Hydrogen-fired gas turbine plant and its operating method

Abstract

Minimize damage to hydrogen-fired gas turbine plants. [Solution] The hydrogen-fired gas turbine plant comprises a gas turbine, a fuel valve capable of adjusting the flow rate of a fuel mainly composed of hydrogen gas supplied to a plurality of combustors of the gas turbine, an exhaust duct through which exhaust gas from the gas turbine can flow, a pressure relief stack capable of exhausting the gas in the exhaust duct to the outside, a pressure relief damper capable of blocking the flow of gas from the pressure relief stack to the outside, and a pressure relief controller that controls the opening and closing of the pressure relief damper. The pressure relief controller controls the pressure relief damper so that it is open at the latest when the fuel is turned on by opening the fuel valve during the auxiliary rotation period when the gas turbine rotor is rotated by the starting motor, and closes at the latest by the end of the auxiliary rotation period.

Description

Technical Field

[0001] The present disclosure relates to a hydrogen-fired gas turbine plant and an operation method thereof.

Background Art

[0002] As a gas turbine plant, for example, there is a plant described in Patent Document 1 below. This gas turbine plant includes a gas turbine, an exhaust duct through which exhaust gas from the gas turbine flows, a waste heat recovery boiler that generates steam using the heat of the exhaust gas that has passed through the exhaust duct, and a steam turbine driven by the steam from the waste heat recovery boiler. A bypass duct capable of exhausting the gas in the exhaust duct to the outside is connected to the exhaust duct midway through the exhaust duct. The bypass duct is provided with a bypass valve (or bypass damper) capable of blocking the flow of gas in this bypass duct. The exhaust duct is further provided with an inlet valve (or in-duct damper) capable of blocking the flow of gas from the exhaust duct to the waste heat recovery boiler. This inlet valve (or in-duct damper) is provided downstream of the connection position of the bypass duct in the exhaust duct.

[0003] In the plant operation method described in this Patent Document 1, the bypass valve is opened and the inlet valve is closed from before starting the gas turbine. In this plant operation method, the gas turbine is started, and after reaching the rated rotational speed, the gas turbine is operated at a low load. Then, during this low-load operation, the bypass damper is closed and the inlet valve is opened to guide the exhaust gas from the gas turbine into the waste heat recovery boiler. The waste heat recovery boiler starts generating steam due to the inflow of exhaust gas. During this low-load operation, the shaft portion of the steam turbine is sealed with the steam generated from the waste heat recovery boiler. When the temperature of the steam generated from the waste heat recovery boiler during the low-load operation of the gas turbine reaches a temperature that satisfies the conditions as the driving steam for the steam turbine, steam supply to the steam turbine is started, and the steam turbine is driven with this steam. At the timing of starting the driving of the steam turbine, the low-load operation of the gas turbine is terminated, and the gas turbine is shifted to the rated-load operation.

Prior Art Documents

[0004] [Patent Document 1] Japanese Patent Application Publication No. 55-064107 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, the development of hydrogen-fired gas turbine plants has been progressing from a decarbonization perspective. Hydrogen gas has a lower explosive limit concentration than natural gas, which is commonly used as fuel for gas turbines. Therefore, when using a gas with hydrogen as the main component as fuel for a gas turbine, it is important to minimize plant damage caused by hydrogen explosions.

[0006] Therefore, this disclosure aims to provide a technology that can reduce damage to hydrogen-fired gas turbine plants. [Means for solving the problem]

[0007] A hydrogen-fired gas turbine plant as one embodiment for achieving the above objective comprises a gas turbine having a plurality of combustors capable of generating combustion gas by burning fuel in compressed air, a gas turbine rotor rotatable by the combustion gas from the plurality of combustors, and a gas turbine casing covering the gas turbine rotor; a starter motor capable of rotating the gas turbine rotor during the startup process of the gas turbine; a fuel line capable of supplying the plurality of combustors with a gas containing 50 vol% or more of hydrogen gas as fuel; a fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line; an exhaust duct connected to the gas turbine through which exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow; a heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct; a pressure relief stack connected to the exhaust duct and capable of exhausting the gas inside the exhaust duct to the outside from the middle of the exhaust duct; a pressure relief damper capable of blocking the flow of gas from the pressure relief stack to the outside; and a control device. The control device includes a fuel controller that instructs the fuel valve on the degree of opening, an auxiliary rotation controller that controls the operation of the starter motor, and a pressure relief controller that controls the opening and closing of the pressure relief damper. The pressure relief controller controls the pressure relief damper so that it is open at the latest when the fuel controller opens the fuel valve (fuel-on) during the auxiliary rotation period when the gas turbine rotor is rotated by the starter motor to start the gas turbine, and closes at the latest by the end of the auxiliary rotation period.

[0008] A predetermined time elapses from the moment the fuel controller opens the fuel valve and fuel begins to be supplied to multiple combustors until the fuel ignites in all of them. During this time, some of the fuel supplied to the multiple combustors does not burn in the combustors but passes through the turbine casing and into the exhaust duct. In this embodiment, the fuel is hydrogen gas. Hydrogen gas has a lower explosive limit concentration than natural gas, which is commonly used as fuel for gas turbines. Therefore, when using hydrogen gas as fuel for a gas turbine, as in this embodiment, it is necessary to prepare for damage to the exhaust duct, heat recovery boiler, etc., due to hydrogen explosions.

[0009] Therefore, in this embodiment, the pressure relief damper is opened at the latest when the fuel is turned on. As a result, in this embodiment, even if unburned hydrogen gas as fuel is present in the exhaust duct and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack, suppressing the instantaneous rise in pressure inside the exhaust duct. Furthermore, the inflow of the high-pressure gas generated by the hydrogen explosion into the waste heat recovery boiler is also suppressed.

[0010] If the pressure relief damper remains open, some of the exhaust gas from the turbine will be released to the outside through the pressure relief stack, reducing the flow rate of exhaust gas into the heat recovery boiler. When the flow rate of exhaust gas into the heat recovery boiler is reduced, the timing at which the steam turbine starts to be driven by the steam from the heat recovery boiler will be delayed. In the worst case, the temperature of the steam in the heat recovery boiler may not rise to a temperature that can be supplied to the steam turbine, making it impossible to drive the steam turbine.

[0011] Therefore, in this embodiment, the pressure relief damper is closed before the auxiliary rotation period in which the gas turbine rotor is rotated by the starting motor ends.

[0012] As described above, this embodiment can suppress damage to the hydrogen-fired gas turbine plant. Furthermore, this embodiment can suppress the delay in the timing at which the steam turbine starts to be driven by steam from the waste heat recovery boiler.

[0013] Another embodiment for achieving the aforementioned objective is a hydrogen-fired gas turbine plant, The gas turbine comprises: a plurality of combustors capable of generating combustion gas by burning fuel in compressed air; a gas turbine rotor that can be rotated by the combustion gas from the plurality of combustors; and a gas turbine casing covering the gas turbine rotor; a fuel line capable of supplying the plurality of combustors with a gas containing 50 vol% or more of hydrogen gas as fuel; a fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line; an exhaust duct connected to the gas turbine through which exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow; a heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct; a pressure relief stack connected to the exhaust duct and capable of exhausting the gas in the exhaust duct to the outside; a pressure relief damper capable of blocking the flow of gas from the pressure relief stack to the outside; and a control device. The control device includes a fuel controller that instructs the fuel valve on the degree of opening, and a pressure relief controller that controls the opening and closing of the pressure relief damper. When the pressure relief controller receives a turbine trip signal, it outputs an open command to the pressure relief damper.

[0014] In this embodiment, when the pressure relief controller receives a turbine trip signal, it opens the pressure relief damper. Therefore, in this embodiment, even if unburned hydrogen gas exists in the exhaust duct after the turbine trip signal is received, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack.

[0015] One method for operating a hydrogen-fired gas turbine plant to achieve the aforementioned objective is applicable to the following hydrogen-fired gas turbine plant. This hydrogen-fired gas turbine plant comprises a gas turbine having a plurality of combustors capable of burning fuel in compressed air to generate combustion gas, a gas turbine rotor that can be rotated by the combustion gas from the plurality of combustors, and a gas turbine casing that covers the gas turbine rotor; a starter motor capable of rotating the gas turbine rotor during the startup process of the gas turbine; a fuel line capable of supplying the fuel to the plurality of combustors; a fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line; an exhaust duct connected to the gas turbine through which exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow; and a heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct. In this hydrogen-fired gas turbine plant operation method, the following steps are performed: an auxiliary rotation step in which the gas turbine rotor is rotated by the starter motor in order to start the gas turbine; a fuel supply step in which the fuel valve is opened and gas containing 50 vol% or more of hydrogen gas is supplied as fuel to the multiple combustors; and a duct pressure relief step in which the gas in the exhaust duct is exhausted to the outside from the middle of the exhaust duct. In the fuel supply step, during the auxiliary rotation period in which the gas turbine rotor is rotated by the starter motor, the fuel valve is opened and the supply of fuel to the multiple combustors is started. During the auxiliary rotation period, the duct pressure relief step is started at the latest when the fuel is turned on, which is when the supply of fuel to the multiple combustors begins, and is finished at the latest by the end of the auxiliary rotation period.

[0016] In this embodiment, damage to the hydrogen-fired gas turbine plant can be suppressed, similar to the hydrogen-fired gas turbine plant in the previous embodiment. Furthermore, in this embodiment, the delay in the timing at which the steam turbine starts to be driven by steam from the waste heat recovery boiler can be suppressed.

[0017] Another method of operating a hydrogen-fired gas turbine plant to achieve the aforementioned objective is applicable to the following hydrogen-fired gas turbine plants. This hydrogen-fired gas turbine plant comprises a gas turbine having a plurality of combustors capable of burning fuel in compressed air to generate combustion gas, a gas turbine rotor that can be rotated by the combustion gas from the plurality of combustors, and a gas turbine casing that covers the gas turbine rotor; a starter motor capable of rotating the gas turbine rotor during the startup process of the gas turbine; a fuel line capable of supplying the fuel to the plurality of combustors; a fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line; an exhaust duct connected to the gas turbine through which exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow; and a heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct. In this hydrogen-fired gas turbine plant operation method, a fuel supply step is performed in which the fuel valve is opened and gas containing 50 vol% or more of hydrogen gas is supplied as fuel to the multiple combustors, and a duct pressure relief step is performed in which the gas inside the exhaust duct is exhausted to the outside from the middle of the exhaust duct. When a turbine trip signal is generated, the duct pressure relief step is started.

[0018] In this embodiment, when a turbine trip signal is generated, the duct pressure relief process is initiated. Therefore, in this embodiment, even if unburned hydrogen gas exists in the exhaust duct after the turbine trip signal is generated, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion can be exhausted to the outside. [Effects of the Invention]

[0019] In one aspect of this disclosure, damage to a hydrogen-fired gas turbine plant can be reduced. [Brief explanation of the drawing]

[0020] [Figure 1] This is a diagram of the hydrogen-fired gas turbine plant in the first embodiment of the present disclosure. [Figure 2]The figure is a schematic diagram showing the gas turbine in the first embodiment according to the present disclosure as viewed from the position of the thermometer toward the upstream side. [Figure 3] The figure is an explanatory diagram showing the change in the rotational speed of the gas turbine rotor with time and the operation of the hydrogen-fired gas turbine plant in the first embodiment according to the present disclosure. [Figure 4] The figure is a system diagram of the hydrogen-fired gas turbine plant in the second embodiment according to the present disclosure.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments and modifications of the hydrogen-fired gas turbine plant according to the present disclosure will be described with reference to the drawings.

[0022] 「First Embodiment」 Hereinafter, the first embodiment of the hydrogen-fired gas turbine plant according to the present disclosure will be described with reference to FIGS. 1 to 3.

[0023] As shown in FIG. 1, the hydrogen-fired gas turbine plant in the present embodiment includes a gas turbine 1, a generator 6 that generates electricity by being driven by the gas turbine 1, a fuel line 4, a fuel valve 5, an exhaust duct 20 through which the exhaust gas exhausted from the gas turbine 1 can flow, a pressure relief stack 21, a pressure relief damper 22, an exhaust heat utilization facility 30 that utilizes the heat of the exhaust gas passing through the exhaust duct 20, and a control device 100.

[0024] The gas turbine 1 includes a compressor 10 capable of compressing air A, a plurality of combustors 14 capable of burning fuel F in compressed air, which is the air compressed by the compressor 10, to generate combustion gas, a turbine 17 that can be driven by the high-temperature and high-pressure combustion gas, and an intermediate casing 3m.

[0025] The compressor 10 includes a compressor rotor 11 that rotates around the rotor axis Ar, a compressor casing 12 that covers the compressor rotor 11, and an intake volume regulator 13. Here, the direction in which the rotor axis Ar extends is defined as the axial direction Da, and of the two sides of this axial direction Da, one side is defined as the upstream side Dau and the other side as the downstream side Da.

[0026] The compressor rotor 11 has a compressor rotor shaft 11s extending in the axial direction Da with respect to the rotor axis Ar, and a plurality of rotor blade rows 11b fixed to this compressor rotor shaft 11s. The plurality of rotor blade rows 11b are arranged in the axial direction Da. Each of the plurality of rotor blade rows 11b has a plurality of rotor blades arranged in the circumferential direction Dc with respect to the rotor axis Ar. The intake volume regulator 13 has a plurality of inlet guide vanes (IGVs) 13v located within the compressor casing 12 and axially upstream Dau from the plurality of rotor blade rows 11b, and a drive unit 13d that can change the orientation of each inlet guide vane 13v.

[0027] The turbine 17 is located downstream of the compressor 10's axis, on the Da side. This turbine 17 has a turbine rotor 18 that rotates around the rotor axis Ar by combustion gases from a plurality of combustors 14, and a turbine casing 19 that covers the turbine rotor 18.

[0028] The turbine rotor 18 has a turbine rotor shaft 18s extending in the axial direction Da with respect to the rotor axis Ar, and a plurality of rotor blade rows 18b fixed to this turbine rotor shaft 18s. The plurality of rotor blade rows 18b are arranged in the axial direction Da. Each of the plurality of rotor blade rows 18b has a plurality of rotor blades arranged in the circumferential direction Dc with respect to the rotor axis Ar.

[0029] The turbine rotor 18 and the compressor rotor 11 are interconnected so as to be able to rotate together around the same rotor axis Ar, forming the gas turbine rotor 2. The rotational speed of this gas turbine rotor 2 is detected by a tachometer 7. The rotor of the generator 6 is connected to this gas turbine rotor 2. The generator 6 is equipped with an output meter 8 that detects the electricity generated by the generator 6, in other words, the actual output PWr, which is the actual output of the gas turbine 1. The generator 6 in this embodiment also functions as a starting motor. For this reason, the generator 6 may also be referred to as the starting motor 6 below.

[0030] The intermediate casing 3m is positioned in the axial direction Da between the compressor casing 12 and the turbine casing 19, connecting the compressor casing 12 and the turbine casing 19. Compressed air discharged from the compressor 10 flows into this intermediate casing 3m. The gas turbine casing 3 comprises the compressor casing 12, the intermediate casing 3m, and the turbine casing 19.

[0031] As shown in Figures 1 and 2, the multiple combustors 14 are fixed to the intermediate casing 3m, arranged in the circumferential direction Dc. Each of the multiple combustors 14 has a combustion chamber (or tail chamber) 14p and a burner 14b capable of injecting fuel F and compressed air into the combustion chamber 14p. In this embodiment, there are more than ten multiple combustors 14. Some of the multiple combustors 14 are provided with a spark plug 15 capable of generating a spark in the combustion chamber 14p. This spark plug 15 is movable forward and backward relative to the combustion chamber 14p. In this embodiment, the combustors 14 equipped with the spark plug 15 are two combustors 14 adjacent to each other in the circumferential direction Dc. The combustion chamber 14p of each of the multiple combustors 14 is connected to the combustion chamber 14p of an adjacent combustor 14 in the circumferential direction Dc by a flame propagation tube 16. Fuel F can flow through the fuel line 4. This fuel line 4 has a main fuel line 4m and branch fuel lines 4b that branch off from the main fuel line 4m for each of the multiple combustors 14. The main fuel line 4m is equipped with the aforementioned fuel valve 5 that adjusts the flow rate of the fuel F flowing through the main fuel line 4m. Each branch fuel line 4b is connected to the burner 14b of one of the burners 14b of each of the multiple combustors 14.

[0032] In this embodiment, fuel F is a gas whose main component is hydrogen gas. Specifically, fuel F in this embodiment is a gas containing 50 vol% or more of hydrogen gas. Alternatively, fuel F in this embodiment may contain 80 vol% or more of hydrogen gas. Furthermore, in fuel F, a portion of the gas excluding hydrogen gas, or all of the gas excluding hydrogen gas, may be natural gas.

[0033] The exhaust duct 20 is connected to the downstream end Da of the turbine 17's axis and is a duct through which exhaust gas, which is combustion gas exhausted from the turbine 17, can flow. A pressure relief stack 21 is connected to the exhaust duct 20 from a point along the exhaust duct 20, allowing the gas inside the exhaust duct 20 to be exhausted to the outside. The point along the exhaust duct 20 is the position between the upstream end and the downstream end of the exhaust duct 20 in the direction of gas flow within the exhaust duct 20. The pressure relief damper 22 can block the flow of gas from the pressure relief stack 21 to the outside. The exhaust duct 20 is equipped with multiple thermometers 9 located upstream of the pressure relief stack 21, which can detect the temperature of the combustion gas that has passed through the final stage of the multiple rotor blade rows 18b of the turbine rotor 18. Multiple thermometers 9 are provided for each of the multiple combustors 14. Therefore, if the number of combustors 14 is several dozen, as mentioned above, the number of thermometers 9 will also be several dozen. As shown in Figure 2, the position of each thermometer 9 coincides with the position in the circumferential direction Dc of one of the combustion cylinders 14p of each combustor 14. For this reason, the combustion gas from one combustion cylinder 14p mainly reaches the area around the thermometer 9 whose position in the circumferential direction Dc coincides with the position of that combustion cylinder 14p. Thus, the ignition and combustion status of each combustor 14 can be determined by the temperature detected by the thermometers 9. From the above, the thermometers 9 function as ignition detectors.

[0034] The waste heat utilization equipment 30 includes a waste heat recovery boiler 31, a chimney 32, a steam turbine 33 that can be driven by steam from the waste heat recovery boiler 31, a main steam line 34 that can guide steam generated in the waste heat recovery boiler 31 to the steam turbine 33, a condenser 35 that can convert the steam exhausted from the steam turbine 33 back into water, a feedwater line 36 that can guide the water in the condenser 35 to the waste heat recovery boiler 31, and a feedwater pump 37 provided in the feedwater line 36. The rotor of the steam turbine 33 is connected to a drive object that can be rotated by the rotation of this rotor. Examples of such drive objects include the rotor of a generator 6, the rotor of an ST generator independent of the generator 6, and the impeller of a pump.

[0035] The waste heat recovery boiler 31 can generate steam by evaporating water using the heat from the exhaust gas, which is the combustion gas exhausted from the turbine 17. This waste heat recovery boiler 31 has a boiler casing 31c connected to the exhaust duct 20 and heat transfer tubes 31t arranged inside the boiler casing 31c. The exhaust gas from the exhaust duct 20 flows into the boiler casing 31c. Liquid water or gaseous water flows into the heat transfer tubes 31t. One end of the heat transfer tubes 31t forms a water inlet and is connected to the feedwater line 36. The other end of the heat transfer tubes 31t forms a steam outlet and is connected to the main steam line 34. The chimney 32 is connected to the boiler casing 31c of the waste heat recovery boiler 31.

[0036] The control device 100 includes a main controller 101, a fuel controller 102, an IGV controller 103, an auxiliary rotation controller 104, an ignition controller 105, and a pressure relief controller 106.

[0037] The main controller 101 receives various plant-related instructions from the outside, including the requested output PWc required for the gas turbine 1, the actual output PWr detected by the output meter 8, the rotational speed Nr detected by the rotational speed meter 7, the exhaust gas temperature detected by the thermometer 9, etc., and controls the other controllers.

[0038] The fuel controller 102 receives the requested output PWc and actual output PWr from the main controller 101, determines the opening degree of the fuel valve 5 according to the deviation between the requested output PWc and the actual output PWr, and instructs the fuel valve 5 to this opening degree. Changes in the flow rate of fuel F supplied to the combustor 14 have a positive correlation with changes in the opening degree of the fuel valve 5. Also, changes in the opening degree of the fuel valve 5 have a positive correlation with changes in the requested output PWc. Therefore, changes in the flow rate of fuel F supplied to the combustor 14 have a positive correlation with changes in the requested output PWc. Consequently, when the requested output PWc increases, the flow rate of fuel F supplied to the combustor 14 increases, and when the requested output PWc decreases, the flow rate of fuel F supplied to the combustor 14 decreases.

[0039] The IGV controller 103 receives the actual output PWr from the main controller 101, determines the IGV opening θ according to this actual output PWr, and instructs the intake air volume controller 13 to set this IGV opening θ. The change in the IGV opening θ has a positive correlation with the change in the actual output PWr. Therefore, as the actual output PWr increases, the IGV opening θ also increases, and as the actual output PWr decreases, the IGV opening θ also decreases.

[0040] As mentioned above, when starting up the gas turbine 1, the generator 6 also functions as an electric motor to rotate the gas turbine rotor 2. The auxiliary rotation controller 104 controls the operation of the generator 6, which functions as a starting motor when starting up the gas turbine 1.

[0041] The ignition controller 105 controls the operation of the spark plug 15 in response to instructions from the main controller 101.

[0042] The pressure relief controller 106 controls the operation of the pressure relief damper 22 based on instructions from the main controller 101.

[0043] Next, the operation of the control device 100 will be explained using Figure 3.

[0044] When the main controller 101 receives a start command from an external source, the auxiliary rotation controller 104 controls the operation of the starter motor 6 so that the gas turbine rotor 2 rotates according to a predetermined start-up rotation speed pattern (auxiliary rotation process S1). This auxiliary rotation process S1 is performed until the gas turbine rotor 2 reaches a self-sustaining rotation speed Ns, which allows it to rotate independently without the assistance of the starter motor 6. In this embodiment, the self-sustaining rotation speed Ns is, for example, about 70% of the rated rotation speed Nrad.

[0045] In this auxiliary rotation process S1, when the auxiliary rotation controller 104 receives a start command from the main controller 101, it gradually increases the rotational speed of the starter motor 6 from the turning speed Nt. As a result, the rotational speed of the gas turbine rotor 2 gradually increases. The turning speed Nt is, for example, 2 to 4 rpm.

[0046] When the rotational speed of the gas turbine rotor 2 detected by the tachometer 7 reaches the purge rotational speed Np, the auxiliary rotation controller 104 controls the rotational speed of the starting motor 6 so that the rotational speed of the gas turbine rotor 2 is maintained at the purge rotational speed Np for a predetermined time (gas purge process S1a). In this embodiment, the purge rotational speed Np is, for example, about 20% of the rated rotational speed Nrad.

[0047] This gas purging process S1a is performed to exhaust unburned hydrogen gas (fuel F) to the outside via the heat recovery boiler 31 and chimney 32, even if hydrogen gas remains inside the gas turbine 1, exhaust duct 20, and heat recovery boiler 31 during the previous operation of the gas turbine 1.

[0048] Once the gas purging process S1a is complete, the auxiliary rotation controller 104 controls the rotation speed of the starting motor 6 so that the rotation speed of the gas turbine rotor 2 is maintained at the ignition rotation speed Ni for a predetermined time (ignition process S1b). In this embodiment, the ignition rotation speed Ni is, for example, slightly lower than the purging rotation speed Np so that the fuel F is reliably ignited in the multiple combustors 14.

[0049] The ignition controller 105 instructs the spark plug 15 to generate a spark when the rotational speed of the gas turbine rotor 2 reaches the ignition speed Ni. As a result, the tip of the spark plug 15 enters the combustion chamber 14p, and a spark is generated from this tip (ignition process S2).

[0050] The fuel controller 102 outputs an open command to the fuel valve 5 so that fuel F is supplied to the burners 14b of each of the multiple combustors 14 at the time when the spark plug 15 generates a spark (Spark Plug ON Igon) or immediately after Spark Plug ON Igon (Fuel Supply Process S3). In other words, the ignition controller 105 instructs the spark plug 15 to generate a spark at the time when the fuel controller 102 opens the fuel valve 5 (Fuel ON Fon) or immediately before Fuel ON Fon. Immediately after Spark Plug ON Igon is, for example, within 1 second from Spark Plug ON Igon. Immediately before Fuel ON Fon is within 1 second before Fuel ON Fon. As a result, the fuel valve 5 opens and fuel F is supplied to the burners 14b of each of the multiple combustors 14. Both Spark Plug ON Igon and Fuel ON Fon occur during the ignition process S1b.

[0051] In this fuel supply process S3, the fuel F supplied to the burner 14b of each of the multiple combustors 14 is, as mentioned above, a gas mainly composed of hydrogen gas. Specifically, fuel F is a gas containing 50 vol% or more of hydrogen gas. Fuel F may also be a gas containing 80 vol% or more of hydrogen gas. Furthermore, in fuel F, some of the gas excluding hydrogen gas, or all of the gas excluding hydrogen gas, may be natural gas.

[0052] When the fuel supply process S3 begins, the fuel F in the combustor 14 equipped with the spark plug 15 is ignited. Once the fuel F in the combustor 14 equipped with the spark plug 15 is ignited, the fuel F in the other combustors 14 adjacent to the combustor 14 equipped with the spark plug 15 in the circumferential direction Dc is ignited. Subsequently, the fuel F in the combustors 14 adjacent in the circumferential direction Dc is ignited sequentially. In this fuel supply process S3, until the generator 6 is connected to the external power grid, the fuel controller 102 controls the fuel valve 5 so that the flow rate of fuel F supplied to the multiple combustors 14 gradually increases according to the startup fuel pattern.

[0053] In this embodiment, a spark is generated at the spark plug 15 when the fuel is turned on or immediately before the fuel is turned on. Therefore, the fuel F that flows into the combustor 14 can be ignited earlier than when the spark is generated at the spark plug 15 after the fuel is turned on. For this reason, in this embodiment, the amount of fuel F that does not burn in the combustor 14 and instead passes through the turbine casing 19 to the exhaust duct 20 can be reduced.

[0054] The main controller 101 recognizes that fuel F has ignited in all combustors 14 when the temperature detected by all of the thermometers (ignition detectors) 9 exceeds a predetermined temperature (ignition detection process S4).

[0055] When the fuel F ignites in the combustor 14 and the generation of combustion gases begins, the combustion gases are sent into the turbine 17, and rotational force is imparted to the turbine rotor 18 by these combustion gases.

[0056] Once the ignition process S1b is complete, the auxiliary rotation controller 104 gradually increases the rotational speed of the starter motor 6. Furthermore, the combustion gas imparts rotational force to the turbine rotor 18. As a result, the rotational speed of the gas turbine rotor 2 gradually increases. As mentioned above, when the rotational speed of the gas turbine rotor detected by the rotational speed meter 7 reaches the self-sustaining rotational speed Ns, the auxiliary rotation process S1 ends.

[0057] When the rotational speed of the gas-powered rotor, as detected by the rotational speed meter 7, reaches the rated rotational speed Nrad, the generator 6 is electrically connected to the external power grid and starts generating power.

[0058] After the generator 6 starts generating power, the fuel controller 102 determines the opening degree of the fuel valve 5 according to the deviation between the requested output PWc and the actual output PWr, as described above, and instructs the fuel valve 5 to this opening degree. The IGV controller 103 also determines the IGV opening degree θ according to this actual output PWr and instructs the intake air volume controller 13 to this IGV opening degree θ.

[0059] The pressure relief controller 106 opens the pressure relief damper 22 during the auxiliary rotation time when the auxiliary rotation process S1 is being executed, and exhausts the gas in the exhaust duct 20 to the outside through the pressure relief stack 21 (duct pressure relief process S5). This duct pressure relief process S5 is started during the auxiliary rotation time, from the latter half of the gas purging time when the gas purging process S1a is being executed until the fuel is turned on (Fon). In other words, during the auxiliary rotation time, from the latter half of the gas purging time when the gas purging process S1a is being executed until the fuel is turned on (Fon), the pressure relief controller 106 outputs an open command to the pressure relief damper 22. Therefore, the pressure relief controller 106 opens the pressure relief damper 22 at the latest by the time the fuel is turned on (Fon). Furthermore, this duct pressure relief process S5 is completed between the time of ignition detection, when the multiple thermometers (ignition detectors) 9 detect that the fuel F has ignited in all the combustors 14, and the end of the auxiliary rotation period. In other words, between the time of ignition detection and the end of the auxiliary rotation period, the pressure relief controller 106 outputs a closing instruction to the pressure relief damper 22. Therefore, the pressure relief controller 106 closes the pressure relief damper 22 no later than the end of the auxiliary rotation period.

[0060] After the fuel controller 102 opens the fuel valve 5 and fuel F begins to be supplied to the multiple combustors 14, a predetermined time (several seconds) is required for the fuel F to ignite in all of the combustors 14. During this time, some of the fuel F supplied to the multiple combustors 14 does not burn in the combustors 14, but instead passes through the turbine casing 19 and into the exhaust duct 20. In this embodiment, fuel F is a gas mainly composed of hydrogen gas. Hydrogen gas has a lower explosive limit concentration than natural gas, which is commonly used as fuel for gas turbines. Even if fuel F is a gas containing both hydrogen gas and natural gas, the explosive limit concentration of this gas is lower than that of natural gas. Therefore, when using a gas mainly composed of hydrogen gas as fuel F for the gas turbine 1, as in this embodiment, it is necessary to prepare for damage to the exhaust duct 20, the heat recovery boiler 31, etc., due to hydrogen explosions.

[0061] Therefore, in this embodiment, the pressure relief damper 22 is opened no later than when the fuel is turned on (Fon). As a result, in this embodiment, even if unburned hydrogen gas as fuel F is present in the exhaust duct 20 and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside through the pressure relief stack 21, suppressing the instantaneous rise in pressure inside the exhaust duct 20. Furthermore, the inflow of the high-pressure gas generated by the hydrogen explosion into the waste heat recovery boiler 31 is also suppressed. Thus, in this embodiment, damage to the exhaust duct 20 and the waste heat recovery boiler 31 can be suppressed.

[0062] Incidentally, if the pressure relief stack 21 is not provided, the explosion of hydrogen gas inside the exhaust duct 20 will cause a momentary increase in the pressure inside the exhaust duct 20. Also, even if the pressure relief stack 21 is provided, if a silencer is provided on this pressure relief stack 21, this silencer will act as resistance to the gas passing through the pressure relief stack 21, and it may not be possible to suppress the momentary increase in pressure inside the exhaust duct 20. For this reason, the pressure relief stack 21 in this embodiment is not provided with a silencer.

[0063] From the viewpoint of suppressing the pressure rise in the exhaust duct 20, the opening timing of the pressure relief damper 22 only needs to be at the latest when the fuel is turned on (Fon), so basically it can be anytime before the fuel is turned on (Fon). For this reason, the opening timing of the pressure relief damper 22 may be, for example, in the latter half of the gas purging time period when the gas purging process S1a is being performed, but before the spark plug is turned on (Igon). In this embodiment, the gas purging process S1a is performed. If the pressure relief damper 22 is opened before the latter half of the gas purging time period, the gas in the gas turbine 1 and the exhaust duct 20 will be exhausted to the outside through the pressure relief damper 22, so the efficiency of exhausting the gas in the heat recovery boiler 31 to the outside will decrease. In other words, if the pressure relief damper 22 is opened before the latter half of the gas purging time period, the effect of the gas purging process S1a will decrease. Therefore, when performing the gas purging process S1a as in this embodiment, it is preferable to open the pressure relief damper 22 in the latter half of the gas purging period.

[0064] If the pressure relief damper 22 remains open, some of the exhaust gas discharged from the turbine 17 is discharged to the outside through the pressure relief stack 21, reducing the flow rate of exhaust gas into the heat recovery boiler 31. When the flow rate of exhaust gas into the heat recovery boiler 31 decreases, the timing at which the steam turbine 33 starts to be driven by the steam from the heat recovery boiler 31 is delayed. In the worst case, the temperature of the steam in the heat recovery boiler 31 may not rise to a temperature that can be supplied to the steam turbine 33, making it impossible to drive the steam turbine 33.

[0065] Therefore, in this embodiment, the closing timing of the pressure relief damper 22 is from the time of ignition detection until the end of the auxiliary rotation period in which the gas turbine rotor 2 is rotated by the starter motor 6. For this reason, the closing timing of the pressure relief damper 22 may be before the rotational speed of the turbine rotor 18 reaches 50% of the rated rotational speed Nrad, or even before the rotational speed of the turbine rotor 18 reaches 30% of the rated rotational speed Nrad. In addition, the pressure relief controller 106 may output a closing instruction to the pressure relief damper 22 when ignition is detected.

[0066] If, after the generator 6 has been electrically connected to the external power system and started generating power, a situation arises that requires the gas turbine 1 to be stopped, the pressure relief controller 106 receives a turbine trip signal from the main controller 101. The main controller 101 may generate the turbine trip signal in response to signals from various detectors, or it may generate this turbine trip signal after receiving an external turbine trip signal. When the main controller 101 generates a turbine trip signal (TTre), the electrical connection between the generator 6 and the external power system is cut off, the fuel valve 5 closes, the fuel supply to the multiple combustors 14 is cut off, and the fuel F stops burning in each combustor 14.

[0067] Even when the fuel valve 5 is closed, fuel F remains in the fuel line 4 between the fuel valve 5 and the burner 14b, and inside the burner 14b. Not all of this remaining fuel F is burned in the combustor 14. The remaining fuel F that is not burned in the combustors 14 passes through the turbine casing 19 and into the exhaust duct 20.

[0068] Therefore, when the pressure relief controller 106 receives a turbine trip signal from the main controller 101 (TTre), it outputs an open command to the pressure relief damper 22. As a result, the pressure relief damper 22 opens, and even if unburned hydrogen gas F exists in the exhaust duct 20 after the turbine trip signal is received (TTre), and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack 21 (duct pressure relief process S5).

[0069] As described above, this embodiment can suppress damage to the hydrogen-fired gas turbine plant. Furthermore, this embodiment can suppress the delay in the timing at which the steam turbine 33 starts to be driven by steam from the waste heat recovery boiler 31.

[0070] "Second Embodiment" A second embodiment of the hydrogen-fired gas turbine plant described herein will be explained below with reference to Figure 4.

[0071] As shown in Figure 4, the hydrogen-fired gas turbine plant in this embodiment is a plant that adds a duct damper 23, a bypass stack 24, and a bypass damper 26 to the hydrogen-fired gas turbine plant in the first embodiment.

[0072] The duct damper 23 is located downstream of the pressure relief stack 21 in the direction of gas flow within the exhaust duct 20 and is a damper capable of blocking the flow of gas within the exhaust duct 20. The bypass stack 24 is located upstream of the duct damper 23 in the direction of gas flow within the exhaust duct 20 and downstream of the pressure relief stack 21 in the direction of gas flow, and is connected to the exhaust duct 20, and is a stack capable of exhausting the gas in the exhaust duct 20 to the outside. The bypass damper 26 is a damper capable of blocking the flow of gas from the bypass stack 24 to the outside. The bypass stack 24 is equipped with a silencer 25 to suppress noise generated when a portion of the gas in the exhaust duct 20 passes through the bypass stack 24.

[0073] The control device 100 in this embodiment is the control device 100 in the first embodiment with the addition of a bypass controller 107 that controls the opening and closing of the duct damper 23 and the bypass stack 24.

[0074] In this embodiment, the main controller 101, fuel controller 102, IGV controller, auxiliary rotation controller 104, ignition controller 105, and pressure relief controller 106 of the control device 100 all operate in the same manner as in the first embodiment.

[0075] The main controller 101 receives a bypass operation instruction from an external source, for example, when it drives the gas turbine 1 but does not generate steam in the heat recovery boiler 31 and does not drive the steam turbine 33, i.e., when the gas turbine 1 is driven alone (simple cycle operation). When the bypass controller 107 receives this bypass operation instruction from the main controller 101, it outputs a close instruction to the duct damper 23 and an open instruction to the bypass damper 26. As a result, the duct damper 23 closes, preventing gas in the exhaust duct 20 from flowing into the heat recovery boiler 31, while the gas in the exhaust duct 20 is exhausted to the outside from the bypass stack 24 (bypass operation process).

[0076] The pressure relief stack 21 is not equipped with a silencer. This is because, as mentioned above, if the pressure relief stack 21 is equipped with a silencer, this silencer will act as resistance to the gas passing through the pressure relief stack 21, and it may not be possible to suppress the instantaneous rise in pressure inside the exhaust duct 20. On the other hand, in the bypass operation process, although the pressure inside the exhaust duct 20 does not rise instantaneously, the bypass damper 26 is kept open for a much longer period of time than the pressure relief damper 22 is kept open. For this reason, it is preferable to provide a silencer 25 in the bypass stack 24.

[0077] In this embodiment, a bypass stack 24 and a bypass damper 26 are provided, but even when performing a bypass operation process, the bypass stack 24 and bypass damper 26 may be omitted. In this case, the pressure relief stack 21 functions as a bypass stack, and the pressure relief damper 22 functions as a bypass damper. However, in this case, during the bypass operation process, the gas in the exhaust duct 20 is exhausted to the outside from the pressure relief stack 21 which functions as a bypass stack, and therefore it is not possible to suppress noise during this bypass operation process.

[0078] "Variations" The generator 6 in the above embodiment also functions as a starting motor. However, a separate starting motor may be provided in addition to the generator 6.

[0079] In the above embodiment, multiple thermometers 9 installed in the exhaust duct 20 function as ignition detectors. However, a flame detector may also be provided to detect the generation of a flame in the combustor 14 that is furthest in the circumferential direction Dc from the combustor 14 in which the spark plug 15 is installed, and this flame detector may be used as an ignition detector.

[0080] In the above embodiment, the pressure relief damper 22 is opened during the auxiliary rotation time, from the latter half of the gas purging time when the gas purging process S1a is performed until the fuel-on time Fon. However, if the gas purging process S1a is not performed, the pressure relief damper 22 may be kept open from the time the rotational speed of the gas turbine rotor 2 reaches the turning speed Nt.

[0081] Furthermore, this disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, and partial deletions are possible, without departing from the conceptual idea and spirit of the present invention derived from the claims and their equivalents.

[0082] "Addendum" The hydrogen-fired gas turbine plants in the above embodiments and modifications can be understood, for example, as follows.

[0083] (1) The hydrogen-fired gas turbine plant in the first embodiment is A gas turbine 1 having a plurality of combustors 14 capable of generating combustion gas by burning fuel F in compressed air, a gas turbine rotor 2 that can be rotated by the combustion gas from the plurality of combustors 14, and a gas turbine casing 3 that covers the gas turbine rotor 2; a starter motor 6 capable of rotating the gas turbine rotor 2 during the startup process of the gas turbine 1; a fuel line 4 capable of supplying the plurality of combustors 14 with a gas containing 50 vol% or more of hydrogen gas as the fuel F; and a mechanism for adjusting the flow rate of the fuel F flowing through the fuel line 4. The system comprises a fuel valve 5, an exhaust duct 20 connected to the gas turbine 1 through which the exhaust gas, which is the combustion gas exhausted from the gas turbine 1, can flow, a heat recovery boiler 31 connected to the exhaust duct 20 and capable of generating steam using the heat of the exhaust gas from the exhaust duct 20, a pressure relief stack 21 connected to the exhaust duct 20 and capable of exhausting the gas inside the exhaust duct 20 to the outside from the middle of the exhaust duct 20, a pressure relief damper 22 capable of blocking the flow of gas from the pressure relief stack 21 to the outside, and a control device 100. The control device 100 includes a fuel controller 102 that instructs the fuel valve 5 on the degree of opening, an auxiliary rotation controller 104 that controls the operation of the starter motor 6, and a pressure relief controller 106 that controls the opening and closing of the pressure relief damper 22. The pressure relief controller 106 controls the pressure relief damper 22 so that it is open at the latest when the fuel controller 102 opens the fuel valve 5 (Fon) during the auxiliary rotation period when the gas turbine rotor 2 is rotated by the starter motor 6 in order to start the gas turbine 1, and closes at the latest by the end of the auxiliary rotation period.

[0084] A predetermined time elapses from the moment the fuel controller 102 opens the fuel valve 5 and fuel F begins to be supplied to the multiple combustors 14 until the fuel F ignites in all of the combustors 14. During this time, some of the fuel F supplied to the multiple combustors 14 does not burn in the combustors 14 but passes through the turbine casing 19 and into the exhaust duct 20. In this embodiment, the fuel F is hydrogen gas. Hydrogen gas has a lower explosive limit concentration than natural gas, which is commonly used as fuel for gas turbines. Therefore, when using hydrogen gas as fuel F for the gas turbine 1, as in this embodiment, it is necessary to prepare for damage to the exhaust duct 20, the heat recovery boiler 31, etc., due to hydrogen explosions.

[0085] Therefore, in this embodiment, the pressure relief damper 22 is opened at the latest when the fuel is turned on (Fon). As a result, in this embodiment, even if unburned hydrogen gas as fuel F is present in the exhaust duct 20 and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack 21, suppressing the instantaneous rise in pressure inside the exhaust duct 20. Furthermore, the inflow of the high-pressure gas generated by the hydrogen explosion into the waste heat recovery boiler 31 is also suppressed.

[0086] If the pressure relief damper 22 remains open, some of the exhaust gas discharged from the turbine 17 is discharged to the outside through the pressure relief stack 21, reducing the flow rate of exhaust gas into the heat recovery boiler 31. When the flow rate of exhaust gas into the heat recovery boiler 31 decreases, the timing at which the steam turbine 33 starts to be driven by the steam from the heat recovery boiler 31 is delayed. In the worst case, the temperature of the steam in the heat recovery boiler 31 may not rise to a temperature that can be supplied to the steam turbine 33, making it impossible to drive the steam turbine 33.

[0087] Therefore, in this embodiment, the pressure relief damper 22 is closed before the auxiliary rotation period in which the gas turbine rotor 2 is rotated by the starting motor 6 ends.

[0088] As described above, this embodiment can suppress damage to the hydrogen-fired gas turbine plant. Furthermore, this embodiment can suppress the delay in the timing at which the steam turbine 33 starts to be driven by the steam from the waste heat recovery boiler 31.

[0089] (2) The hydrogen-fired gas turbine plant in the second embodiment is In the hydrogen-fired gas turbine plant according to the first embodiment, the pressure relief controller 106 controls the pressure relief damper 22 so that it closes when the rotational speed of the gas turbine rotor 2 reaches at least 50% of the rated rotational speed Nrad.

[0090] At the end of the auxiliary rotation period, when the gas turbine rotor 2 is being rotated by the starting motor 6, the rotational speed of the gas turbine rotor 2 is approximately 70% of the rated rotational speed Nrad of the gas turbine rotor 2. Therefore, closing the pressure relief damper 22 at 50% of the rated rotational speed Nrad results in an earlier closing timing of the pressure relief damper 22 than closing it at the end of the auxiliary rotation period. Consequently, in this embodiment, a portion of the exhaust gas discharged from the turbine 17 is not discharged to the outside from the pressure relief stack 21 earlier than when the pressure relief damper 22 is closed at the end of the auxiliary rotation period, and the timing of the exhaust gas flowing into the heat recovery boiler 31 is earlier. Therefore, in this embodiment, the timing at which the steam turbine 33 starts to be driven by steam from the heat recovery boiler can be advanced compared to closing the pressure relief damper 22 at the end of the auxiliary rotation period.

[0091] (3) The hydrogen-fired gas turbine plant in the third embodiment is In the hydrogen-fired gas turbine plant according to the first embodiment, the pressure relief controller 106 controls the pressure relief damper 22 so that it closes when the rotational speed of the gas turbine rotor 2 reaches at least 30% of the rated rotational speed Nrad.

[0092] In this embodiment, the timing at which the steam turbine 33 starts to be driven by steam from the heat recovery boiler can be advanced compared to closing the pressure relief damper 22 at 50% of the rated rotational speed Nrad.

[0093] (4) The hydrogen-fired gas turbine plant in the fourth embodiment is In the hydrogen-fired gas turbine plant according to the first embodiment, an ignition detector 9 is provided that can detect that the fuel F has ignited in all of the combustors 14. When the ignition detector 9 detects that the fuel F has ignited in all of the combustors 14, the pressure relief controller 106 outputs a closing instruction to the pressure relief damper 22.

[0094] In this embodiment, the timing at which the steam turbine 33 starts to be driven by steam from the heat recovery boiler can be advanced compared to closing the pressure relief damper 22 at 30% of the rated rotational speed Nrad.

[0095] (5) The hydrogen-fired gas turbine plant in the fifth embodiment is In the hydrogen-fired gas turbine plant according to the first embodiment, the gas turbine 1 has a spark plug 15 capable of generating a spark in at least one of the combustors 14 among the plurality of combustors 14. The control device 100 has an ignition controller 105 that controls the generation of a spark in the spark plug 15. The ignition controller 105 generates a spark in the spark plug 15 immediately before or at the time of fuel on Fon. The pressure relief controller 106 outputs an open command to the pressure relief damper 22 before spark plug on Igon, which is when the spark plug 15 is generated.

[0096] In this embodiment, the fuel F flowing into the combustor 14 can be ignited faster than when a spark is generated at the spark plug 15 after the fuel is turned on (Fon). Therefore, in this embodiment, the amount of fuel F that does not burn in the combustor 14 and instead passes through the turbine casing 19 to the exhaust duct 20 can be reduced.

[0097] Furthermore, in this embodiment, the pressure relief damper 22 opens earlier than when the pressure relief damper 22 is opened when the fuel is turned on (Fon). Therefore, even if unburned hydrogen gas as fuel F is present in the exhaust duct 20 and this hydrogen gas explodes due to a spark caused by static electricity, in this embodiment, the high-pressure gas generated by the hydrogen gas explosion can be exhausted to the outside from the pressure relief stack 21 with sufficient margin against this explosion.

[0098] (6) The hydrogen-fired gas turbine plant in the sixth embodiment is In the hydrogen-fired gas turbine plant according to the first embodiment, the auxiliary rotation controller 104 performs a gas purging process S1a during the auxiliary rotation time, before the fuel-on time Fon, in which it rotates the gas turbine rotor 2 at a predetermined rotational speed in order to exhaust the gas inside the gas turbine 1, the exhaust duct 20, and the waste heat recovery boiler 31 to the outside via the waste heat recovery boiler 31. The pressure relief controller 106 outputs an open command to the pressure relief damper 22 from the latter half of the gas purging time when the auxiliary rotation controller 104 is performing the gas purging process S1a.

[0099] In a hydrogen-fired gas turbine plant, it is conceivable to perform a gas purging process S1a before the fuel is turned on (Fon). This gas purging process S1a is a process in which the gas turbine rotor 2 is rotated at a predetermined rotational speed in order to exhaust the gas inside the gas turbine 1, the exhaust duct 20, and the heat recovery boiler 31 to the outside via the heat recovery boiler 31. If the pressure relief damper 22 is opened before the latter half of the gas purging period, the efficiency of exhausting the gas inside the gas turbine 1, the exhaust duct 20, and the heat recovery boiler 31 to the outside via the heat recovery boiler 31 will decrease. In other words, if the pressure relief damper 22 is opened before the latter half of the gas purging period, the effect of the gas purging process S1a will decrease. For this reason, when performing the gas purging process S1a as in this embodiment, it is preferable to open the pressure relief damper 22 after the latter half of the gas purging period.

[0100] (7) The hydrogen-fired gas turbine plant in the seventh embodiment is In a hydrogen-fired gas turbine plant according to any one of the first to sixth embodiments, a duct damper 23 is provided that can shut off the flow of gas in the exhaust duct 20 downstream of the pressure relief stack 21 in the direction of gas flow within the exhaust duct 20. The control device 100 has a bypass controller 107 that controls the opening and closing of the duct damper 23.

[0101] In this embodiment, by closing the damper 23 inside the duct, the inflow of exhaust gas discharged from the gas turbine 1 into the heat recovery boiler 31 can be stopped. Therefore, in this embodiment, steam generation from the heat recovery boiler 31 can be stopped while the gas turbine 1 is being driven.

[0102] (8) The hydrogen-fired gas turbine plant in the eighth aspect is In the hydrogen-fired gas turbine plant according to the seventh embodiment, a bypass stack 24 is connected to the exhaust duct 20 upstream of the duct damper 23 in the direction of gas flow within the exhaust duct 20, and downstream of the pressure relief stack 21, and is capable of exhausting gas from the exhaust duct 20 to the outside; and a bypass damper 26 is capable of blocking the flow of gas from the bypass stack 24 to the outside. The bypass controller 107 controls the opening and closing of the bypass damper 26.

[0103] In this embodiment, by opening the bypass damper 26 while the duct damper 23 is closed, the exhaust gas discharged from the gas turbine 1 can be exhausted to the outside through the bypass stack 24.

[0104] (9) The hydrogen-fired gas turbine plant in the ninth embodiment is In the hydrogen-fired gas turbine plant according to any one of the first to eighth embodiments described above, the pressure relief stack 21 is not provided with a silencer to suppress noise generated when a portion of the gas in the exhaust duct 20 passes through the pressure relief stack 21.

[0105] (10) The hydrogen-fired gas turbine plant in the tenth embodiment is In the hydrogen-fired gas turbine plant according to any one of the first to ninth embodiments described above, when the pressure relief controller 106 receives a turbine trip signal, it outputs an open instruction to the pressure relief damper 22.

[0106] When an emergency occurs in the gas turbine plant, the pressure relief controller 106 receives a turbine trip signal. When a turbine trip signal is generated, the electrical connection between the generator 6 and the external power system is cut off, the fuel valve 5 closes, and the fuel supply to the multiple combustors 14 is interrupted, preventing the fuel F from burning in each combustor 14. Even when the fuel valve 5 is closed, fuel F remains in the fuel line 4 between the fuel valve 5 and the burner 14b, and inside the burner 14b. Not all of this remaining fuel F burns in the combustors 14. The remaining fuel F that does not burn in the multiple combustors 14 passes through the turbine casing 19 and into the exhaust duct 20.

[0107] In this embodiment, when the pressure relief controller 106 receives a turbine trip signal, it outputs an open command to the pressure relief damper 22. As a result, the pressure relief damper 22 opens, and even if unburned hydrogen gas F exists in the exhaust duct 20 after the turbine trip signal is received, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack 21.

[0108] (11) The hydrogen-fired gas turbine plant in the eleventh embodiment is The gas turbine 1 comprises a plurality of combustors 14 capable of generating combustion gas by burning fuel F in compressed air, a gas turbine rotor 2 that can be rotated by the combustion gas from the plurality of combustors 14, and a gas turbine casing 3 that covers the gas turbine rotor 2; a fuel line 4 capable of supplying the plurality of combustors 14 with a gas containing 50 vol% or more of hydrogen gas as fuel F; a fuel valve 5 capable of adjusting the flow rate of the fuel F flowing through the fuel line 4; an exhaust duct 20 connected to the gas turbine 1 through which exhaust gas, which is the combustion gas exhausted from the gas turbine 1, can flow; a heat recovery boiler 31 connected to the exhaust duct 20 and capable of generating steam using the heat of the exhaust gas from the exhaust duct 20; a pressure relief stack 21 connected to the exhaust duct 20 and capable of exhausting the gas in the exhaust duct 20 to the outside; a pressure relief damper 22 capable of blocking the flow of gas from the pressure relief stack 21 to the outside; and a control device 100. The control device 100 includes a fuel controller 102 that instructs the fuel valve 5 on the degree of opening, and a pressure relief controller 106 that controls the opening and closing of the pressure relief damper 22. When the pressure relief controller 106 receives a turbine trip signal, it outputs an open command to the pressure relief damper 22.

[0109] In this embodiment, similar to the hydrogen-fired gas turbine plant in the tenth embodiment, when the pressure relief controller 106 receives a turbine trip signal, it opens the pressure relief damper 22. Therefore, in this embodiment, even if unburned hydrogen gas as fuel F exists in the exhaust duct 20 after the turbine trip signal is received, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion is exhausted to the outside from the pressure relief stack 21.

[0110] (12) The operating method for a hydrogen-fired gas turbine plant in the twelfth embodiment applies to the following hydrogen-fired gas turbine plants. This hydrogen-fired gas turbine plant comprises a gas turbine 1 having a plurality of combustors 14 capable of generating combustion gas by burning fuel F in compressed air, a gas turbine rotor 2 that can be rotated by the combustion gas from the plurality of combustors 14, and a gas turbine casing 3 that covers the gas turbine rotor 2; a starter motor 6 capable of rotating the gas turbine rotor 2 during the startup process of the gas turbine 1; a fuel line 4 capable of supplying the fuel F to the plurality of combustors 14; a fuel valve 5 capable of adjusting the flow rate of the fuel F flowing through the fuel line 4; an exhaust duct 20 connected to the gas turbine 1 through which exhaust gas, which is the combustion gas exhausted from the gas turbine 1, can flow; and a waste heat recovery boiler 31 connected to the exhaust duct 20 and capable of generating steam using the heat of the exhaust gas from the exhaust duct 20. In this hydrogen-fired gas turbine plant operation method, the following steps are performed: an auxiliary rotation step S1 in which the gas turbine rotor 2 is rotated by the starting motor 6 in order to start the gas turbine 1; a fuel supply step S3 in which the fuel valve 5 is opened and gas containing 50 vol% or more of hydrogen gas is supplied as the fuel F to the multiple combustors 14; and a duct pressure relief step S5 in which the gas inside the exhaust duct 20 is exhausted to the outside from the middle of the exhaust duct 20. In the fuel supply process S3, during the auxiliary rotation period when the gas turbine rotor 2 is being rotated by the starter motor 6, the fuel valve 5 is opened to begin supplying the fuel F to the multiple combustors 14. The duct pressure relief process S5 is started at the latest when the fuel is turned on (Fon), which is the start of the supply of the fuel F to the multiple combustors 14 during the auxiliary rotation period, and is completed at the latest before the auxiliary rotation period ends.

[0111] In this embodiment, damage to the hydrogen-fired gas turbine plant can be suppressed, similar to the hydrogen-fired gas turbine plant in the first embodiment. Furthermore, in this embodiment, the delay in the timing at which the steam turbine 33 starts to be driven by the steam from the waste heat recovery boiler 31 can be suppressed.

[0112] (13) The operating method of the hydrogen-fired gas turbine plant in the thirteenth aspect is: In the operating method of the hydrogen-fired gas turbine plant according to the twelfth embodiment described above, when a turbine trip signal is generated, the duct pressure relief process S5 is started.

[0113] In this embodiment, when a turbine trip signal is generated, the duct pressure relief process S5 is initiated. Therefore, in this embodiment, even if unburned hydrogen gas as fuel F exists in the exhaust duct 20 after the turbine trip signal is generated, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion can be exhausted to the outside.

[0114] (14) The operating method for a hydrogen-fired gas turbine plant in the fourteenth embodiment applies to the following hydrogen-fired gas turbine plants. This hydrogen-fired gas turbine plant comprises a gas turbine 1 having a plurality of combustors 14 capable of generating combustion gas by burning fuel F in compressed air, a gas turbine rotor 2 that can be rotated by the combustion gas from the plurality of combustors 14, and a gas turbine casing 3 that covers the gas turbine rotor 2; a starter motor 6 capable of rotating the gas turbine rotor 2 during the startup process of the gas turbine 1; a fuel line 4 capable of supplying the fuel F to the plurality of combustors 14; a fuel valve 5 capable of adjusting the flow rate of the fuel F flowing through the fuel line 4; an exhaust duct 20 connected to the gas turbine 1 through which exhaust gas, which is the combustion gas exhausted from the gas turbine 1, can flow; and a waste heat recovery boiler 31 connected to the exhaust duct 20 and capable of generating steam using the heat of the exhaust gas from the exhaust duct 20. In this hydrogen-fired gas turbine plant operation method, a fuel supply step S3 is performed in which the fuel valve 5 is opened and gas containing 50 vol% or more of hydrogen gas is supplied as fuel F to the multiple combustors 14, and a duct pressure relief step S5 is performed in which the gas inside the exhaust duct 20 is exhausted to the outside from the middle of the exhaust duct 20. When a turbine trip signal is generated, the duct pressure relief step S5 is started.

[0115] In this embodiment, similar to the operating method of the hydrogen-fired gas turbine plant in the twelfth embodiment, when a turbine trip signal is generated, the duct pressure relief process S5 is started. Therefore, in this embodiment, even if unburned hydrogen gas as fuel F exists in the exhaust duct 20 after the generation of the turbine trip signal, and this hydrogen gas explodes due to a spark caused by static electricity, the high-pressure gas generated by the hydrogen gas explosion can be exhausted to the outside.

[0116] (15) The operating method of the hydrogen-fired gas turbine plant in the fifteenth embodiment is: In the operating method of a hydrogen-fired gas turbine plant according to any one of the twelve to fourteen embodiments, the fuel F supplied to the plurality of combustors 14 in the fuel supply step S3 is a gas containing 80 vol% or more of hydrogen gas.

[0117] (16) The operating method for a hydrogen-fired gas turbine plant in the sixteenth embodiment applies to the following hydrogen-fired gas turbine plants. In the operating method of a hydrogen-fired gas turbine plant according to any one of the twelve to fourteen embodiments, the fuel F supplied to the plurality of combustors 14 in the fuel supply step S3 is a gas containing 50 vol% or more of hydrogen gas, as well as natural gas. [Explanation of Symbols]

[0118] 1: Gas turbine 2: Gas turbine rotor 3: Gas turbine casing 3m: Intermediate casing 4: Fuel line 4m: Main fuel line 4b: Branch fuel line 5: Fuel valve 6: Generator (or starting motor) 7: Tachometer 8: Output meter 9: Thermometer (ignition detector) 10: Compressor 11: Compressor rotor 11s: Compressor rotor shaft 11b: Moving blade row 12: Compressor casing 13: Intake volume regulator 13v: Inlet Guide Vane (IGV) 13d: Drive unit 14: Combustor 14b: Burner 14p: Combustion tube (tail tube) 15: Spark hydrant 16: Flame propagation tube 17: Turbine 18: Turbine rotor 18s: Turbine rotor shaft 18b: Moving blade row 19: Turbine casing 20: Exhaust duct 21: Pressure relief stack 22: Pressure relief damper 23: Damper inside the duct 24: Bypass Stack 25: Silencer 26: Bypass damper 30: Waste heat utilization equipment 31: Heat recovery boiler 31c: Boiler casing 31t: Heat transfer tube 32: Chimney 33: Steam turbine 34: Main steam line 35: Condenser 36: Water supply line 37: Water supply pump 100: Control device 101: Main Controller 102: Fuel controller 103: IGV controller 104: Auxiliary rotation controller 105: Ignition controller 106: Pressure relief controller 107: Bypass Controller A: Air F:Fuel Ar: Rotor axis Da: Axial direction Dau: Upstream side of the axis Dad: Downstream side of the axis DC: Zhou Direction

Claims

1. A gas turbine comprising: a plurality of combustors capable of generating combustion gas by burning fuel in compressed air; a gas turbine rotor rotatable by the combustion gas from the plurality of combustors; and a gas turbine casing covering the gas turbine rotor; During the startup process of the gas turbine, a starting motor capable of rotating the gas turbine rotor is provided, A fuel line capable of supplying a gas containing 50 vol% or more of hydrogen gas as the fuel to the plurality of combustors, A fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line, An exhaust duct connected to the gas turbine, through which the exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow, A heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct, A pressure relief stack connected to the exhaust duct, which is capable of exhausting the gas inside the exhaust duct to the outside from the middle of the exhaust duct, A pressure relief damper capable of blocking the flow of gas from the pressure relief stack to the outside, Control device and Equipped with, The control device is A fuel controller that instructs the opening degree of the fuel valve, An auxiliary rotation controller for controlling the operation of the aforementioned starting motor, A pressure relief controller that controls the opening and closing of the aforementioned pressure relief damper, It has, The pressure relief controller controls the pressure relief damper so that it is open at the latest when the fuel controller opens the fuel valve during the auxiliary rotation period when the gas turbine rotor is rotated by the starter motor to start the gas turbine, and closes at the latest by the end of the auxiliary rotation period. Hydrogen-fired gas turbine plant.

2. In the hydrogen-fired gas turbine plant according to claim 1, The pressure relief controller controls the pressure relief damper so that it closes when the rotational speed of the gas turbine rotor reaches at least 50% of the rated rotational speed. Hydrogen-fired gas turbine plant.

3. In the hydrogen-fired gas turbine plant according to claim 1, The pressure relief controller controls the pressure relief damper so that it closes when the rotational speed of the gas turbine rotor reaches at least 30% of the rated rotational speed. Hydrogen-fired gas turbine plant.

4. In the hydrogen-fired gas turbine plant according to claim 1, The system includes an ignition detector capable of detecting that the fuel has ignited in all of the aforementioned multiple combustion chambers. When the ignition detector detects that the fuel has ignited in all of the multiple combustors, the pressure relief controller outputs a closing instruction to the pressure relief damper. Hydrogen-fired gas turbine plant.

5. In the hydrogen-fired gas turbine plant according to claim 1, The gas turbine has a spark plug capable of generating a spark in at least one of the combustors among the plurality of combustors. The control device has an ignition controller that controls the generation of sparks from the spark plug, The ignition controller generates a spark at the spark plug immediately before or when the fuel is turned on. The pressure relief controller outputs an open command to the pressure relief damper before the spark plug is turned on, which is when the spark plug is generated. Hydrogen-fired gas turbine plant.

6. In the hydrogen-fired gas turbine plant according to claim 1, The auxiliary rotation controller, during the auxiliary rotation time, before the fuel is turned on, performs a gas purging process in which it rotates the gas turbine rotor at a predetermined rotational speed in order to exhaust the gas inside the gas turbine, inside the exhaust duct, and inside the heat recovery boiler to the outside via the heat recovery boiler. The pressure relief controller outputs an open command to the pressure relief damper from the latter half of the gas purging period when the auxiliary rotation controller is performing the gas purging process. Hydrogen-fired gas turbine plant.

7. In the hydrogen-fired gas turbine plant according to any one of claims 1 to 6, A duct damper capable of blocking the flow of gas within the exhaust duct is provided downstream of the pressure relief stack in the direction of gas flow within the exhaust duct. The control device has a bypass controller that controls the opening and closing of the damper inside the duct. Hydrogen-fired gas turbine plant.

8. In the hydrogen-fired gas turbine plant according to claim 7, A bypass stack is connected to the exhaust duct, located upstream of the duct damper in the direction of gas flow within the exhaust duct, and downstream of the pressure relief stack, and capable of exhausting the gas within the exhaust duct to the outside. A bypass damper capable of blocking the flow of gas from the bypass stack to the outside, Equipped with, The bypass controller controls the opening and closing of the bypass damper. Hydrogen-fired gas turbine plant.

9. In the hydrogen-fired gas turbine plant according to any one of claims 1 to 6, The aforementioned pressure relief stack is not equipped with a silencer to suppress noise generated when a portion of the gas in the exhaust duct passes through the pressure relief stack. Hydrogen-fired gas turbine plant.

10. In the hydrogen-fired gas turbine plant according to any one of claims 1 to 6, When the pressure relief controller receives a turbine trip signal, it outputs an open command to the pressure relief damper. Hydrogen-fired gas turbine plant.

11. A gas turbine comprising: a plurality of combustors capable of generating combustion gas by burning fuel in compressed air; a gas turbine rotor rotatable by the combustion gas from the plurality of combustors; and a gas turbine casing covering the gas turbine rotor; A fuel line capable of supplying a gas containing 50 vol% or more of hydrogen gas as the fuel to the plurality of combustors, A fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line, An exhaust duct connected to the gas turbine, through which the exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow, A heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct, A pressure relief stack connected to the exhaust duct and capable of exhausting the gas inside the exhaust duct to the outside, A pressure relief damper capable of blocking the flow of gas from the pressure relief stack to the outside, Control device and Equipped with, The control device is A fuel controller that instructs the opening degree of the fuel valve, A pressure relief controller that controls the opening and closing of the aforementioned pressure relief damper, It has, When the pressure relief controller receives a turbine trip signal, it outputs an open command to the pressure relief damper. Hydrogen-fired gas turbine plant.

12. A gas turbine comprising: a plurality of combustors capable of generating combustion gas by burning fuel in compressed air; a gas turbine rotor rotatable by the combustion gas from the plurality of combustors; and a gas turbine casing covering the gas turbine rotor; During the startup process of the gas turbine, a starting motor capable of rotating the gas turbine rotor is provided, A fuel line capable of supplying the fuel to the plurality of combustors, A fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line, An exhaust duct connected to the gas turbine, through which the exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow, A heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct, In a method for operating a hydrogen-fired gas turbine plant equipped with, An auxiliary rotation step is performed to rotate the gas turbine rotor using the starting motor in order to start the gas turbine, A fuel supply step in which the fuel valve is opened and a gas containing 50 vol% or more of hydrogen gas is supplied as the fuel to the plurality of combustors, A duct pressure relief step is performed to exhaust the gas inside the exhaust duct to the outside from the middle of the exhaust duct, Execute, In the fuel supply process, during the auxiliary rotation period when the gas turbine rotor is rotated by the starter motor, the fuel valve is opened to start supplying the fuel to the plurality of combustors. During the auxiliary rotation period, the duct pressure relief process is started at the latest when the fuel is turned on, which is when the fuel supply to the multiple combustors begins, and the duct pressure relief process is completed at the latest by the end of the auxiliary rotation period. Operating procedures for hydrogen-fired gas turbine plants.

13. In the method for operating a hydrogen-fired gas turbine plant according to claim 12, When a turbine trip signal is generated, the duct pressure relief process is initiated. Operating procedures for hydrogen-fired gas turbine plants.

14. A gas turbine comprising: a plurality of combustors capable of generating combustion gas by burning fuel in compressed air; a gas turbine rotor rotatable by the combustion gas from the plurality of combustors; and a gas turbine casing covering the gas turbine rotor; During the startup process of the gas turbine, a starting motor capable of rotating the gas turbine rotor is provided, A fuel line capable of supplying the fuel to the plurality of combustors, A fuel valve capable of adjusting the flow rate of the fuel flowing through the fuel line, An exhaust duct connected to the gas turbine, through which the exhaust gas, which is the combustion gas exhausted from the gas turbine, can flow, A heat recovery boiler connected to the exhaust duct and capable of generating steam using the heat of the exhaust gas from the exhaust duct, In a method for operating a hydrogen-fired gas turbine plant equipped with, A fuel supply step in which the fuel valve is opened and a gas containing 50 vol% or more of hydrogen gas is supplied as the fuel to the plurality of combustors, A duct pressure relief step is performed to exhaust the gas inside the exhaust duct to the outside from the middle of the exhaust duct, Execute, When a turbine trip signal is generated, the duct pressure relief process is initiated. Operating procedures for hydrogen-fired gas turbine plants.

15. In the method for operating a hydrogen-fired gas turbine plant according to any one of claims 12 to 14, In the fuel supply process, the fuel supplied to the plurality of combustors is a gas containing 80 vol% or more of hydrogen gas. Operating procedures for hydrogen-fired gas turbine plants.

16. In the method for operating a hydrogen-fired gas turbine plant according to any one of claims 12 to 14, In the fuel supply process, the fuel supplied to the plurality of combustors is a gas containing 50 vol% or more of hydrogen gas, as well as natural gas. Operating procedures for hydrogen-fired gas turbine plants.

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