Gas Turbine System

Abstract

To suppress generation of NOx while stably burning ammonia.SOLUTION: A fuel supply facility includes: a main ammonia line in which liquid ammonia flows; a vaporizer connected to an end of the main ammonia line and heating and vaporizing the liquid ammonia by exchanging heat between a heating medium and the liquid ammonia; a gas ammonia line connected to the vaporizer and guiding gas ammonia that is ammonia vaporized by the vaporizer to a combustor of a gas turbine as fuel; a liquid ammonia line for guiding the liquid ammonia that has not undergone heat exchange with the heating medium in the vaporizer to the combustor as fuel; and a switching device capable of switching an ammonia supply state between a first state of guiding the gas ammonia from the gas ammonia line to the combustor and a second state of guiding the liquid ammonia from the liquid ammonia line to the combustor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure provides: Ammonia-fueled gas Starby System Regarding do. [Background technology]

[0002] A gas turbine includes a compressor that compresses air, a combustor that burns fuel in the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas. Patent Document 1 listed below discloses an example in which ammonia is used as fuel to be supplied to the combustor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 181002 Summary of the Invention [Problem to be solved by the invention]

[0004] When ammonia is used as a fuel for a gas turbine, part of the nitrogen that forms the ammonia becomes NOx. Therefore, when ammonia is used as a fuel for a gas turbine, it is desirable to reduce the amount of NOx produced. Furthermore, even when ammonia is used as a fuel for a gas turbine, it is desirable to burn the ammonia as stably as possible, just as when natural gas or the like is used as a fuel for a gas turbine.

[0005] Therefore, an object of the present disclosure is to provide a technology that, when ammonia is used as a fuel for a gas turbine, can stably supply ammonia and stably combust ammonia from the start-up of the gas turbine to rated load operation, while suppressing the generation of NOx. [Means for solving the problem]

[0006] One aspect of the gas turbine system for achieving the above object is a gas turbine system including a combustor, a turbine connected to the combustor, a heating unit for heating liquid ammonia as fuel, a first fuel supply line capable of supplying the fuel heated by the heating unit to at least one fuel nozzle provided in the combustor, and a fuel supply line for supplying liquid ammonia that is not heated by the heating unit to at least one fuel nozzle provided in the combustor. In liquid form and a second fuel supply line capable of supplying the at least one fuel nozzle. In this case, the heating unit vaporizes the liquid ammonia as fuel. The first fuel supply line is capable of supplying the vaporized gaseous ammonia to the fuel nozzle. Furthermore, a gas turbine system as another aspect for achieving the above object includes a combustor, a turbine connected to the combustor, a heating unit that heats and vaporizes liquid ammonia as fuel, a first fuel supply line that can supply the vaporized gaseous ammonia to at least one fuel nozzle provided in the combustor, and a second fuel supply line that can supply the liquid ammonia in a liquid state to the at least one fuel nozzle.

[0007] In this aspect, it is possible to introduce either gaseous ammonia or liquid ammonia into the combustor. Considering the operation of a gas turbine, gaseous ammonia cannot be supplied to the combustor at a predetermined pressure during startup unless energy is supplied from an external source. Therefore, it is preferable to supply liquid ammonia to the combustor during startup. Meanwhile, when gaseous ammonia is injected as fuel from the fuel nozzle of the combustor, the generation of NOx can be suppressed. Incidentally, when the fuel flow rate is low, the possibility of fuel misfire is high, but the amount of NOx generated is low because the ammonia flow rate itself is low. Conversely, when the fuel flow rate is high, the possibility of fuel misfire is low, but the amount of NOx generated is high because the ammonia flow rate itself is high. Therefore, when the fuel flow rate is low, liquid ammonia is introduced into the combustor to reduce the possibility of fuel misfire and ensure stable fuel combustion. Furthermore, when the fuel flow rate is high, gaseous ammonia is introduced into the combustor to suppress the generation of NOx. As a result, in this aspect, by supplying liquid ammonia to the combustor during startup, ammonia as fuel can be supplied to the combustor even without external thermal energy supply. Furthermore, in this embodiment, from start-up to rated operation, it is possible to suppress the generation of NOx while stably burning ammonia without using any fuel other than ammonia. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, it is possible to suppress the generation of NOx while stably burning ammonia. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a system diagram of a gas turbine plant according to a first embodiment of the present disclosure. FIG. [Figure 2] FIG. 1 is a cross-sectional view of an embodiment of a fuel nozzle according to the present disclosure. [Figure 3] 4 is a flowchart illustrating a procedure for executing a fuel supply method according to an embodiment of the present disclosure. [Figure 4] 10 is a graph illustrating fuel flow percentage over time in one embodiment according to the present disclosure. [Figure 5] 4 is a graph showing the relationship between fuel-air ratio and NOx concentration in one embodiment according to the present disclosure. [Figure 6] FIG. 4 is a system diagram of a gas turbine plant according to a second embodiment of the present disclosure. [Figure 7] FIG. 10 is a system diagram of a gas turbine plant according to a third embodiment of the present disclosure. [Figure 8] 10 is a graph showing the change in fuel flow rate percentage over time in a first variation according to the present disclosure. [Figure 9] FIG. 10 is a system diagram of a gas turbine plant according to a second modified example of the present disclosure. [Figure 10] FIG. 10 is a system diagram of a gas turbine plant according to a third modified example of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, various embodiments and modifications according to the present disclosure will be described with reference to the drawings.

[0014] "First embodiment" A first embodiment of a gas turbine plant according to the present disclosure will be described below with reference to FIGS.

[0015] 1, the gas turbine plant of this embodiment includes a gas turbine 10, a denitration device 20 that decomposes NOx contained in exhaust gas from the gas turbine 10, a heat recovery boiler 21 that generates steam by utilizing the heat of the exhaust gas flowing out from the denitration device 20, a chimney 22 that discharges the exhaust gas from the heat recovery boiler 21 to the outside, a steam turbine 23 that is driven by the steam from the heat recovery boiler 21, a condenser 24 that converts the steam from the steam turbine 23 back into water, a pump 25 that sends water in the condenser 24 to the heat recovery boiler 21, a fuel supply facility 40 that supplies fuel to the gas turbine 10, and a control device 60. Note that the denitration device 20 may be disposed inside the heat recovery boiler 21.

[0016] The gas turbine 10 includes a compressor 14 that compresses air A, a combustor 15 that burns fuel in the air compressed by the compressor 14 to generate combustion gas, and a turbine 16 that is driven by the high-temperature, high-pressure combustion gas.

[0017] The compressor 14 includes a compressor rotor 14r that rotates about a rotor axis Ar, a compressor casing 14c that covers the compressor rotor 14r, and an inlet guide vane (IGV) 14i that is provided at the intake port of the compressor casing 14c. The IGV 14i adjusts the flow rate of air drawn into the compressor casing 14c in accordance with instructions from the control device 60.

[0018] The turbine 16 has a turbine rotor 16r that rotates about a rotor axis Ar by combustion gas from the combustor 15, and a turbine casing 16c that covers the turbine rotor 16r. The turbine rotor 16r and the compressor rotor 14r are connected to each other so as to be rotatable about the same rotor axis Ar, thereby forming a gas turbine rotor 11. To this gas turbine rotor 11, for example, a rotor of a generator is connected.

[0019] The gas turbine 10 further includes an intermediate casing 12. The intermediate casing 12 is disposed between the compressor casing 14c and the turbine casing 16c in the direction in which the rotor axis Ar extends, and connects the compressor casing 14c and the turbine casing 16c. Compressed air discharged from the compressor 14 flows into the intermediate casing 12.

[0020] The combustor 15 is fixed to the intermediate casing 12. The combustor 15 includes a combustion liner (or transition piece) 15c that forms a combustion chamber 15s therein, and a combustor main body 15b that injects fuel and compressed air into the combustion chamber 15s. The combustion liner 15c that forms the combustion chamber 15s serves as a combustion chamber former. In the combustion chamber 15s, fuel is combusted in the compressed air. Combustion gas generated by the combustion of the fuel flows through the combustion chamber 15s and is sent to the turbine 16. The combustor main body 15b has a fuel nozzle 15n that injects fuel into the combustion chamber 15s.

[0021] Ammonia is supplied to the denitration device 20. The denitration device 20 uses the ammonia to decompose NOx contained in the exhaust gas from the gas turbine 10 into nitrogen and water vapor.

[0022] The heat recovery steam generator 21 and the condenser 24 are connected by a water supply line 26. A pump 25 is provided on this water supply line 26 to send water from the condenser 24 to the heat recovery steam generator 21. The heat recovery steam generator 21 and the steam turbine 23 are connected by a main steam line 27. The heat recovery steam generator 21 uses the heat of the exhaust gas from the gas turbine 10 to turn the water from the water supply line 26 into steam. This steam is sent to the steam turbine 23 via the main steam line 27. A rotor of a generator, for example, is connected to the rotor of the steam turbine 23. The steam exhausted from the steam turbine 23 is returned to water by the condenser 24.

[0023] The fuel supply facility 40 includes an ammonia tank 41, a main ammonia line 42, a flow control valve 43, a main ammonia pump 44, a vaporizer 45, a gaseous ammonia line 46, a liquid ammonia line 47, a switch 48, a gaseous ammonia compressor 51, a liquid ammonia pump 52, a heating medium line 53, a heating medium valve 54, and a heating medium recovery line 55.

[0024] Liquid ammonia NH3L is stored in an ammonia tank 41. A main ammonia line 42 is connected to this ammonia tank 41. This main ammonia line 42 is provided with a main ammonia pump 44 that pressurizes the liquid ammonia NH3L from the ammonia tank 41, and a flow rate control valve 43 that adjusts the flow rate of ammonia flowing through the main ammonia line 42. An end of the main ammonia line 42 is connected to an ammonia inlet of a vaporizer 45.

[0025] The vaporizer 45 is a heat exchanger that exchanges heat between steam, which is a heating medium, and liquid ammonia (NH3L) to heat and vaporize the liquid ammonia (NH3L). One end of a heating medium line 53 is connected to a medium inlet of the vaporizer 45. The other end of the heating medium line 53 is connected to the main steam line 27. A heating medium valve 54 that adjusts the flow rate of steam flowing through the heating medium line 53 is provided in the heating medium line 53. One end of a heating medium recovery line 55 is connected to a medium outlet of the vaporizer 45. The other end of the heating medium recovery line 55 is connected to the condenser 24. The other end of the heating medium recovery line 55 may be connected to a portion of the heat recovery steam generator 21 through which water flows, instead of the condenser 24.

[0026] One end of a gaseous ammonia line 46 is connected to the ammonia outlet of the vaporizer 45. The other end of this gaseous ammonia line 46 is connected to the fuel nozzle 15n of the combustor 15. This gaseous ammonia line 46 is provided with a gaseous ammonia compressor 51 that increases the pressure of the gaseous ammonia NH3G flowing therethrough.

[0027] One end of the liquid ammonia line 47 is connected to a position in the main ammonia line 42 between the main ammonia pump 44 and the vaporizer 45. The other end of the liquid ammonia line 47 is connected to the fuel nozzle 15n of the combustor 15. The liquid ammonia line 47 is provided with a liquid ammonia pump 52 that pressurizes the liquid ammonia NH3L flowing therethrough.

[0028] The flow rate control valve 43 is provided in the main ammonia line 42 at a position between the connection position with the liquid ammonia line 47 and the main ammonia pump 44. This flow rate control valve 43 adjusts the flow rate of the liquid ammonia NH3L flowing through the main ammonia line 42, thereby adjusting the flow rate of the fuel supplied to the combustor 15.

[0029] The switch 48 switches the ammonia supply state among a first state in which gaseous ammonia NH3G is guided from the gaseous ammonia line 46 to the fuel nozzle 15n of the combustor 15, a second state in which liquid ammonia NH3L is guided from the liquid ammonia line 47 to the fuel nozzle 15n of the combustor 15, and a third state in which gaseous ammonia NH3G from the gaseous ammonia line 46 and liquid ammonia NH3L from the liquid ammonia line 47 are guided to the fuel nozzle 15n of the combustor 15. The switch 48 has a gaseous ammonia flow rate control valve 48g and a liquid ammonia flow rate control valve 48i. The gaseous ammonia flow rate control valve 48g is provided in the main ammonia line 42 at a position between the connection position with the liquid ammonia line 47 and the vaporizer 45. The gaseous ammonia flow rate control valve 48g adjusts the flow rate of liquid ammonia NH3L flowing from the main ammonia line 42 into the vaporizer 45, thereby adjusting the flow rate of gaseous ammonia NH3G supplied to the combustor 15 via the gaseous ammonia line 46. The liquid ammonia flow rate control valve 48i is provided in the liquid ammonia line 47. The liquid ammonia flow rate control valve 48i controls the flow rate of the liquid ammonia NH3L flowing through the liquid ammonia line 47.

[0030] The first state can be achieved by closing the liquid ammonia flow rate control valve 48i and opening the gaseous ammonia flow rate control valve 48g. The second state can be achieved by opening the liquid ammonia flow rate control valve 48i and closing the gaseous ammonia flow rate control valve 48g. The third state can be achieved by half-opening both the liquid ammonia flow rate control valve 48i and the gaseous ammonia flow rate control valve 48g.

[0031] The switch 48 can be substituted with a single three-way valve instead of the gaseous ammonia flow rate control valve 48g and the liquid ammonia flow rate control valve 48i. In this case, the three-way valve is provided at the connection position of the main ammonia line 42 and the liquid ammonia line 47. This three-way valve adjusts the ratio between the flow rate of liquid ammonia NH3L flowing into the vaporizer 45 and the flow rate of liquid ammonia NH3L flowing into the liquid ammonia line 47.

[0032] In this embodiment, the fuel combustion facility includes a fuel supply facility 40 and a combustor 15 .

[0033] The control device 60 receives a required output of the gas turbine 10 from the outside, and controls the operations of the flow rate control valve 43 and the switch 48 in accordance with this required output. This control device 60 is a computer. In terms of hardware, the control device 60 has a CPU (Central Processing Unit) that performs various calculations, a main storage device such as memory that serves as a work area for the CPU, an auxiliary storage device such as a hard disk drive, input devices such as a keyboard and a mouse, and a display device. This control device 60 functions, for example, when the CPU executes a control program stored in the auxiliary storage device.

[0034] As shown in FIG. 2, the fuel nozzle 15n of the combustor 15 includes a cylindrical inner cylinder 31 and an outer cylinder 32. The outer cylinder 32 is also cylindrical and disposed around the nozzle axis An and is disposed on the outer periphery of the inner cylinder 31. The direction in which the nozzle axis An extends is referred to as the axial direction Da. One side of the axial direction Da is referred to as the rear side Dab, and the other side is referred to as the front side Daf. The positions of the ends of the front side Daf of the inner cylinder 31 and the front side Daf of the outer cylinder 32 are substantially the same in the axial direction Da. The inner periphery of the inner cylinder 31 forms a liquid fuel flow path 33. The liquid fuel flow path 33 has a liquid fuel inlet 33i and a liquid fuel ejection port 33o. The end of the rear side Dab of the liquid fuel flow path 33 forms the liquid fuel inlet 33i, and the end of the front side Daf of the liquid fuel flow path 33 forms the liquid fuel ejection port 33o. A liquid ammonia line 47 is connected to the liquid fuel inlet 33i. A gas fuel flow path 34 is formed between the outer circumferential side of the inner cylinder 31 and the inner circumferential side of the outer cylinder 32. The gas fuel flow path 34 has a gas fuel inlet 34i and a gas fuel injection port 34o. An opening is formed in the outer circumferential surface of the outer cylinder 32 at the rear Dab portion of the outer cylinder 32. This opening forms the gas fuel inlet 34i of the gas fuel flow path 34, and the end of the front Daf of the gas fuel flow path 34 forms the gas fuel injection port 34o. A gas ammonia line 46 is connected to the gas fuel inlet 34i. Compressed air Acom from the compressor 14 flows as combustion air from the end of the front Daf of the outer cylinder 32 toward the front Daf, on the outer circumferential side of the outer cylinder 32.

[0035] Next, the procedure of the fuel supply method in the gas turbine plant described above will be described with reference to the flowchart shown in FIG.

[0036] In this fuel supply method, an ammonia pressure increasing step S1, a flow rate adjusting step S2, a switching control step S3, a steam generating step S4, a vaporizing step S5, and a switching step S6 are performed.

[0037] In the ammonia pressurization step S1, the main ammonia pump 44 pressurizes the liquid ammonia NH3L that has flowed from the ammonia tank 41 into the main ammonia line 42. In the flow rate adjustment step S2, the flow rate control valve 43 adjusts the flow rate of the liquid ammonia NH3L flowing through the main ammonia line 42. The flow rate of the fuel supplied to the combustor 15 is adjusted by adjusting the flow rate of the liquid ammonia NH3L. The control device 60 receives the required output of the gas turbine 10. The control device 60 determines the flow rate of the fuel supplied to the combustor 15 in accordance with this required output. The fuel flow rate is determined so as to have a positive correlation with the required output. In other words, the fuel flow rate is determined so that the fuel flow rate increases as the required output increases. The control device 60 instructs the flow rate control valve 43 to adjust the flow rate of the fuel supplied to the combustor 15 to the determined flow rate.

[0038] In the switching control step S3, the control device 60 determines one of the first state, the second state, and the third state as the fuel supply state, and instructs the switch 48 to enter this one state.

[0039] A method for determining the fuel supply state by the control device 60 will be described with reference to Fig. 4. The amount of fuel supplied to the gas turbine 10 gradually increases over time from startup to rated operation. As described above, when the required output is smaller than the rated output, the flow rate of fuel supplied to the combustor 15 is less than the flow rate of fuel supplied to the combustor 15 when the required output is the rated output. Here, if the fuel flow rate percentage when the required output is the rated output is 100%, the fuel flow rate percentage before startup is 0%. Furthermore, the fuel flow rate percentage when the required output is a predetermined output smaller than the rated output is α%.

[0040] When the fuel flow rate percentage determined according to the required output is greater than 0% and less than α%, i.e., when the fuel flow rate is low, the control device 60 selects the second state from among the first, second, and third states. As described above, this second state is a state in which only liquid ammonia NH3L is introduced to the fuel nozzle 15n. When the fuel flow rate percentage determined according to the required output is α%, the control device 60 selects the third state from among the first, second, and third states, as described above. This third state is a state in which liquid ammonia NH3L and gaseous ammonia NH3G are introduced to the fuel nozzle 15n. When the fuel flow rate percentage determined according to the required output is greater than α%, i.e., when the fuel flow rate is high, the control device 60 selects the first state from among the first, second, and third states. As described above, this first state is a state in which only gaseous ammonia NH3G is introduced to the fuel nozzle 15n. The control device 60 instructs the switch 48 to enter the selected state.

[0041] In the steam generation step S4, the heat recovery boiler 21 exchanges heat between the exhaust gas from the gas turbine 10 and water to turn the water into steam.

[0042] The vaporization step S5 is executed when the first state or the third state is determined as the fuel supply state in the switching control step S3, and is not executed when the second state is determined as the fuel supply state. In the vaporization step S5, liquid ammonia NH3L is heated by a heating medium in the vaporizer 45 and vaporized. As the steam serving as the heating medium, part of the steam generated in the steam generation step S4 is used.

[0043] In the switching step S6, the switch 48 operates to switch to one of the first state, second state, and third state instructed by the control device 60.

[0044] For example, when the control device 60 commands the first state, of the gaseous ammonia flow control valve 48g and the liquid ammonia flow control valve 48i of the switch 48, the gaseous ammonia flow control valve 48g is opened and the liquid ammonia flow control valve 48i is closed. As a result, liquid ammonia NH3L is guided to the vaporizer 45 via the main ammonia line 42 and the gaseous ammonia flow control valve 48g, where it becomes gaseous ammonia NH3G. This gaseous ammonia NH3G is guided to the combustor 15 via the gaseous ammonia line 46 and the gaseous ammonia compressor 51. On the other hand, liquid ammonia NH3L pressurized by the main ammonia pump 44 does not flow into the liquid ammonia line 47. Therefore, in the first state executed at a high fuel flow rate, only gaseous ammonia NH3G is supplied as fuel to the fuel nozzle 15n of the combustor 15. This gaseous ammonia NH3G flows through the gaseous fuel flow path 34 of the fuel nozzle 15n and is injected into the combustion liner 15c from the gaseous fuel injection port 34o.

[0045] Furthermore, when the control device 60 commands the second state, of the gaseous ammonia flow control valve 48g and the liquid ammonia flow control valve 48i of the switch 48, the gaseous ammonia flow control valve 48g is closed and the liquid ammonia flow control valve 48i is opened. As a result, liquid ammonia NH3L is guided to the combustor 15 via the liquid ammonia line 47, the liquid ammonia flow control valve 48i, and the liquid ammonia pump 52. On the other hand, the liquid ammonia NH3L pressurized by the main ammonia pump 44 is not guided to the vaporizer 45. Therefore, in the second state executed when the fuel flow rate is low, only liquid ammonia NH3L is supplied as fuel to the fuel nozzle 15n of the combustor 15. This liquid ammonia NH3L flows through the liquid fuel flow path 33 of the fuel nozzle 15n and is injected into the combustion liner 15c from the liquid fuel injection port 33o.

[0046] Furthermore, when the control device 60 commands the third state, both the gaseous ammonia flow control valve 48g and the liquid ammonia flow control valve 48i of the switch 48 are half-open. As a result, liquid ammonia NH3L is guided to the vaporizer 45 via the main ammonia line 42 and the gaseous ammonia flow control valve 48g, where it becomes gaseous ammonia NH3G. This gaseous ammonia NH3G is guided to the combustor 15 via the gaseous ammonia line 46 and the gaseous ammonia compressor 51. The liquid ammonia NH3L also flows into the liquid ammonia line 47 and is guided to the combustor 15 via the liquid ammonia line 47, the liquid ammonia flow control valve 48i, and the liquid ammonia pump 52. Therefore, in the third state, which is executed at an α% fuel flow rate between the low fuel flow rate and the high fuel flow rate, both liquid ammonia NH3L and gaseous ammonia NH3G are supplied as fuel to the fuel nozzle 15n of the combustor 15. This gaseous ammonia NH3G flows through the gaseous fuel flow path 34 of the fuel nozzle 15n and is injected into the combustion liner 15c from the gaseous fuel injection port 34o. Also, this liquid ammonia NH3L flows through the liquid fuel flow path 33 of the fuel nozzle 15n and is injected into the combustion liner 15c from the liquid fuel injection port 33o.

[0047] As shown in FIG. 4, when the system transitions from a low fuel flow rate to a high fuel flow rate via an α% fuel flow rate, the α% fuel flow rate is maintained for a predetermined time or more. In the third state executed at the α% fuel flow rate, the liquid ammonia flow rate control valve 48i gradually closes over time, and the flow rate of liquid ammonia NH3L introduced to the combustor 15 gradually decreases over time. In the third state, the gaseous ammonia flow rate control valve 48g gradually opens over time, and the flow rate of gaseous ammonia NH3G introduced to the combustor 15 gradually increases over time. Also, when the system transitions from a high fuel flow rate to a low fuel flow rate via an α% fuel flow rate, the α% fuel flow rate is maintained for a predetermined time or more. In the third state executed at the α% fuel flow rate, the gaseous ammonia flow rate control valve 48g gradually closes over time, and the flow rate of gaseous ammonia NH3G introduced to the combustor 15 gradually decreases over time. In this third state, during this predetermined time, the liquid ammonia flow rate control valve 48i gradually opens over time, and the flow rate of liquid ammonia NH3L introduced into the combustor 15 gradually increases over time.

[0048] When ammonia is used as fuel for the gas turbine 10, some of the nitrogen that forms the ammonia becomes NOx. The amount of NOx produced depends on the flow rate of the ammonia used as fuel and the fuel-air ratio. The higher the flow rate of the ammonia used as fuel, the greater the amount of NOx produced, and vice versa. As shown in FIG. 5, the NOx concentration in the combustion gas is maximized when the fuel-air ratio is at a certain value r. This NOx concentration gradually decreases as the fuel-air ratio becomes smaller than a certain value r. This NOx concentration also gradually decreases as the fuel-air ratio becomes larger than a certain value r.

[0049] Therefore, in this embodiment, the fuel-air ratio is controlled so that the value of the fuel-air ratio does not become a value within a predetermined fuel-air ratio range R in which the NOx concentration becomes higher than a predetermined value c. This control of the fuel-air ratio is executed by the control device 60. As described above, the control device 60 determines the fuel flow rate in accordance with the required output. Then, the control device 60 determines the opening degree of the IGV 14i based on the determined fuel flow rate, and instructs this opening degree to the IGV 14i. At this time, the control device 60 determines the opening degree of the IGV 14i so that the value of the fuel-air ratio, which is the ratio between the determined fuel flow rate and the flow rate of air taken in by the compressor 14, does not become a value within the above-mentioned predetermined fuel-air ratio range R.

[0050] As described above, in this embodiment, it is possible to introduce gaseous ammonia NH3G or liquid ammonia NH3L into the combustor 15. When liquid ammonia NH3L is injected as fuel from the fuel nozzle 15n of the combustor 15, misfires and the like are suppressed, enabling stable combustion of the fuel. On the other hand, when gaseous ammonia NH3G is injected as fuel from the fuel nozzle 15n of the combustor 15, it is possible to suppress the generation of NOx. Incidentally, when the fuel flow rate is low, the possibility of fuel misfire is high, but the amount of NOx generated is low because the ammonia flow rate itself is low. Conversely, when the fuel flow rate is high, the possibility of fuel misfire is low, but the amount of NOx generated is high because the ammonia flow rate itself is high. Therefore, in this embodiment, as described above, when the fuel flow rate is low, liquid ammonia NH3L is introduced into the combustor 15 to reduce the possibility of fuel misfire and ensure stable combustion of the fuel. Furthermore, in this embodiment, when the fuel flow rate is high, gaseous ammonia NH3G is introduced into the combustor 15 to suppress the generation of NOx. Therefore, in this embodiment, by supplying liquid ammonia to the combustor at the time of startup, it is possible to supply ammonia as fuel to the combustor without supplying thermal energy from the outside. Furthermore, in this embodiment, from startup to rated operation, it is possible to suppress the generation of NOx while stably burning ammonia without using any fuel other than ammonia.

[0051] Furthermore, in this embodiment, as described above, the fuel-air ratio is controlled so that the value of the fuel-air ratio does not fall within the predetermined fuel-air ratio range R in which the NOx concentration becomes higher than the predetermined value c. Therefore, in this embodiment, the generation of NOx can be suppressed from this viewpoint as well.

[0052] Furthermore, in this embodiment, the combustion gas exhausted from the gas turbine 10 passes through the denitration device 20 and is then discharged to the outside through the chimney 22. Therefore, in this embodiment, it is possible to suppress the amount of NOx emissions.

[0053] When transitioning from a state in which only gaseous ammonia NH3G is introduced to the combustor 15 to a state in which only liquid ammonia NH3L is introduced to the combustor 15, or conversely, when transitioning from a state in which only liquid ammonia NH3L is introduced to the combustor 15 to a state in which only gaseous ammonia NH3G is introduced to the combustor 15, a sudden change in the phase of the fuel injected from the fuel nozzle 15n of the combustor 15 would impair stable combustibility of the fuel. The fuel nozzle 15n of this embodiment has a liquid fuel flow path 33 and a gaseous fuel flow path 34 and can simultaneously inject liquid ammonia NH3L and gaseous ammonia NH3G. Furthermore, in this embodiment, during the process of transition from the first state to the second state or from the second state to the first state, both liquid ammonia NH3L and gaseous ammonia NH3G are introduced as fuel to the fuel nozzle 15n of the combustor 15. Therefore, in this embodiment, stable combustibility of the fuel can be ensured during the transition process described above.

[0054] Second Embodiment A second embodiment of a gas turbine plant according to the present disclosure will be described below with reference to FIG.

[0055] Similar to the gas turbine plant of the first embodiment, the gas turbine plant of this embodiment includes a gas turbine 10, a denitrification device 20, a heat recovery steam generator 21, a steam turbine 23, a condenser 24, a pump 25, a fuel supply system 40a, and a control device 60. However, the fuel supply system 40a of this embodiment is different from the fuel supply system 40 of the first embodiment.

[0056] Similar to the fuel supply equipment 40 of the first embodiment, the fuel supply equipment 40a of the present embodiment includes an ammonia tank 41, a main ammonia line 42, a main ammonia pump 44, a vaporizer 45, a gaseous ammonia line 46, a liquid ammonia line 47, a switch 48, a heating medium line 53, a heating medium valve 54, and a heating medium recovery line 55. However, the fuel supply equipment 40a of the present embodiment does not include the flow rate control valve 43, the gaseous ammonia compressor 51, and the liquid ammonia pump 52 of the fuel supply equipment 40 of the first embodiment. Therefore, in the present embodiment, the liquid ammonia flow rate control valve 48i and the gaseous ammonia flow rate control valve 48g that constitute the switch 48 also fulfill the function of the flow rate control valve 43 in the first embodiment. Furthermore, in the present embodiment, the main ammonia pump 44 also fulfills the functions of the gaseous ammonia compressor 51 and the liquid ammonia pump 52.

[0057] As described above, the fuel supply equipment 40a of the present embodiment does not have the flow rate control valve 43, the gaseous ammonia compressor 51, and the liquid ammonia pump 52 of the fuel supply equipment 40 of the first embodiment. Therefore, in the present embodiment, the equipment manufacturing cost can be reduced more than in the first embodiment.

[0058] "Third embodiment" A third embodiment of a gas turbine plant according to the present disclosure will be described below with reference to FIG.

[0059] Similar to the gas turbine plants of the first and second embodiments, the gas turbine plant of this embodiment includes a gas turbine 10, a denitration device 20, a heat recovery steam generator 21, a steam turbine 23, a condenser 24, a pump 25, a fuel supply system 40b, and a control device 60. However, the fuel supply system 40b of this embodiment is different from the fuel supply systems 40 and 40a of the first and second embodiments.

[0060] Similar to the fuel supply equipment 40 of the first embodiment, the fuel supply equipment 40b of the present embodiment includes an ammonia tank 41, a main ammonia line 42, a flow rate control valve 43, a main ammonia pump 44, a vaporizer 45, a gaseous ammonia line 46, a switch 48b, a heating medium line 53, a heating medium valve 54, and a heating medium recovery line 55. However, in the fuel supply equipment 40b of the present embodiment, the gaseous ammonia line 46 also serves as the liquid ammonia line 47 in the first embodiment. Therefore, the fuel supply equipment 40b of the present embodiment does not have a liquid ammonia line 47 independent of the gaseous ammonia line 46. Therefore, similar to the fuel supply equipment 40a of the second embodiment, the fuel supply equipment 40b of the present embodiment does not include a gaseous ammonia compressor 51 and a liquid ammonia pump 52. Furthermore, the switch 48b of this embodiment has a heating medium valve 54, and does not have the liquid ammonia flow rate control valve 48i and the gaseous ammonia flow rate control valve 48g, as in the switch 48 of the first and second embodiments.

[0061] In this embodiment, when the second state is realized, the heating medium valve 54 is closed. As a result, the steam serving as the heating medium is not led to the vaporizer 45, and even if liquid ammonia NH3L flows into the vaporizer 45 from the main ammonia line 42, it is not heated by the heating medium and flows out of the vaporizer 45 in the form of liquid ammonia NH3L. This liquid ammonia NH3L is led to the fuel nozzle 15n of the combustor 15 via the gaseous ammonia line 46, which also serves as the liquid ammonia line 47.

[0062] In this embodiment, when the first state is realized, the heating medium valve 54 is opened. As a result, steam, which is the heating medium, is led to the vaporizer 45. When liquid ammonia (NH3L) flows into the vaporizer 45 from the main ammonia line 42, the liquid ammonia (NH3L) is heated by the heating medium, vaporized, and then flows out of the vaporizer 45. This gaseous ammonia (NH3G) is led to the fuel nozzle 15n of the combustor 15 via the gaseous ammonia line 46, which also serves as the liquid ammonia line 47.

[0063] As described above, in the fuel supply equipment 40b of this embodiment, the gaseous ammonia line 46 also serves as the liquid ammonia line 47, and therefore the equipment manufacturing costs can be reduced compared to the first and second embodiments.

[0064] In addition, in the fuel supply equipment 40b of the present embodiment, there is no liquid ammonia line 47 independent of the gaseous ammonia line 46, and therefore the fuel nozzle 15n of the present embodiment does not have two types of fuel flow paths as in the first and second embodiments, but has only one type of fuel flow path.

[0065] In the heat recovery boiler 21, hot water is produced in the process of turning water into steam. Therefore, in each of the above embodiments, this hot water may be used as the heating medium to be subjected to heat exchange with the liquid ammonia NH3L.

[0066] "First Variant" In the first embodiment, as described with reference to Fig. 4, when the fuel flow rate transitions from a low fuel flow rate through an α% fuel flow rate to a high fuel flow rate, and when the fuel flow rate transitions from a high fuel flow rate through an α% fuel flow rate to a low fuel flow rate, the α% fuel flow rate is maintained for a predetermined period of time or longer. However, during such transitions, the α% fuel flow rate does not have to be maintained for a predetermined period of time or longer.

[0067] Here, as shown in Fig. 8, a fuel flow rate percentage greater than α% and less than 100% is defined as β%. Also, it is assumed that the amount of fuel supplied to the gas turbine 10 increases linearly with time from startup to rated operation. Therefore, it is assumed that the amount of fuel supplied to the gas turbine 10 also increases linearly with time from the α% fuel flow rate to the β% fuel flow rate in the process from startup to rated operation.

[0068] In this modified example, the second state is executed when the fuel flow rate is low and the fuel flow rate percentage is less than α%, the first state is executed when the fuel flow rate is high and the fuel flow rate percentage is greater than β%, and the third state is executed when the fuel flow rate percentage is greater than α% and less than β%.

[0069] When transitioning from a low fuel flow rate to a high fuel flow rate, in the third state, which is executed when the fuel flow rate percentage is equal to or greater than α% and equal to or less than β%, the liquid ammonia flow rate control valve 48i gradually closes over time, and the flow rate of liquid ammonia NH3L introduced to the combustor 15 gradually decreases over time. On the other hand, the gaseous ammonia flow rate control valve 48g gradually opens over time, and the flow rate of gaseous ammonia NH3G introduced to the combustor 15 gradually increases over time. Also, when transitioning from a high fuel flow rate to a low fuel flow rate, in the third state, which is executed when the fuel flow rate percentage is equal to or greater than α% and equal to or less than β%, the gaseous ammonia flow rate control valve 48g gradually closes over time, and the flow rate of gaseous ammonia NH3G introduced to the combustor 15 gradually decreases over time. On the other hand, the liquid ammonia flow rate control valve 48i gradually opens over time, and the flow rate of liquid ammonia NH3L introduced to the combustor 15 gradually increases over time.

[0070] "Second Variant" In each of the above embodiments, steam or hot water generated in the heat recovery boiler 21 is used as the heating medium to be heat exchanged with the liquid ammonia NH3L. However, the exhaust gas flowing in the heat recovery boiler 21 may also be used as the heating medium to be heat exchanged with the liquid ammonia NH3L. Therefore, a modified example in which the exhaust gas flowing in the heat recovery boiler 21 is used as the heating medium to be heat exchanged with the liquid ammonia NH3L will be described with reference to Fig. 9.

[0071] The fuel supply system 40c of this modification is a modification of the fuel supply system 40 of the first embodiment. A portion of the exhaust gas flowing through the heat recovery steam generator 21 is guided to the vaporizer 45 of this modification. Therefore, one end of a heating medium line 53c is connected to a medium inlet of the vaporizer 45 of this modification, and the other end of the heating medium line 53c is connected to the heat recovery steam generator 21. The heating medium line 53c is provided with a heating medium valve 54c that adjusts the flow rate of the exhaust gas flowing through the heating medium line 53c. One end of a heating medium recovery line 55c is connected to a medium outlet of the vaporizer 45. The other end of the heating medium recovery line 55c is connected to, for example, the chimney 22. The other end of the heating medium recovery line 55c may be connected to a position in the heat recovery steam generator 21 downstream of the position where the other end of the heating medium line 53c is connected, instead of the chimney 22. The downstream side here refers to the downstream side of the flow of exhaust gas flowing through the heat recovery steam generator 21.

[0072] "Third Variant" The fuel supply equipment 40c of the second modified example described above is a fuel supply equipment configured such that a vaporizer 45 is arranged outside the heat recovery boiler 21 and exhaust gas flowing inside the heat recovery boiler 21 is guided to this vaporizer 45. However, as shown in Fig. 10, a heat transfer tube 45d as a vaporizer may be arranged inside the heat recovery boiler 21, liquid ammonia NH3L may be flowed inside this heat transfer tube 45d, and this liquid ammonia NH3L may be heated by exhaust gas flowing outside the heat transfer tube 45d inside the heat recovery boiler 21. In the case of this fuel supply equipment 40d, an end of the main ammonia line 42 is connected to one end of the heat transfer tube 45d, and one end of the gaseous ammonia line 46 is connected to the other end of the heat transfer tube 45d.

[0073] The fuel supply equipment 40d of the third modified example and the fuel supply equipment 40c of the second modified example are modified examples of the fuel supply equipment 40 of the first embodiment, but in the fuel supply equipment 40a of the second embodiment and the fuel supply equipment 40b of the third embodiment, as in the third modified example or the second modified example, the exhaust gas flowing inside the heat recovery boiler 21 may be used as the heating medium to be subjected to heat exchange with the liquid ammonia NH3L.

[0074] Although the embodiments and modifications of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments and modifications. Various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention derived from the content defined in the claims and their equivalents.

[0075] "Addendum" The fuel supply system in the above embodiment can be understood, for example, as follows.

[0076] (1) The fuel supply equipment in the first aspect includes: a main ammonia line 42 connected to an ammonia tank 41 capable of storing liquid ammonia (NH3L); a main ammonia pump 44 provided in the main ammonia line 42 and capable of pressurizing the liquid ammonia (NH3L) from the ammonia tank 41; a vaporizer 45 connected to an end of the main ammonia line 42 and capable of heating and vaporizing the liquid ammonia (NH3L) by heat exchange between a heating medium and the liquid ammonia (NH3L) pressurized by the main ammonia pump 44; and a gas turbine 10 connected to the vaporizer 45 and using gaseous ammonia (NH3G), which is the ammonia vaporized by the vaporizer 45, as fuel. a gaseous ammonia line 46 that can guide the liquid ammonia NH3G to the combustor 15; a liquid ammonia line 47 that can guide the liquid ammonia NH3G that is pressurized by the main ammonia pump 44 and has not undergone heat exchange with the heating medium in the vaporizer 45, to the combustor 15 as fuel; and switches 48, 48b that can switch an ammonia supply state between a plurality of states including a first state in which the gaseous ammonia NH3G is guided to the combustor 15 from the gaseous ammonia line 46 and a second state in which the liquid ammonia NH3G is guided to the combustor 15 from the liquid ammonia line 47.

[0077] In this embodiment, it is possible to introduce gaseous ammonia NH3G or liquid ammonia NH3L into the combustor 15. When liquid ammonia NH3L is injected as fuel from the fuel nozzle 15n of the combustor 15, misfires and the like are suppressed, enabling stable combustion of the fuel. On the other hand, when gaseous ammonia NH3G is injected as fuel from the fuel nozzle 15n of the combustor 15, the generation of NOx can be suppressed. Incidentally, when the fuel flow rate is low, the possibility of fuel misfire is high, but the amount of NOx generated is small because the ammonia flow rate itself is low. Conversely, when the fuel flow rate is high, the possibility of fuel misfire is low, but the ammonia flow rate itself is high, resulting in a large amount of NOx generated. Therefore, when the fuel flow rate is low, liquid ammonia NH3L is introduced into the combustor 15 to reduce the possibility of fuel misfire and ensure stable combustion of the fuel. Furthermore, when the fuel flow rate is high, gaseous ammonia NH3G is introduced into the combustor 15 to suppress the generation of NOx. As a result, in this embodiment, it is possible to stably burn ammonia while suppressing the generation of NOx.

[0078] (2) The fuel supply equipment in the second aspect is In the fuel supply equipment according to the first aspect, the switches 48, 48b can switch an ammonia supply state among a third state in which the gaseous ammonia NH3G from the gaseous ammonia line 46 and the liquid ammonia NH3L from the liquid ammonia line 47 are introduced to the combustor 15, the first state, and the second state.

[0079] When transitioning from a state in which only gaseous ammonia NH3G is introduced to the combustor 15 to a state in which only liquid ammonia NH3L is introduced to the combustor 15, or conversely, when transitioning from a state in which only liquid ammonia NH3L is introduced to the combustor 15 to a state in which only gaseous ammonia NH3G is introduced to the combustor 15, a sudden change in the phase of the fuel injected from the fuel nozzle 15n of the combustor 15 would impair stable combustibility of the fuel. Therefore, in this embodiment, the third state is executed in the process of transitioning from the first state to the second state, or in the process of transitioning from the second state to the first state. Therefore, in this embodiment, stable combustibility of the fuel can be ensured during the transition process described above.

[0080] (3) The fuel supply equipment in the third aspect is The fuel supply facility according to the first or second aspect further includes a flow rate adjustment valve that adjusts the flow rate of the fuel supplied to the combustor.

[0081] (4) The fuel supply equipment in the fourth aspect is In the fuel supply system according to any one of the first to third aspects, an end of the liquid ammonia line 47 is connected to a position in the main ammonia line 42 between the main ammonia pump 44 and the vaporizer 45.

[0082] (5) In the fifth aspect, the fuel supply equipment comprises: In the fuel supply facility according to the fourth aspect, the switch 48 is valves 48g and 48i that can switch an ammonia supply state between a state in which the liquid ammonia NH3L pressurized by the main ammonia pump 44 is introduced to the vaporizer 45 in order to realize the first state, and a state in which the liquid ammonia NH3L pressurized by the main ammonia pump 44 is introduced to the liquid ammonia line 47 in order to realize the second state.

[0083] (6) The fuel supply equipment in the sixth aspect is The fuel supply facility according to the fourth or fifth aspect further includes: a liquid ammonia pump 52 that is provided in the liquid ammonia line 47 and is capable of pressurizing the liquid ammonia NH3L flowing through the liquid ammonia line 47; and a gaseous ammonia compressor 51 that is provided in the gaseous ammonia line 46 and is capable of pressurizing the gaseous ammonia NH3G flowing through the gaseous ammonia line 46.

[0084] In this embodiment, the pressure of the liquid ammonia NH3L introduced to the combustor 15 via the liquid ammonia line 47 can be easily adjusted to the target pressure, and the pressure of the gaseous ammonia NH3G introduced to the combustor 15 via the gaseous ammonia line 46 can also be easily adjusted to the target pressure.

[0085] (7) In a seventh aspect, the fuel supply equipment comprises: In the fuel supply system according to any one of the first to third aspects, the gaseous ammonia line 46 also serves as the liquid ammonia line 47. The switch 48b is a heating medium valve 54 that switches the supply state of the heating medium between a state in which the heating medium is guided to the vaporizer 45 to achieve the first state and a state in which the heating medium is not guided to the vaporizer 45 to achieve the second state.

[0086] In this embodiment, the gaseous ammonia line 46 also serves as the liquid ammonia line 47, which simplifies the line configuration and reduces the cost of manufacturing the equipment.

[0087] (8) In an eighth aspect, the fuel supply equipment comprises: The fuel supply equipment according to any one of the first to seventh aspects further includes a control device that receives a required output of the gas turbine from the outside, determines one of a plurality of states including the first state and the second state according to the required output, and instructs the switches to enter the one state.

[0088] The flow rate of fuel supplied to the combustor 15 varies depending on the required output. The control device 60 of this embodiment determines one of a plurality of states including the first state and the second state depending on the required output. Therefore, in this embodiment, the fuel supply state can be set to the first state when the fuel flow rate is high, and the fuel supply state can be set to the second state when the fuel flow rate is low.

[0089] The fuel combustion facility in the above embodiment can be understood, for example, as follows. (9) In a ninth aspect, the fuel combustion equipment comprises: The present invention includes a fuel supply system according to any one of the first to eighth aspects, and the combustor 15 that burns the fuel from the fuel supply system 40 in compressed air Acom to generate combustion gas.

[0090] (10) In a tenth aspect, the fuel combustion equipment comprises: In the fuel combustion facility according to the ninth aspect, the combustor 15 includes a combustion chamber forming device 15c that forms a combustion chamber 15s in which the fuel is burned and in which the combustion gas generated by the combustion of the fuel can be guided to a turbine 16, and a combustor main body 15b that can inject the fuel and compressed air Acom into the combustion chamber 15s. The combustor main body 15b has a fuel nozzle 15n that can inject the fuel into the combustion chamber 15s. The fuel nozzle 15n includes a gas fuel flow path 34 that is connected to the gaseous ammonia line 46 and can inject the gaseous ammonia NH3G that has flowed through the gaseous ammonia line 46 into the combustion chamber 15s, and a liquid fuel flow path 33 that is connected to the liquid ammonia line 47 and can inject the liquid ammonia NH3L that has flowed through the liquid ammonia line 47 into the combustion chamber 15s.

[0091] The gas turbine plant in the above embodiment can be understood, for example, as follows. (11) In an eleventh aspect, the gas turbine plant comprises: The fuel supply facility according to any one of the first to eighth aspects includes the gas turbine 10. The gas turbine 10 includes a compressor 14 that compresses air to generate compressed air Acom, the combustor 15 that burns the fuel from the fuel supply facility 40 in the compressed air Acom to generate combustion gas, and a turbine 16 that can be driven by the combustion gas.

[0092] (12) A gas turbine plant according to a twelfth aspect comprises: In the gas turbine plant according to the eleventh aspect, the combustor 15 includes a combustion chamber former 15c that forms a combustion chamber 15s in which the fuel is combusted and in which the combustion gas generated by the combustion of the fuel can be guided to the turbine 16, and a combustor main body 15b that can inject the fuel and the compressed air Acom into the combustion chamber 15s. The combustor main body 15b has a fuel nozzle 15n that can inject the fuel into the combustion chamber 15s. The fuel nozzle 15n includes a gas fuel flow path 34 that is connected to the gaseous ammonia line 46 and can inject the gaseous ammonia NH3G that has flowed through the gaseous ammonia line 46 into the combustion chamber 15s, and a liquid fuel flow path 33 that is connected to the liquid ammonia line 47 and can inject the liquid ammonia NH3L that has flowed through the liquid ammonia line 47 into the combustion chamber 15s.

[0093] In this embodiment, gaseous ammonia NH3G and liquid ammonia NH3L can be simultaneously injected from the fuel nozzle 15n.

[0094] (13) A gas turbine plant according to a thirteenth aspect comprises: The gas turbine plant of the eleventh or twelfth aspect further includes a heat recovery boiler 21 that generates steam by utilizing the heat of the exhaust gas, which is the combustion gas discharged from the turbine 16, and a heating medium line 53 that leads a portion of the steam generated in the heat recovery boiler 21 or a portion of the water heated in the heat recovery boiler 21 as the heating medium to the vaporizer 45.

[0095] (14) A gas turbine plant according to a fourteenth aspect comprises: In the gas turbine plant according to the eleventh or twelfth aspect, the vaporizer 45 can heat and vaporize the liquid ammonia NH3L by exchanging heat between the exhaust gas, which is the combustion gas exhausted from the turbine 16 as the heating medium, and the liquid ammonia NH3L pressurized by the main ammonia pump 44.

[0096] The fuel supply method in the above embodiment can be understood, for example, as follows. (15) A fuel supply method according to a fifteenth aspect includes the steps of: an ammonia pressurization step S1 of pressurizing liquid ammonia NH3L from an ammonia tank 41 storing the liquid ammonia NH3L; a vaporization step S5 of heating and vaporizing the liquid ammonia NH3L by heat exchange between a heating medium and the liquid ammonia NH3L pressurized in the ammonia pressurization step S1; and a switching step S6 of switching an ammonia supply state between a plurality of states including a first state in which gaseous ammonia NH3G, which is the ammonia vaporized in the vaporization step S5, is introduced as fuel into a combustor 15 of a gas turbine 10, and a second state in which liquid ammonia NH3L pressurized in the ammonia pressurization step S1 and which has not been heat exchanged with the heating medium in the vaporization step S5 is introduced as fuel into the combustor 15.

[0097] In this embodiment, similarly to the first embodiment described above, it is possible to suppress the generation of NOx while stably burning ammonia.

[0098] (16) A fuel supply method according to a sixteenth aspect includes the steps of: In the fuel supply method according to the fifteenth aspect, in the switching step S6, an ammonia supply state is switched among a third state in which the gaseous ammonia NH3G and the liquid ammonia NH3L are introduced into the combustor 15, the first state, and the second state.

[0099] In this aspect, similar to the second aspect described above, by executing the third state during the process of transition from the first state to the second state, or during the process of transition from the second state to the first state, stable combustion of fuel can be ensured during the transition process.

[0100] (17) A fuel supply method according to a seventeenth aspect includes the steps of: The fuel supply method according to the fifteenth or sixteenth aspect further includes a flow rate adjusting step S2 of adjusting the flow rate of the fuel supplied to the combustor 15.

[0101] (18) A fuel supply method according to an eighteenth aspect includes the steps of: In the fuel supply method according to any one of the fifteenth to seventeenth aspects, the vaporization step S5 is performed by a vaporizer 45 into which the liquid ammonia NH3L pressurized in the ammonia pressurization step S1 and the heating medium flow and which performs heat exchange between the liquid ammonia NH3L and the heating medium. In the switching step S6, an ammonia supply state is switched between a state in which the liquid ammonia NH3L pressurized in the ammonia pressurization step S1 is introduced to the vaporizer 45 to achieve the first state, and a state in which the liquid ammonia NH3L pressurized in the ammonia pressurization step S1 is not introduced to the vaporizer 45 to achieve the second state.

[0102] (19) A fuel supply method according to a nineteenth aspect includes the steps of: In the fuel supply method according to any one of the fifteenth to seventeenth aspects, the vaporization step S5 is performed by a vaporizer 45 into which the liquid ammonia NH3L pressurized in the ammonia pressurization step S1 and the heating medium flow and which exchanges heat between the liquid ammonia NH3L and the heating medium. In the switching step S6, a supply state of the heating medium is switched between a state in which the heating medium is introduced to the vaporizer 45 to achieve the first state and a state in which the heating medium is not introduced to the vaporizer 45 to achieve the second state.

[0103] (20) A fuel supply method according to a twentieth aspect includes the steps of: In the fuel supply method according to any one of the fifteenth to nineteenth aspects, a required output of the gas turbine is received from the outside, and one of a plurality of states including the first state and the second state is determined according to the required output, and a switching control step S3 is executed to execute the one state in the switching step S6.

[0104] The flow rate of fuel supplied to the combustor 15 varies depending on the required output. In this embodiment, similar to the eighth embodiment described above, the fuel supply state can be set to the first state when the fuel flow rate is high, and the fuel supply state can be set to the second state when the fuel flow rate is low.

[0105] (21) A fuel supply method according to a twenty-first aspect includes the steps of: In the fuel supply method according to any one of the fifteenth to twentieth aspects, a steam generation step S4 is further performed in which heat of exhaust gas discharged from the gas turbine 10 is utilized to generate steam, and in the vaporization step S5, a portion of the steam generated in the steam generation step S4 or hot water generated during the execution of the steam generation step S4 is used as the heating medium.

[0106] (22) A fuel supply method according to a twenty-second aspect includes the steps of: In the fuel supply method according to any one of the fifteenth to twentieth aspects, in the vaporization step S5, exhaust gas discharged from the gas turbine 10 is used as the heating medium. [Industrial Applicability]

[0107] According to one embodiment of the present disclosure, it is possible to suppress the generation of NOx while stably burning ammonia. [Explanation of symbols]

[0108] 10: Gas turbine 11: Gas turbine rotor 12: Intermediate casing 14: Compressor 14r: Compressor rotor 14c: Compressor casing 14i: Intake volume regulator (or IGV) 15: Combustor 15c: Combustion tube (or transition tube, or combustion chamber former) 15s: Combustion chamber 15b: Combustor body 15n: fuel nozzle 16: Turbine 16r: Turbine rotor 16c: Turbine casing 20: Denitration equipment 21: Waste heat recovery boiler 22: Chimney 23: Steam turbine 24: Condenser 25: Pump 26: Water supply line 27: Main steam line 31: Inner cylinder 32: Outer cylinder 33: Liquid fuel flow path 33i:Liquid fuel inlet 33o:Liquid fuel injection port 34: Gaseous fuel flow path 34i: Gaseous fuel inlet 34o: Gaseous fuel nozzle 40,40a,40b,40c,40d:Fuel supply equipment 41: Ammonia tank 42: Main ammonia line 43: Flow control valve 44: Main ammonia pump 45: Vaporizer 45d: Heat transfer tube (evaporator) 46: Gaseous ammonia line 47: Liquid ammonia line 48,48b:Switch 48g: Gaseous ammonia flow control valve 48i: Liquid ammonia flow control valve 51: Gaseous ammonia compressor 52: Liquid ammonia pump 53: Heating medium line 54: Heating medium valve 55: Heating medium recovery line 60: Control device A: Air Acom: Compressed air NH3G: Gaseous ammonia NH3L: Liquid ammonia An: nozzle axis Ar: rotor axis Da: Axial direction Dab: rear Daf: Front

Claims

1. A combustor; a turbine connected to the combustor; a heating unit that heats liquid ammonia as fuel; a first fuel supply line capable of supplying the fuel heated by the heating unit to at least one fuel nozzle provided in the combustor; a second fuel supply line capable of supplying liquid ammonia in a liquid state that is not heated by the heating unit to the at least one fuel nozzle; A gas turbine system comprising:

2. The heating unit vaporizes the liquid ammonia that is a fuel, The gas turbine system according to claim 1 , wherein the first fuel supply line is capable of supplying the vaporized gaseous ammonia to the fuel nozzle.

3. A combustor; a turbine connected to the combustor; a heating unit that heats and vaporizes liquid ammonia, which is a fuel; a first fuel supply line capable of supplying the vaporized gaseous ammonia to at least one fuel nozzle provided in the combustor; a second fuel supply line capable of supplying liquid ammonia in a liquid state to the at least one fuel nozzle; A gas turbine system comprising:

4. The heating unit is 4. The gas turbine system according to claim 1, further comprising a heat exchanger that exchanges heat between the fuel and at least a portion of steam generated by a heat recovery boiler that recovers heat contained in combustion gas exhausted from the turbine.

5. The fuel nozzle includes: a gaseous fuel injection port connected to the first fuel supply line and capable of injecting gaseous ammonia; a liquid fuel injection port connected to the second fuel supply line and capable of injecting liquid ammonia; 4. The gas turbine system according to claim 2 or 3, comprising:

6. 6. The gas turbine system according to claim 5, wherein the fuel nozzle is capable of simultaneously injecting gaseous ammonia and liquid ammonia from the gas fuel injection port and the liquid fuel injection port, respectively.

7. 6. The gas turbine system according to claim 5, wherein gaseous ammonia and liquid ammonia are simultaneously injected into the combustor from the gaseous fuel injection port and the liquid fuel injection port of the fuel nozzle, respectively, and burned.

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