Cooling device, gas turbine installation with the same and method for operating the cooling device

Abstract

Cooling device (60;60a;60b) comprising: a hot-section cooling system (70; 70a; 70b) comprising a compressor (77) operable independently of a gas turbine (10), the hot-section cooling system (70; 70a; 70b) being configured to extract air in a casing (15, 16) of the gas turbine (10) from the casing (15, 16) via a hot-section cooling line (71; 71b), to pressurize the air with the compressor (77) and to direct the air to a hot section forming part of the gas turbine (10) and coming into contact with the combustion gas; and a rotor cooling system (80) configured to extract the air in the housing (15, 16) from the housing (15, 15) and to direct the air to a rotor (51) of the gas turbine (10); characterized by a connection system (90) configured to direct the air pressurized by the compressor (77) in the hot-part cooling system (70; 70a; 70b) to the rotor cooling system (80) while a fuel supply to the gas turbine (10) is interrupted, wherein the connection system (90) comprises: a connecting line (91) connected to the hot part cooling line (71,71b) at a position closer to the hot part than a position where the compressor (77) is arranged, and configured to guide the air pressurized by the compressor (77) to the rotor cooling system (80); a connection control valve (98) provided on the connection line (91); and a control device (100) which closes the connection control valve (98) during the fuel supply to the gas turbine (10) and opens the connection control valve (98) when the fuel supply is interrupted.

Description

Technical area

[0001] The present invention relates to a cooling device of a gas turbine, a gas turbine installation equipped with the cooling device and a method for operating the cooling device.

[0002] A gas turbine includes a compressor that compresses atmospheric air to produce compressed air, a combustion chamber that burns fuel in the compressed air to produce combustion gas, and a turbine driven by the combustion gas. The compressor includes a compressor rotor that rotates about an axis and a compressor housing that covers the compressor rotor while allowing the compressor rotor to rotate. The turbine includes a turbine rotor that rotates about an axis and a turbine housing that covers the turbine rotor while allowing the turbine rotor to rotate.

[0003] A predetermined clearance (hereinafter referred to as a tip clearance) is required between the outer end, in the radial direction, of a blade of the turbine rotor and the inner peripheral surface of the turbine casing. In terms of turbine efficiency, it is desirable to minimize the tip clearance as much as possible.

[0004] Furthermore, when the gas turbine is stopped, the temperature of the turbine rotor disposed inside the turbine casing decreases more slowly than that of the turbine casing exposed to the outside air. Therefore, after the gas turbine is stopped, the reduction in thermal expansion per unit time of the turbine rotor is smaller than the reduction in thermal expansion per unit time of the turbine casing. Consequently, when the gas turbine is stopped, the tip clearance is temporarily reduced. When the gas turbine is started in this state, the position of the outer end of the blade in the radial direction is shifted to the outer side in the radial direction due to centrifugal force acting on the turbine rotor, which in turn may cause the blade of the turbine rotor to come into contact with the inner peripheral surface of the turbine casing.

[0005] Therefore, in the technology disclosed in the following Patent Document 1, at the start of the gas turbine, the turbine rotor is cooled by pressurized air taken from a gas turbine casing using a fan and by supplying the air into the turbine rotor. In the technology disclosed in JP H11-050809A, cooling the turbine rotor in the manner described above to increase the tip clearance at the start of the gas turbine prevents the blade of the turbine rotor from contacting the inner peripheral surface of the turbine casing. Technical problem

[0006] In the technology disclosed in JP H11-050 809 A, although the turbine rotor is cooled at the start of the gas turbine, there is a time difference between the start of cooling and the enlargement of the tip clearance, which may cause tip contact.

[0007] Document DE 697 07 863 T2 discloses a closed cooling circuit system for combustion turbines for cooling hot parts on the stator side and rotor blades with cooling air extracted from a compressor of the gas turbine and compressed with an auxiliary compressor. Document JP 2001-271 655 A discloses a cooling device of a gas turbine with several separate cooling lines for stator-side and rotor-side components, both of which extract compressed air from the casing of the gas turbine, wherein the cooling air of the stator-side cooling line is additionally recompressed by a separate compressor.

[0008] The document US 2010 / 0 154 434 A1 discloses a gas turbine with an additional compressor which, when the gas turbine is shut down, extracts cooling air from the compressor of the gas turbine and compresses it before it is fed to a hot part in the turbine.

[0009] The document US 2011 / 0 138 818 A1 discloses a gas turbine with an air inlet duct for taking in outside air to cool turbine parts.

[0010] In view of the foregoing, an object of the present invention is to provide a technology that can ensure a tip clearance at the start of a gas turbine. Technical solution

[0011] The inventive solution to this problem provides a cooling device with the features of patent claim 1 and a method for operating a cooling device with the features of patent claim 7. Preferred embodiments are specified in the dependent claims.

[0012] A cooling device according to one aspect of the invention to solve the problems described above comprises: a hot part cooling system including a compressor that can be operated independently of a gas turbine, the hot part cooling system being configured to extract air in a casing of the gas turbine from the casing, pressurize the air with the compressor, and supply the air to a hot part that forms part of the gas turbine and comes into contact with combustion gas; a rotor cooling system configured to extract the air in the casing from the casing and supply the air to a rotor of the gas turbine; and a connection system configured to supply the air pressurized by the compressor to the rotor cooling system while a fuel supply to the gas turbine is interrupted.

[0013] During fuel supply to the gas turbine, the cooling device can cause the hot-section cooling system to cool the hot section with air drawn from inside the casing. During fuel supply to the gas turbine, the cooling device can further cause the rotor cooling system to cool the rotor with air drawn from inside the casing. Even if the fuel supply to the gas turbine is interrupted, the cooling device can also direct the air pressurized by the hot-section cooling system compressor to the rotor via the connection system and the rotor cooling system. Consequently, the cooling device can cool the rotor even if the fuel supply to the gas turbine is interrupted.

[0014] According to the invention, the hot-part cooling system of the cooling device comprises a hot-part cooling line provided with the compressor, which extracts the air in the casing from the casing and guides the air to the hot part. According to the invention, the connection system comprises a connection line connected to the hot-part cooling line at a position closer to the hot part than a position where the compressor is provided, and which guides the air pressurized by the compressor to the rotor cooling system; a connection control valve provided on the connection line; and a control device that closes the connection control valve during fuel supply to the gas turbine and opens the connection control valve when fuel supply is interrupted.

[0015] Because the connecting control valve in the cooling device at the fuel supply to the gas turbine is closed, the air pressurized by the hot-section cooling system's compressor does not flow into the connecting line and flows entirely into the hot-section cooling line. Consequently, during the fuel supply to the gas turbine, the cooling device can efficiently direct the air pressurized by the hot-section cooling system's compressor to the hot section.

[0016] Furthermore, in the cooling device with the control device, the hot-section cooling system may include a hot-section cooling control valve arranged on the hot-section cooling line at a position closer to the hot section than a position where the connecting line is connected to the hot-section cooling line. The control device may open the hot-section cooling control valve during fuel supply to the gas turbine and may close the hot-section cooling control valve when the fuel supply is interrupted.

[0017] Because the hot-end cooling control valve in the cooling device is closed when the fuel supply to the gas turbine is interrupted, the air pressurized by the hot-end cooling system compressor does not flow toward the hot-end side of the hot-end cooling line, but flows entirely into the connecting line. Consequently, when the fuel supply to the gas turbine is interrupted, the cooling device can efficiently direct the air pressurized by the hot-end cooling system compressor to the rotor cooling system via the connecting system.

[0018] In any of the cooling devices described above with the control device, the rotor cooling system may include: a rotor cooling line that takes the air in the casing from the casing and supplies the air to the rotor of the gas turbine; and a rotor cooling control valve provided in the rotor cooling line. The connecting line may be connected to the rotor cooling line at a position closer to the rotor than a position where the rotor cooling control valve is disposed. The control device may open the rotor cooling control valve during fuel supply to the gas turbine and may close the rotor cooling control valve when the fuel supply is interrupted.

[0019] Consequently, when the fuel supply to the gas turbine is cut off in the cooling device, the air pressurized by the compressor of the hot-end cooling system flows into the rotor cooling line via the connecting line. Since the rotor cooling control valve, which is connected to the connecting line in the rotor cooling line at a position closer to the casing than a position where the rotor cooling line is provided, is closed in the cooling device when the fuel supply to the gas turbine is cut off, the air flowing from the connecting line into the rotor cooling line does not flow toward the casing but flows entirely toward the rotor. Thus, while the fuel supply to the gas turbine is cut off, the cooling device can efficiently direct the air pressurized by the compressor of the hot-end cooling system to the rotor.

[0020] In each of the cooling devices described above with the control device, the control device can cause the compressor to be driven at least temporarily during a required cooling period, which begins when the fuel supply to the gas turbine is interrupted and ends at a predetermined time. If the fuel supply to the gas turbine is not resumed during the required cooling period, the control device can cause the compressor to stop after the required cooling period has elapsed.

[0021] Since the drive time of the compressor in the refrigeration device can be restricted, the energy consumption for driving the compressor can be suppressed.

[0022] In any of the cooling devices having the control device described above, the hot-part cooling system may include: an air intake duct connected to the hot-part cooling duct at a position closer to the casing than the position where the compressor is provided, and taking in atmospheric air; a filter that removes foreign matter from the atmospheric air flowing through the air intake duct; and an air intake regulating valve provided on the air intake duct at a position closer to a connection position of an air intake duct with the hot-part cooling duct than the filter. The control device may close the air intake regulating valve during fuel supply to the gas turbine and may open the air intake regulating valve when fuel supply is interrupted.

[0023] While the fuel supply to the gas turbine is interrupted in the cooling device, atmospheric air, which has a lower temperature than the air in the casing, can be drawn into the hot-section cooling system. After the air is pressurized by the compressor, the air can be supplied to the rotor. Consequently, the cooling device can efficiently cool the rotor while the fuel supply to the gas turbine is interrupted.

[0024] A gas turbine installation according to an aspect of the invention for solving the above-described problem includes each of the above-described cooling devices and the gas turbine.

[0025] A method of operating a cooling device according to one aspect of the invention to solve the problems described above is a method of operating a cooling device including: a hot part cooling system that includes a compressor that can be operated independently of a gas turbine, and that takes air in a casing of the gas turbine from the casing to pressurize the air with the compressor and supply the air to a hot part that forms part of the gas turbine and comes into contact with combustion gas; and a rotor cooling system that takes the air in the casing from the casing and supplies the air to a rotor of the gas turbine.The method of operating the cooling device includes: a hot part cooling step for cooling the hot part by driving the compressor during fuel supply to the gas turbine and supplying air from the hot part cooling system to the hot part; a first rotor cooling step for cooling the rotor by supplying air from the rotor cooling system to the rotor during fuel supply to the gas turbine; and a second rotor cooling step for cooling the rotor by driving the compressor while fuel supply to the gas turbine is interrupted and supplying the air pressurized by the compressor to the rotor via the rotor cooling system.

[0026] In the operating method, during the fuel supply to the gas turbine, the hot part can be cooled by the hot part cooling system with the air taken from inside the casing. Furthermore, in the operating method, during the fuel supply to the gas turbine, the rotor can be cooled with the air taken from inside the casing as a result of the execution of the first rotor cooling step of the rotor cooling system. Furthermore, in the operating method, even if the fuel supply to the gas turbine is interrupted, the air pressurized by the compressor of the hot part cooling system can be supplied to the rotor via the rotor cooling system by performing the second rotor cooling step. Thus, in the operating method, the rotor can be cooled even if the fuel supply to the gas turbine is interrupted.

[0027] In the method of operating the cooling device here, in the second rotor cooling step, the air pressurized by the compressor may be propelled to flow into the rotor cooling system, and the air pressurized by the compressor may be prevented from flowing into the hot part.

[0028] Further, in any of the above-described methods for operating the cooling device in the second rotor cooling step, the air pressurized by the compressor and flowing into the rotor cooling system may be prevented from flowing toward the casing in the rotor cooling system and may be propelled to flow toward the rotor in the rotor cooling system.

[0029] Furthermore, in any of the above-described methods for operating the cooling device in the hot part cooling step, the air pressurized by the compressor may be prevented from flowing into the rotor cooling system, and the air pressurized by the compressor may be propelled to flow into the hot part.

[0030] Furthermore, in any of the above-described methods for operating the cooling device, the second rotor cooling step may be performed by driving the compressor at least temporarily during a necessary cooling period that begins when the fuel supply to the gas turbine is interrupted and ends at a predetermined time. If the fuel supply to the gas turbine is resumed during the necessary cooling period, the hot-part cooling step and the first rotor cooling step may be performed after the second rotor cooling step is completed. If the fuel supply to the gas turbine is not resumed during the necessary cooling period, the second rotor cooling step may be completed by stopping the compressor after the necessary cooling period has elapsed.

[0031] In any of the methods for operating the cooling device described above, in the second rotor cooling step, atmospheric air may be taken in by the compressor in the hot part cooling system, and the atmospheric air may be supplied to the rotor via the rotor cooling system. Advantageous effects of the invention

[0032] According to one aspect of the present invention, a tip clearance can be secured during start-up of the gas turbine. Short description of the drawings Fig. 1 is an entire side sectional view of main portions of a gas turbine of an embodiment according to the present invention. Fig. 2 is a cross-sectional view of the main portions of the gas turbine of the embodiment according to the present invention. Fig. 3 is an explanatory diagram showing a configuration of a cooling device of the embodiment according to the present invention. Fig. 4 is a cross-sectional view of a combustion liner of the embodiment according to the present invention. Fig. 5 is a cross-sectional view taken along a line VV of Fig. 4. Fig. 6 is a perspective sectional view of main portions of the combustion liner of the embodiment according to the present invention. Fig. 7 is a timing chart of different cooling steps of the embodiment according to the present invention. Fig. 8 is an explanatory diagram showing a configuration of a cooling device of a first modified example of the embodiment according to the present invention. Fig. 9 is an explanatory diagram showing a configuration of a cooling device of a second modified example of the embodiment according to the present invention.

[0033] An embodiment of a gas turbine installation according to the present invention and modified examples of the embodiment will be described in detail below with reference to the drawings. Embodiment

[0034] An embodiment of a gas turbine installation according to the present invention will be described below with reference to Fig. 1 to 7 described.

[0035] As in Fig. 1, the gas turbine installation of the present embodiment includes a gas turbine 10 and a cooling device 60 that cools some components of the gas turbine 10.

[0036] The gas turbine 10 includes a compressor 20 that compresses air, a combustion chamber 30 that burns fuel in the air compressed by the compressor 20 to produce combustion gas, and a turbine 50 driven by the combustion gas.

[0037] As in Fig. 2, the compressor 20 includes a compressor rotor 21 that rotates around an axis Ar, a compressor housing 25 that covers the compressor rotor 21 while allowing the compressor rotor 21 to rotate, and a plurality of vane stages 26. Note that in the following description, a direction in which the axis Ar extends is referred to as an axial direction Da, a compressor side in the axial direction Da is referred to as an upstream side, and a turbine side is referred to as a downstream side. Further, a circumferential direction around the axis Ar is simply referred to as a circumferential direction Dc, and a perpendicular direction with respect to the axis Ar is referred to as a radial direction Dr. The compressor rotor 21 includes a rotor shaft 22 that extends in the axial direction Da along the axis Ar and a plurality of vane stages 23 attached to the rotor shaft 22.The plurality of blade stages 23 are arranged side by side in the axial direction Da. Each of the blade stages 23 consists of a plurality of blades 23a arranged side by side in the circumferential direction Dc. The vane stage 26 is arranged on the downstream side of each of the plurality of blade stages 23. Each of the vane stages 26 is provided within the compressor housing 25. Each of the vane stages 26 consists of a plurality of vanes 26a arranged side by side in the circumferential direction Dc. An annular space defined between the outer peripheral side of the rotor shaft 22 in the radial direction and the inner peripheral side of the compressor housing 25 in the radial direction forms, in a region where the blades 26a and the vanes 23a are arranged in the axial direction Da, an air compression flow channel 29 in which air is compressed while flowing therethrough.

[0038] The turbine 50 includes a turbine rotor 51 rotating around the axis Ar, a turbine casing 55 covering the turbine rotor 51 while allowing the turbine rotor 51 to rotate, and a plurality of vane stages 56. The turbine rotor 51 includes a rotor shaft 52 extending in the axial direction Da along the axis Ar and a plurality of vane stages 53 attached to the rotor shaft 52. The plurality of vane stages 53 are arranged side by side in the axial direction Da. Each of the vane stages 53 consists of a plurality of blades 53a arranged side by side in the circumferential direction Dc. The vane stage 56 is arranged on the upstream side of each of the plurality of vane stages 53. Each of the vane stages 56 is provided within the turbine casing 55. Each of the vane stages 56 consists of a plurality of vanes 56a arranged side by side in the circumferential direction Dc.The turbine housing 55 includes a cylindrical turbine housing main body 55a forming an outer shell of the turbine housing 55, and a plurality of ring segments 55b secured within the turbine housing 55. Each of the plurality of ring segments 55b is disposed at a position between the plurality of vane stages 56. Consequently, the vane stage 53 is disposed on the inner side of each of the ring segments 55b in the radial direction. An annular space defined between the outer peripheral side of the rotor shaft 52 and the inner peripheral side of the turbine housing 55 forms a combustion gas flow channel 59 through which combustion gas G flows from the combustion chamber 30 in a region where the vanes 56a and the vanes 53a are disposed in the axial direction Da. A cooling air flow channel 52p is formed in the rotor shaft 52 through which cooling air flows.Furthermore, a cooling air flow channel 53p is formed in each of the blades 53a, which communicates with the cooling air flow channel 52p of the rotor shaft 52. One end of the cooling air flow channel 53p formed in the blade 53a is open on a surface of the blade 53a. Specifically, the cooling air flow channel 53p formed in the blade 53a communicates with the combustion gas flow channel 59.

[0039] The compressor rotor 21 and the turbine rotor 51 are positioned on the same axis Ar and are connected to each other to form a gas turbine rotor 11. A rotor of a generator (not shown), for example, is connected to this gas turbine rotor 11. Further, the compressor housing 25 and the turbine housing 55 are connected to each other to form a gas turbine housing 15. The air compression flow channel 29 and the combustion gas flow channel 59 are separated from each other in the axial direction Da. In the gas turbine housing 15, an intermediate housing 16 is formed between the air compression flow channel 29 and the combustion gas flow channel 59 in the axial direction Da. The combustion chamber 30 is attached to the intermediate housing 16.

[0040] As in Fig. 2 and Fig. As shown in Figure 3, the combustion chamber 30 includes a combustion liner (or transition piece) 41 through which the high-temperature, high-pressure combustion gas G flows into the combustion gas flow passage 59 of the turbine 50, and a fuel supply unit 31 that supplies fuel and compressed air into the combustion liner 41. The fuel supply unit 31 includes a plurality of nozzles 32 that inject fuel into the combustion liner 41. A fuel line 34 is connected to each of the nozzles 32. The fuel line 34 is provided with a fuel flow rate control valve 35 that controls a flow rate of the fuel supplied to the plurality of nozzles 32. The combustion chamber 30 further includes a cooling air distributor 46 positioned closer to the combustion gas flow channel 59 of the turbine 50 and attached to the outer periphery of the combustion liner 41.The cooling air distributor 46 and the outer circumference of the combustion cylinder 41 define a space therebetween, allowing the cooling air to accumulate therein.

[0041] As in Fig. As shown in Figures 4 to 6, the combustion liner 41 consists of an outer peripheral wall plate 41o and an inner peripheral wall plate 41i. The outer peripheral wall plate 41o and the inner peripheral wall plate 41i are joined together by brazing and the like. A plurality of grooves 42 are formed in one of the outer peripheral wall plates 41o and the inner peripheral wall plates 41i, each of which is recessed in the direction away from the outer wall plate and elongated in the direction along the center axis of the combustion liner 41. Clearances between the inner surfaces of the grooves 42 and the surface of the outer wall plate form cooling air flow channels 43 through which the cooling air flows. In portions of the outer peripheral plate 41o where the cooling air distributor 46 is provided, a plurality of inlet openings 44 are formed, which penetrate into a clearance in the cooling air distributor 46 from the cooling air flow channels 43.Furthermore, in a region of the outer peripheral plate 41o located on the upstream side of the cooling air distributor 46, a plurality of outlet openings 45 are formed over the entire circumference of the region. The plurality of outlet openings 45 penetrate from the cooling air flow channels 43 to the inside of the intermediate casing 16, which is the outer side of the combustion liner 41. Note that the upstream side mentioned here is the upstream side of the combustion chamber 30, namely, a side on which the fuel supply unit 31 is positioned with respect to the combustion liner 41.

[0042] The compressor 20 draws in outside air and compresses the air as the air flows through the air compression flow channel 29. The compressed air, namely the compressed air, flows from the air compression flow channel 29 of the compressor 20 into the intermediate housing 16. The compressed air is supplied to the combustion liner 41 via the fuel supply unit 31 of the combustion chamber 30. Fuel is injected into the combustion liner 41 from the plurality of nozzles 32 of the fuel supply unit 31. The fuel is combusted in the compressed air in the combustion liner 41. The combustion gas G is generated as a result of this combustion, and this combustion gas G flows from the combustion liner 41 into the combustion gas flow channel 59 of the turbine 50. The turbine rotor 51 rotates by passing the combustion gas G through the combustion gas flow channel 59.

[0043] As described above, among the components of the gas turbine 10, the combustion liner 41, the blades 53a, the vanes 56a, the ring segments 55b, and the like are all in contact with the high-temperature combustion gas G. Consequently, the combustion liner 41, the blades 53a, the vanes 56a, the ring segments 55b, and the like constitute hot parts.

[0044] As in Fig. 3, the cooling device 60 includes a hot part cooling system 70 that extracts the air in the intermediate housing 16 from the interior of the intermediate housing 16, cools the air, then pressurizes the air and directs the air to the combustion liner 41, a rotor cooling system 80 that extracts the air in the intermediate housing 16 from the interior of the intermediate housing 16, cools the air, and then directs the air to the rotor shaft 52 of the turbine rotor 51, and a connection system 90 that directs the air in the hot part cooling system 70 to the rotor cooling system 80.

[0045] The hot-section cooling system 70 includes a hot-section cooling line 71 that draws the compressed air from the interior of the intermediate housing 16 and directs the air to the cooling air manifold 46 located on the combustion liner 41. The hot-section cooling system 70 further includes a cooler A 76, an auxiliary compressor 77, and a hot-section cooling control valve 78, all located in the hot-section cooling line 71.

[0046] The cooler A 76 can be any type of cooler as long as the cooler can cool the compressed air taken from the intermediate casing 16. Specifically, the cooler A 76 can be a water-cooling type that cools the compressed air using a coolant such as water, or an air-cooling type that cools the compressed air by supplying air to a pipe through which compressed air flows, for example, using a blower or the like. The auxiliary compressor 77 pressurizes the compressed air taken from the intermediate casing 16. This auxiliary compressor 77 can be operated independently of the gas turbine 10. Consequently, the auxiliary compressor 77 can operate even when the gas turbine 10 is turned off.

[0047] The hot-section cooling line 71 includes a shell-to-chassis A line 72 connecting the intermediate shell 16 and the chiller A 76, a chiller A-to-compressor line 73 connecting the chiller A 76 and a suction port of the auxiliary compressor 77, a compressor-to-chassis line 74 connecting an exhaust port of the auxiliary compressor 77 and the intermediate shell 16, and an in-chassis A line 75 connecting the compressor-to-chassis line 74 and the cooling air manifold 46 provided on the combustion liner 41. The hot-section cooling control valve 78 is arranged on the compressor-to-chassis line 74. The compressed air in the intermediate housing 16 can flow into the cooling air distributor 46 through the housing-to-cooler A line 72, the cooler A-to-compressor line 73, the compressor-to-housing line 74 and the in-housing A line 75.

[0048] The rotor cooling system 80 includes a rotor cooling line 81 that draws the compressed air from the interior of the intermediate housing 16 and directs the air to the rotor shaft 52 of the turbine 50. The rotor cooling system 80 further includes a cooler B 86 provided in the rotor cooling line 81, an inertia filter 87, and a rotor cooling control valve 88.

[0049] Like cooler A 76, cooler B 86 can be any type of cooler as long as the cooler cools the compressed air taken from the intermediate housing 16, and it can be, for example, a water-cooling type or an air-cooling type. A curved flow channel is formed in the inertia filter 87. The inertia filter 87 has a section configured to capture foreign matter in the air flowing out by inertia. Note that a filter used here does not necessarily have to be such an inertia filter. Furthermore, the rotor cooling system 80 does not necessarily require the filter, and the filter may be omitted.

[0050] The rotor cooling line 81 includes a casing-to-cooler B line 82 connecting the intermediate casing 16 and the cooler B 86, a cooler B-to-filter line 83 connecting the cooler B 86 and the inertia filter 87, a filter-to-casing line 84 connecting the inertia filter 87 and the intermediate casing 16, and an in-casing B line 85 connecting the filter-to-casing line 84 and the rotor shaft 52 of the turbine 50. The rotor cooling control valve 88 is arranged on a casing-to-cooler line. The in-casing B line 85 is connected to the above-described cooling air flow channel 52p formed in the rotor shaft 52 of the turbine 50.

[0051] The connection system 90 includes a connection line 91 that directs the air in the hot-section cooling line 71 into the rotor cooling line 81, and a connection control valve 98 disposed on the connection line 91. One end of the connection line 91 is connected to a position between the auxiliary compressor 77, which is disposed in the compressor-to-casing line 74, and the hot-section cooling control valve 78. Furthermore, the other end of the connection line 91 is connected to the cooler B-to-filter line 83. The connection system 90 further includes a control device 100 that controls operation of the connection control valve 98.

[0052] The control device 100 includes a main control unit 101, which receives external charging commands, signals from various sensors, and the like; a fuel control unit 102, which controls the lifting of the fuel flow rate control valve 35 in accordance with an instruction from the main control unit 101; a compressor control unit 104, which controls the operation of the auxiliary compressor 77; and a valve control unit 105, which controls the operation of each of the control valves 78, 88, and 98 of the cooling device 60. The valve control unit 105 of this control device 100 controls not only the operation of the above-described connection control valve 98, but also the operations of the hot-part cooling control valve 78 and the rotor cooling control valve 88.The valve control unit 105 and the compressor control unit 104 constitute the control device 103 of the drive unit (each of the control valves and the auxiliary compressor 77) arranged in the cooling device 60.

[0053] Now, an operation of the gas turbine installation described above is described.

[0054] As described above, during operation of the gas turbine 10, the compressor 20 compresses the air to generate compressed air.

[0055] The main control unit 101 of the control device 100 determines a flow rate of the fuel supplied to the plurality of nozzles 32 of the fuel supply unit 31 in accordance with the charging commands or the signals from the various sensors. The fuel control unit 102 determines a valve lift of the fuel flow rate control valve 35 in accordance with the fuel flow rate determined by the main control unit 101 and transmits a signal indicative of the valve lift to the fuel flow rate control valve 35. The fuel flow rate control valve 35 is driven in accordance with this signal and is adjusted to the valve lift indicated by the signal. Consequently, the fuel is supplied to the plurality of nozzles 32 at a flow rate determined by the main control unit 101.

[0056] The compressed air generated by the compressor 20 flows into the combustion chamber 30 via the interior of the intermediate casing 16. The fuel supply unit 31 of the combustion chamber 30 supplies the compressed air into the combustion liner 41. Further, the plurality of nozzles 32 of the fuel supply unit 31 inject the fuel supplied via the fuel flow rate control valve 35 into the combustion liner 41. The fuel is burned in the compressed air in the combustion liner 41. This combustion generates the combustion gas G, and this combustion gas G flows from the combustion liner 41 into the combustion gas flow channel 59 of the turbine 50. The turbine rotor 51 rotates as this combustion gas G is passed through the combustion gas flow channel 59.

[0057] During operation of this gas turbine 10, the hot-section cooling control valve 78 of the hot-section cooling system 70 is opened in accordance with the instruction from the valve control unit 105, and the connection control valve 98 of the connection system 90 is closed in accordance with the instruction from the valve control unit 105. During operation of this gas turbine 10, the auxiliary compressor 77 of the hot-section cooling system 70 is driven in accordance with the instruction from the compressor control unit 104. Consequently, a portion of the compressed air in the intermediate casing 16 is extracted, then caused to flow into the cooler A 76 through the casing-to-cooler A line 72 of the hot-section cooling system 70, and is cooled in the cooler A 76. The compressed air that has been cooled flows through the cooler A-to-compressor line 73 as cooling air into the auxiliary compressor 77 and is further pressurized in the auxiliary compressor 77.The cooling air flows into the cooling air distributor 46 of the combustion chamber 30 through the compressor-to-housing line 74 and the in-housing A line 75.

[0058] As in Fig. 6, cooling air CA, which passed through the cooling air distributor 46, flows through the cooling air flow channel 43 of the combustion liner 41 through the inlet ports 44 of the combustion liner 41 and returns to the interior of the intermediate casing 16 through the outlet ports 45 of the combustion liner 41. The cooling air CA, which is the compressed air cooled in the cooler A 76, exchanges heat with the combustion liner 41 to cool the combustion liner 41 while passing through the cooling air flow channel 43 of the combustion liner 41.

[0059] As described above, the compressed air that cools the combustion liner 41 is taken from the inside of the intermediate casing 16, pressurized by the auxiliary compressor 77, and then returns to the inside of the intermediate casing 16 through the cooling air flow passage 43 of the combustion liner 41.

[0060] During operation of the gas turbine 10, the rotor cooling control valve 88 of the rotor cooling system 80 is opened in accordance with the instruction from the valve control unit 105. Consequently, a portion of the compressed air in the intermediate casing 16 is taken out, then caused to flow into the cooler B 86 through the casing-to-cooler B line 82 of the rotor cooling system 80, and is cooled in the cooler B 86. The cooled compressed air flows as cooling air through the cooler B-to-filter line 83 into the inertia filter 87, and foreign matter is removed in the inertia filter 87. This cooling air flows through the filter-to-casing line 84 and the in-casing B line 85 into the cooling air flow channel 52p formed in the rotor shaft 52 of the turbine rotor 51. The cooling air exchanges heat with the rotor shaft 52 to cool the rotor shaft 52 as it flows through the cooling air flow channel 52p of the rotor shaft 52.Further, the cooling air flows into the cooling air flow channel 53p formed in each of the plurality of blades 53a of the turbine rotor 51. The cooling air exchanges heat with the blade 53a to cool the blade 53a as it passes through the cooling air flow channel 53p of the blade 53a. The cooling air that has cooled the blade 53a flows into the combustion gas flow channel 59 from the cooling air flow channel 53p and is mixed with the combustion gas G.

[0061] As described above, during operation of the gas turbine, in which the fuel is supplied to the gas turbine 10 as in Fig. 7, the combustion liner 41, which is a hot part, is cooled as a result of the cooling air being supplied from the hot part cooling system 70 to the combustion liner 41 (S1: a hot part cooling step), and at the same time, the turbine rotor 51 is cooled as a result of the cooling air being supplied from the rotor cooling system 80 to the turbine rotor 51 (S2: a first rotor cooling step).

[0062] The main control unit 101 instructs the fuel control unit 102 to cut off the fuel supply through the external charge command or the like, and simultaneously notifies the valve control unit 105 that the fuel supply has been cut off. Upon receiving this instruction, the fuel control unit 102 transmits a signal indicating the valve lift to the fuel flow rate control valve 35 as zero. Specifically, the fuel control unit 102 instructs the fuel flow rate control valve 35 to close the valve. Consequently, the fuel flow rate control valve 35 is closed, thus cutting off the supply of fuel to the plurality of nozzles 32 of the fuel supply unit 31.

[0063] Further, upon receiving the message from the main control unit 101 indicating that the fuel supply has been cut off, the valve control unit 105 instructs the hot-end cooling control valve 78 and the rotor cooling control valve 88 to close, and simultaneously instructs the link control valve 98 to open. Consequently, the hot-end cooling control valve 78 and the rotor cooling control valve 88 are closed, and the link control valve 98 is opened. Consequently, a portion of the air in the intermediate housing 16 is extracted, then caused to flow into the cooler A 76 through the housing-to-cooler A line 72 of the hot-end cooling system 70, and is cooled in the cooler A 76. The cooled air flows through the cooler A-to-compressor line 73 as cooling air into the auxiliary compressor 77 and is pressurized in the auxiliary compressor 77.This cooling air flows through part of the compressor-to-casing line 74 and the connecting line 91 of the connecting system 90 into the inertial filter 87 of the rotor cooling system 80, and foreign matter is removed in the inertial filter 87. The cooling air flows through the filter-to-casing line 84 and the in-casing B line 85 of the rotor cooling system 80 into the cooling air flow channel 52p formed in the rotor shaft 52 of the turbine rotor 51. The cooling air exchanges heat with the rotor shaft 52 to cool the rotor shaft 52 as it flows through the cooling air flow channel 52p of the rotor shaft 52. Further, the cooling air flows into the combustion gas flow passage 59 through the cooling air flow passage 53p formed in each of the plurality of blades 53a of the turbine rotor 51.

[0064] In a state where the fuel supply to the gas turbine 10 is cut off, no combustion gas G is generated, and the compressor rotor 21 and the turbine rotor 51 are not actually rotating. The pressure in the intermediate casing 16 and the pressure in the combustion gas flow passage 59 are substantially equal to atmospheric pressure. Therefore, in the present embodiment, in the fuel supply cut off state, a portion of the compressed air is extracted from the interior of the intermediate casing 16, pressurized by the auxiliary compressor 77, and then supplied to the turbine rotor 51 to cool the turbine rotor 51 (S3: a second rotor cooling step).

[0065] As described above, in the state where the fuel supply to the gas turbine 10 is cut off, the cooling air pressurized by the auxiliary compressor 77 of the hot-section cooling system 70 is not supplied to the cooling air manifold 46 of the combustor 30 because the hot-section cooling control valve 78 is closed. Specifically, when the fuel supply to the gas turbine 10 is cut off, the hot-section cooling step (S1) is terminated. Further, as described above, in the state where the fuel supply to the gas turbine 10 is cut off, since the rotor cooling control valve 88 is closed, the air in the intermediate casing 16 does not flow into the cooler B 86 through the casing-to-cooler B line 82 of the rotor cooling system 80. Specifically, when the fuel supply to the gas turbine 10 is cut off, the first rotor cooling step (S2) is also terminated.

[0066] As in Fig. 7, when in particular the fuel supply to the gas turbine 10 is interrupted, the hot part cooling step (S1) and the first rotor cooling step (S2) are terminated, while on the other hand the second rotor cooling step (S3) is started.

[0067] In the state where the fuel supply to the gas turbine 10 is cut off and the combustion gas G is not generated, the temperature of the turbine rotor 51 disposed in the turbine casing 55 drops more slowly than that of the turbine casing 55 exposed to the outside air. Therefore, after the fuel supply to the gas turbine 51 is cut off, the amount of reduction in thermal expansion per unit time of the turbine rotor 51 is smaller than the amount of reduction in thermal expansion per unit time of the turbine casing 55. Consequently, after the fuel supply to the turbine rotor 51 is cut off, a tip clearance C is temporarily reduced. The tip clearance C is a clearance between the outer end of the blade 53a of the turbine rotor 51 in the radial direction and the inner peripheral surface of the turbine casing 55, namely, the inner peripheral surface of the ring segment 55b.As described above, when the gas turbine 10 is started with the reduced tip clearance C, the position of the outer end, in the radial direction, of the blade 53a is shifted to the outside in the radial direction due to the centrifugal force acting on the turbine rotor 51, which in turn may cause the blade 53a of the turbine rotor 51 to come into contact with the inner peripheral surface of the turbine casing 55.

[0068] Therefore, in the present embodiment, even in a state where the fuel supply to the gas turbine 10 is stopped and the combustion gas G is not generated, the air taken out from the intermediate casing 16 is pressurized by the auxiliary compressor 77 of the hot part cooling system 70, and this air is supplied to the inside of the turbine rotor 51 to cool the turbine rotor 51.

[0069] Incidentally, when a predetermined necessary cooling period elapses after the fuel supply to the gas turbine 10 is stopped, the turbine rotor 51 and the turbine casing 55 cool sufficiently, and a temperature difference between the turbine rotor 51 and the turbine casing 55 almost disappears. Therefore, when the predetermined necessary cooling period elapses after the fuel supply to the gas turbine 10 is stopped, the tip clearance C becomes larger than the tip clearance C obtained when the turbine rotor 51 is not cooled during the necessary cooling period, and the risk of the blade 53a of the turbine rotor 51 coming into contact with the inner peripheral surface of the turbine casing 55 is therefore eliminated.

[0070] As described above, in the present embodiment, during the predetermined necessary cooling period after the fuel supply to the gas turbine 10 is interrupted, the air taken from the intermediate casing 16 is directed to the inside of the turbine rotor 51 to thereby cool the turbine rotor 51. Consequently, as shown in Fig. 7, even when the gas turbine 10 is started during the necessary cooling period and the fuel supply to the gas turbine 10 is resumed, namely, even when the gas turbine 10 is warm-started, the contact between the blade 53a of the turbine rotor 51 and the inner peripheral surface of the turbine casing 55 can be prevented.

[0071] As in Fig. As shown in Figure 7, when the gas turbine 10 is started during the required cooling period T and the fuel supply to the gas turbine 10 is resumed, the second rotor cooling step (S3) is terminated, and the first rotor cooling step (S2) and a hot-section cooling step (S1) are resumed. Specifically, when the fuel supply to the gas turbine 10 is resumed in accordance with the instructions from the valve control unit 105, the hot-section cooling control valve 78 and the rotor cooling control valve 88 are opened, and the communication control valve 98 is closed.

[0072] Further, in the present embodiment, when the necessary cooling period T elapses without the gas turbine 10 being started during the necessary cooling period T , the main control unit 101 notifies the compressor control unit 104 that the necessary cooling period T elapses. Upon receiving the notification, the compressor control unit 104 stops the auxiliary compressor 77. Consequently, when the necessary cooling period T elapses without the gas turbine 10 being started during the necessary cooling period T , the second rotor cooling step (S3) is also terminated.

[0073] As described above, in the present embodiment, since the turbine rotor 51 is cooled during the necessary cooling period T after the fuel supply to the gas turbine 10 is stopped, even when the gas turbine 10 is warm-started, namely, when the gas turbine 10 is started during the necessary cooling period T, the contact between the blade 53a of the turbine rotor 51 and the inner peripheral surface of the turbine casing 55 can be prevented. Consequently, in the present embodiment, the tip clearance C obtained during steady-state operation can be further reduced, and the efficiency of the gas turbine 10 can therefore be improved.

[0074] Given that the hot-end cooling system 70 and the rotor cooling system 80 are already provided in the gas turbine 10, the cooling device 60 of the present embodiment can be formed by newly installing the connection system 90. Therefore, cooling of the turbine rotor 51 can be performed in a state where the fuel supply to the gas turbine 10 is interrupted. Consequently, in the present embodiment, installation costs can be reduced compared to a case where a device for cooling the turbine rotor 51 after the fuel supply to the gas turbine 10 is interrupted is separately provided. First modified example

[0075] A first modified example of the above-described embodiment of the gas turbine installation will be described below with reference to Fig. 8 described.

[0076] A gas turbine installation of the present modified example is a gas turbine installation obtained by changing a part of the cooling device 60 in the gas turbine installation of the above-described embodiment.

[0077] A hot part cooling system 70a in a cooling device 60a of the present modified example is a hot part cooling system obtained by adding an air intake duct 61 that takes in atmospheric air, a filter 62 that removes foreign matter from the atmospheric air flowing through the air intake duct 61, and an air intake control valve 68 arranged on the air intake duct 61 to the hot part cooling system 70 of the above-described structure.

[0078] One end of the air intake line 61 is open to the atmospheric air, and the other end is connected to the cooler A-to-compressor line 73. The filter 62 is provided on the air intake line 61. Further, the air intake control valve 68 is provided on the air intake line 61 at a position between the filter 62 and a connection position of the air intake line 61 to the cooler A-to-compressor line 73. The air intake control valve 68 is controlled by the valve control unit 105 of the control device 100.

[0079] In the present modified example, while the fuel is being supplied to the gas turbine 10, the valve control unit 105 instructs the hot-section cooling control valve 78 and the rotor cooling control valve 88 to open, and simultaneously instructs the communication control valve 98 to close, as in the above-described embodiment. Furthermore, in the present modified example, the valve control unit 105 instructs the air inlet control valve 68 to close. Consequently, the hot-section cooling control valve 78 and the rotor cooling control valve 88 are opened, and the communication control valve 98 and the air inlet control valve 68 are closed. Thus, while the fuel is being supplied to the gas turbine 10 in the same manner as in the above-described embodiment, the compressed air within the intermediate casing 16 is extracted by the hot-section cooling system 70a, and after being further cooled, this compressed air is supplied to the combustion liner 41 as cooling air.Furthermore, the compressed air within the intermediate casing 16 is extracted by the rotor cooling system 80, and after being further cooled, this compressed air is supplied to the turbine rotor 51 as cooling air. Specifically, in the present modified example, while the fuel is supplied to the gas turbine 10, the hot-part cooling step (S1) and the first rotor cooling step (S2) are also performed in the same manner as in the above-described embodiment.

[0080] In the present modified example, when the fuel supply to the gas turbine 10 is interrupted, the valve control unit 105 further instructs the hot-section cooling control valve 78 and the rotor cooling control valve 88 to close, and simultaneously instructs the communication control valve 98 to open, as in the above-described embodiment. Furthermore, in the present embodiment, the valve control unit 105 instructs the air intake control valve 68 to open. Consequently, the hot-section cooling control valve 78 and the rotor cooling control valve 88 are closed, and the communication control valve 98 and the air intake control valve 68 are opened. Consequently, in the present modified example, the outside air is taken into the auxiliary compressor 77 as the cooling air through the filter 62 and the air intake duct 61 and pressurized.Thereafter, the cooling air pressurized by the auxiliary compressor 77 is supplied to the turbine rotor 51 through the connecting line 91 of the connecting system 90 and the inertial filter 87, the filter-to-casing line 84 and the in-casing B line 85 of the rotor cooling system 80 in the same manner as in the embodiment described above.

[0081] Even after the fuel supply to the gas turbine 10 is interrupted, the temperature of the outside air is substantially lower than the temperature of the air in the intermediate casing 16. Therefore, even if the outside air is taken into the hot part cooling system 70a while the fuel supply to the gas turbine 10 is interrupted, the turbine rotor 51 can be cooled.

[0082] As described above, in the present modified example, the second rotor cooling step (S3) is implemented by taking in the outside air in the hot part cooling system 70a and supplying the outside air as the cooling air to the turbine rotor 51.

[0083] For example, when the cooler A 76 of the hot part cooling system 70a is configured so as not to be able to cool the air in the intermediate casing 16 after the fuel supply to the gas turbine 10 is stopped, the cooling of the turbine rotor 51 may be carried out in a state where the fuel supply to the gas turbine 10 has been stopped, taking in the outside air as a coolant for the turbine rotor 51, as in the present modified example.

[0084] Note that, in the present modified example, a second air inlet control valve is further provided in the radiator A-to-compressor line 73 at a position between the radiator A 76 and a connection position of the radiator A-to-compressor line 73 with the air inlet line 61 or in the case-to-radiator A line 72. The second air inlet control valve is opened when the air inlet control valve 68 provided on the air inlet line 61, namely the first air inlet control valve 68, is closed, and closed when the first air inlet control valve 68 is open. In this way, by providing the second air inlet control valve, the auxiliary compressor 77 is allowed to take in the outside air exclusively through the air inlet line 61 in the second rotor cooling step (S3). Alternatively, a three-way valve may be provided instead of the first air inlet control valve 68 and the second air inlet control valve. Second modified example

[0085] A second modified example of the above-described embodiment of the gas turbine installation will be described with reference to Fig. 9 described.

[0086] The hot-part cooling systems of the above-described embodiment and the first modified example are configured to cool the combustion liner 41 under the hot parts of the gas turbine 10. However, the hot-part cooling system may be configured to cool other hot parts.

[0087] As in Fig. For example, as shown in FIG. 9, a hot-part cooling system 70b of a cooling device 60b may be configured to cool the plurality of blades 56a. In this case, a hot-part cooling line 71b of the hot-part cooling system 70b is connected to the plurality of blades 56a of the turbine 50. A cooling air flow channel 56p through which the cooling air flows is formed in the blade 56a. The hot-part cooling line 71b is connected to the cooling air flow channel 56p. The cooling air flow channel 56a is open on the surface of the blade 56a. Specifically, the cooling air flow channel 56p formed in the blade 56a communicates with the combustion gas flow channel 59. Therefore, in the present modified example, the blade 56a, which is a hot part, can be cooled.

[0088] Note that in the present modified example, a method of using steam or the like for cooling the combustion liner 41 may be considered. Furthermore, in the present modified example, the cooling air is discharged into the combustion gas flow channel 59, but instead, the cooling air may be collected.

[0089] Furthermore, the hot part cooling system may be configured to cool the ring segments 55b, which are Fig. 2. Furthermore, the hot part cooling system may be configured to cool a plurality of types of hot parts among different types of hot parts. Another, modified example

[0090] In the above-described embodiment and the modified examples, immediately after the fuel supply to the gas turbine 10 is interrupted, the hot-part cooling step (S1) and the first rotor cooling step (S2) are stopped, and the second rotor cooling step (S3) is performed simultaneously. However, if the fuel supply to the gas turbine 10 is interrupted after the hot-part cooling step (S1) and the first rotor cooling step (S2) are stopped accordingly, the second rotor cooling step (S3) can be performed after a time interval.

[0091] Furthermore, in the above-described embodiment and modified examples, after the fuel supply to the gas turbine 10 is interrupted, if the gas turbine 10 is not started during the necessary cooling period T, the second rotor cooling step (S3) is continuously performed. However, the second rotor cooling step (S3) may be performed intermittently during the necessary cooling period T. Furthermore, while the fuel supply to the gas turbine 10 is interrupted, the second rotor cooling step (S3) may only be performed when a warm restart is scheduled. Industrial applicability

[0092] According to one aspect of the present invention, a tip clearance can be secured during start-up of the gas turbine. List of reference symbols 10 gas turbines 11 Gas turbine rotor 15 gas turbine casing 16 intermediate housing (or housing) 20 compressor 21 Compressor rotor 25 Compressor housing 30 combustion chamber 31 Fuel supply unit 41 Combustion lining (transition piece or hot section) 43 Cooling air flow channel 46 cooling air distributors 50 turbines 51 Turbine rotor 52 Rotor shaft 52p cooling air flow channel 53 Shovel stage 53a Shovel 53p Cooling air flow channel 55 Turbine housing 55a Turbine housing main body 55b ring segment 56 wing stage 56a Wing 56p cooling air flow channel 60, 60a, 60b cooling device 61 Air intake line 62 filters 68 Air intake control valve (first air intake control valve) 70, 70a, 70b Hot part cooling system 71, 71b, hot part cooling line 76 Radiator A 77 Additional compressor (or simply compressor) 78 Hot part cooling control valve 80 Rotor cooling system 81 Rotor cooling line 86 Radiator B 87 Inertial filters 88 Rotor cooling control valve 90 connection system 91 connecting line 98 connecting control valve 100 control device 101 Main control unit 102 Fuel control unit 104 Compressor control unit 105 Valve control unit

Claims

A cooling device (60; 60a; 60b) comprising: a hot-section cooling system (70; 70a; 70b) comprising a compressor (77) operable independently of a gas turbine (10), the hot-section cooling system (70; 70a; 70b) being configured to extract air in a casing (15, 16) of the gas turbine (10) from the casing (15, 16) via a hot-section cooling line (71; 71b), to pressurize the air with the compressor (77) and to direct the air to a hot section forming part of the gas turbine (10) and coming into contact with the combustion gas; anda rotor cooling system (80) configured to extract the air in the housing (15, 16) from the housing (15, 15) and to direct the air to a rotor (51) of the gas turbine (10);characterized bya connection system (90) configured to connect the air pressurized by the compressor (77) in the hot-section cooling system (70; 70a;70b) to the rotor cooling system (80) while a fuel supply to the gas turbine (10) is interrupted, wherein the connection system (90) comprises: a connection line (91) that is connected to the hot part cooling line (71, 71b) at a position closer to the hot part than a position at which the compressor (77) is arranged, and that is configured to direct the air pressurized by the compressor (77) to the rotor cooling system (80); a connection control valve (98) that is provided on the connection line (91); and a control device (100) that closes the connection control valve (98) during the fuel supply to the gas turbine (10) and opens the connection control valve (98) when the fuel supply is interrupted. The cooling device (60; 60a; 60b) according to claim 1, wherein the hot-part cooling system (70; 70a; 70b) comprises a hot-part cooling control valve (78) arranged on the hot-part cooling line (71; 71b) at a position closer to the hot part than a position at which the connecting line (91) is connected to the hot-part cooling line (71; 71b); and the control device (100) opens the hot-part cooling control valve (78) during fuel supply to the gas turbine (10) and closes the hot-part cooling control valve (78) when the fuel supply is interrupted. The cooling device (60; 60a; 60b) according to claim 1 or 2, wherein the rotor cooling system (80) comprises: a rotor cooling line (81) configured to extract the air in the casing from the casing and direct the air to the rotor of the gas turbine; and a rotor cooling control valve (88) arranged on the rotor cooling line (81), wherein the connecting line (91) is connected to the rotor cooling line (81) at a position closer to the rotor (51) than a position at which the rotor cooling control valve (88) is arranged, and wherein the control device (100) opens the rotor cooling control valve (80) during the fuel supply to the gas turbine (10) and closes the rotor cooling control valve (88) when the fuel supply is interrupted. Cooling device (60; 60a; 60b) according to one of claims 1 to 3, wherein the control device (100) is configured to drive the compressor (77) at least temporarily during a necessary cooling period that starts when the fuel supply to the gas turbine (10) is interrupted and ends at a predetermined time, and is configured to stop the compressor (77) after the necessary cooling period has elapsed if the fuel supply to the gas turbine (10) is not resumed during the necessary cooling period. Cooling device (60; 60a; 60b) according to one of claims 1 to 4, wherein the hot part cooling system (70; 70a; 70b) comprises: an air inlet duct (61) connected to the hot part cooling duct (71; 71b) at a position closer to the housing (15, 16) than the position where the compressor (77) is arranged, and receiving the atmospheric air; a filter (62) configured to remove foreign matter from the atmospheric air flowing through the air inlet duct (61); andan air inlet control valve (68) arranged on the air inlet line (61) at a position closer to a connection position of the air inlet line (61) with the hot part cooling line (71; 71b) than the filter (62), andwherein the control device (100) closes the air inlet control valve (68) during the fuel supply to the gas turbine (10) and opens the air inlet control valve (68) when the fuel supply is interrupted. Gas turbine installation comprising:the cooling device according to one of claims 1 to 5, andthe gas turbine (10). A method for operating a cooling device (60; 60a; 60b) comprising a hot-section cooling system (70; 70a; 70b) which comprises a compressor (77) which can be operated independently of a gas turbine (10), and which extracts air in a casing (15, 16) of the gas turbine (10) from the casing (15, 16) in order to pressurize the air with the compressor (77) and to direct the air to a hot section which forms part of the gas turbine (10) and comes into contact with combustion gas, and which comprises a rotor cooling system (80) which extracts the air in the casing (15, 16) from the casing (15, 16) and supplies the air to a rotor (51) of the gas turbine (10), the method comprising: a hot-section cooling step (S1) for cooling the hot section by operating the compressor (77) during a fuel supply to the gas turbine (10) and by directing air from the hot part cooling system (70;70a;70b) to the hot part;anda first rotor cooling step (S2) for cooling the rotor (51) by directing air from the rotor cooling system (80) to the rotor (51) during the fuel supply to the gas turbine (10);characterized byinstalling a connection system (90) that can direct the air in the hot-section cooling system (70; 70a; 70b) to the rotor cooling system (80); anda second rotor cooling step (S3) for cooling the rotor (51) by driving the compressor (77) while the fuel supply to the gas turbine (10) is interrupted, and directing air pressurized by the compressor (77) in the hot-section cooling system (70; 70a; 70b) via the connection system (90) to the rotor cooling system (80) and therein to the rotor (51). A method of operating the cooling device (60; 60a; 60b) according to claim 7, wherein in the second rotor cooling step (S3), the air pressurized by the compressor (77) is propelled to flow into the rotor cooling system (80) and the air pressurized by the compressor (77) is prevented from flowing into the hot part. A method for operating the cooling device (60; 60a; 60b) according to claim 7 or 8, wherein in the second rotor cooling step (S3), the air pressurized by the compressor (77) and flowing into the rotor cooling system (80) is prevented from flowing toward the housing (15, 16) in the rotor cooling system (80) and is propelled to flow toward the rotor (51) in the rotor cooling system (80). A method for operating the cooling device (60; 60a; 60b) according to any one of claims 7 to 9, wherein in the hot part cooling step (S1), the air pressurized by the compressor (77) is prevented from flowing into the rotor cooling system (80), and the air pressurized by the compressor (77) is propelled to flow into the hot part. A method for operating the cooling device (60; 60a; 60b) according to any one of claims 7 to 10, wherein the second rotor cooling step (S3) is carried out by driving the compressor (77) at least temporarily during a necessary cooling period that starts when the fuel supply to the gas turbine (10) is interrupted and ends at a predetermined time; when the fuel supply to the gas turbine (10) is resumed during the necessary cooling period, the hot part cooling step (S1) and the first rotor cooling step (S2) are carried out after the second rotor cooling step (S3) has been terminated; and if the fuel supply to the gas turbine (10) is not resumed during the necessary cooling period, the second rotor cooling step (S3) is terminated by stopping the compressor (77) after the necessary cooling period has elapsed. Method for operating the cooling device (60; 60a; 60b) according to one of claims 7 to 11, wherein in the second rotor cooling step (S3) atmospheric air is taken in by the compressor (77) in the hot part cooling system (70; 70a; 70b) and the atmospheric air is passed to the rotor (51) via the rotor cooling system (80).

Images