Gas Turbine Systems

Abstract

A gas turbine system 1 comprising: an ammonia tank 14; a combustor 13 connected to the ammonia tank 14; an exhaust flow path 42 connected to the combustor 13; a turbine 11b provided in the exhaust flow path 42; a decomposed gas reservoir 17 connected to the combustor 13; and an ammonia decomposition catalyst 16 disposed on the downstream side of the turbine 11b in the exhaust flow path 42 and connected to the ammonia tank 14 and the decomposed gas reservoir 17.

Description

[Technical Field]

[0001] This disclosure relates to a gas turbine system. This application claims the benefit of priority to Japanese Patent Application No. 2021-057442, filed on March 30, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Gas turbine systems that obtain power by burning fuel in a combustor are used. For example, as disclosed in Patent Document 1, some gas turbine systems use ammonia as fuel. Using ammonia as fuel reduces carbon dioxide emissions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-191507 Summary of the Invention [Problem to be solved by the invention]

[0004] Ammonia is less flammable than other fuels (i.e., it is flame-retardant). Therefore, in combustors using ammonia as fuel, ignition can fail. Even if ignition is successful, there is a risk that some of the fuel will be discharged without burning.

[0005] An object of the present disclosure is to provide a gas turbine system capable of improving combustibility in a combustor in which ammonia is used as fuel. [Means for solving the problem]

[0006] In order to solve the above problems, a gas turbine system according to the present disclosure includes: 1. A gas turbine system comprising:an ammonia decomposition catalyst disposed in the exhaust flow path downstream of the turbine and connected to the ammonia tank and the decomposition gas reservoir; Gas turbine system During operation, it is determined whether the temperature of the ammonia decomposition catalyst is above a reference temperature, and if the temperature of the ammonia decomposition catalyst is above the reference temperature, it controls the supply of ammonia from the ammonia tank to the ammonia decomposition catalyst. During operation of the gas turbine system, the amount of ammonia supplied from the ammonia tank to the ammonia decomposition catalyst is controlled so that the pressure in the cracked gas reservoir becomes a reference pressure, and when the pressure in the cracked gas reservoir is lower than the reference pressure, the gas turbine system is not stopped but the supply of ammonia from the ammonia tank to the ammonia decomposition catalyst is continued, and when the pressure in the cracked gas reservoir becomes equal to or higher than the reference pressure, the gas turbine system is stopped, and when the gas turbine system is started, the supply of cracked gas from the cracked gas reservoir to the combustor is started, and thereafter the supply of ammonia from the ammonia tank to the combustor is controlled to start. .

[0007] A cooling device may be provided in the flow path connecting the ammonia decomposition catalyst and the decomposition gas reservoir.

[0008] The cooling device may be a first heat exchanger provided in a flow path connecting the ammonia decomposition catalyst and the decomposition gas reservoir, and the flow path connecting the ammonia tank and the ammonia decomposition catalyst may pass through the first heat exchanger.

[0009] A second heat exchanger may be provided in the exhaust flow path downstream of the ammonia decomposition catalyst, and the flow path connecting the ammonia tank and the ammonia decomposition catalyst may pass through the second heat exchanger.

[0010] A first flow control valve may be provided in a flow path connecting the ammonia tank and the ammonia decomposition catalyst, and a control device may be provided that controls the first flow control valve so that ammonia is supplied from the ammonia tank to the ammonia decomposition catalyst during operation of the gas turbine system.

[0011] A second flow control valve may be provided in a flow path connecting the cracked gas reservoir and the combustor, and a third flow control valve may be provided in a flow path connecting the ammonia tank and the combustor, and the control device may control the second flow control valve and the third flow control valve at the start of the gas turbine system so that the supply of ammonia from the ammonia tank to the combustor starts after the supply of cracked gas from the cracked gas reservoir to the combustor starts. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to improve the combustibility in a combustor in which ammonia is used as fuel. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a gas turbine system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a flowchart illustrating an example of a flow of processing performed by the control device according to the embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram showing the configuration of a gas turbine system according to a first modified example. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of a gas turbine system according to a second modified example. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of a gas turbine system according to a third modified example. [Figure 6] FIG. 6 is a schematic diagram showing the configuration of a gas turbine system according to a fourth modified example. [Figure 7] FIG. 7 is a schematic diagram showing the configuration of a gas turbine system according to a fifth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for ease of understanding and, unless otherwise specified, do not limit the present disclosure. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0015] Fig. 1 is a schematic diagram showing the configuration of a gas turbine system 1 according to this embodiment. As shown in Fig. 1, the gas turbine system 1 includes a turbocharger 11, a generator 12, a combustor 13, an ammonia tank 14, a pump 15, an ammonia decomposition catalyst 16, a decomposition gas storage tank 17, a first flow control valve 21, a second flow control valve 22, a third flow control valve 23, and a control device 31.

[0016] Of the gas turbine system 1, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage tank 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, and the control device 31 are included in the combustion device 10.

[0017] The turbocharger 11 has a compressor 11a and a turbine 11b. The compressor 11a and the turbine 11b rotate as a unit. The compressor 11a and the turbine 11b are connected by a shaft.

[0018] The compressor 11a is provided in an intake air flow path 41 connected to the combustor 13. Air to be supplied to the combustor 13 flows through the intake air flow path 41. An intake port (not shown) through which air is taken in from the outside is provided at the upstream end of the intake air flow path 41. The air taken in through the intake port passes through the compressor 11a and is sent to the combustor 13. The compressor 11a compresses the air and discharges it downstream.

[0019] The turbine 11b is provided in an exhaust flow path 42 connected to the combustor 13. Exhaust gas discharged from the combustor 13 flows through the exhaust flow path 42. An exhaust port (not shown) through which the exhaust gas is discharged to the outside is provided at the downstream end of the exhaust flow path 42. The exhaust gas discharged from the combustor 13 passes through the turbine 11b and is sent to the exhaust port. The turbine 11b is rotated by the exhaust gas to generate rotational power.

[0020] The generator 12 is connected to the turbocharger 11. The generator 12 generates electricity using the rotational power generated by the turbocharger 11.

[0021] Ammonia is used as fuel and combusted in the combustor 13. As will be described later, fuel other than ammonia (for example, cracked gas as ignition fuel, which will be described later) is also used when starting up the gas turbine system 1 (i.e., when starting up the combustion device 10).

[0022] The combustor 13 has a combustion chamber 13a and an ignition device 13b. Air compressed by the compressor 11a is supplied to the combustion chamber 13a from the intake passage 41. Fuel is supplied to the combustion chamber 13a. For example, liquid ammonia is supplied as fuel from an ammonia tank 14 to the combustion chamber 13a (specifically, sprayed). An air-fuel mixture containing fuel and air is generated in the combustion chamber 13a. The ignition device 13b ignites the air-fuel mixture in the combustion chamber 13a. For example, the ignition device 13b is provided inside the combustion chamber 13a. Exhaust gas generated by combustion in the combustion chamber 13a is discharged to the exhaust passage 42.

[0023] Liquid ammonia is stored in the ammonia tank 14. The ammonia tank 14 is connected to both the combustor 13 and the ammonia decomposition catalyst 16. This allows ammonia to be supplied from the ammonia tank 14 to both the combustor 13 and the ammonia decomposition catalyst 16.

[0024] A flow path 43 is connected to the ammonia tank 14. A flow path 44 and a flow path 45 are connected to the downstream end of the flow path 43. The flow path 44 is connected to the combustor 13. That is, the ammonia tank 14 is connected to the combustor 13 via the flow paths 43 and 44. Liquid ammonia is supplied from the ammonia tank 14 to the combustor 13 (specifically, the combustion chamber 13a) via the flow paths 43 and 44. The flow path 45 is connected to the ammonia decomposition catalyst 16. That is, the ammonia tank 14 is connected to the ammonia decomposition catalyst 16 via the flow paths 43 and 45. Liquid ammonia is supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16 via the flow paths 43 and 45.

[0025] A pump 15 is provided in the flow path 43. The pump 15 sends ammonia supplied from the ammonia tank 14 to the downstream side. The ammonia sent by the pump 15 passes through the flow path 43 and is sent to the flow paths 44 and 45.

[0026] A third flow control valve 23 is provided in the flow path 44. The third flow control valve 23 controls (i.e., adjusts) the flow rate of ammonia flowing through the flow path 44. That is, the third flow control valve 23 adjusts the amount of ammonia supplied from the ammonia tank 14 to the combustor 13. By adjusting the opening degree of the third flow control valve 23, the amount of ammonia supplied from the ammonia tank 14 to the combustor 13 is adjusted.

[0027] A first flow control valve 21 is provided in the flow path 45. The first flow control valve 21 controls (i.e., adjusts) the flow rate of ammonia flowing through the flow path 45. In other words, the first flow control valve 21 adjusts the amount of ammonia supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16. By adjusting the opening degree of the first flow control valve 21, the amount of ammonia supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16 is adjusted.

[0028] The ammonia decomposition catalyst 16 is a catalyst that decomposes ammonia and generates decomposition gas. The ammonia decomposition catalyst 16 decomposes ammonia into hydrogen and nitrogen. That is, the decomposition gas contains hydrogen and nitrogen. Note that the decomposition gas may contain undecomposed ammonia in addition to hydrogen and nitrogen. The decomposition of ammonia by the ammonia decomposition catalyst 16 is performed only when the temperature of the ammonia decomposition catalyst 16 is equal to or higher than a reference temperature (for example, approximately 400°C to 500°C). That is, when the temperature of the ammonia decomposition catalyst 16 is equal to or higher than the reference temperature, the ammonia decomposition catalyst 16 begins to actively decompose ammonia.

[0029] In this embodiment, the ammonia decomposition catalyst 16 is disposed in the exhaust passage 42 downstream of the turbine 11b. More specifically, heat exchange is possible between the ammonia decomposition catalyst 16 and the exhaust gas in the exhaust passage 42, with the internal space of the ammonia decomposition catalyst 16 and the exhaust passage 42 not in communication with each other. The exhaust gas flowing through the exhaust passage 42 is at a high temperature (for example, about 550°C). Therefore, while the gas turbine system 1 is operating (i.e., while the combustion device 10 is operating), the ammonia decomposition catalyst 16 is heated by the exhaust gas flowing through the exhaust passage 42 to a temperature at which ammonia decomposition is actively carried out (i.e., a temperature equal to or higher than the reference temperature).

[0030] A temperature sensor 16a is provided in the ammonia decomposition catalyst 16. The temperature sensor 16a detects the temperature of the ammonia decomposition catalyst 16.

[0031] The cracked gas reservoir 17 stores the cracked gas. The cracked gas reservoir 17 is connected to the ammonia decomposition catalyst 16 via a flow path 46. The cracked gas generated by decomposition by the ammonia decomposition catalyst 16 is sent to the cracked gas reservoir 17 via the flow path 46. Note that the flow path 46 may be provided with a check valve, a shutoff valve, or the like, for preventing backflow of the cracked gas from the cracked gas reservoir 17 to the ammonia decomposition catalyst 16.

[0032] A pressure sensor 17a is provided in the decomposition gas reservoir 17. The pressure sensor 17a detects the pressure inside the decomposition gas reservoir 17.

[0033] The cracked gas reservoir 17 is connected to the combustor 13 via a flow path 47. The cracked gas is supplied from the cracked gas reservoir 17 via the flow path 47 to the combustor 13 (specifically, the combustion chamber 13a).

[0034] A second flow control valve 22 is provided in the flow path 47. The second flow control valve 22 controls (i.e., adjusts) the flow rate of the cracked gas flowing through the flow path 47. That is, the second flow control valve 22 adjusts the amount of cracked gas supplied from the cracked gas reservoir 17 to the combustor 13. By adjusting the aperture of the second flow control valve 22, the amount of cracked gas supplied from the cracked gas reservoir 17 to the combustor 13 is adjusted.

[0035] The control device 31 includes a central processing unit (CPU), a ROM storing programs and the like, a RAM as a work area, and the like, and controls the entire gas turbine system 1. For example, the control device 31 controls the ignition device 13b, the pump 15, the first flow control valve 21, the second flow control valve 22, and the third flow control valve 23. The control device 31 also acquires detection results from the temperature sensor 16a and the pressure sensor 17a.

[0036] Fig. 2 is a flowchart showing an example of the flow of processing performed by the control device 31. The processing flow shown in Fig. 2 is executed, for example, when a user performs an input operation to start up the gas turbine system 1. The input operation by the user is received, for example, by the control device 31.

[0037] 2 starts, in step S101, the control device 31 determines whether or not a startup condition is met. The startup condition is a condition for permitting startup of the gas turbine system 1. For example, the startup condition is that no abnormality occurs in each device of the gas turbine system 1 (for example, that there are no abnormal values ​​in the output values ​​output from each device, or that there is no fluid leakage in each flow path, etc.).

[0038] If it is determined that the start-up conditions are met (step S101 / YES), the process proceeds to step S102. On the other hand, if it is determined that the start-up conditions are not met (step S101 / NO), the process proceeds to step S111, where the gas turbine system 1 is stopped, as described below.

[0039] If the determination in step S101 is YES, in step S102, the control device 31 causes the ignition device 13b to perform ignition. Next, in step S103, the control device 31 starts the supply of cracked gas from the cracked gas storage device 17 to the combustor 13. Specifically, the control device 31 controls the second flow control valve 22 so that the supply of cracked gas from the cracked gas storage device 17 to the combustor 13 starts. In other words, the control device 31 opens the second flow control valve 22 that is closed.

[0040] As will be described later, in the gas turbine system 1, cracked gas is generated by the ammonia decomposition catalyst 16 during operation of the gas turbine system 1, and the generated cracked gas is stored in the cracked gas storage device 17. Therefore, at the start of the process flow shown in Fig. 2, the cracked gas is stored in advance in the cracked gas storage device 17. However, at the time of initial startup of the gas turbine system 1, the cracked gas is stored in advance in the cracked gas storage device 17 by another method.

[0041] As described above, in this embodiment, when the gas turbine system 1 is started up, ignition is performed while the cracked gas is being supplied to the combustor 13. That is, the cracked gas is used as the fuel for ignition. Unlike ammonia, hydrogen contained in the cracked gas is easily combustible and therefore easily ignited. Therefore, ignition failures are suppressed, and the reliability of ignition is improved.

[0042] Next, in step S104, the control device 31 determines whether or not the ignition has been successful. If it is determined that the ignition has been successful (step S104 / YES), the process proceeds to step S105. On the other hand, if it is determined that the ignition has not been successful (step S104 / NO), the process proceeds to step S111, where the gas turbine system 1 is stopped, as will be described later.

[0043] If the determination in step S104 is YES, in step S105, the control device 31 increases the supply amount of cracked gas. Specifically, the control device 31 controls the second flow control valve 22 so as to increase the supply amount of cracked gas from the cracked gas storage device 17 to the combustor 13. In other words, the control device 31 increases the opening degree of the second flow control valve 22. For example, the control device 31 increases the supply amount of cracked gas from the cracked gas storage device 17 to the combustor 13 so that it changes according to a preset trend.

[0044] Next, in step S106, the control device 31 determines whether the supply amount of the cracked gas has reached a reference supply amount. For example, the reference supply amount is set to a value that maintains the combustibility in the combustor 13 at a predetermined level or higher even when the supply of ammonia to the combustor 13 is started (that is, that prevents a situation in which some ammonia does not burn).

[0045] If it is determined that the supply amount of cracked gas has reached the standard supply amount (step S106 / YES), the control device 31 determines that the combustibility in the combustor 13 will be maintained at a predetermined level or higher even if the supply of ammonia to the combustor 13 is started, and proceeds to step S107. On the other hand, if it is determined that the supply amount of cracked gas has not reached the standard supply amount (step S106 / NO), the control device 31 determines that the combustibility in the combustor 13 will fall below the predetermined level if the supply of ammonia to the combustor 13 is started, and returns to step S105.

[0046] If the determination in step S106 is YES, in step S107, the control device 31 permits the supply of ammonia from the ammonia tank 14 to the combustor 13. That is, when the required output of the gas turbine system 1 is equal to or greater than the reference output, the control device 31 starts the supply of ammonia from the ammonia tank 14 to the combustor 13. In this case, the control device 31 drives the pump 15 and controls the third flow control valve 23 so as to start the supply of ammonia from the ammonia tank 14 to the combustor 13. That is, the control device 31 opens the third flow control valve 23 that is closed. This starts combustion using ammonia as fuel. Note that when the required output of the gas turbine system 1 is smaller than the reference output, the supply of ammonia from the ammonia tank 14 to the combustor 13 is unnecessary.

[0047] In the gas turbine system 1, the cracked gas is supplied to the combustor 13, and combustion using ammonia as fuel is started in a state where the combustibility is maintained at a predetermined level or higher. That is, the cracked gas is used as a fuel for supporting combustion (i.e., a fuel for supporting combustion). This prevents a situation in which a portion of the ammonia does not burn. After the supply of ammonia to the combustor 13 is started, the control device 31 may continue or stop the supply of the cracked gas to the combustor 13.

[0048] Next, in step S108, the control device 31 determines whether or not a cracked gas generation condition is met. The cracked gas generation condition is a condition for permitting the generation of cracked gas (i.e., decomposition of ammonia) by the ammonia decomposition catalyst 16. For example, the cracked gas generation condition is that the temperature of the ammonia decomposition catalyst 16 is equal to or higher than a reference temperature (i.e., a temperature at which the ammonia decomposition catalyst 16 actively decomposes ammonia).

[0049] If it is determined that the decomposed gas generation condition is met (step S108 / YES), the process proceeds to step S109. On the other hand, if it is determined that the decomposed gas generation condition is not met (step S108 / NO), the process proceeds to step S110 without executing step S109.

[0050] If the determination in step S108 is YES, in step S109, the control device 31 causes ammonia to be supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16. Specifically, the control device 31 controls the first flow control valve 21 so that ammonia is supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16. That is, the control device 31 opens the first flow control valve 21 that is closed. As a result, ammonia is decomposed in the ammonia decomposition catalyst 16, generating a decomposed gas. The generated decomposed gas is then sent to the decomposed gas reservoir 17, and the pressure in the decomposed gas reservoir 17 increases.

[0051] In step S109, the control device 31 controls the amount of ammonia supplied to the ammonia decomposition catalyst 16 using the first flow control valve 21 so that the pressure in the cracked gas storage device 17 becomes equal to the reference pressure. Such control of the amount of ammonia supplied to the ammonia decomposition catalyst 16 (specifically, control of the aperture of the first flow control valve 21) is specifically achieved by feedback control. The reference pressure is an index for determining whether the amount of cracked gas stored in the cracked gas storage device 17 is sufficient to be used until the supply of ammonia to the combustor 13 is started (hereinafter also simply referred to as the required amount). For example, when the pressure in the cracked gas storage device 17 is lower than the reference pressure, this corresponds to the case where the required amount of cracked gas is not stored in the cracked gas storage device 17.

[0052] Next, in step S110, the control device 31 determines whether or not a stop condition is met. The stop condition is a condition for permitting the stop of the gas turbine system 1. For example, the stop condition is that there is no longer a demand for power generation and the pressure in the cracked gas storage device 17 is equal to or higher than a reference pressure.

[0053] If it is determined that the stop condition is met (step S110 / YES), the process proceeds to step S111. On the other hand, if it is determined that the stop condition is not met (step S110 / NO), the process returns to step S108.

[0054] If the determination in step S110 is YES, in step S111, the control device 31 shuts down the gas turbine system 1, and the process flow shown in Fig. 2 ends. Specifically, the control device 31 shuts down the gas turbine system 1 by stopping the supply of ammonia to the combustor 13, the supply of decomposition gas to the combustor 13, and the supply of ammonia to the ammonia decomposition catalyst 16.

[0055] As described above, when the pressure in the cracked gas storage device 17 is lower than the reference pressure, the control device 31 does not shut down the gas turbine system 1, but continues to supply ammonia from the ammonia tank 14 to the ammonia decomposition catalyst 16. This allows the gas turbine system 1 to be shut down after the pressure in the cracked gas storage device 17 has recovered to the reference pressure or higher.

[0056] As described above, in the gas turbine system 1, the ammonia decomposition catalyst 16 is disposed downstream of the turbine 11b in the exhaust flow path 42. As a result, the ammonia decomposition catalyst 16 is heated by the exhaust gas flowing through the exhaust flow path 42 to a temperature at which ammonia decomposition is actively carried out (i.e., a temperature equal to or higher than the reference temperature). In this way, the ammonia decomposition catalyst 16 is heated by effectively utilizing the heat of the exhaust gas flowing through the exhaust flow path 42. Therefore, the ammonia decomposition catalyst 16 can be heated without using a dedicated heater.

[0057] Furthermore, in the gas turbine system 1, the ammonia decomposition catalyst 16 is connected to the combustor 13 via a cracked gas storage device 17. As a result, during operation of the gas turbine system 1, the ammonia decomposition catalyst 16 decomposes ammonia to generate cracked gas, and the cracked gas can be stored in the cracked gas storage device 17. Then, at the next startup of the gas turbine system 1, ignition is performed using the cracked gas stored in the cracked gas storage device 17, thereby suppressing ignition failures and improving the reliability of ignition.

[0058] As described above, according to the gas turbine system 1, the combustibility in the combustor 13 can be improved.

[0059] In particular, the control device 31 controls the first flow control valve 21 so that ammonia is supplied from the ammonia tank 14 to the ammonia decomposition catalyst 16 while the gas turbine system 1 is operating (i.e., while the combustion device 10 is operating). This makes it possible to appropriately cause the ammonia decomposition catalyst 16 to generate cracked gas and store the cracked gas in the cracked gas reservoir 17 while the gas turbine system 1 is operating.

[0060] In particular, the control device 31 controls the second flow control valve 22 and the third flow control valve 23 so that, at the start of the gas turbine system 1 (i.e., at the start of the combustion device 10), the supply of ammonia from the ammonia tank 14 to the combustor 13 starts after the supply of cracked gas from the cracked gas storage device 17 to the combustor 13 starts. As a result, at the start of the gas turbine system 1, the cracked gas is used as fuel for ignition, which appropriately suppresses ignition failures in the combustor 13 and improves the reliability of ignition.

[0061] Gas turbine systems according to each modification will be described below with reference to Fig. 3 to Fig. 7. In the gas turbine systems according to each modification described below, the processing performed by the control device 31 is the same as that in the gas turbine system 1 described above, and therefore description thereof will be omitted.

[0062] Fig. 3 is a schematic diagram showing the configuration of a gas turbine system 1A according to a first modified example. As shown in Fig. 3, the gas turbine system 1A according to the first modified example differs from the gas turbine system 1 described above in that a heat exchanger 51 is provided in a flow path 46, and the flow path 45 passes through the heat exchanger 51. The heat exchanger 51 corresponds to an example of a first heat exchanger according to the present disclosure.

[0063] In the first modified example, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage tank 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, the control device 31, and the heat exchanger 51 of the gas turbine system 1A are included in the combustion device 10A.

[0064] As described above, the flow path 46 connects the ammonia decomposition catalyst 16 and the decomposition gas reservoir 17. A heat exchanger 51 is provided in the flow path 46. As described above, the flow path 45 connects the ammonia tank 14 and the ammonia decomposition catalyst 16. The flow path 45 passes through the heat exchanger 51.

[0065] In the heat exchanger 51, heat is exchanged between the cracked gas flowing through the flow path 46 and the ammonia flowing through the flow path 45. The temperature of the cracked gas flowing through the flow path 46 is higher than the temperature of the ammonia flowing through the flow path 45. Therefore, in the heat exchanger 51, heat is transferred from the cracked gas flowing through the flow path 46 to the ammonia flowing through the flow path 45. As a result, the cracked gas flowing through the flow path 46 is cooled. In this way, the heat exchanger 51 corresponds to a cooling device that cools the cracked gas flowing through the flow path 46.

[0066] The temperature of the cracked gas sent to the cracked gas storage tank 17 is high (for example, about 500°C). However, the temperature of the cracked gas in the cracked gas storage tank 17 decreases between the time the gas turbine system 1 is stopped and the time it is next started. The greater the decrease in the temperature of the cracked gas in the cracked gas storage tank 17, the greater the decrease in the pressure in the cracked gas storage tank 17.

[0067] In the gas turbine system 1A, a cooling device (specifically, a heat exchanger 51) is provided in the flow path 46 connecting the ammonia decomposition catalyst 16 and the cracked gas storage device 17. This can lower the temperature of the cracked gas sent to the cracked gas storage device 17. Therefore, the amount of decrease in the temperature of the cracked gas in the cracked gas storage device 17 can be reduced from when the gas turbine system 1 is stopped until the next start-up, and therefore the decrease in pressure in the cracked gas storage device 17 can be suppressed. This can make the pressure in the cracked gas storage device 17 higher than the pressure in the combustion chamber 13a, allowing the cracked gas to be appropriately supplied from the cracked gas storage device 17 to the combustor 13.

[0068] In the above, an example has been described in which the heat exchanger 51 through which the flow path 45 passes is provided as a cooling device in the flow path 46. However, the cooling device provided in the flow path 46 is not limited to the heat exchanger 51. For example, a device that cools the cracked gas flowing through the flow path 46 with cooling water or air may be provided in the flow path 46 as a cooling device.

[0069] Fig. 4 is a schematic diagram showing the configuration of a gas turbine system 1B according to a second modification. As shown in Fig. 4, the gas turbine system 1B according to the second modification is different from the gas turbine system 1 described above in that a heat exchanger 52 is provided in the exhaust flow path 42, and the flow path 45 passes through the heat exchanger 52. The heat exchanger 52 corresponds to an example of a second heat exchanger according to the present disclosure.

[0070] In the second modified example, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage device 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, the control device 31, and the heat exchanger 52 of the gas turbine system 1B are included in the combustion device 10B.

[0071] The heat exchanger 52 is provided in the exhaust flow path 42 downstream of the ammonia decomposition catalyst 16. As described above, the flow path 45 connects the ammonia tank 14 and the ammonia decomposition catalyst 16. Such a flow path 45 passes through the heat exchanger 52.

[0072] In the heat exchanger 52, heat is exchanged between the ammonia flowing through the flow path 45 and the exhaust gas flowing through the exhaust flow path 42. The temperature of the exhaust gas flowing through the exhaust flow path 42 is higher than the temperature of the ammonia flowing through the flow path 45. Therefore, in the heat exchanger 51, heat is transferred from the exhaust gas flowing through the exhaust flow path 42 to the ammonia flowing through the flow path 45. Therefore, the ammonia flowing through the flow path 45 is heated and vaporized.

[0073] In the gas turbine system 1B, the ammonia flowing through the flow path 45 is heated in the heat exchanger 52 by the exhaust gas flowing through the exhaust flow path 42, and then sent to the ammonia decomposition catalyst 16. This improves the efficiency of ammonia decomposition in the ammonia decomposition catalyst 16. Therefore, the decomposition gas can be efficiently stored in the decomposition gas storage device 17.

[0074] Fig. 5 is a schematic diagram showing the configuration of a gas turbine system 1C according to a third modification. As shown in Fig. 5, the gas turbine system 1C according to the third modification differs from the gas turbine system 1 described above in that heat exchangers 53 and 54 are provided in the exhaust flow path 42, and the flow path 48 passes through the heat exchangers 53 and 54.

[0075] In the third modified example, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage device 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, and the control device 31 of the gas turbine system 1C are included in the combustion device 10C.

[0076] Water flows through the flow path 48. Although the flow path 48 is shown in a simplified form in FIG. 5, the flow path 48 is a closed circuit. In other words, water circulates within the flow path 48. A turbine (not shown) is provided in the flow path 48, and power is generated by the turbine using the flow of water (specifically, steam). The flow path 48, the heat exchanger 53, the heat exchanger 54, and the turbine (not shown) are included in a system separate from the gas turbine system 1C. Details of the separate system will be described with reference to FIG. 7.

[0077] Heat exchanger 53 is provided downstream of heat exchanger 54 in exhaust flow path 42. Heat exchanger 53 is provided upstream of heat exchanger 54 in flow path 48. In heat exchanger 53, liquid water flowing through flow path 48 is heated by exhaust gas flowing through exhaust flow path 42. Then, in heat exchanger 54, the heated liquid water is heated again by exhaust gas flowing through exhaust flow path 42 and vaporized into gas (i.e., water vapor). Then, a turbine (not shown) is rotated by the water vapor, generating rotational power.

[0078] As described above, the gas turbine system 1C shares a portion with another system. The configuration and use of the other system that shares a portion with the gas turbine system 1C are not limited to the above example. Even in such a case, the same effects as those of the gas turbine system 1 described above are achieved. In the example of FIG. 5 , the ammonia decomposition catalyst 16 is disposed upstream of the heat exchangers 53 and 54 in the exhaust flow path 42. This allows the ammonia decomposition catalyst 16 to be effectively heated by the exhaust gas. However, in the exhaust flow path 42, the ammonia decomposition catalyst 16 may be disposed between the heat exchangers 54 and 53, or may be disposed downstream of the heat exchanger 53.

[0079] Fig. 6 is a schematic diagram showing the configuration of a gas turbine system 1D according to a fourth modified example. As shown in Fig. 6, the gas turbine system 1D according to the fourth modified example differs from the gas turbine system 1C described above in that a heat exchanger 52 is provided in the exhaust flow path 42, and the flow path 45 passes through the heat exchanger 52. The heat exchanger 52 is provided in the exhaust flow path 42 downstream of the heat exchanger 53.

[0080] In the fourth modified example, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage tank 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, the control device 31, and the heat exchanger 52 of the gas turbine system 1D are included in the combustion device 10D.

[0081] In the gas turbine system 1D, similar to the combustion device 10B of the gas turbine system 1B described above, ammonia flowing through the flow path 45 is heated in the heat exchanger 52 by exhaust gas flowing through the exhaust flow path 42 and then sent to the ammonia decomposition catalyst 16. This improves the efficiency of ammonia decomposition in the ammonia decomposition catalyst 16 compared to the gas turbine system 1C described above. Therefore, the decomposition gas can be efficiently stored in the decomposition gas storage tank 17. Furthermore, when the heat exchanger 52 is added to the gas turbine system 1C described above, it is preferable to provide the heat exchanger 52 downstream of the heat exchanger 53 in the exhaust flow path 42, as described above. Ammonia vaporizes at a relatively low temperature (for example, approximately 60°C at 2 MPa), so the ammonia can be vaporized in the heat exchanger 52 in this case as well. Furthermore, the addition of the heat exchanger 52 promotes ammonia decomposition, and the heat exchangers 53 and 54 improve the efficiency of the power generation system as a whole.

[0082] However, in the gas turbine system 1D, the exhaust gas flowing through the exhaust passage 42 is cooled in the heat exchangers 54 and 53, and then further cooled in the heat exchanger 52. Therefore, compared to the gas turbine system 1C described above, the temperature of the exhaust gas is lower downstream of the exhaust passage 42. Therefore, in order to suppress the occurrence of condensation in the exhaust passage 42 and the heat exchanger 52, it is preferable to use stainless steel or the like as the material for the members forming the exhaust passage 42 and the heat exchanger 52.

[0083] Fig. 7 is a schematic diagram showing the configuration of a gas turbine system 1E according to a fifth modified example. As shown in Fig. 7, the gas turbine system 1E according to the fifth modified example differs from the gas turbine system 1D described above in that a heat exchanger 55 is provided in the flow path 48, and the flow path 45 passes through the heat exchanger 55.

[0084] In the fifth modified example, the combustor 13, the ammonia tank 14, the pump 15, the ammonia decomposition catalyst 16, the decomposition gas storage tank 17, the first flow control valve 21, the second flow control valve 22, the third flow control valve 23, the control device 31, the heat exchanger 52, and the heat exchanger 55 of the gas turbine system 1E are included in the combustion device 10E.

[0085] 7 also shows parts of system 2 including flow path 48 that were not shown in FIGS. 5 and 6. System 2 is a power generation system that includes flow path 48, heat exchangers 53, 54, 55, turbine 56, generator 57, and drum 58. As described above, liquid water flowing through flow path 48 is heated and vaporized into gas (i.e., water vapor) in heat exchangers 53 and 54. Turbine 56 is provided in flow path 48 downstream of heat exchanger 54. Turbine 56 is rotated by the water vapor flowing through flow path 48 to generate rotational power.

[0086] The generator 57 is connected to the turbine 56. The generator 57 generates electricity using the rotational power generated by the turbine 56. A heat exchanger 55 and a drum 58 are provided in this order from upstream to downstream of the turbine 56 and upstream of the heat exchanger 53 in the flow path 48. In the heat exchanger 55, heat exchange occurs between the steam that has passed through the turbine 56 and the ammonia that flows through the flow path 45. In the heat exchanger 55, the steam that has passed through the turbine 56 is cooled by the ammonia that flows through the flow path 45. A portion of the steam that passes through the heat exchanger 55 is liquefied. Then, the steam or water that has passed through the heat exchanger 55 is supplied to the drum 58. Water is sent from the drum 58 toward the heat exchanger 53.

[0087] In the gas turbine system 1E, the ammonia flowing through the flow path 45 is heated in the heat exchanger 55 by steam flowing through the flow path 48. Thereafter, the ammonia flowing through the flow path 45 is heated again in the heat exchanger 52 by the exhaust gas flowing through the exhaust flow path 42, and then sent to the ammonia decomposition catalyst 16. This improves the efficiency of ammonia decomposition in the ammonia decomposition catalyst 16 compared to the gas turbine system 1D described above. Therefore, the decomposition gas can be efficiently stored in the decomposition gas storage device 17.

[0088] In the example of FIG. 7, a heat exchanger 52 is provided in the exhaust flow path 42, and the flow path 45 passes through the heat exchanger 52. However, the heat exchanger 52 may be omitted from the example of FIG. 7. In this case, the ammonia flowing through the flow path 45 passes through the heat exchanger 55 and is then sent to the ammonia decomposition catalyst 16 without exchanging heat with the exhaust gas flowing through the exhaust flow path 42. This reduces the degree to which the exhaust gas flowing through the exhaust flow path 42 is cooled, thereby suppressing a decrease in the temperature of the exhaust gas downstream of the exhaust flow path 42. This increases the degree of freedom in selecting materials for the members that form the exhaust flow path 42.

[0089] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such embodiments. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present disclosure.

[0090] In the above, an example has been described in which the rotational power generated by the turbocharger 11 is used as energy to drive the generator 12 in the gas turbine system 1, gas turbine system 1A, gas turbine system 1B, gas turbine system 1C, gas turbine system 1D, and gas turbine system 1E. However, in the gas turbine system 1, gas turbine system 1A, gas turbine system 1B, gas turbine system 1C, gas turbine system 1D, and gas turbine system 1E, the rotational power generated by the turbocharger 11 may be used for other purposes (for example, to drive a moving body such as a ship).

[0091] In the above, an example has been described in which liquid ammonia is mainly supplied to the combustor 13 and the ammonia decomposition catalyst 16 in the gas turbine system 1, the gas turbine system 1A, the gas turbine system 1B, the gas turbine system 1C, the gas turbine system 1D, and the gas turbine system 1E. Specifically, gaseous ammonia is supplied to the ammonia decomposition catalyst 16 in the gas turbine system 1B, the gas turbine system 1D, and the gas turbine system 1E. Alternatively, gaseous ammonia may be supplied to the combustor 13 and the ammonia decomposition catalyst 16 in the gas turbine system 1, the gas turbine system 1A, the gas turbine system 1B, the gas turbine system 1C, the gas turbine system 1D, and the gas turbine system 1E. For example, a vaporizer may be provided downstream of the pump 15, and the ammonia may be vaporized by the vaporizer and then supplied to the combustor 13 or the ammonia decomposition catalyst 16. In this case, an accumulator may be provided downstream of the vaporizer. The vaporizer and the accumulator may be provided in the flow path 43, or in the flow path 44 and the flow path 45, respectively.

[0092] In the above, the gas turbine system 1A has been described in which a cooling device (specifically, the heat exchanger 51) is additionally provided in the flow path 46 compared to the gas turbine system 1. However, a cooling device (specifically, the heat exchanger 51) may be additionally provided in the flow path 46 in the gas turbine system 1B, the gas turbine system 1C, the gas turbine system 1D, and the gas turbine system 1E. [Explanation of symbols]

[0093] 1: Gas turbine system 1A: Gas turbine system 1B: Gas turbine system 1C: Gas turbine system 1D: Gas turbine system 1E: Gas turbine system 11b: Turbine 13: Combustor 14: Ammonia tank 16: Ammonia decomposition catalyst 17: Cracked gas storage tank 21: First flow control valve 22: Second flow control valve 23: Third flow control valve 31: Control device 42: Exhaust flow path 43: Flow path 44: Flow path 45: Flow path 46: Flow path 47: Flow path 51: Heat exchanger (cooling device, first heat exchanger) 52: Heat exchanger (second heat exchanger)

Claims

1. A gas turbine system, comprising: An ammonia tank; A combustor connected to the ammonia tank; an exhaust flow path connected to the combustor; A turbine provided in the exhaust flow path; a cracked gas storage tank connected to the combustor; an ammonia decomposition catalyst disposed downstream of the turbine in the exhaust passage and connected to the ammonia tank and the decomposition gas storage; Equipped with determining whether or not a temperature of the ammonia decomposition catalyst is equal to or higher than a reference temperature during operation of the gas turbine system, and controlling ammonia to be supplied from the ammonia tank to the ammonia decomposition catalyst when the temperature of the ammonia decomposition catalyst is equal to or higher than the reference temperature; During operation of the gas turbine system, an amount of ammonia supplied from the ammonia tank to the ammonia decomposition catalyst is controlled so that the pressure in the cracked gas storage tank becomes a reference pressure, and when the pressure in the cracked gas storage tank is lower than the reference pressure, the gas turbine system is not stopped, but the supply of ammonia from the ammonia tank to the ammonia decomposition catalyst is continued, and when the pressure in the cracked gas storage tank becomes equal to or higher than the reference pressure, the gas turbine system is stopped; control so that, at the start of the gas turbine system, the supply of the cracked gas from the cracked gas storage to the combustor is started, and thereafter, the supply of the ammonia from the ammonia tank to the combustor is started; Gas turbine systems.

2. A cooling device is provided in a flow path connecting the ammonia decomposition catalyst and the decomposition gas storage tank. The gas turbine system of claim 1 .

3. the cooling device is a first heat exchanger provided in a flow path connecting the ammonia decomposition catalyst and the decomposition gas storage device, A flow path connecting the ammonia tank and the ammonia decomposition catalyst passes through the first heat exchanger. The gas turbine system of claim 2 .

4. a second heat exchanger is provided in the exhaust passage downstream of the ammonia decomposition catalyst, A flow path connecting the ammonia tank and the ammonia decomposition catalyst passes through the second heat exchanger. The gas turbine system according to any one of claims 1 to 3.

5. a first flow control valve is provided in a flow path connecting the ammonia tank and the ammonia decomposition catalyst; a control device that controls the first flow control valve so that ammonia is supplied from the ammonia tank to the ammonia decomposition catalyst during operation of the gas turbine system. The gas turbine system according to any one of claims 1 to 4.

6. a second flow control valve is provided in a flow path connecting the cracked gas storage vessel and the combustor; a third flow control valve is provided in a flow path connecting the ammonia tank and the combustor; the control device controls the second flow control valve and the third flow control valve so that, at a start of the gas turbine system, the supply of the ammonia from the ammonia tank to the combustor starts after the supply of the cracked gas from the cracked gas storage tank to the combustor starts. The gas turbine system of claim 5 .

Images