbine is in operation and fuel is supplied to the pilot system, main system A, and main system B. Also, as an example, it is assumed that valves 111, 121, 211, 221, 243, 245, 247, 311, 321, 343, 345, and 347 are closed.

[0028] First, the signal acquisition unit 11 acquires a signal instructing the main B system to be stopped (step S1). A few seconds later, the main B system purge control unit 13 performs purge control of the fuel remaining in the main B system (step S2). First, the main B system purge control unit 13 opens valves 311 and 343 to perform a water purge for several minutes. Once the water purge is complete, the main B system purge control unit 13 closes valve 311 and opens valve 321 to perform an air purge for several minutes. Once the air purge is complete, the main B system purge control unit 13 opens valves 321 and 343. This causes high-pressure air to accumulate in the purge system 340. The main B system purge control unit 13 notifies the depressurization control unit 14 of the completion of the purge control.

[0029] Upon receiving the notification that the purge control is complete, the depressurization control unit 14 then performs depressurization control (step S3). The depressurization control unit 14 opens the vent valve 347 and performs depressurization control. This reduces the pressure in the purge system 340. The depressurization control unit 14 keeps the vent valve 347 open for, for example, about 10 seconds, and then closes the vent valve 347.

[0030] Next, the signal acquisition unit 11 acquires a signal instructing the gas turbine to stop (step S4). The reverse blow control unit 15 starts monitoring the gas turbine rotation speed acquired by the signal acquisition unit 11 and waits until the rotation speed drops to a predetermined value (step S5; No). When the rotation speed drops to the predetermined value (step S5; Yes), the reverse blow control unit 15 measures the time since the rotation speed reached the predetermined value and waits until the predetermined time has passed (step S6; No). When the predetermined time has passed after the rotation speed has dropped (step S6; Yes), the reverse blow control unit 15 executes reverse blow control (step S7). The reverse blow control unit 15 opens the drain valves 121, 245, and 345 and closes the other valves. As a result, the fuel remaining in the pilot system, main A system, and main B system, and the fuel purged to the combustor 400 side by the purge control of the main B system, are collected in the drain tank. The reverse blow control may be started immediately after (at the same time as) the rotational speed of the gas turbine is reduced to a predetermined value.

[0031] (effect) As described above, according to this embodiment, the reverse blow control can recover unused fuel remaining in the pilot system, main A system, and main B system. The recovered fuel can be used to operate the gas turbine. Furthermore, if fuel remains in the pilot system, main A system, or main B system or flows into the combustor 400, it may solidify due to coking or other factors, causing nozzle blockage or adverse effects such as oxidation. However, recovering the fuel through the reverse blow control can prevent these problems. Furthermore, if the reverse blow control is performed after the purge control of the main B system, the high-pressure air supplied to the main B system by the air purge may cause fuel to spill over from the drain tank during the reverse blow control. However, according to this embodiment, depressurization control is performed after the purge control of the main B system and before the reverse blow control, preventing fuel from spilling over.

[0032] 5 is a diagram showing an example of the hardware configuration of the control device 10 according to the embodiment. The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The control device 10 described above is implemented in the computer 900. The above-described functions are stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 also allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 also allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0033] A program for implementing all or part of the functions of the control device 10 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, if a WWW system is used, the term "computer system" also includes a homepage provision environment (or display environment). Furthermore, the term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. Furthermore, if the program is distributed to the computer 900 via a communication line, the computer 900 that receives the program may load the program into the main storage device 902 and execute the above-described processing. Furthermore, the program may be for implementing part of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system.

[0034] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0035] <Additional Notes> The control device, the fuel supply system for a gas turbine, the control method, and the program described in the embodiments can be understood, for example, as follows.

[0036] (1) The control device 10 according to the first aspect includes a means for performing reverse blow control, which, starting from the point when the rotation speed of the gas turbine reaches a predetermined low speed that is lower than the rated rotation speed after the gas turbine stops operating, causes air from the combustor to flow back through a nozzle provided in the combustor into a fuel supply system associated with the nozzle, and directs the air into a fuel recovery system connected to the fuel supply system for recovering fuel. This makes it possible to recover fuel remaining in the nozzle of the combustor of the gas turbine.

[0037] (2) A control device according to a second aspect is the control device of (1), wherein the means for performing the reverse blow control executes the reverse blow control when a predetermined time has elapsed since the rotational speed has decreased to the low rotational speed. This allows the reverse blow control to be executed starting from the point when the rotation speed of the gas turbine reaches a low rotation speed.

[0038] (3) A control device according to a third aspect is the control device of (1), wherein the means for performing the reverse blow control performs the reverse blow control at the same time that the rotational speed is reduced to the low rotational speed. This allows the reverse blow control to be executed starting from the point when the rotation speed of the gas turbine reaches a low rotation speed.

[0039] (4) A control device according to a fourth aspect is a control device of (1) to (3), wherein the means for performing the reverse blow control guides the air by changing a drain valve provided in the fuel recovery system from closed to open during the reverse blow control. This allows the fuel remaining in the fuel supply system to be led to the fuel recovery system.

[0040] (5) A control device according to a fifth aspect is a control device according to any one of (1) to (4), further comprising a depressurization means for controlling a first fuel supply system, which stops the supply of fuel before the operation of the gas turbine is stopped, to reduce the pressure before the reverse blow control, among a plurality of fuel supply systems that supply fuel to the combustor. This makes it possible to avoid the phenomenon in which high-pressure air that has accumulated in the first fuel supply system is ejected during reverse blow control.

[0041] (6) A control device according to a sixth aspect is the control device of (5), further comprising a purge means for supplying high-pressure air to the first fuel supply system to purge the first fuel supply system before the gas turbine is shut down. This makes it possible to purge the fuel remaining in the first fuel supply system.

[0042] (7) A control device according to a seventh aspect is the control device of (5) to (6), wherein the pressure relief means reduces the pressure by opening a vent valve provided in a pipe connected to the first fuel supply system. This makes it possible to reduce the pressure in the first fuel supply system.

[0043] (8) A fuel supply system for a gas turbine according to an eighth aspect includes a combustor of the gas turbine, a fuel supply system that supplies fuel to the combustor, a fuel recovery system that recovers the fuel and is connected to the fuel supply system, a drain valve provided in the fuel recovery system, and a control device described in (1) to (7).

[0044] (9) A control method according to a ninth aspect includes, after a gas turbine has stopped operating, starting from a point at which the rotational speed of the gas turbine reaches a predetermined low rotational speed that is lower than a rated rotational speed, controlling air in the combustor to flow back through a nozzle provided in the combustor into a fuel supply system associated with the nozzle, and controlling the air to be guided to a fuel recovery system connected to the fuel supply system for recovering fuel.

[0045] (10) A program according to a tenth aspect causes a computer to function as a means for performing reverse blow control, which, starting from the point at which the rotation speed of the gas turbine reaches a predetermined low speed that is lower than the rated rotation speed after the gas turbine has stopped operating, causes air in the combustor to flow back through a nozzle provided in the combustor into a fuel supply system associated with the nozzle, and also directs the air into a fuel recovery system connected to the fuel supply system for recovering fuel. [Explanation of symbols]

[0046] 10. Control device 11. Signal acquisition unit 12 Control section 13 Main B system purge control unit 14. Decompression control section 15. Reverse blow control section 100...Fuel supply system 101 Valve 110 Air supply system 111···Valve 120 Fuel recovery system 121 Valve 130...Flow rate distributor 131, 132...Fuel supply system 133, 134 Pilot nozzle 200...Fuel supply system 201 Valve 210...Water supply system 211···Valve 220 High-pressure air supply system 221 Valve 230...Flow rate distributor 231, 232...Fuel supply system 233, 234 Main A nozzle 240, 241, 242... Purge system 243 Valve 244 Fuel recovery system 245···Valve 246···Discarded System 247 Valve 300...Fuel supply system 301 Valve 310...Water supply system 311···Valve 320 High-pressure air supply system 321···Valve 330...Flow rate distributor 231, 332...Fuel supply system 333, 334...Main B nozzle 340, 341, 342... Purge system 343 Valve 344 Fuel recovery system 345···Valve 346···Discarded system 347 Valve 900···Computer 901 CPU 902...Main memory 903...Auxiliary storage device 904 Input / Output Interface 905···Communication Interface

Claims

1. a means for performing reverse blow control for, starting from a point when the rotation speed of the gas turbine reaches a predetermined low speed that is lower than a rated rotation speed after the gas turbine has stopped operating, causing air in the combustor to flow back through a nozzle provided in the combustor into a fuel supply system related to the nozzle, and guiding the air to a fuel recovery system connected to the fuel supply system for recovering fuel; A control device comprising:

2. the means for performing the reverse blow control performs the reverse blow control when a predetermined time has elapsed since the rotation speed has decreased to the low rotation speed. The control device according to claim 1 .

3. the means for performing the reverse blow control executes the reverse blow control at the same time that the rotation speed is reduced to the low rotation speed. The control device according to claim 1 .

4. The means for performing the reverse blow control introduces the air by switching a drain valve provided in the fuel recovery system from closed to open during the reverse blow control. The control device according to any one of claims 1 to 3.

5. a depressurization means for performing control to reduce pressure before the reverse blow control in a first fuel supply system that stops the supply of fuel before the operation of the gas turbine is stopped, among a plurality of fuel supply systems that supply fuel to the combustor; The control device according to any one of claims 1 to 3, further comprising:

6. purge means for supplying high-pressure air to the first fuel supply system before shutting down the gas turbine; The control device of claim 5 further comprising:

7. the pressure relief means reduces the pressure by opening a vent valve provided in a pipe connected to the first fuel supply system. The control device according to claim 5 .

8. a combustor of a gas turbine; a fuel supply system for supplying fuel to the combustor; a fuel recovery system connected to the fuel supply system for recovering the fuel; a drain valve provided in the fuel recovery system; The control device according to claim 1 or 2; A gas turbine fuel supply system comprising:

9. and controlling the air in the combustor to flow back through a nozzle provided in the combustor into a fuel supply system associated with the nozzle, and to guide the air to a fuel recovery system connected to the fuel supply system for recovering fuel, starting from a point at which the rotational speed of the gas turbine reaches a predetermined low rotational speed that is lower than a rated rotational speed after the gas turbine has stopped operating. Control method.

10. Computer, a means for performing reverse blow control for, starting from a point when the rotation speed of the gas turbine reaches a predetermined low speed that is lower than a rated rotation speed after the gas turbine has stopped operating, causing air in the combustor to flow back through a nozzle provided in the combustor into a fuel supply system related to the nozzle, and guiding the air to a fuel recovery system connected to the fuel supply system for recovering fuel; A program to function as a

Images