Plant control apparatus, plant, plant control method, and program

Abstract

To provide a control device of a plant capable of producing hydrogen in addition to steam used in generated power and a production process, and capable of efficiently operating the plant by restraining reduction in a plant load by demand fluctuation.SOLUTION: And a control unit that adjusts at least one of an amount of steam generated by the heat recovery steam generator, a flow rate of a steam supply pipe of the steam turbine, a flow rate of a steam supply pipe of the ammonia decomposition device, or a flow rate of a steam supply pipe of the production process based on the received signal such that a demand indicated by the signal is satisfied with a current load of the gas turbine.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a plant control device, a plant, a plant control method, and a program. [Background technology]

[0002] Boilers have traditionally been used for a variety of purposes. Steam generated in industrial boilers is sent to factories and used in the production process of industrial products. In addition, in cogeneration plants, steam generated in boilers is also used to generate electricity, separate from being sent to factories. The generated electricity is used in the factory's production process and sold to an external grid (external sales).

[0003] Furthermore, ammonia, which can reduce carbon dioxide emissions, is sometimes used as fuel for power plants. For example, Patent Document 1 describes the configuration of a thermal power plant in which steam generated in a boiler is supplied to an ammonia decomposition device, and hydrogen decomposed from ammonia by the heat of the steam is supplied to the boiler as fuel. Furthermore, Patent Document 2 describes the configuration of a gas turbine system in which high-temperature compressed air is supplied from a compressor to an ammonia decomposition catalyst, and hydrogen decomposed from ammonia by the heat of the compressed air is supplied to a combustor as fuel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-96616 [Patent Document 2] International Publication No. 2022 / 209562 Summary of the Invention [Problem to be solved by the invention]

[0005] Gas turbine combined cycle (GTCC) cogeneration plants generate electricity using gas turbines and steam turbines powered by exhaust gas from the gas turbines. Demand for steam used in production processes and for electricity used in production processes and for external sales fluctuates seasonally, monthly, weekly, and daily. The plant's control system must adjust the power output of the plant (gas turbines and steam turbines) and the steam generation rate of the heat recovery steam generator, which uses exhaust gas from the gas turbine to generate steam, in response to these demand fluctuations. However, flexibly adjusting the power output and steam generation rate in response to demand fluctuations is difficult when plants are started and stopped. Furthermore, increasing the frequency of plant start-ups and shutdowns can cause repeated thermal stress due to temperature increases and decreases, affecting the plant's equipment lifespan. Furthermore, plants that use natural gas as fuel for startup generate carbon dioxide (CO2) during startup, resulting in increased CO2 emissions.

[0006] For this reason, conventional technology adjusts the amount of power generation and steam generation by operating the gas turbine at partial load. Figure 18 is a diagram illustrating fluctuations in demand and boiler load factor of a cogeneration plant using conventional technology. The vertical axis of Figure 18 represents the steam generation rate (plant load factor) of the heat recovery boiler and plant efficiency, and the horizontal axis represents time. Figure 18 is a stacked graph showing the changes in the amount of steam generated by the heat recovery boiler in response to the power demand and steam demand over a day. Of the steam generation rate of the heat recovery boiler, a represents the amount of steam supplied to the steam turbine to meet the power demand, and b represents the amount of steam supplied to the production process. Furthermore, of the amount of steam supplied to the steam turbine, a1 represents the amount of steam used for in-house power generation, and a2 represents the amount of steam used for external sales of power. The dashed line E represents the plant efficiency.

[0007] As shown in Figure 18, when power demand decreases, for example, at time t1, the gas turbine is operated at partial load, reducing its power output. This reduces the heat content of the exhaust gas from the gas turbine, which in turn reduces the amount of steam generated in the heat recovery steam generator and the power output of the steam turbine. However, when a gas turbine operates at partial load, its power generation efficiency (plant efficiency E) decreases. Furthermore, gas turbines generally have difficulty operating at low loads (for example, a minimum load factor of about 50%) and have low load adjustment capabilities. Therefore, adjusting the gas turbine output when power demand decreases reduces plant efficiency and reduces economic viability. Furthermore, if the gas turbine is shut down due to a low load below the minimum load factor, the gas turbine's availability rate decreases, further reducing economic viability. Furthermore, as described above, the start-stop operation of the gas turbine also has the potential to shorten the equipment's lifespan and increase CO2 emissions.

[0008] Furthermore, in cogeneration plants, steam is generated in the heat recovery boiler in anticipation of the amount of power to be generated, so when the steam demand for the production process is low, there may be an excess supply of steam. In such cases, conventional cogeneration plants have no choice but to discard the excess steam, which is uneconomical.

[0009] An object of the present disclosure is to provide a plant control device, a plant, a plant control method, and a program that can produce hydrogen in addition to the generated electricity and steam used in the production process, and that can operate the plant efficiently by suppressing a decrease in plant load due to demand fluctuations. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a plant control device is provided which includes a gas turbine, a heat recovery boiler which generates steam using exhaust gas from the gas turbine, a steam turbine which is rotationally driven by the steam, a generator which converts the rotational power of the steam turbine into electric power, an ammonia decomposer which decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply piping which supplies the steam to the steam turbine, the ammonia decomposer, and a production process which utilizes the steam for production, and which includes: a signal receiving unit which receives a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and a control unit which adjusts, based on the received signal, at least one of the steam generation amount of the heat recovery boiler, the flow rate of the steam supply piping of the steam turbine, the flow rate of the steam supply piping of the ammonia decomposer, and the flow rate of the steam supply piping of the production process so as to satisfy the demand indicated by the signal with a current load of the gas turbine.

[0011] According to one aspect of the present disclosure, a plant includes a gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, an ammonia decomposition unit that decomposes ammonia using the heat of the steam to produce hydrogen, steam supply piping that supplies the steam to the steam turbine, the ammonia decomposition unit, and a production process that utilizes the steam for production, and the above-mentioned control device.

[0012] According to one aspect of the present disclosure, a plant control method includes a gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, an ammonia decomposer that decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply piping that supplies the steam to the steam turbine, the ammonia decomposer, and a production process that utilizes the steam for production, the plant control method comprising the steps of: receiving a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and adjusting, based on the received signal, at least one of the steam generation amount of the heat recovery boiler, the flow rate of the steam supply piping of the steam turbine, the flow rate of the steam supply piping of the ammonia decomposer, and the flow rate of the steam supply piping of the production process so as to satisfy the demand indicated by the signal with a current load of the gas turbine.

[0013] According to one aspect of the present disclosure, a program causes a control device of a plant including a gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, an ammonia decomposer that decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply piping that supplies the steam to the steam turbine, the ammonia decomposer, and a production process that uses the steam for production, to receive a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process, and adjust, based on the received signal, at least one of the steam generation amount of the heat recovery boiler, the flow rate of the steam supply piping of the steam turbine, the flow rate of the steam supply piping of the ammonia decomposer, and the flow rate of the steam supply piping of the production process so as to meet the demand indicated by the signal with a current load of the gas turbine.

[0014] According to one aspect of the present disclosure, a plant control device includes a gas turbine, an ammonia decomposition device that decomposes ammonia using heat from exhaust gas of the gas turbine to produce hydrogen, a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, and steam supply piping that supplies the steam to the steam turbine and to each of production processes that utilize the steam for production, and the plant control device includes: a signal receiving unit that receives a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and a control unit that adjusts at least one of the amount of exhaust gas from the gas turbine, the amount of steam generated by the heat recovery boiler, the amount of heat absorbed by the ammonia decomposition device, the flow rate in the steam supply piping of the steam turbine, and the flow rate in the steam supply piping of the production process so as to satisfy the demand indicated by the received signal.

[0015] According to one aspect of the present disclosure, a plant includes a gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from exhaust gas of the gas turbine to produce hydrogen, a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition unit, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electricity, steam supply piping that supplies the steam to the steam turbine and to each of the production processes that utilize the steam for production, and the above-mentioned control device.

[0016] According to one aspect of the present disclosure, a plant control method includes a gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from exhaust gas of the gas turbine to produce hydrogen, a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition unit, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, and steam supply piping that supplies the steam to the steam turbine and to each of production processes that utilize the steam for production, the plant control method comprising the steps of: receiving a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and adjusting at least one of an amount of exhaust gas from the gas turbine, an amount of steam generated by the heat recovery boiler, an amount of heat absorbed by the ammonia decomposition unit, a flow rate in the steam supply piping of the steam turbine, and a flow rate in the steam supply piping of the production process, so as to satisfy the demand indicated by the received signal.

[0017] According to one aspect of the present disclosure, a program causes a control device of a plant including a gas turbine, an ammonia decomposition device that decomposes ammonia using heat from exhaust gas of the gas turbine to produce hydrogen, a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device, a steam turbine that is rotationally driven by the steam, a generator that converts the rotational power of the steam turbine into electric power, and steam supply piping that supplies the steam to the steam turbine and to each of production processes that utilize the steam for production, to execute the steps of receiving a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process, and adjusting at least one of an amount of exhaust gas from the gas turbine, an amount of steam generated by the heat recovery boiler, an amount of heat absorbed by the ammonia decomposition device, a flow rate in the steam supply piping of the steam turbine, and a flow rate in the steam supply piping of the production process, so as to satisfy the demand indicated by the received signal. [Effects of the Invention]

[0018] According to the above aspect, in addition to the generated power and steam used in the production process, hydrogen can be produced, and the plant can be operated efficiently by suppressing a decrease in plant load due to demand fluctuations. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing the overall configuration of a plant according to a first embodiment. [Figure 2] FIG. 1 is a schematic process flow diagram of an ammonia decomposition apparatus according to a first embodiment. [Figure 3] 2 is a block diagram showing the functional configuration of a control device according to the first embodiment. FIG. [Figure 4] 4 is a first flowchart showing an example of processing by the control device according to the first embodiment. [Figure 5] 6 is a second flowchart showing an example of processing by the control device according to the first embodiment. [Figure 6] FIG. 2 is a first diagram illustrating fluctuations in demand and load factor of the plant according to the first embodiment. [Figure 7] FIG. 4 is a second diagram illustrating fluctuations in demand and load factor of the plant according to the first embodiment. [Figure 8] FIG. 1 is a first schematic diagram showing the overall configuration of a plant according to a second embodiment. [Figure 9] FIG. 2 is a second schematic diagram showing the overall configuration of the plant according to the second embodiment. [Figure 10] 10 is a first flowchart showing an example of processing by a control device according to a second embodiment. [Figure 11] 10 is a second flowchart showing an example of processing by the control device according to the second embodiment. [Figure 12] FIG. 10 is a schematic diagram showing the overall configuration of a plant according to a third embodiment. [Figure 13] FIG. 10 is a schematic diagram showing the overall configuration of a plant according to a fourth embodiment. [Figure 14] 10 is a first flowchart showing an example of processing by a control device according to a fourth embodiment. [Figure 15] 20 is a second flowchart showing an example of processing by the control device according to the fourth embodiment. [Figure 16] FIG. 10 is a schematic diagram showing the overall configuration of a plant according to a fifth embodiment. [Figure 17] FIG. 10 is a schematic diagram showing the overall configuration of a plant according to a sixth embodiment. [Figure 18] FIG. 1 is a diagram illustrating fluctuations in demand and load factor of a plant in the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0020] First Embodiment The first embodiment will be described in detail below with reference to FIGS.

[0021] (Overall plant configuration) FIG. 1 is a schematic diagram showing the overall configuration of a plant according to a first embodiment. As shown in FIG. 1, the plant 1 includes a gas turbine system 2, a heat recovery steam generator (HRSG) 3, a steam turbine system 4, an ammonia decomposition unit 5, and a control device 10. The plant 1 of this embodiment is a gas turbine combined cycle (GTCC) power plant, and is, for example, a cogeneration plant that generates steam for use in a production process at a facility and generates electricity for use at the facility and for sale to an external grid, to which the ammonia decomposition unit 5 has been added to enable hydrogen production. A vaporizer or the like may be installed in the ammonia supply pipe L2 from the ammonia tank 51 to the ammonia decomposition unit 5, but this is not shown in FIG. 1. The hydrogen in the hydrogen tank 52 is in the form of gas or liquid, but hydrogen liquefaction equipment is not shown in FIG. 1.

[0022] The gas turbine system 2 includes a compressor 21, a combustor 22, a gas turbine 23, and a generator 24. The compressor 21 takes in air from the outside and generates compressed air. The combustor 22 burns the compressed air generated by the compressor 21 with fuel to generate combustion gas. The gas turbine 23 is driven by the combustion gas supplied from the combustor 22. The generator 24 converts the rotational power of the gas turbine 23 into electricity. The heat recovery steam generator 3 uses the exhaust gas from the gas turbine 23 to generate steam for use in the steam turbine system 4, the factory's production process, and the ammonia cracker 5. The steam turbine system 4 includes a steam turbine 41 and a generator 42. The steam turbine 41 is driven by steam supplied from the heat recovery steam generator 3. The generator 42 is connected to the rotor of the steam turbine 41 and converts the rotational power of the steam turbine 41 into electricity. The electricity generated by the generator 24 of the gas turbine system 2 and the generator 42 of the steam turbine system 4 is used within the facility. In another embodiment, the gas turbine system 2 and the steam turbine system 4 may be coaxial, and the gas turbine generator 24 and the steam turbine generator 42 may be coaxially connected in series or combined into a common generator. In addition, surplus power generated by these generators 24, 42 may be sold (externally sold) to an external grid. The ammonia decomposition unit 5 decomposes ammonia (NH3) supplied from an ammonia tank 51 using the heat of steam to produce hydrogen (H2). The hydrogen produced by the ammonia decomposition unit 5 is stored in a hydrogen tank 52. The hydrogen stored in the hydrogen tank 52 may be used as fuel for the heat recovery steam generator 3 or for the facility's production processes, or may be sold to hydrogen consumers outside the facility.

[0023] An exhaust gas duct L4, through which exhaust gas from the gas turbine 23 is delivered, is connected to the heat recovery steam generator 3. A main pipe L1, through which steam generated by the heat recovery steam generator 3 is delivered, is also connected to the heat recovery steam generator 3. A pressure gauge P4 and a thermometer T4 are provided on the main pipe L1. Steam supply pipes L11, L12, and L13, which deliver steam to the steam turbine 41, the production process, and the ammonia cracker 5, respectively, branch off from the main pipe L1. The steam supply pipe L11 is provided with at least a flow control valve V1, a flow meter F1, a pressure gauge P1, and a thermometer T1, which adjust the flow rate of steam supplied to the steam turbine 41. The steam supply pipe L12 is provided with at least a flow control valve V2, which adjusts the flow rate of steam supplied to the production process, and a flow meter F2. The steam supply pipe L13 is provided with at least a flow control valve V3, a flow meter F3, a pressure gauge P3, and a thermometer T3 that adjust the flow rate of steam supplied to the ammonia decomposer 5. The ammonia tank 51 and the ammonia decomposer 5 are connected via the ammonia supply pipe L2. The ammonia supply pipe L2 is provided with at least a flow control valve V4 and a flow meter F4 that adjust the flow rate of ammonia supplied to the ammonia decomposer 5. The measured values ​​of the sensors (flow meter, pressure gauge, and thermometer) are sequentially transmitted to the control device 10. While the present embodiment describes an example in which a flow meter, pressure gauge, and thermometer are provided as sensors, other measuring instruments may be provided to measure various other measured values, such as ammonia concentration and pump rotation speed. To measure the amount of hydrogen supplied, a flow meter may be provided in the hydrogen pipe between the ammonia decomposer 5 and the hydrogen tank 52 or in the hydrogen pipe from the hydrogen tank 52 to a consumer facility, or a level gauge may be provided in the hydrogen tank 52.

[0024] The control device 10 controls the amount of steam generated by the heat recovery steam generator 3 and the flow rate of steam supplied to each component based on a signal D1 indicating the power demand of the power consumer, a signal D2 indicating the steam demand of the steam consumer, and a signal D3 indicating the hydrogen demand of the hydrogen consumer. At this time, the control device 10 adjusts the flow rate of steam supplied to each component so as to suppress a decrease in the load of the heat recovery steam generator 3 due to fluctuations in demand. The power consumer includes at least one of the facility in which the plant 1 is installed and an external grid. The steam consumer includes a production process in the facility in which the plant 1 is installed. The hydrogen consumer includes at least one of the heat recovery steam generator 3 of the plant 1, the production process in the facility in which the plant 1 is installed, and hydrogen consumers outside the facility.

[0025] (Functional configuration of ammonia decomposition unit) Fig. 2 is a schematic process flow diagram of the ammonia decomposition apparatus according to the first embodiment. As shown in Fig. 2, the ammonia decomposition apparatus 5 includes a decomposition reactor 53, an absorption tower 54, a regeneration tower 55, and a hydrogen purification unit 56.

[0026] The decomposition reactor 53 decomposes ammonia supplied from the ammonia tank 51 by a pump 501 into a cracked gas containing nitrogen and hydrogen through an endothermic reaction using steam supplied from the heat recovery boiler 3 as a heat source (NH3 + 46 kJ → 3 / 2H2 + 1 / 2N2). The ammonia supplied from the ammonia tank 51 is liquid, and is vaporized in an evaporator 502, heated in a heat exchanger 503, and introduced into the decomposition reactor 53. A cracked gas pipe L21 is connected to the outlet of the decomposition reactor 53. The cracked gas delivered from the decomposition reactor 53 is cooled in the heat exchanger 503 and a condenser 504 and introduced into the absorption tower 54.

[0027] A cracked gas pipe L21 is connected to the bottom of the absorption tower 54, and cracked gas is introduced therein. A water pipe L22 is connected to the top of the absorption tower 54. Water (H2O) supplied from the water pipe L22 is sprayed into the inside of the absorption tower 54. In the absorption tower 54, residual ammonia in the cracked gas is dissolved in the sprayed water, thereby removing the residual ammonia from the cracked gas. The treated gas (H2, N2) from which the residual ammonia has been removed rises inside the absorption tower 54 and is sent to the hydrogen purification section 56 through a treated gas pipe L23 connected to the top end of the absorption tower 54. The ammonia water in which the residual ammonia has been dissolved is stored in the bottom of the absorption tower 54 and sent to the regeneration tower 55 through an ammonia water pipe L24 connected to the bottom end of the absorption tower 54.

[0028] An ammonia water pipe L24 is connected to the top of the regeneration tower 55, and ammonia water containing dissolved residual ammonia is introduced therein. A circulation pipe L25 is provided to the regeneration tower 55. A reboiler 507 is provided to the circulation pipe L25, and the ammonia water extracted from the bottom of the regeneration tower 55 is heated to separate and distill the ammonia in the ammonia water as gaseous ammonia. The water in the ammonia water is stored in the bottom of the regeneration tower 55. A portion of the water stored in the regeneration tower 55 is sent to the absorption tower 54 via the water pipe L22 by a pump 505. At this time, a heat exchanger 506 exchanges heat between the water sent from the regeneration tower 55 and the ammonia water sent from the absorption tower 54, cooling the water and heating the ammonia water. An ammonia recovery pipe L26 is also connected to the top end of the regeneration tower 55, and a gas containing gaseous ammonia separated from the ammonia water is sent to the ammonia supply pipe L2 by a pump 509. A condenser 508 is provided in the ammonia recovery pipe L26, and cools the gas flowing through the ammonia recovery pipe L26 and returns the moisture in the gas to the regeneration tower 55.

[0029] The hydrogen purification unit 56 separates and purifies hydrogen from the treated gas delivered from the absorption tower 54. The hydrogen purification unit 56 has adsorption towers 561 and 562, each equipped with an adsorbent Ad. While FIG. 2 shows an example in which the hydrogen purification unit 56 has two adsorption towers 561 and 562, the number of adsorption towers may be changed as desired. The treated gas pipe L23 is connected to the inlets of the adsorption towers 561 and 562, and the hydrogen pipe L27 is connected to the outlets. The adsorbent Ad adsorbs or desorbs components other than hydrogen contained in the treated gas depending on changes in pressure. The adsorption towers 561 and 562 adsorb nitrogen in the treated gas using the adsorbent Ad and discharge hydrogen with a purity above a reference value (e.g., 99.9% or higher). If the treated gas contains ammonia, the adsorbent Ad also adsorbs the ammonia. The hydrogen discharged from the absorption tower 54 is stored in the hydrogen tank 52 via the hydrogen pipe L27. Furthermore, the remaining off-gas containing nitrogen, hydrogen and ammonia is discharged through the off-gas pipe L28.

[0030] (Functional configuration of the control device) 3 is a block diagram showing the functional configuration of the control device according to the first embodiment. As shown in FIG. 3, the control device 10 includes a processor 11, a memory 12, a storage 13, and a communication interface 14.

[0031] The processor 11 operates in accordance with a predetermined program to function as a signal receiving unit 111 and a control unit 112 .

[0032] The signal receiving unit 111 receives signals indicating measurement values ​​from each sensor (flow meter, pressure gauge, thermometer). The signal receiving unit 111 receives a signal D1 indicating the power demand of a power consumer, a signal D2 indicating the steam demand of a steam consumer, and a signal D3 indicating the hydrogen demand of a hydrogen consumer. The signal receiving unit 111 also receives a signal D4 indicating the power generated by the gas turbine system 2 (generator 24), a signal D5 indicating the amount of steam generated by the heat recovery boiler 3, a signal D6 indicating the power generated by the steam turbine system 4 (generator 42), and a signal D7 indicating the amount of hydrogen produced by the ammonia decomposer 5.

[0033] Based on the various signals received by the signal receiving unit 111, the control unit 112 adjusts at least one of the steam generation amount of the heat recovery boiler 3, the steam supply amount to the steam turbine 41, the steam supply amount to the ammonia decomposer 5, and the steam supply amount to the production process so as to meet the demand indicated by the signals within the current load range of the gas turbine 23. At this time, the control unit 112 transmits a signal D5 that instructs the heat recovery boiler 3 on the steam generation amount, a signal D6 that instructs the steam turbine system 4 on the power generation amount, a signal D7 that instructs the ammonia decomposer 5 on the hydrogen production amount, and signals S1 to S4 that instruct the flow rate to each of the flow rate control valves V1 to V4, thereby adjusting the steam generation amount, steam supply amount, etc.

[0034] The memory 12 has a memory area necessary for the operation of the processor 11 .

[0035] The storage 13 is a so-called auxiliary storage device, such as a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 13 stores data that each part of the processor 11 acquires, generates, and refers to during processing.

[0036] The communication interface 14 is an interface for transmitting and receiving signals including measurement values, commands, etc. to and from each unit.

[0037] (Controller processing example 1) Fig. 4 is a first flowchart showing an example of processing by the control device according to the first embodiment. Fig. 4 shows an example of processing when the power demand of a power consumer increases. The control device 10 of this embodiment increases the amount of power generated by the steam turbine system 4 to cover the increase in power demand.

[0038] First, the signal receiving unit 111 receives a signal D1 indicating the power demand of a power consumer at every predetermined control period. When the signal receiving unit 111 receives the signal D1 indicating an increase in power demand (for example, the power demand amount of the previous signal D1<the power demand amount of the current signal D1) (step ST101), the control unit 112 determines whether the amount of steam generated by the heat recovery boiler 3 can be increased (step ST102).

[0039] For example, if it is possible to increase the amount of steam generated by burning the air or combustion gas remaining in the exhaust gas using an auxiliary burner (not shown) (step ST102; YES), the control unit 112 sends a signal D5 including an instruction to the exhaust heat recovery boiler 3 to increase the amount of steam generated in response to the increase in power demand based on the signal D1 (step ST103).

[0040] Furthermore, the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 of the steam supply pipe L11 to the steam turbine 41 to increase the amount of steam supplied to the steam turbine 41 in accordance with an increase in the amount of steam generated by the exhaust heat recovery steam generator 3 (step ST104). The flow rate control valve V1 increases its opening in accordance with the signal S1. This increases the amount of steam supplied to the steam turbine 41, and the amount of power generated by the generator 42 increases accordingly.

[0041] On the other hand, if the amount of steam generated by the heat recovery steam generator 3 cannot be increased (step ST102; NO), the control unit 112 determines whether the amount of steam supplied to the production process can be reduced (step ST105). For example, the control unit 112 inquires of the production process, and if the control unit 112 receives a response that the amount of steam supplied to the production process can be reduced, determines that the amount of steam supplied to the production process can be reduced (step ST105; YES). Furthermore, the control unit 112 may automatically determine whether the amount of steam supplied to the production process can be reduced based on a steam usage plan for each time period of the production process that has been notified in advance.

[0042] When it is determined that the amount of steam supplied to the production process can be reduced (step ST105; YES), the control unit 112 transmits a signal D2 to the production process, including a command to reduce the amount of steam supplied in accordance with the increase in power demand based on the signal D1 (step ST106). The control unit 112 also transmits a signal S2 to the flow rate control valve V2 of the steam supply pipe L12, including a command to reduce the amount of steam supplied to the production process (step ST107). The flow rate control valve V2 reduces its opening in accordance with the signal S2.

[0043] Next, the control unit 112 monitors the measurement value of the flow meter F2, and if the flow rate in the steam supply pipe L12 (i.e., the amount of steam supplied to the production process) has not decreased to the supply rate commanded by the signal S2 (step ST108; NO), the control unit 112 waits until the flow rate decreases. If the flow rate in the steam supply pipe L12 has decreased to the supply rate commanded by the signal S2 (step ST108; YES), the control unit 112 transmits a signal S1 including a command to the flow control valve V1 to increase the amount of steam supplied to the steam turbine 41 by the amount of the decrease in the amount of steam supplied to the production process (step ST104). The flow control valve V1 increases its opening in accordance with the signal S1. As a result, the amount of steam supplied to the steam turbine 41 is increased, and the amount of power generated by the generator 42 increases accordingly.

[0044] On the other hand, if the control unit 112 determines that it is not possible to reduce the amount of steam supplied to the production process (step ST105; NO), it transmits a signal D7 to the ammonia decomposition device 5 including a command to reduce the amount of hydrogen produced in accordance with the increase in electricity demand based on the signal D1, and also transmits a signal D3 to hydrogen consumers notifying them of the reduction in the amount of hydrogen produced (step ST109).

[0045] Furthermore, the control unit 112 transmits a signal S4 including a command to the flow rate control valve V4 of the ammonia supply pipe L2 to decrease the amount of ammonia supplied in accordance with the decrease in the amount of hydrogen produced (step ST110). The flow rate control valve V4 decreases its opening in accordance with the signal S4.

[0046] Next, the control unit 112 monitors the measurement value of the flow meter F4. If the flow rate through the ammonia supply pipe L2 (i.e., the ammonia supply rate) has not decreased to the supply rate commanded by the signal S4 (step ST111; NO), the control unit 112 waits until the flow rate decreases. If the flow rate through the ammonia supply pipe L2 has decreased to the supply rate commanded by the signal S4 (step ST111; YES), the control unit 112 transmits a signal S3 to the flow control valve V3, including a command to reduce the steam supply rate to the ammonia decomposer 5 by the amount of the decrease in the hydrogen production rate (step ST112). The flow control valve V3 reduces its aperture in accordance with the signal S3. If the temperature, flow rate, and pressure of ammonia and steam are not maintained in appropriate states, the success rate and production amount of hydrogen production will be affected. Therefore, by reducing the steam supply rate after the ammonia supply rate has decreased to the command value, it is possible to prevent the temperature and pressure of the ammonia decomposer 5 from being unable to be maintained in appropriate states due to a lack of steam. In other words, it is possible to prevent a decrease in the productivity and quality of hydrogen produced in the ammonia decomposer 5.

[0047] The control unit 112 monitors the measurement value of the flow meter F3, and if the flow rate in the steam supply pipe L13 (i.e., the amount of steam supplied to the ammonia decomposer 5) has not decreased to the supply rate commanded by the signal S3 (step ST113; NO), the control unit 112 waits until the flow rate decreases. If the flow rate in the steam supply pipe L13 has decreased to the supply rate commanded by the signal S3 (step ST113; YES), the control unit 112 transmits a signal S1 including a command to the flow control valve V1 to increase the amount of steam supplied to the steam turbine 41 by the amount of the decrease in the amount of steam supplied to the ammonia decomposer 5 (step ST104). The flow control valve V1 increases its opening in accordance with the signal S1. This increases the amount of steam supplied to the steam turbine 41, and the amount of power generated by the generator 42 increases.

[0048] In this way, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation in response to an increase in power demand without changing the current load on the gas turbine 23, by increasing the amount of steam generated by the heat recovery steam generator 3 or adjusting (reducing) the amount of steam supplied to the production process or the ammonia decomposer 5. Furthermore, as described above, the steam supplied to the production process is handed over to the steam turbine 41 only when it is possible to reduce the amount of steam supplied to the production process, so that an increase in power demand can be met while minimizing the impact on the production process. Furthermore, even if the amount of steam supplied to the ammonia decomposer 5 is temporarily reduced, the hydrogen demand can be met using the hydrogen stored in the hydrogen tank 52. Therefore, an increase in power demand can be met while minimizing the impact on hydrogen consumers caused by adjusting the amount of steam supplied.

[0049] (Controller processing example 2) Fig. 5 is a second flowchart showing an example of processing by the control device according to the first embodiment. Fig. 5 shows an example of processing when the power demand of a power consumer decreases. The control device 10 of this embodiment responds to the decrease in power demand by reducing the power generation amount of the steam turbine system 4 without changing the load on the gas turbine 23.

[0050] The signal receiving unit 111 receives a signal D1 indicating the power demand of a power consumer at every predetermined control period. When the signal receiving unit 111 receives the signal D1 indicating a decrease in power demand (for example, the power demand amount of the previous signal D1 > the power demand amount of the current signal D1) (step ST201), the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 to reduce the amount of steam supplied to the steam turbine 41 in accordance with the decrease in power demand (step ST202). The flow rate control valve V1 reduces its opening in accordance with the signal S1. As a result, the amount of power generated by the steam turbine system 4 decreases in accordance with the decrease in the amount of steam supplied.

[0051] Next, the control unit 112 transmits a signal D7 to the ammonia decomposer 5, which includes a command to increase the amount of hydrogen produced in response to the decrease in power demand based on the signal D1, and transmits a signal D3 to the hydrogen consumer notifying them of the increase in the amount of hydrogen produced (step ST203).

[0052] Furthermore, the control unit 112 transmits a signal S3 to the flow rate adjustment valve V3, which includes a command to increase the amount of steam supplied to the ammonia decomposition device 5 in accordance with the increase in the amount of hydrogen produced (step ST204). The flow rate adjustment valve V3 increases its opening in accordance with the signal S3.

[0053] Next, the control unit 112 monitors the measured values ​​of the thermometer T3 and the flowmeter F3, and determines whether the temperature and flow rate (steam supply rate) of the steam supplied to the ammonia decomposition unit 5 satisfy the conditions (step ST205). The temperature condition is set based on the temperature at which the thermal decomposition efficiency of ammonia is equal to or greater than a predetermined value. For example, the temperature condition is deemed to be satisfied when the steam temperature at the inlet of the ammonia decomposition unit 5 is equal to or greater than 300°C. Furthermore, the flow rate condition is deemed to be satisfied when the flow rate in the steam supply pipe L13 increases to the steam supply rate commanded by signal S3. If at least one of the temperature and flow rate does not satisfy the condition (step ST205; NO), the control unit 112 waits until both conditions are satisfied.

[0054] On the other hand, if both the temperature and flow rate satisfy the conditions (step ST205; YES), the control unit 112 transmits a signal S4 to the flow rate control valve V4 of the ammonia supply pipe L2, including a command to increase the ammonia supply rate in accordance with the increase in the hydrogen production rate (step ST206). The flow rate control valve V4 increases its aperture in accordance with the signal S4. As described above, if the temperature, flow rate, and pressure of ammonia and steam are not maintained at appropriate levels, the success rate and production rate of hydrogen production will be affected. Therefore, by increasing the ammonia supply rate after the conditions for the steam used in ammonia decomposition are satisfied, the hydrogen production rate in the ammonia decomposition device 5 can be increased while suppressing a decrease in the efficiency of ammonia thermal decomposition. In other words, the hydrogen production rate can be increased while suppressing a decrease in the productivity and quality of hydrogen produced in the ammonia decomposition device 5.

[0055] In this way, the control device 10 can respond to fluctuations (decrease) in power demand without adjusting the load on the gas turbine 23 (i.e., without reducing the load on the gas turbine 23 and the heat recovery steam generator 3) by adjusting the amount of steam supplied to the ammonia decomposer 5. In addition, excess hydrogen produced is stored in the hydrogen tank 52. By storing the hydrogen produced in this way in the hydrogen tank 52, it becomes possible to meet the hydrogen demand with the stored hydrogen even when, for example, the demand for power or steam is high and a sufficient amount of steam cannot be secured for supply to the ammonia decomposer 5.

[0056] 6 and 7 are diagrams illustrating fluctuations in demand and load factor of the plant according to the first embodiment. FIGS. 6 and 7 show examples in which the amount of steam generated by the heat recovery steam generator 3 and the amount of steam supplied to each component are adjusted in accordance with daily demand fluctuations according to the processing shown in FIGS. 4 and 5. FIGS. 6 and 7 also show examples in which the load factor of the plant (gas turbine 23 and heat recovery steam generator 3) is controlled to be always maintained at 100%. FIG. 6 shows an example in which control is performed when, for example, the price of electricity is high and priority is given to power generation (external sales of electricity), while FIG. 7 shows an example in which control is performed when, for example, the price of hydrogen is high and priority is given to hydrogen generation (external sales of hydrogen).

[0057] Even if the demand for electricity and steam decreases at time t1 in Fig. 6, the control device 10 does not adjust the load on the gas turbine 23, but instead increases the amount of steam supplied to the ammonia decomposition device 5 by an amount corresponding to the decrease in the amounts of steam supplied a and b to the steam turbine 41 and the production process, thereby utilizing the excess steam for generating hydrogen. In this way, it is possible to suppress the decrease in plant load and plant efficiency E due to fluctuations in demand, and to suppress a decrease in economic efficiency, compared to the conventional technology (Fig. 18).

[0058] 4 has been described as an example in which the amount of steam generated by the heat recovery boiler 3 is increased and the amount of steam supplied to each component is adjusted in response to an increase in power demand, but the present invention is not limited to this. For example, when a signal D2 indicating an increase in steam demand in the production process is received in step ST101 of FIG. 4, the control unit 112 may increase the amount of steam generated by the heat recovery boiler 3 in steps ST102 and ST103, and may transmit a signal S2 including a command to the flow rate adjustment valve V2 to increase the amount of steam supplied in step ST104. In this case, if it is not possible to increase the amount of steam generated by the heat recovery boiler 3 (step ST102; NO), the control unit 112 reduces the amount of steam supplied to the ammonia decomposer 5 in steps ST109 to ST113, and increases the amount of steam supplied to the production process accordingly.

[0059] 4, when signal D3 indicating an increase in hydrogen demand is received, control unit 112 may increase the amount of steam generated by heat recovery boiler 3 in steps ST102 and ST103, and perform steps ST203 to ST206 in FIG. 5 instead of step ST104, thereby increasing the amount of ammonia and steam supplied to ammonia decomposer 5. If it is not possible to increase the amount of steam generated by heat recovery boiler 3 (step ST102; NO), control unit 112 reduces the amount of steam supplied to the production process in steps ST105 to ST108, and increases the amount of steam supplied to ammonia decomposer 5 accordingly. If it is not possible to reduce the amount of steam supplied to the production process (step ST105; NO), as in the example of FIG. 7, the sale of hydrogen may be prioritized over the sale of generated electricity. In this case, the following process is performed instead of steps ST109 to ST113. First, the control unit 112 transmits a signal D5 to the steam turbine 41, including a command to reduce the amount of power sold in response to an increase in hydrogen demand, and also transmits a signal D1 notifying the reduction in power sold. Next, the control unit 112 transmits a signal S1 to the flow control valve V1, including a command to reduce the amount of steam supplied to the steam turbine 41, and after the flow rate in the steam supply pipe L11 is reduced, the control unit 112 performs the processing of steps ST203 to ST206 in Fig. 5 to increase the amount of ammonia supplied and the amount of steam supplied to the ammonia decomposer 5. By doing this, for example, when hydrogen can be sold at a higher price than electricity, the amount of power sold can be reduced and the amount of hydrogen produced can be increased accordingly, thereby increasing the profits of the plant 1 while economically operating the exhaust heat recovery steam generator 3.

[0060] Similarly, although an example has been described in Fig. 5 in which the amount of steam supplied to the ammonia decomposer 5 is adjusted (increased) in response to a decrease in power demand to increase the amount of hydrogen produced, the present invention is not limited to this. For example, when signal D2 indicating a decrease in steam demand in the production process is received in step ST201 of Fig. 5, control unit 112 may transmit signal S2 including a command to flow rate adjustment valve V2 to decrease the amount of steam supplied to the production process in step ST202, and then execute steps ST203 to ST206 to increase the amount of hydrogen produced.

[0061] Even when the sale of hydrogen is prioritized over the sale of generated power as shown in FIG. 7, there are cases where the amount of hydrogen produced (hydrogen demand) must be reduced, for example, when the free space in the hydrogen tank 52 is insufficient. In this case, in step ST201 of FIG. 5, a signal D3 indicating a decrease in hydrogen demand is received. The control unit 112 then executes steps ST109 to ST113 of FIG. 4 instead of step ST202 to reduce the amount of ammonia supplied and the amount of steam supplied to the ammonia decomposer 5. Thereafter, the amount of steam supplied to the steam turbine 41 is increased to increase the amount of power sold by the amount corresponding to the decrease in the amount of steam supplied to the ammonia decomposer 5. Specifically, instead of steps ST203 to ST206, the control unit 112 performs the following processing. First, the control unit 112 transmits a signal D5 to the steam turbine 41, which includes a command to increase the amount of power sold in response to the decrease in hydrogen demand, and also transmits a signal D1 notifying the increase in power sold. Next, the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 to increase the amount of steam supplied to the steam turbine 41. In this way, when it is necessary to reduce the amount of hydrogen produced, the amount of power generated for external sale can be increased accordingly, thereby enabling the plant 1 to be operated economically without reducing the load on the gas turbine 23 or the heat recovery steam generator 3, while suppressing a decrease in the profits of the plant 1.

[0062] (Action and effect) As described above, the plant 1 according to this embodiment includes the gas turbine 23, the heat recovery boiler 3 that generates steam using exhaust gas from the gas turbine 23, the steam turbine 41 that is rotationally driven by steam, the generator 42 that converts the rotational power of the steam turbine 41 into electricity, the ammonia decomposer 5 that decomposes ammonia using the heat of the steam to produce hydrogen, steam supply pipes L11, L12, and L13 that supply steam to the steam turbine 41, the ammonia decomposer 5, and the production process that uses the steam for production, and the control device 10. The control device 10 includes a signal receiving unit 111 that receives a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process, and a control unit 112 that adjusts, based on the received signal, at least one of the steam generation amount of the heat recovery boiler 3, the steam supply amount to the steam turbine 41, the steam supply amount to the ammonia decomposer 5, and the steam supply amount to the production process so that the demand indicated by the signal is met with the current load of the gas turbine 23.

[0063] In this way, the plant 1 can produce hydrogen in addition to the generated electricity and steam used in the production process. By using carbon-neutral or carbon-free fuels such as hydrogen and ammonia as fuel for the combustor 22 of the gas turbine system 2, the plant 1 can sell the generated hydrogen as green hydrogen.

[0064] Furthermore, the control device 10 can appropriately adjust the amount of steam supplied to the steam turbine 41, the ammonia cracker 5, and the production process in accordance with demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 and the heat recovery boiler 3 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0065] In addition, when the control unit 112 receives a signal indicating an increase in electricity demand, hydrogen demand, or steam demand, it determines whether it is possible to increase the amount of steam generated by the heat recovery boiler 3, and if it is possible to increase the amount of steam generated, it instructs the heat recovery boiler 3 to increase the amount of steam generated in accordance with the increase in electricity demand, hydrogen demand, or steam demand.

[0066] In this way, when electricity demand increases, for example, the control device 10 can increase the steam generation rate of the heat recovery steam generator 3, increase the steam supply rate to the steam turbine 41, and increase power generation while minimizing the impact on other ammonia crackers 5 and production processes (reduction in the steam supply rate). Similarly, when hydrogen or steam demand increases, the increase in hydrogen or steam demand can be accommodated without affecting other consumers. Although the steam and electricity used in the production process fluctuate over time, the time and amount of fluctuation are generally consistent and less variable than the electricity and hydrogen sold for sale, making it easier to develop a control plan for boiler steam allocation. For example, solar power generation, for example, fluctuates depending on the weather on that day. Therefore, when electricity demand is high and the power generated by solar power generation or other sources is low, the power sold from this plant 1 (power generated by generators 24 and 42) can contribute to grid power stability as backup power. Similarly, sudden increases in hydrogen demand can also be accommodated. If the demand for both electricity and hydrogen increases, the distribution of steam may be adjusted to prioritize either power generation or hydrogen generation depending on the prices of electricity and hydrogen.

[0067] Furthermore, when the control unit 112 receives a signal indicating an increase in electricity demand or hydrogen demand and it is not possible to increase the amount of steam generated by the heat recovery steam generator 3, it determines whether it is possible to reduce the amount of steam supplied to the production process, and if it is possible to reduce the amount of steam supplied to the production process, it reduces the flow rate of the steam supply pipe L12 for the production process in accordance with the increase in electricity demand or hydrogen demand, and increases the flow rate of the steam supply pipe L11 of the steam turbine 41 or the steam supply pipe L13 of the ammonia decomposition unit 5.

[0068] In this way, when the amount of steam generated by the heat recovery steam generator 3 cannot be increased, the control device 10 transfers the amount of steam supplied to the production process to the steam turbine 41 or the ammonia decomposition device 5, thereby enabling it to respond to increases in demand for electricity and hydrogen.

[0069] Furthermore, when control unit 112 receives signal D1 indicating an increase in power demand and it is not possible to reduce the amount of steam supplied to the production process, it reduces the amount of ammonia supplied to ammonia decomposer 5 in accordance with the increase in power demand, and after the amount of ammonia supplied to ammonia decomposer 5 has decreased, it reduces the flow rate of the steam supply pipe L13 of ammonia decomposer 5 in accordance with the increase in power demand, and increases the flow rate of the steam supply pipe L11 of steam turbine 41.

[0070] In this way, the control device 10 can respond to an increase in power demand by increasing the amount of steam supplied to the steam turbine 41 by the amount corresponding to the decrease in the amount of steam supplied to the ammonia decomposer 5. Furthermore, by reducing the amount of ammonia supplied to the ammonia decomposer 5 and then reducing the amount of steam supplied, it is possible to suppress a decrease in the efficiency of thermal decomposition of ammonia due to insufficient steam flow rate, temperature, or pressure, and a decrease in the quality and productivity of hydrogen. Note that by storing hydrogen generated when demand for power or steam is low in the hydrogen tank 52, the impact of such a decrease in the amount of hydrogen produced (shortage of hydrogen supply) can be suppressed.

[0071] Furthermore, when the control unit 112 receives a signal D1 indicating a decrease in power demand, it reduces the flow rate of the steam supply pipe L11 of the steam turbine 41 in accordance with the decrease in power demand, increases the flow rate of the steam supply pipe L13 of the ammonia decomposer 5, and increases the amount of ammonia supplied to the ammonia decomposer 5 after the flow rate of the steam supply pipe L13 of the ammonia decomposer 5 has increased.

[0072] In this way, the control device 10 can respond to a decrease in power demand without reducing the loads on the gas turbine 23 and the heat recovery steam generator 3, and can effectively utilize the surplus steam for hydrogen production. Furthermore, by increasing the ammonia supply amount after the flow rate and temperature of the steam supplied to the ammonia decomposition device 5 satisfy predetermined conditions, it is possible to prevent a decrease in the efficiency of ammonia thermal decomposition due to insufficient flow rate, temperature, or pressure of the steam, and a decrease in the quality and productivity of hydrogen.

[0073] <Second embodiment> Next, the second embodiment will be described in detail with reference to Figures 8 to 11. Components common to the above-described embodiment will be given the same reference numerals and detailed description will be omitted.

[0074] FIG. 8 is a first schematic diagram showing the overall configuration of a plant according to a second embodiment. For example, as shown in FIG. 8, the ammonia decomposition unit 5 may use steam extracted or exhausted from a steam turbine 41, instead of steam generated by the heat recovery steam generator 3. In the example of FIG. 8, a pipe L3 through which exhaust steam from the steam turbine 41 flows is connected to the outlet of the steam turbine 41. A steam supply pipe L13 that supplies steam to the ammonia decomposition unit 5 branches off from the pipe L3. The pipe L3 may be connected to an intermediate stage of the steam turbine 41 and may pass steam extracted from the steam turbine 41. The steam supply pipe L12 that supplies steam to the production process may branch off from the main pipe L1 as in the example of FIG. 1, or may branch off from the pipe L3 as in the example of FIG. 8. If the temperature of the exhaust steam (or extracted steam) from the steam turbine 41 is too high, a temperature-reducing spray 43 may be provided upstream of the steam supply pipe L12 of the production process, as in the configuration example of FIG. 8. In addition, in the configuration shown in FIG. 1 and other configurations, the temperature reducing spray 43 may be provided as needed.

[0075] Fig. 9 is a second schematic diagram showing the overall configuration of the plant according to the second embodiment. As shown in Fig. 9, the steam supply pipe L13 to the ammonia decomposition apparatus 5 may branch off from the steam supply pipe L12 to the production process.

[0076] 8 and 9, a return pipe L29 may be added that returns the steam used in the ammonia decomposition apparatus 5 to the upstream side. For example, as shown in FIG. 8, the return pipe L29 is connected upstream of the steam supply pipe L12 to the production process, and returns the steam used in the ammonia decomposition apparatus 5 to the gas supply system of the production process. Also, as shown in FIG. 9, the return pipe L29 may be connected to the main pipe L1. Although not shown, the return pipe L29 may be connected upstream of the steam supply pipe L11 to the steam turbine 41, and return the steam used in the ammonia decomposition apparatus 5 to the gas supply system of the steam turbine 41.

[0077] For example, as shown in FIG. 8, in a configuration in which exhaust steam from the outlet of the steam turbine 41 (or extracted steam from the intermediate stage) is supplied to the production process and the ammonia decomposition unit 5, the control device 10 adjusts the amount of steam supplied to the ammonia decomposition unit 5 in accordance with the steam demand.

[0078] 10 is a first flowchart showing an example of the processing of the control device according to the second embodiment. For example, when the signal receiving unit 111 receives a signal D2 indicating an increase in steam demand in the production process (step ST301), the control unit 112 reduces the amount of ammonia and steam supplied to the ammonia decomposer 5 (steps ST302 to ST306) and executes processing to increase the amount of steam supplied to the production process accordingly (step ST307). The processing of steps ST302 to ST306 in FIG. 10 is the same as the processing of steps ST109 to ST113 in FIG. 4. In this way, the amount of steam supplied to the ammonia decomposer 5 can be adjusted to respond to the increase in steam demand in the production process while maintaining the loads on the gas turbine 23 and the heat recovery steam generator 3 constant.

[0079] 11 is a second flowchart showing an example of the processing of the control device according to the second embodiment. For example, when the signal receiving unit 111 receives a signal D2 indicating a decrease in steam demand in the production process (step ST401), the control unit 112 reduces the amount of steam supplied to the production process (step ST402) and executes processing to increase the amount of steam supplied to the ammonia decomposer 5 by that amount (steps ST403 to ST406). The processing of steps ST403 to ST406 in FIG. 11 is the same as the processing of steps ST203 to ST206 in FIG. 5. In this way, the amount of steam supplied to the ammonia decomposer 5 can be adjusted to respond to the decrease in steam demand in the production process while maintaining the loads on the gas turbine 23 and the heat recovery steam generator 3 constant.

[0080] As described above, the configuration of the steam supply pipes L11 to L13 may be changed as desired. This allows for efficient reuse of the thermal energy of the steam generated in the heat recovery steam generator 3 and the steam exhausted (extracted) from the steam turbine 41, thereby improving the economic efficiency of the plant 1. A temperature-reducing spray 43 for lowering the steam temperature may be provided upstream of the steam supply pipe L12 for the production process. Furthermore, a return pipe L29 may be provided to return the steam used in the ammonia decomposition unit 5 to the mother pipe L1, the steam supply pipe L11 to the steam turbine 41, or the steam supply pipe L12 to the production process. This allows for efficient reuse of the steam used in the ammonia decomposition unit 5, thereby improving the economic efficiency of the plant 1.

[0081] <Third embodiment> Next, the second embodiment will be described in detail with reference to Fig. 12. Components common to the above-described embodiment will be given the same reference numerals and detailed description will be omitted.

[0082] Fig. 12 is a schematic diagram showing the overall configuration of a plant according to a third embodiment. As shown in Fig. 12, the off-gas pipe L28 of the ammonia decomposition apparatus 5 is connected to the heat recovery boiler 3. The off-gas contains hydrogen. That is, in this embodiment, the off-gas of the ammonia decomposition apparatus 5 is reused as fuel for the heat recovery boiler 3. The heat recovery boiler 3 of this embodiment may be provided with an auxiliary burner that heats the off-gas to increase the amount of steam generated.

[0083] In this way, by reusing the off-gas from the ammonia decomposition device 5, it is possible to improve the thermal efficiency of the exhaust heat recovery boiler 3. Furthermore, the resource (ammonia) input to the ammonia decomposition device 5 can be used without waste.

[0084] <Fourth embodiment> Next, the fourth embodiment will be described in detail with reference to Figures 13 to 15. Components common to the above-described embodiments will be given the same reference numerals and detailed description will be omitted.

[0085] (Overall plant configuration) FIG. 13 is a schematic diagram showing the overall configuration of a plant according to a fourth embodiment. As shown in FIG. 13, in the plant 1 of this embodiment, an ammonia decomposition unit 5 is additionally installed between the gas turbine 23 and the heat recovery steam generator 3. That is, the ammonia decomposition unit 5 uses the exhaust gas from the gas turbine 23 as a heat source for ammonia decomposition (hydrogen production). In the first embodiment (FIG. 2), the decomposition reactor 53 of the ammonia decomposition unit 5 receives steam generated by the heat recovery steam generator 3 as a heat source via the steam supply pipe L13. In this embodiment, however, the exhaust gas from the gas turbine 23 is supplied as a heat source via the exhaust gas duct L4. The exhaust gas duct L4 is provided with at least a flowmeter F6, a pressure gauge P6, and a thermometer T6, and measurements of the flow rate, pressure, and temperature of the exhaust gas supplied to the ammonia decomposition unit 5 are sequentially transmitted to the control device 10. A vaporizer or the like may be installed in the ammonia supply pipe L2 from the ammonia tank 51 to the ammonia decomposition unit 5, but this is omitted from FIG. 13. Furthermore, the hydrogen in the hydrogen tank 52 may be in the form of a gas or liquid, but the hydrogen liquefaction equipment is not shown in Figure 13. In this embodiment, an example is described in which a flow meter, a pressure gauge, and a thermometer are provided as sensors, but other measuring instruments may be provided to measure various other values, such as ammonia concentration and pump rotation speed. Furthermore, in order to measure the amount of hydrogen supplied, a flow meter may be installed in the hydrogen piping between the ammonia decomposition unit 5 and the hydrogen tank 52 or in the hydrogen piping from the hydrogen tank 52 to a consumer facility, or a level gauge may be installed in the hydrogen tank 52.

[0086] Furthermore, the exhaust gas that has passed through the ammonia decomposition unit 5 is introduced into the heat recovery boiler 3 and used to generate steam. Steam supply pipes L11 and L12 that send steam to the steam turbine 41 and the production process, respectively, branch off from the main pipe L1. As in the example of Figure 13, a temperature reducing spray 43 may be provided upstream of the steam supply pipe L12 for the production process, or the temperature reducing spray 43 may be omitted.

[0087] The control device 10 of this embodiment increases or decreases the amount of hydrogen produced by adjusting the calorific value of the exhaust gas used for heat exchange in the ammonia decomposition device 5 (the amount of heat absorbed by the decomposition reactor 53). Specifically, the control device 10 increases or decreases the amount of ammonia supplied to the ammonia decomposition device 5 to adjust the amount of heat absorbed.

[0088] (Controller processing example 1) Fig. 14 is a first flowchart showing an example of processing by the control device according to the fourth embodiment. Fig. 14 shows an example of processing when the power demand of a power consumer increases. First, when the signal receiving unit 111 receives a signal D1 indicating an increase in power demand (step ST501), the control unit 112 determines whether the exhaust gas of the gas turbine 23 can be increased (step ST502).

[0089] For example, if the load factor of the gas turbine 23 has not reached the upper limit (100%) and the amount of exhaust gas can be increased by increasing the gas turbine load factor within the allowable load range (step ST502; YES), the control unit 112 transmits a signal D4 including a command to increase the amount of exhaust gas to the gas turbine system 2 in response to an increase in power demand based on the signal D1 (step ST503). At this time, the amount of hydrogen produced in the ammonia decomposer 5 does not change, so the calorific value of the exhaust gas supplied to the heat recovery steam generator 3 increases by the amount corresponding to the increase in the flow rate of the exhaust gas. Therefore, the amount of steam generated by the heat recovery steam generator 3 increases.

[0090] Furthermore, the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 of the steam supply pipe L11 to the steam turbine 41 to increase the amount of steam supplied to the steam turbine 41 in accordance with an increase in the amount of steam generated by the exhaust heat recovery steam generator 3 (step ST504). The flow rate control valve V1 increases its opening in accordance with the signal S1. This increases the amount of steam supplied to the steam turbine 41, and the amount of power generated by the generator 42 increases accordingly.

[0091] On the other hand, if the amount of exhaust gas from the gas turbine 23 cannot be increased (step ST502; NO), the control unit 112 determines whether the amount of steam generated by the heat recovery steam generator 3 can be increased (step ST505). For example, if the amount of steam generated can be increased by an auxiliary burner (step ST505; YES), the control unit 112 transmits a signal D5 including a command to the heat recovery steam generator 3 to increase the amount of steam generated in response to an increase in power demand based on the signal D1 (step ST506). Furthermore, the control unit 112 transmits a signal S1 including a command to increase the amount of steam supplied to the steam turbine 41 to the flow control valve V1 of the steam supply pipe L11 to the steam turbine 41 in response to an increase in the amount of steam generated by the heat recovery steam generator 3 (step ST504). The flow control valve V1 increases its aperture in accordance with the signal S1. This increases the amount of steam supplied to the steam turbine 41, and the amount of power generated by the generator 42 increases accordingly.

[0092] Furthermore, if the amount of steam generated by the heat recovery steam generator 3 cannot be increased (step ST505; NO), the control unit 112 determines whether the amount of steam supplied to the production process can be reduced (step ST507). If the amount of steam supplied to the production process can be reduced (step ST507; YES), the control unit 112 reduces the amount of steam supplied to the production process (steps ST508 to ST510) and performs processing to increase the amount of steam supplied to the steam turbine 41 by that amount (step ST504). The processing of steps ST507 to ST510 is the same as the processing of ST105 to ST108 in FIG. 4.

[0093] If it is not possible to reduce the amount of steam supplied to the production process (step ST507; NO), the control unit 112 transmits a signal D7 to the ammonia decomposition device 5 including a command to reduce the amount of hydrogen produced in accordance with the increase in power demand based on the signal D1, and also transmits a signal D3 to hydrogen consumers notifying them of the reduction in the amount of hydrogen produced (step ST511).

[0094] Furthermore, the control unit 112 transmits a signal S4 including a command to the flow rate control valve V4 of the ammonia supply pipe L2 to decrease the amount of ammonia supplied in response to the decrease in the amount of hydrogen produced (step ST512). The flow rate control valve V4 decreases its opening in accordance with the signal S4.

[0095] When the ammonia supply rate decreases, the amount of heat absorbed by the ammonia decomposition device 5 (decomposition reactor 53) decreases, and the amount of heat of the exhaust gas flowing into the heat recovery boiler 3 increases. This increases the amount of steam generated by the heat recovery boiler 3. The control unit 112 monitors the measurement value of the flow meter F4, and if the flow rate through the ammonia supply pipe L2 (i.e., the ammonia supply rate) has not decreased to the supply rate commanded by the signal S4 (step ST513; NO), the control unit 112 waits until the flow rate decreases. If the flow rate through the ammonia supply pipe L2 has decreased to the supply rate commanded by the signal S4 (step ST513; YES), the control unit 112 transmits a signal S1 to the flow control valve V1, which includes a command to increase the steam supply rate to the steam turbine 41 (step ST504). The flow control valve V1 increases its aperture in accordance with the signal S1. This increases the amount of steam supplied to the steam turbine 41, and accordingly increases the amount of power generated by the generator 42.

[0096] In this way, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation in response to an increase in power demand by increasing the amount of exhaust gas from the gas turbine 23, increasing the amount of steam generated by the heat recovery steam generator 3, adjusting (reducing) the amount of steam supplied to the production process, and adjusting (reducing) the amount of ammonia supplied to the ammonia decomposer 5. Furthermore, as described above, only when the amount of steam supplied to the production process can be reduced is the steam turbine 41 handed over to be sent to the production process. This makes it possible to meet the increase in power demand while minimizing the impact on the production process. Furthermore, even if the amount of ammonia supplied to the ammonia decomposer 5 / the amount of hydrogen generated is temporarily reduced, the hydrogen demand can be met using the hydrogen stored in the hydrogen tank 52. Therefore, it is possible to meet the increase in power demand while minimizing the impact on hydrogen consumers caused by adjusting the amount of steam supplied.

[0097] (Controller processing example 2) Fig. 15 is a second flowchart showing an example of the process of the control device according to the fourth embodiment. Fig. 15 shows an example of the process when the power demand of the power consumer decreases.

[0098] When the signal receiving unit 111 receives a signal D1 indicating a decrease in power demand (step ST601), the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 to decrease the amount of steam supplied to the steam turbine 41 in accordance with the decrease in power demand (step ST602). The flow rate control valve V1 decreases its opening in accordance with the signal S1. As a result, the amount of power generated by the steam turbine system 4 decreases in accordance with the decrease in the amount of steam supplied.

[0099] Next, the control unit 112 transmits a signal D7 to the ammonia decomposer 5, which includes a command to increase the amount of hydrogen produced in response to the decrease in power demand based on the signal D1, and transmits a signal D3 to the hydrogen consumer notifying them of the increase in the amount of hydrogen produced (step ST603).

[0100] Next, the control unit 112 monitors the measured values ​​of the thermometer T6 and the flow meter F6, and determines whether the temperature and flow rate of the exhaust gas supplied to the ammonia decomposition unit 5 satisfy the conditions (step ST604). The temperature conditions are the same as those in the first embodiment. If at least one of the temperature and the flow rate does not satisfy the conditions (step ST604; NO), the control unit 112 waits until both satisfy the conditions.

[0101] On the other hand, if both the temperature and the flow rate satisfy the conditions (step ST604; YES), the control unit 112 transmits a signal S4 to the flow rate control valve V4 of the ammonia supply pipe L2, including a command to increase the amount of ammonia supplied in accordance with the increase in the amount of hydrogen produced (step ST605). The flow rate control valve V4 increases its opening in accordance with the signal S4. In this way, the amount of power generated by the plant 1 can be reduced without reducing the load on the gas turbine 23 in accordance with a decrease in power demand, and the amount of hydrogen produced can be increased, making it possible to use the exhaust gas from the gas turbine 23 without waste.

[0102] 14 has described an example in which the amount of exhaust gas from the gas turbine 23 is increased, the amount of steam generated by the heat recovery boiler 3 is increased, or the amount of steam supplied to each section is adjusted in response to an increase in power demand, but the present invention is not limited to this. For example, when a signal D2 indicating an increase in steam demand in the production process is received in step ST501 of Fig. 14, the control unit 112 may increase the amount of exhaust gas from the gas turbine 23 in steps ST502 and ST503, or increase the amount of steam generated by the heat recovery boiler 3 in steps ST505 and ST506, and then transmit a signal S2 including a command to increase the amount of steam supplied to the flow rate adjustment valve V2 in step ST504. In this case, if it is not possible to increase the amount of exhaust gas from the gas turbine 23 and the amount of steam generated by the heat recovery boiler 3 (step ST502; NO and ST505; NO), the control unit 112 reduces the amount of heat absorbed by the exhaust gas in the ammonia decomposition unit 5 in steps ST511 to ST513, and accordingly increases the amount of steam generated by the heat recovery boiler 3 and the amount of steam supplied to the production process.

[0103] 14, when signal D3 indicating an increase in hydrogen demand is received, control unit 112 may increase the amount of exhaust gas from gas turbine 23 in steps ST502 and ST503, and then perform the processing of steps ST603 to ST605 in FIG. 15 instead of step ST504, thereby increasing the amount of ammonia supplied to ammonia decomposer 5 and the amount of hydrogen produced. If the amount of exhaust gas cannot be increased (step ST502; NO), control unit 112 reduces the amount of steam supplied to the production process in steps ST507 to ST510, thereby increasing the amount of hydrogen produced (amount of heat absorbed) in ammonia decomposer 5 accordingly. Although the calorific value of the exhaust gas flowing to heat recovery steam generator 3 decreases by the amount of hydrogen produced in ammonia decomposer 5, the amount of steam supplied to the production process is reduced by the amount of power produced. Therefore, the amount of steam supplied to steam turbine 41 according to the power demand can be maintained. If it is not possible to reduce the amount of steam supplied to the production process (step ST507; NO), the sale of hydrogen may be prioritized over the sale of generated electricity. In this case, the following processing is performed instead of steps ST511 to ST513. First, the control unit 112 transmits a signal D6 to the steam turbine 41, including a command to reduce the amount of electricity generated for sale in response to an increase in hydrogen demand, and also transmits a signal D1 notifying the reduction in electricity for sale. Next, the control unit 112 transmits a signal S1 to the flow control valve V1, including a command to reduce the amount of steam supplied to the steam turbine 41. After the flow rate in the steam supply pipe L11 is reduced, the control unit 112 performs the processing of steps ST603 to ST605 in FIG. 15 to increase the amount of ammonia supplied to the ammonia decomposer 5. The increased amount of hydrogen produced by the ammonia decomposer 5 reduces the calorific value of the exhaust gas flowing to the heat recovery steam generator 3. However, the amount of steam supplied to the steam turbine 41 is reduced accordingly, so that the amount of steam supplied to the production process can be maintained in accordance with the steam demand. By doing this, for example, if hydrogen can be sold at a higher price than electricity, the amount of electricity generated for external sale can be reduced and the amount of hydrogen produced can be increased accordingly, thereby increasing the profits of the plant 1 while operating the gas turbine 23 economically.

[0104] Similarly, in Fig. 15, an example has been described in which the amount of steam supplied to the ammonia decomposer 5 is adjusted (increased) in response to a decrease in power demand to increase the amount of hydrogen produced, but the present invention is not limited to this. For example, when a signal D2 indicating a decrease in steam demand in the production process is received in step ST601 of Fig. 15, the control unit 112 may transmit a signal S2 including a command to the flow rate adjustment valve V2 to decrease the amount of steam supplied to the production process in step ST602, and then execute steps ST603 to ST605 to increase the amount of hydrogen produced.

[0105] Even when the sale of hydrogen is prioritized over the sale of generated power, there are cases where the amount of hydrogen produced (hydrogen demand) must be reduced, for example, when the free space in the hydrogen tank 52 is insufficient. In this case, in step ST601 of FIG. 15, a signal D3 indicating a decrease in hydrogen demand is received. The control unit 112 then executes steps ST511 to ST513 of FIG. 14 instead of step ST602 to decrease the amount of ammonia supplied to the ammonia decomposer 5, thereby decreasing the amount of heat absorbed and increasing the calorific value of the exhaust gas flowing into the heat recovery steam generator 3. This increases the amount of steam generated by the heat recovery steam generator 3, thereby correspondingly increasing the amount of steam supplied to the steam turbine 41 to increase the amount of power sold. Specifically, the following processing is performed instead of steps ST603 to ST605 of FIG. 15. First, the control unit 112 transmits a signal D5 to the steam turbine 41, which includes a command to increase the amount of power sold in response to the decrease in hydrogen demand, and also transmits a signal D1 notifying the increase in power sold. Next, the control unit 112 transmits a signal S1 including a command to the flow rate control valve V1 to increase the amount of steam supplied to the steam turbine 41. In this way, when it is necessary to reduce the amount of hydrogen produced, the amount of power generated for external sale can be increased accordingly, thereby enabling the plant 1 to be operated economically without reducing the load on the gas turbine 23 or the heat recovery steam generator 3, while suppressing a decrease in the profits of the plant 1.

[0106] (Action and effect) As described above, the plant 1 according to this embodiment includes the gas turbine 23, the ammonia decomposition unit 5 that decomposes ammonia using heat from the exhaust gas of the gas turbine 23 to produce hydrogen, the heat recovery boiler 3 that generates steam using the exhaust gas that has passed through the ammonia decomposition unit 5, the steam turbine 41 that is rotationally driven by the steam, the generator 42 that converts the rotational power of the steam turbine 41 into electric power, steam supply pipes L11 and L12 that supply steam to the steam turbine 41 and to each of the production processes that utilize the steam for production, and the control device 10. The control device 10 includes a signal receiving unit 111 that receives a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process, and a control unit 112 that adjusts at least one of the amount of exhaust gas from the gas turbine 23, the amount of steam generated by the heat recovery boiler 3, the amount of heat absorbed by the ammonia decomposition unit 5, the flow rate in the steam supply pipe L11 of the steam turbine 41, and the flow rate in the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the received signal.

[0107] In this way, the plant 1 can use the exhaust gas from the gas turbine 23 to generate electricity, generate steam for use in the production process, and also produce hydrogen. By using carbon-neutral or carbon-free fuels such as hydrogen or ammonia as fuel for the combustor 22 of the gas turbine system 2, the plant 1 can sell the generated hydrogen as green hydrogen.

[0108] Furthermore, the control device 10 can appropriately adjust the amount of heat absorbed by the ammonia decomposition device 5 and the amount of steam supplied to the steam turbine 41 and the production process in accordance with demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0109] Furthermore, when the control unit 112 receives a signal indicating an increase in the demand for electricity, hydrogen, or steam, it determines whether it is possible to increase the amount of exhaust gas from the gas turbine 23, and if it is possible to increase the amount of exhaust gas, it instructs the gas turbine 23 to increase the amount of exhaust gas in accordance with the increase in the demand for electricity, hydrogen, or steam.

[0110] In this way, when, for example, the demand for electricity increases, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation while suppressing the impact on other ammonia decomposition units 5 and production processes. Similarly, when the demand for hydrogen or steam increases, it becomes possible to respond to the increase in demand for hydrogen or steam without affecting other consumers.

[0111] In addition, when it is not possible to increase the amount of exhaust gas from the gas turbine 23, the control unit 112 determines whether it is possible to increase the amount of steam generated by the heat recovery boiler 3, and if it is possible to increase the amount of steam generated, it instructs the heat recovery boiler 3 to increase the amount of steam generated in accordance with an increase in electricity demand or steam demand.

[0112] In this way, when, for example, the demand for electricity increases, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation while suppressing the impact on other ammonia decomposition units 5 and production processes. Similarly, when the demand for steam increases, it becomes possible to respond to the increase in steam demand without affecting other consumers.

[0113] In addition, the control unit 112 receives a signal D1 indicating an increase in electricity demand, and if it is not possible to increase the amount of exhaust gas from the gas turbine 23 and the amount of steam generated by the heat recovery boiler 3, determines whether it is possible to reduce the amount of steam supplied to the production process, and if it is possible to reduce the amount of steam supplied to the production process, reduces the flow rate of the steam supply pipe L12 for the production process in accordance with the increase in electricity demand, and increases the flow rate of the steam supply pipe L11 for the steam turbine 41.

[0114] In this way, if the control device 10 cannot increase the amount of exhaust gas from the gas turbine 23 and the amount of steam generated by the heat recovery boiler 3, it can respond to the increase in electricity demand by transferring the amount of steam supplied to the production process to the steam turbine 41.

[0115] When control unit 112 receives signal D1 indicating an increase in power demand and it is not possible to reduce the amount of steam supplied to the production process, control unit 112 reduces the amount of ammonia supplied to ammonia decomposer 5 in accordance with the increase in power demand, thereby reducing the amount of heat absorbed by ammonia decomposer 5, and after the amount of ammonia supplied to ammonia decomposer 5 has decreased, increases the flow rate of steam supply pipe L11 of steam turbine 41.

[0116] In this way, the control device 10 can increase the amount of heat of the exhaust gas flowing into the heat recovery boiler 3 by the amount of the decrease in the amount of heat absorbed by the ammonia decomposition device 5, thereby increasing the amount of steam generated. This increases the amount of steam supplied to the steam turbine 41, making it possible to respond to increases in power demand. Note that by storing hydrogen generated when power demand and steam demand are low in the hydrogen tank 52, the effect of reducing the amount of hydrogen generated in this way (shortage of hydrogen supply) can be suppressed.

[0117] Furthermore, when the control unit 112 receives a signal D1 indicating a decrease in power demand, it reduces the flow rate of the steam supply pipe L11 of the steam turbine 41 in accordance with the decrease in power demand, and then increases the amount of ammonia supplied to the ammonia decomposer 5 to increase the amount of heat absorbed by the ammonia decomposer.

[0118] In this way, the control device 10 can respond to the decrease in power demand without reducing the load on the heat recovery steam generator 3, and can effectively utilize the heat quantity of the surplus exhaust gas for generating hydrogen.

[0119] <Fifth embodiment> Next, the fifth embodiment will be described in detail with reference to Fig. 16. Components common to the above-described embodiments will be given the same reference numerals and detailed description will be omitted.

[0120] FIG. 16 is a schematic diagram showing the overall configuration of a plant according to a fourth embodiment. For example, as shown in FIG. 16, the production process may utilize steam extracted or exhausted from a steam turbine 41, rather than steam generated by a heat recovery steam generator 3. In the example of FIG. 16, a pipe L3 through which steam extracted from the steam turbine 41 flows is connected to an intermediate stage of the steam turbine 41. A steam supply pipe L13 that supplies steam to the production process branches off from the pipe L3. Note that the pipe L3 may be connected to the outlet of the steam turbine 41 and may also pass steam exhausted from the steam turbine 41. Note that if the temperature of the extracted steam (or exhaust steam) from the steam turbine 41 is too high, a temperature reducing spray 43 may be provided upstream of the steam supply pipe L12 of the production process, as in the configuration example of FIG. 16.

[0121] As described above, the configuration of the steam supply pipes L11 to L12 may be changed as desired. Furthermore, a temperature reducing spray 43 for lowering the steam temperature may be provided upstream of the steam supply pipe L12 for the production process. This allows the thermal energy of the steam discharged (extracted) from the steam turbine 41 to be efficiently reused, thereby improving the economic efficiency of the plant 1.

[0122] Sixth Embodiment Next, the sixth embodiment will be described in detail with reference to Fig. 17. Components common to the above-described embodiments will be given the same reference numerals and detailed description will be omitted.

[0123] FIG. 17 is a schematic diagram showing the overall configuration of a plant according to the sixth embodiment. As shown in Fig. 17, the off-gas pipe L28 of the ammonia decomposer 5 is connected to the heat recovery boiler 3. The off-gas contains hydrogen. That is, similar to the third embodiment, the off-gas of the ammonia decomposer 5 is reused as fuel for the heat recovery boiler 3. Note that, similar to the third embodiment, the heat recovery boiler 3 may be provided with a supporting burner.

[0124] In this way, by reusing the off-gas from the ammonia decomposition device 5, it is possible to improve the thermal efficiency of the exhaust heat recovery boiler 3. Furthermore, the resource (ammonia) input to the ammonia decomposition device 5 can be used without waste.

[0125] <Other embodiments> Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0126] <Additional Notes> The above-described embodiment can be understood, for example, as follows.

[0127] (1) According to a first aspect, the control device 10 of the plant 1 includes a gas turbine 23, a heat recovery boiler 3 that generates steam using exhaust gas from the gas turbine 23, a steam turbine 41 that is rotationally driven by steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, an ammonia decomposer 5 that decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply pipes L11, L12, and L13 that supply steam to the steam turbine 41, the ammonia decomposer 5, and a production process that uses the steam for production, and the control device 10 includes: a signal receiving unit 111 that receives a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process; and a control unit 112 that adjusts, based on the received signal, at least one of the steam generation amount of the heat recovery boiler 3, the flow rate of the steam supply pipe L11 of the steam turbine 41, the flow rate of the steam supply pipe L13 of the ammonia decomposer 5, and the flow rate of the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the signal with the current load of the gas turbine 23.

[0128] In this way, the control device 10 can appropriately adjust the amount of steam supplied to the steam turbine 41, the ammonia cracker 5, and the production process in accordance with demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 and the heat recovery boiler 3 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0129] (2) According to the second aspect, in the control device 10 of the plant 1 relating to the first aspect, when the control unit 112 receives a signal indicating an increase in electricity demand, hydrogen demand, or steam demand, it determines whether it is possible to increase the amount of steam generated by the heat recovery boiler 3, and if it is possible to increase the amount of steam generated, it instructs the heat recovery boiler 3 to increase the amount of steam generated in accordance with the increase in electricity demand, hydrogen demand, or steam demand.

[0130] In this way, when the demand for electricity increases, for example, the control device 10 can increase the amount of steam generated by the heat recovery boiler 3, increase the amount of steam supplied to the steam turbine 41, and increase the amount of power generation, while suppressing the impact (reduction in the amount of steam supplied) on other ammonia decomposition units 5 and production processes. Similarly, when the demand for hydrogen or steam increases, it becomes possible to respond to the increase in demand for hydrogen or steam without affecting other consumers.

[0131] (3) According to the third aspect, in the control device 10 of the plant 1 according to the second aspect, when the control unit 112 receives a signal indicating an increase in the demand for electricity or hydrogen and it is not possible to increase the amount of steam generated by the heat recovery steam generator 3, it determines whether it is possible to reduce the amount of steam supplied to the production process, and if it is possible to reduce the amount of steam supplied to the production process, it reduces the flow rate of the steam supply pipe L12 of the production process in accordance with the increase in the demand for electricity or hydrogen, and increases the flow rate of the steam supply pipe L11 of the steam turbine 41 or the steam supply pipe L13 of the ammonia decomposition unit.

[0132] In this way, when the amount of steam generated by the heat recovery steam generator 3 cannot be increased, the control device 10 transfers the amount of steam supplied to the production process to the steam turbine 41 or the ammonia decomposition device 5, thereby enabling it to respond to increases in demand for electricity and hydrogen.

[0133] (4) According to the fourth aspect, in the control device 10 of the plant 1 according to the third aspect, when the control unit 112 receives a signal D1 indicating an increase in power demand and it is not possible to reduce the amount of steam supplied to the production process, the control unit 112 reduces the amount of ammonia supplied to the ammonia decomposer 5 in accordance with the increase in power demand, and after the amount of ammonia supplied to the ammonia decomposer 5 has decreased, the control unit 112 reduces the flow rate of the steam supply pipe L13 of the ammonia decomposer 5 in accordance with the increase in power demand, and increases the flow rate of the steam supply pipe L11 of the steam turbine.

[0134] In this way, the control device 10 can respond to an increase in power demand by increasing the amount of steam supplied to the steam turbine 41 by an amount corresponding to the reduction in the amount of steam supplied to the ammonia decomposer 5. Furthermore, by reducing the amount of ammonia supplied to the ammonia decomposer 5 and then reducing the amount of steam supplied, it is possible to suppress a decrease in the efficiency of thermal decomposition of ammonia due to insufficient steam flow rate, temperature, or pressure, and a decrease in hydrogen quality and productivity.

[0135] (5) According to the fifth aspect, in the control device 10 of the plant 1 according to any one of the first to fourth aspects, when the control unit 112 receives a signal D1 indicating a decrease in power demand, the control unit 112 reduces the flow rate of the steam supply pipe L11 of the steam turbine 41 in accordance with the decrease in power demand, increases the flow rate of the steam supply pipe L13 of the ammonia decomposer 5, and increases the amount of ammonia supplied to the ammonia decomposer 5 after the flow rate and temperature of the steam supplied to the ammonia decomposer 5 satisfy predetermined conditions.

[0136] In this way, the control device 10 can respond to a decrease in power demand without reducing the loads on the gas turbine 23 and the heat recovery steam generator 3, and can effectively utilize the surplus steam for hydrogen production. Furthermore, by increasing the ammonia supply amount after the flow rate and temperature of the steam supplied to the ammonia decomposition device 5 satisfy predetermined conditions, it is possible to prevent a decrease in the efficiency of ammonia thermal decomposition due to insufficient flow rate, temperature, or pressure of the steam, and a decrease in the quality and productivity of hydrogen.

[0137] (6) According to a sixth aspect, the plant 1 includes a gas turbine 23, a heat recovery boiler 3 that generates steam using exhaust gas from the gas turbine 23, a steam turbine 41 that is driven to rotate by steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, an ammonia decomposition unit 5 that decomposes ammonia using the heat of the steam to produce hydrogen, steam supply pipes L11, L12, and L13 that supply steam to each of the steam turbine 41, the ammonia decomposition unit 5, and a production process that uses steam for production, and a control device 10 according to any one of the first to fifth aspects.

[0138] In this way, the plant 1 can produce hydrogen in addition to generating electricity and steam used in the production process. Furthermore, the plant 1 can appropriately adjust the amount of steam supplied to the steam turbine 41, the ammonia cracker 5, and the production process in response to demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 and the heat recovery boiler 3 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0139] (7) According to a seventh aspect, the plant 1 according to the sixth aspect further includes an off-gas pipe L28 that connects the heat recovery steam generator 3 and the ammonia decomposition apparatus 5 and circulates the off-gas discharged after hydrogen is produced in the ammonia decomposition apparatus 5 as fuel for the heat recovery steam generator 3.

[0140] In this way, the plant 1 can improve the thermal efficiency of the heat recovery boiler 3 by reusing the off-gas from the ammonia decomposition unit 5. In addition, the resource (ammonia) input to the ammonia decomposition unit 5 can be used without waste.

[0141] (8) According to an eighth aspect, a control method for a plant 1 includes a gas turbine 23, a heat recovery boiler 3 that generates steam using exhaust gas from the gas turbine 23, a steam turbine 41 that is rotationally driven by steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, an ammonia decomposer 5 that decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply pipes L11, L12, and L13 that supply steam to the steam turbine 41, the ammonia decomposer 5, and a production process that utilizes the steam for production, the control method comprising the steps of: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process; and adjusting, based on the received signal, at least one of the steam generation amount of the heat recovery boiler 3, the flow rate of the steam supply pipe L11 of the steam turbine 41, the flow rate of the steam supply pipe L13 of the ammonia decomposer 5, and the flow rate of the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the signal at the current load of the gas turbine 23.

[0142] (9) According to a ninth aspect, the program causes a control device 10 of a plant 1 including a gas turbine 23, a heat recovery boiler 3 that generates steam using exhaust gas from the gas turbine 23, a steam turbine 41 that is rotationally driven by steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, an ammonia decomposer 5 that decomposes ammonia using the heat of the steam to produce hydrogen, and steam supply pipes L11, L12, and L13 that supply steam to the steam turbine 41, the ammonia decomposer 5, and a production process that uses the steam for production, to execute the following steps: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process; and adjusting, based on the received signal, at least one of the steam generation amount of the heat recovery boiler 3, the flow rate of the steam supply pipe L11 of the steam turbine 41, the flow rate of the steam supply pipe L13 of the ammonia decomposer 5, and the flow rate of the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the signal with a current load of the gas turbine 23.

[0143] (10) According to a tenth aspect, the control device 10 of the plant 1 includes a gas turbine 23, an ammonia decomposition device 5 that decomposes ammonia using heat from exhaust gas of the gas turbine 23 to produce hydrogen, a heat recovery boiler 3 that generates steam using exhaust gas that has passed through the ammonia decomposition device 5, a steam turbine 41 that is rotationally driven by the steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, and steam supply pipes L11 and L12 that supply steam to the steam turbine 41 and to each of the production processes that use the steam for production. The control device 10 of the plant 1 includes a signal receiving unit 111 that receives a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process, and a control unit 112 that adjusts at least one of the amount of exhaust gas from the gas turbine 23, the amount of steam generated by the heat recovery boiler 3, the amount of heat absorbed by the ammonia decomposition device 5, the flow rate in the steam supply pipe L11 of the steam turbine 41, and the flow rate in the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the received signal.

[0144] In this way, the control device 10 can appropriately adjust the amount of heat absorbed by the ammonia decomposition device 5 and the amount of steam supplied to the steam turbine 41 and the production process in accordance with demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0145] (11) According to the eleventh aspect, in the control device 10 of the plant 1 relating to the tenth aspect, when the control unit 112 receives a signal indicating an increase in electricity demand, hydrogen demand, or steam demand, it determines whether it is possible to increase the amount of exhaust gas from the gas turbine 23, and if it is possible to increase the amount of exhaust gas, it instructs the gas turbine 23 to increase the amount of exhaust gas in accordance with the increase in electricity demand, hydrogen demand, or steam demand.

[0146] In this way, when, for example, the demand for electricity increases, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation while suppressing the impact on other ammonia decomposition units 5 and production processes. Similarly, when the demand for hydrogen or steam increases, it becomes possible to respond to the increase in demand for hydrogen or steam without affecting other consumers.

[0147] (12) According to the 12th aspect, in the control device 10 of the plant 1 relating to the 11th aspect, when it is not possible to increase the amount of exhaust gas from the gas turbine 23, the control unit 112 determines whether it is possible to increase the amount of steam generated by the heat recovery boiler 3, and if it is possible to increase the amount of steam generated, instructs the heat recovery boiler 3 to increase the amount of steam generated in accordance with an increase in electricity demand or steam demand.

[0148] In this way, when, for example, the demand for electricity increases, the control device 10 can increase the amount of steam supplied to the steam turbine 41 and increase the amount of power generation while suppressing the impact on other ammonia decomposition units 5 and production processes. Similarly, when the demand for steam increases, it becomes possible to respond to the increase in steam demand without affecting other consumers.

[0149] (13) According to the thirteenth aspect, in the control device 10 of the plant 1 relating to any one of the tenth to twelfth aspects, the control unit 112 receives a signal D1 indicating an increase in power demand, and when it is not possible to increase the amount of exhaust gas from the gas turbine 23 and the amount of steam generated by the heat recovery boiler 3, determines whether it is possible to reduce the amount of steam supplied to the production process, and when it is possible to reduce the amount of steam supplied to the production process, reduces the flow rate of the steam supply pipe L12 of the production process in accordance with the increase in power demand and increases the flow rate of the steam supply pipe L11 of the steam turbine 41.

[0150] In this way, if the control device 10 cannot increase the amount of exhaust gas from the gas turbine 23 and the amount of steam generated by the heat recovery boiler 3, it can respond to the increase in electricity demand by transferring the amount of steam supplied to the production process to the steam turbine 41.

[0151] (14) According to the fourteenth aspect, in the control device 10 of the plant 1 according to the thirteenth aspect, when a signal indicating an increase in power demand is received and it is not possible to reduce the amount of steam supplied to the production process, the control unit 112 reduces the amount of ammonia supplied to the ammonia decomposer 5 in accordance with the increase in power demand to reduce the amount of heat absorbed by the ammonia decomposer 5, and then increases the flow rate of the steam supply pipe L11 of the steam turbine 41.

[0152] In this way, the control device 10 can increase the amount of heat generated by the exhaust gas flowing into the heat recovery boiler 3 by the amount of heat absorption reduced by the ammonia decomposition device 5. This increases the amount of steam supplied to the steam turbine 41, making it possible to respond to an increase in power demand.

[0153] (15) According to the fifteenth aspect, in the control device 10 of the plant 1 according to any one of the tenth to fourteenth aspects, when the control unit 112 receives a signal D1 indicating a decrease in power demand, the control unit 112 reduces the flow rate of the steam supply pipe L11 of the steam turbine 41 in accordance with the decrease in power demand, and then increases the amount of ammonia supplied to the ammonia decomposer 5 to increase the amount of heat absorbed by the ammonia decomposer 5.

[0154] In this way, the control device 10 can respond to the decrease in power demand without reducing the load on the heat recovery steam generator 3, and can effectively utilize the heat quantity of the surplus exhaust gas for generating hydrogen.

[0155] (16) According to the sixteenth aspect, the plant 1 includes a gas turbine 23, an ammonia decomposition unit 5 that decomposes ammonia using heat from exhaust gas of the gas turbine 23 to produce hydrogen, a heat recovery boiler 3 that generates steam using exhaust gas that has passed through the ammonia decomposition unit 5, a steam turbine 41 that is driven to rotate by steam, a generator 42 that converts the rotational power of the steam turbine 41 into electricity, steam supply pipes L11, L12 that supply steam to the steam turbine 41 and to each of the production processes that use the steam for production, and a control device 10 according to any one of the tenth to fifteenth aspects.

[0156] In this way, the plant 1 can use the exhaust gas from the gas turbine 23 to produce hydrogen in addition to the power generation and steam used in the production process. Furthermore, the plant 1 can appropriately adjust the amount of heat absorbed by the ammonia decomposition unit 5 and the amount of steam supplied to the steam turbine 41 and the production process in accordance with demand fluctuations, while suppressing a decrease in the load on the gas turbine 23 due to demand fluctuations. In other words, it is possible to suppress a decrease in the plant load and plant efficiency due to demand fluctuations, and to suppress a decrease in the economic efficiency of the plant 1.

[0157] (17) According to a seventeenth aspect, the plant 1 according to the sixteenth aspect further includes an off-gas pipe L28 that connects the heat recovery steam generator 3 and the ammonia decomposition apparatus 5 and circulates off-gas discharged after hydrogen is produced in the ammonia decomposition apparatus 5 as fuel for the heat recovery steam generator 3.

[0158] In this way, the plant 1 can improve the thermal efficiency of the heat recovery boiler 3 by reusing the off-gas from the ammonia decomposition unit 5. In addition, the resource (ammonia) input to the ammonia decomposition unit 5 can be used without waste.

[0159] (18) According to an eighteenth aspect, a control method for a plant 1 includes a gas turbine 23, an ammonia decomposition unit 5 that decomposes ammonia using heat from exhaust gas of the gas turbine 23 to produce hydrogen, a heat recovery boiler 3 that generates steam using exhaust gas that has passed through the ammonia decomposition unit 5, a steam turbine 41 that is rotationally driven by the steam, a generator 42 that converts the rotational power of the steam turbine 41 into electric power, and steam supply pipes L11 and L12 that supply steam to the steam turbine 41 and to each of production processes that utilize the steam for production, the control method comprising the steps of: receiving a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and adjusting at least one of the amount of exhaust gas from the gas turbine 23, the amount of steam generated by the heat recovery boiler 3, the amount of heat absorbed by the ammonia decomposition unit 5, the flow rate in the steam supply pipe L11 of the steam turbine 41, and the flow rate in the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the received signal and to suppress a decrease in the load of the gas turbine 23.

[0160] (19) According to a nineteenth aspect, the program causes a control device 10 of a plant 1 including a gas turbine 23, an ammonia decomposition device 5 that decomposes ammonia using heat of exhaust gas from the gas turbine 23 to produce hydrogen, a heat recovery boiler 3 that generates steam using exhaust gas that has passed through the ammonia decomposition device 5, a steam turbine 41 that is rotationally driven by the steam, a generator 42 that converts the rotational power of the steam turbine 41 into electric power, and steam supply pipes L11 and L12 that supply steam to the steam turbine 41 and to each of production processes that utilize the steam for production, to execute the following steps: receiving a signal including at least one of an electric power demand, a hydrogen demand, and a steam demand of the production process; and adjusting at least one of the amount of exhaust gas from the gas turbine 23, the amount of steam generated by the heat recovery boiler 3, the amount of heat absorbed by the ammonia decomposition device 5, the flow rate in the steam supply pipe L11 of the steam turbine 41, and the flow rate in the steam supply pipe L12 of the production process so as to satisfy the demand indicated by the received signal and to suppress a decrease in the load of the gas turbine 23. [Explanation of symbols]

[0161] 1. Plant 2 Gas turbine system 21 Compressor 22 Combustor 23 Gas turbine 24 Generator 3. Waste heat recovery boiler 4 Steam Turbine System 41 Steam turbine 42 Generator 43 Reduced Temperature Spray 5. Ammonia decomposition unit 51 Ammonia Tank 52 Hydrogen Tank 53 Decomposition reactor 54 Absorption Tower 55 Regeneration Tower 56 Hydrogen Purification Department 10 Control device 11 processors 111 Signal receiving unit 112 Control Unit 12 Memory 13. Storage 14 Communication Interface L1 main tube L11, L12, L13 Steam supply pipe L2 Ammonia supply pipe L28 Off-gas piping L29 Return piping L4 exhaust gas duct

Claims

1. A gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; an ammonia decomposition device that decomposes ammonia using heat from the steam to produce hydrogen; a steam supply pipe for supplying the steam to the steam turbine, the ammonia decomposition unit, and a production process that utilizes the steam for production; A control device for a plant comprising: a signal receiving unit that receives a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process; a control unit that adjusts at least one of the steam generation amount of the heat recovery boiler, the flow rate of the steam supply pipe of the steam turbine, the flow rate of the steam supply pipe of the ammonia cracker, and the flow rate of the steam supply pipe of the production process based on the received signal so as to meet the demand indicated by the signal with the current load of the gas turbine; A plant control device comprising:

2. The control unit determining whether an increase in steam generation rate of the heat recovery boiler is possible when a signal indicating an increase in electricity demand, hydrogen demand, or steam demand is received; instructing the heat recovery boiler to increase the amount of steam generated in response to an increase in the demand for electricity, the demand for hydrogen, or the demand for steam, when the amount of steam generation can be increased; The plant control device according to claim 1 .

3. the control unit receives a signal indicating an increase in demand for electricity or hydrogen and, when it is not possible to increase the amount of steam generated by the heat recovery boiler, determines whether it is possible to reduce the amount of steam supplied to the production process; when it is possible to reduce the amount of steam supplied to the production process, reducing the flow rate of the steam supply pipe of the production process in response to an increase in the demand for electricity or the demand for hydrogen, and increasing the flow rate of the steam supply pipe of the steam turbine or the steam supply pipe of the ammonia decomposition unit; The plant control device according to claim 2 .

4. The control unit receiving a signal indicating an increase in power demand and, if a decrease in the steam supply to the production process is not possible, decreasing the ammonia supply to the ammonia decomposition unit in response to the increase in power demand; after the amount of ammonia supplied to the ammonia decomposer has decreased, a flow rate of the steam supply pipe of the ammonia decomposer is decreased in response to the increase in the power demand, and a flow rate of the steam supply pipe of the steam turbine is increased. The plant control device according to claim 3 .

5. The control unit when a signal indicating a decrease in power demand is received, reducing a flow rate of a steam supply pipe of the steam turbine in response to the decrease in power demand and increasing a flow rate of a steam supply pipe of the ammonia decomposition unit; increasing the amount of ammonia supplied to the ammonia decomposition device after the flow rate and temperature of the steam supplied to the ammonia decomposition device satisfy predetermined conditions; The plant control device according to claim 1 .

6. A gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; an ammonia decomposition device that decomposes ammonia using heat from the steam to produce hydrogen; a steam supply pipe for supplying the steam to the steam turbine, the ammonia decomposition unit, and a production process that utilizes the steam for production; The control device according to any one of claims 1 to 5; A plant equipped with:

7. The system further includes an off-gas piping that connects the heat recovery boiler and the ammonia decomposition device, and through which off-gas discharged after hydrogen is produced in the ammonia decomposition device flows as fuel for the heat recovery boiler.

7. The plant according to claim 6.

8. A gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; an ammonia decomposition device that decomposes ammonia using heat from the steam to produce hydrogen; a steam supply pipe for supplying the steam to the steam turbine, the ammonia decomposition unit, and a production process that utilizes the steam for production; A method for controlling a plant comprising: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand for the production process; adjusting at least one of the steam generation rate of the heat recovery steam generator, the flow rate of the steam supply pipe of the steam turbine, the flow rate of the steam supply pipe of the ammonia cracker, and the flow rate of the steam supply pipe of the production process based on the received signal so as to meet the demand indicated by the signal at the current load of the gas turbine; A method for controlling a plant having

9. A gas turbine, a heat recovery boiler that generates steam using exhaust gas from the gas turbine; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; an ammonia decomposition device that decomposes ammonia using heat from the steam to produce hydrogen; a steam supply pipe for supplying the steam to the steam turbine, the ammonia decomposition unit, and a production process that utilizes the steam for production; A control device for a plant comprising: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand for the production process; adjusting at least one of the steam generation rate of the heat recovery steam generator, the flow rate of the steam supply pipe of the steam turbine, the flow rate of the steam supply pipe of the ammonia cracker, and the flow rate of the steam supply pipe of the production process based on the received signal so as to meet the demand indicated by the signal at the current load of the gas turbine; A program that executes the following.

10. A gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from the exhaust gas of the gas turbine to produce hydrogen; a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; a steam supply pipe for supplying the steam to the steam turbine and to each of the production processes that utilize the steam for production; A control device for a plant comprising: a signal receiving unit that receives a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand of the production process; a control unit that adjusts at least one of the amount of exhaust gas from the gas turbine, the amount of steam generated by the heat recovery boiler, the amount of heat absorbed by the ammonia cracker, the flow rate of a steam supply pipe for the steam turbine, and the flow rate of a steam supply pipe for the production process so as to satisfy the demand indicated by the received signal; A plant control device comprising:

11. the control unit determines whether an amount of exhaust gas from the gas turbine can be increased when a signal indicating an increase in demand for electricity, hydrogen, or steam is received; commanding the gas turbine to increase the amount of exhaust gas in response to an increase in the demand for electricity, the demand for hydrogen, or the demand for steam, if the increase in the amount of exhaust gas is possible; The plant control device according to claim 10.

12. The control unit determining whether an amount of steam generated by the heat recovery boiler can be increased when the amount of exhaust gas from the gas turbine cannot be increased; When the steam generation amount can be increased, instructing the heat recovery boiler to increase the steam generation amount in response to an increase in the power demand or the steam demand. The plant control device according to claim 11.

13. The control unit receiving a signal indicating an increase in power demand and determining whether a decrease in steam supply to the production process is possible when an increase in the amount of exhaust gas from the gas turbine and an increase in the amount of steam generated by the heat recovery steam generator are not possible; When it is possible to reduce the amount of steam supplied to the production process, a flow rate of the steam supply pipe of the production process is reduced in response to the increase in the power demand, and a flow rate of the steam supply pipe of the steam turbine is increased. The plant control device according to claim 10.

14. The control unit when a signal indicating an increase in power demand is received and it is not possible to reduce the amount of steam supplied to the production process, reducing the amount of ammonia supplied to the ammonia decomposer in accordance with the increase in power demand to reduce the amount of heat absorbed by the ammonia decomposer, and then increasing the flow rate of the steam supply pipe of the steam turbine. The plant control device according to claim 13.

15. The control unit when a signal indicating a decrease in power demand is received, a flow rate of a steam supply pipe of the steam turbine is reduced in accordance with the decrease in power demand, and then an amount of ammonia supplied to the ammonia decomposition device is increased to increase the amount of heat absorbed by the ammonia decomposition device. The plant control device according to claim 10.

16. A gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from the exhaust gas of the gas turbine to produce hydrogen; a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; a steam supply pipe for supplying the steam to the steam turbine and to each of the production processes that utilize the steam for production; A control device according to any one of claims 10 to 15; A plant equipped with:

17. The system further includes an off-gas piping that connects the heat recovery boiler and the ammonia decomposition device, and through which off-gas discharged after hydrogen is produced in the ammonia decomposition device flows as fuel for the heat recovery boiler.

17. The plant of claim 16.

18. A gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from the exhaust gas of the gas turbine to produce hydrogen; a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; a steam supply pipe for supplying the steam to the steam turbine and to each of the production processes that utilize the steam for production; A method for controlling a plant comprising: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand for the production process; adjusting at least one of the amount of exhaust gas from the gas turbine, the amount of steam generated by the heat recovery boiler, the amount of heat absorbed by the ammonia cracker, the flow rate of a steam supply pipe for the steam turbine, and the flow rate of a steam supply pipe for the production process so as to meet the demand indicated by the received signal; A method for controlling a plant having

19. A gas turbine, an ammonia decomposition unit that decomposes ammonia using heat from the exhaust gas of the gas turbine to produce hydrogen; a heat recovery boiler that generates steam using the exhaust gas that has passed through the ammonia decomposition device; a steam turbine that is rotationally driven by the steam; a generator that converts the rotational power of the steam turbine into electric power; a steam supply pipe for supplying the steam to the steam turbine and to each of the production processes that utilize the steam for production; A control device for a plant comprising: receiving a signal including at least one of an electricity demand, a hydrogen demand, and a steam demand for the production process; adjusting at least one of the amount of exhaust gas from the gas turbine, the amount of steam generated by the heat recovery boiler, the amount of heat absorbed by the ammonia cracker, the flow rate of a steam supply pipe for the steam turbine, and the flow rate of a steam supply pipe for the production process so as to meet the demand indicated by the received signal; A program that executes the following.

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