Power generation system, and method for starting the power generation system

Abstract

The present invention provides a power generation system that can reduce carbon dioxide emissions, and a method for starting up the power generation system. [Solution] The power generation system comprises a high-temperature gas reactor, a steam generator capable of generating steam using the heat of the high-temperature gas reactor, a hydrogen production device capable of producing hydrogen using the steam generated by the steam generator, a gas turbine driven by the hydrogen produced by the hydrogen production device, and a power generation device that generates electricity using the rotational force of the gas turbine and can supply power to the hydrogen production device.

Description

Technical Field

[0004] ,

[0006] , , , , , ,

[0005] , , ,

[0003] , , , ,

[0001] The present disclosure relates to a power generation system and a method for starting the power generation system.

Background Art

[0002] In recent years, from the perspective of carbon neutrality, it has been desired to reduce carbon dioxide emissions. Hydrogen has attracted attention as a fuel that does not generate carbon dioxide. For example, Patent Document 1 discloses a hydrogen production system that produces hydrogen using the thermal energy of a high-temperature gas furnace. This hydrogen production system includes a hydrogen production device and a power generation device. The hydrogen production device produces hydrogen using a heat medium heated by the thermal energy of a high-temperature gas furnace. The power generation device generates electricity using the heat medium used in the hydrogen production device and supplies the generated electricity to the hydrogen production device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] ​​​​​​​​​​​​To solve the above problems, the power generation system according to this disclosure comprises a high-temperature gas reactor, a steam generator capable of generating steam using the heat of the high-temperature gas reactor, a hydrogen production device capable of producing hydrogen using the steam generated by the steam generator, and hydrogen produced by the hydrogen production device. Only combustion, secondly, where carbon dioxide is produced during combustion. fuel Either combustion of only the hydrogen produced by the hydrogen production apparatus and the second fuel, or The hydrogen production apparatus includes a power generation device having a gas turbine that can be driven by a motor and a generator that generates electricity using the rotational force of the gas turbine, and a recovery device capable of recovering carbon dioxide in the exhaust gas produced by the power generation device by adsorbing it onto an adsorbent, wherein the recovery device separates the recovered carbon dioxide from the adsorbent by utilizing the heat of the steam generated by the steam generator.

[0007] The method for starting a power generation system according to this disclosure is a method for starting the power generation system described above, comprising the steps of: starting the high-temperature gas reactor; generating steam using the steam generator after the high-temperature gas reactor has been started; supplying the steam generated by the steam generator to the hydrogen production device; determining whether the hydrogen production device has reached a hydrogen production temperature after the supply of steam to the hydrogen production device; and, if the hydrogen production device has reached a hydrogen production temperature, By burning only the second fuel mentioned above The steps include starting up the power generation device and beginning power generation, supplying the power from the power generation device to the hydrogen production device and causing the hydrogen production device to begin hydrogen production, and supplying the hydrogen produced by the hydrogen production device to the power generation device. By co-firing with the second fuel, or by burning only the hydrogen produced by the hydrogen production apparatus, The process includes the step of driving the gas turbine. Furthermore, the method for starting the power generation system according to this disclosure comprises a high-temperature gas reactor, a steam generator capable of generating steam using the heat of the high-temperature gas reactor, a hydrogen production device capable of producing hydrogen using the steam generated by the steam generator, and hydrogen produced by the hydrogen production device. Only combustion, secondly, where carbon dioxide is produced during combustion. fuel Either combustion of only the hydrogen produced by the hydrogen production apparatus and the second fuel, orA method for starting a power generation system comprising a gas turbine that can be driven by a gas turbine, and a power generation device that generates electricity using the rotational force of the gas turbine and can supply power to the hydrogen production device, the method comprising: starting the high-temperature gas reactor; generating steam using the steam generator after the high-temperature gas reactor has been started; supplying the steam generated by the steam generator to the hydrogen production device; determining whether the hydrogen production device has reached a hydrogen production temperature after the steam has been supplied to the hydrogen production device; and if the hydrogen production device has reached a hydrogen production temperature, By burning only the second fuel mentioned above The steps include starting up the power generation device and beginning power generation, supplying the power from the power generation device to the hydrogen production device and causing the hydrogen production device to begin hydrogen production, and supplying the hydrogen produced by the hydrogen production device to the power generation device. By co-firing with the second fuel, or by burning only the hydrogen produced by the hydrogen production apparatus, The process includes the step of driving the gas turbine. [Effects of the Invention]

[0008] The power generation system and the method for starting the power generation system described herein can reduce carbon dioxide emissions. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of a power generation system according to an embodiment of the present disclosure. [Figure 2] This is a schematic diagram of a hydrogen production apparatus according to an embodiment of the present disclosure. [Figure 3] This is a schematic diagram of the recovery device according to the present disclosure. [Figure 4] This flowchart shows the procedure for starting up the power generation system according to the embodiment of this disclosure. [Figure 5] This is a schematic diagram of a power generation system according to another embodiment of the present disclosure. [Figure 6] This is a schematic diagram of a hydrogen production apparatus according to another embodiment of the present disclosure. [Modes for carrying out the invention]

[0010] <First Embodiment> Hereinafter, the power generation system 10 and the method for starting the power generation system 10 according to the embodiment of this disclosure will be described with reference to Figures 1 to 4.

[0011] (Configuration of the power generation system) As shown in Figure 1, the power generation system 10 includes a high-temperature gas reactor 21, an intermediate heat exchanger 22, a first circulator 23, a steam generator 31, a second circulator 32, a hydrogen production device 40, a temperature sensor 46, a power generation device 50, a recovery device 60, a first heat transfer medium circulation path L11, a second heat transfer medium circulation path L12, a water supply path L21, a first steam supply path L31, a second steam supply path L32, a first water discharge path L33, a second water discharge path L34, a hydrogen discharge path L41, a hydrogen return path L42 (see Figure 2), a fuel path L51, an exhaust gas discharge path L52, a first power supply path L61, a second power supply path L62, and a third power supply path L63.

[0012] (High-temperature gas reactor) The high-temperature gas-cooled reactor 21 functions as a heat source capable of generating ultra-high temperature thermal energy, for example, between 900°C and 950°C. The high-temperature gas-cooled reactor 21 is a reactor that uses, for example, ceramic material for the fuel cladding, helium as the coolant, and graphite as the moderator. Such a high-temperature gas-cooled reactor 21 can extract thermal energy at higher temperatures compared to a light water reactor. Furthermore, the high-temperature gas-cooled reactor 21 is a small reactor designed to be smaller than large nuclear power plants. The high-temperature gas-cooled reactor 21 is capable of generating helium gas as a heat transfer medium at temperatures above 900°C. A first heat transfer medium circulation path L11 is connected to the high-temperature gas-cooled reactor 21.

[0013] The first heat transfer medium circulation path L11 is a path for circulating the primary heat transfer medium. In addition to the high-temperature gas furnace 21, the first heat transfer medium circulation path L11 is connected to an intermediate heat exchanger 22 and a first circulator 23.

[0014] (Intermediate heat exchanger) The intermediate heat exchanger 22 performs heat exchange between the primary heat medium flowing through the first heat medium circulation path L11 and the secondary heat medium flowing through the second heat medium circulation path L12. In the present embodiment, the case where the primary heat medium is primary helium and the secondary heat medium is secondary helium will be described. That is, the intermediate heat exchanger 22 heats the secondary heat medium flowing through the second heat medium circulation path L12 to, for example, 900°C by the primary heat medium at, for example, 950°C flowing through the first heat medium circulation path L11. After passing through the intermediate heat exchanger 22, the primary heat medium is sent to the first circulation machine 23.

[0015] (First circulation machine) The first circulation machine 23 is a device that circulates the primary heat medium in the first heat medium circulation path L11. The first circulation machine 23 pumps the primary heat medium that has passed through the intermediate heat exchanger 22 toward the high-temperature gas furnace 21.

[0016] The second heat medium circulation path L12 is a path for circulating the secondary heat medium. In addition to the intermediate heat exchanger 22, a steam generator 31 and a second circulation machine 32 are connected to the second heat medium circulation path L12.

[0017] (Steam generator) The steam generator 31 is capable of generating steam using the heat of the high-temperature gas furnace 21. A water supply path L21 is connected to the steam generator 31. Pressurized water is supplied to the steam generator 31 from a water supply tank (not shown) or the like through the water supply path L21. The steam generator 31 heats water with the heat of the secondary heat medium flowing through the second heat medium circulation path L12 and generates steam. A plurality (for example, two) of steam generators 31 are provided. The two steam generators 31 are connected in series. Of the two steam generators 31 connected in series, the steam generator 31 on the upstream side in the flow direction of the secondary heat medium is referred to as the first steam generator 31a, and the steam generator 31 on the downstream side is referred to as the second steam generator 31b.

[0018] The first steam generator 31a is supplied with a secondary heat transfer medium that has passed through the intermediate heat exchanger 22 and pressurized water flowing through the water supply path L21. The first steam generator 31a heats the water with the heat from the secondary heat transfer medium and generates steam. The steam generated in the first steam generator 31a is supplied to the hydrogen production device 40 through the first steam supply path L31.

[0019] The first steam supply path L31 connects the first steam generator 31a and the hydrogen production device 40. The first steam supply path L31 supplies steam generated in the first steam generator 31a to the hydrogen production device 40.

[0020] The second steam generator 31b is supplied with the secondary heat transfer medium that has passed through the first steam generator 31a and pressurized water flowing through the water supply path L21. The second steam generator 31b heats the water with the heat from the secondary heat transfer medium and generates steam. The steam generated in the second steam generator 31b is supplied to the recovery device 60 through the second steam supply path L32. After passing through the second steam generator 31b, the secondary heat transfer medium is sent to the second circulator 32.

[0021] The second steam supply path L32 connects the second steam generator 31b and the recovery device 60. The second steam supply path L32 supplies the steam generated in the second steam generator 31b to the recovery device 60.

[0022] (2nd circulator) The second circulator 32 is a device that circulates the secondary heat transfer medium in the second heat transfer medium circulation path L12. The second circulator 32 pressurizes the secondary heat transfer medium that has passed through the second steam generator 31b toward the intermediate heat exchanger 22.

[0023] (Hydrogen production equipment) The hydrogen production apparatus 40 is a device capable of producing hydrogen using steam generated by the steam generator 31. The hydrogen production apparatus 40 in this embodiment is a high-temperature solid electrolyte type steam electrolysis cell (Solid Oxide Electrolysis Cell; SOEC) that produces hydrogen by electrolyzing the steam generated by the steam generator 31. As shown in Figure 2, the hydrogen production apparatus 40 has a case 41, a heating device 42, an electrolyte layer 43, a hydrogen electrode layer 44, and an oxygen electrode layer 45. The electrolyte layer 43, the hydrogen electrode layer 44, and the oxygen electrode layer 45 are housed inside the case 41. Steam generated by the first steam generator 31a is supplied to the case 41. The heating device 42 heats the inside of the hydrogen production apparatus 40 to a temperature at which hydrogen can be produced. However, if the hydrogen production apparatus 40 is sufficiently heated by the heat of the steam supplied from the steam generator 31 and the temperature of the hydrogen production apparatus 40 can reach the temperature at which hydrogen can be produced, the heating device 42 may not be provided. For example, the hydrogen production apparatus 40 is equipped with a temperature sensor 46 that measures the temperature of the hydrogen production apparatus 40. In this case, it is determined whether or not the hydrogen production apparatus 40 has been heated to a temperature at which hydrogen can be produced, based on the measurement value of the temperature sensor 46.

[0024] The electrolyte layer 43 is formed of, for example, ceramic. High-temperature steam is supplied to the hydrogen electrode layer 44. When power is supplied to the hydrogen production apparatus 40, a voltage is applied to the hydrogen electrode layer 44 and the oxygen electrode layer 45. The hydrogen production apparatus 40 is connected to a first power supply path L61 that supplies power from the power generator 50 and a second power supply path L62 that supplies power from another power source (not shown). The power supplied from the first power supply path L61 and the second power supply path L62 is used for electrolysis of steam and starting the electric motors (auxiliary equipment) of the hydrogen production apparatus, such as the heating device 42.

[0025] When voltage is applied to the hydrogen production device 40, water vapor is electrolyzed in the hydrogen electrode layer 44, generating hydrogen. The generated hydrogen is discharged into the hydrogen discharge path L41. Meanwhile, oxygen ions generated by electrolysis in the hydrogen electrode layer 44 permeate the electrolyte layer 43, are generated as oxygen in the oxygen electrode layer 45, and are discharged outside the case 41.

[0026] The hydrogen production device 40 generates hydrogen and oxygen based on an electrolysis reaction according to the following formula. H2O → H2 + 1 / 2O2

[0027] The hydrogen production apparatus 40 is supplied with more steam than is necessary for hydrogen production. The excess steam not used for electrolysis is cooled and liquefied into water by a cooler (not shown), for example, and separated from the hydrogen. The hydrogen production apparatus 40 is connected to a first water discharge path L33. This excess water is discharged from the hydrogen production apparatus 40 to the first water discharge path L33. The first water discharge path L33 connects the hydrogen production apparatus 40 to the first steam generator 31a. The first water discharge path L33 supplies the water discharged from the hydrogen production apparatus 40 to the first steam generator 31a.

[0028] Furthermore, a hydrogen discharge path L41 is connected to the hydrogen production unit 40. Hydrogen produced in the hydrogen production unit 40 is discharged into the hydrogen discharge path L41. The hydrogen discharge path L41 connects the hydrogen production unit 40 and the power generation unit 50. The hydrogen discharge path L41 guides the hydrogen produced in the hydrogen production unit 40 to the power generation unit 50. In addition, some of the hydrogen produced in the hydrogen production unit 40 is returned to the hydrogen production unit 40 by the hydrogen return path L42.

[0029] (Power generator) The power generation device 50 is a so-called gas turbine combined cycle power plant (GTCC). The power generation device 50 includes a gas turbine 51, a generator 52, a rotating shaft 53, a heat recovery steam generator (HRSG) 54, and a steam turbine 55 for power generation. The gas turbine 51 and the generator 52 are driven and connected by the rotating shaft 53. The gas turbine 51 is connected to a hydrogen discharge path L41 and a fuel path L51. Hydrogen produced in the hydrogen production device 40 is supplied to the gas turbine 51 through the hydrogen discharge path L41, and fuel such as LNG (Liquefied Natural Gas) is supplied through the fuel path L51. The gas turbine 51 is designed to be driven by hydrogen produced in the hydrogen production device 40 or LNG, etc. The driving rotational force of the gas turbine 51 is transmitted to the generator 52 through the rotating shaft 53. The generator 52 is driven by the driving rotational force of the gas turbine 51 and generates electricity.

[0030] The power generation device 50 generates electricity by co-firing hydrogen with a fuel other than hydrogen, such as LNG. Alternatively, the power generation device 50 may generate electricity by exclusively burning hydrogen. In other words, the power generation device 50 may generate electricity using only hydrogen as fuel. Furthermore, the power generation device 50 may be capable of switching between co-firing and exclusive combustion modes depending on the operating status of the hydrogen production device.

[0031] The power generation device 50 is also equipped with a heat recovery boiler 54 (HRSG) and a power generation steam turbine 55. The heat recovery boiler 54 recovers waste heat from the gas turbine 51. The power generation steam turbine 55 is driven using the steam generated by the heat recovery boiler 54 as a power source. The rotational force of the power generation steam turbine 55 is used to drive a generator (not shown) connected to the power generation steam turbine 55.

[0032] Furthermore, the power generation device 50 is electrically connected to the hydrogen production device 40 and the recovery device 60 by the first power supply path L61. The power generation device 50 is capable of supplying power to the hydrogen production device 40 and the recovery device 60.

[0033] Furthermore, the power generator 50 is connected to an exhaust gas discharge path L52. Exhaust gas G containing carbon dioxide generated by the power generator 50 is discharged into the exhaust gas discharge path L52. The exhaust gas discharge path L52 connects the power generator 50 and the recovery device 60. The exhaust gas G discharged from the power generator 50 is sent to the recovery device 60 through the exhaust gas discharge path L52.

[0034] (Recovery device) The recovery device 60 is a so-called carbon dioxide capture and storage (CCS) system. The recovery device 60 is capable of recovering carbon dioxide from the exhaust gas G generated by the generator 52 by adsorbing it onto an adsorbent. Furthermore, the recovery device 60 uses the heat of the steam generated by the second steam generator 31b to separate the recovered carbon dioxide from the adsorbent. The high-purity carbon dioxide separated from the adsorbent is stored, for example, on the seabed or transported by a transport ship to a facility that utilizes carbon dioxide as a carbon resource. In this embodiment, amine absorbent A is used as the absorbent. As shown in Figure 3, the recovery device 60 includes a cooling tower 61, an absorption tower 62, a regeneration tower 63, a reboiler 64, a regeneration heat exchanger 65, a regeneration cooler 66, an exhaust gas transfer path L71, a first absorbent transfer path L72, a second absorbent transfer path L73, and a carbon dioxide transfer path L74.

[0035] (cooling tower) Exhaust gas G containing carbon dioxide is supplied to the cooling tower 61. The cooling tower 61 cools the exhaust gas G. The cooling tower 61 has a cooling tower body 61a, a pump 61b, a cooler 61c, and a cooling water circulation path L75. Exhaust gas G is supplied to the cooling tower body 61a. The cooling tower body 61a sprays cooling water from top to bottom. This cools the exhaust gas G to a temperature suitable for carbon dioxide recovery (for example, a temperature close to room temperature). The cooling water is then sent to the pump 61b through the cooling water circulation path L75. The pump 61b compresses the cooling water and sends it to the cooler 61c. Once cooled in the cooler 61c, the cooling water is sprayed again in the cooling tower body 61a through the cooling water circulation path L75. The cooling tower body 61a is connected to the bottom of the absorption tower 62 by an exhaust gas transfer path L71. The exhaust gas transfer path L71 supplies the exhaust gas G cooled in the cooling tower 61 to the absorption tower 62.

[0036] (Hydrocopter) The absorption tower 62 sprays amine absorbent A downwards. The amine absorbent A absorbs carbon dioxide from the exhaust gas G by coming into contact with it. After the carbon dioxide has been removed from the exhaust gas G, it is cooled and then discharged as a clean gas from the top of the absorption tower 62. The bottom of the absorption tower 62 is connected to the regeneration tower 63 by a first absorbent transfer path L72. The first absorbent transfer path L72 supplies amine absorbent A to the regeneration tower 63. A pump 67 and a regeneration heat exchanger 65 are provided in the middle section of the first absorbent transfer path L72 that connects the absorption tower 62 and the regeneration tower 63. The pump 67 pumps the amine absorbent A from the absorption tower 62 to the regeneration tower 63. The regeneration heat exchanger 65 will be described later.

[0037] (Regeneration Tower) In the regeneration tower 63, amine absorbent A is sent. A reboiler 64 is installed at the bottom of the regeneration tower 63.

[0038] (Revoila) The reboiler 64 is connected to the second steam generator 31b by a second steam supply path L32. Steam is supplied to the reboiler 64 from the second steam generator 31b through the second steam supply path L32. This steam is generated by the heat of the secondary heat transfer medium after heat has been supplied to the first steam generator 31a.

[0039] The reboiler 64 uses the heat of steam to heat the amine absorbent A, which contains carbon dioxide. When the amine absorbent A is heated to, for example, between 100°C and 140°C, the saturation solubility of carbon dioxide decreases, releasing carbon dioxide from the amine absorbent A. The carbon dioxide absorption capacity is then regenerated by cooling in the regenerative heat exchanger 65. In addition, the steam that has undergone heat exchange with the amine absorbent A in the reboiler 64 liquefies into water. The reboiler 64 is connected to the second steam generator 31b by a second water discharge path L34. The water produced in the reboiler 64 is discharged into the second water discharge path L34. The second water discharge path L34 supplies the water discharged from the reboiler 64 to the second steam generator 31b.

[0040] Furthermore, the bottom of the regeneration tower 63 is connected to the absorption tower 62 by a second absorption liquid transfer path L73. The regeneration tower 63 transfers amine absorption liquid A to the absorption tower 62 through the second absorption liquid transfer path L73. In the middle section of the second absorption liquid transfer path L73, there is a regeneration heat exchanger 65, a pump 68, and a regeneration cooler 66. The regeneration heat exchanger 65 is located upstream of the pump 68 and the regeneration cooler 66. The regeneration heat exchanger 65 is also connected to the middle section of the first absorption liquid transfer path L72. The regeneration heat exchanger 65 performs heat exchange between the amine absorption liquid A transferred from the absorption tower 62 to the regeneration tower 63 and the amine absorption liquid A transferred from the regeneration tower 63 to the absorption tower 62, thereby cooling the amine absorption liquid A transferred from the regeneration tower 63 to the absorption tower 62. The pump 68 is located upstream of the regeneration cooler 66. Pump 68 pumps amine absorbent A from regeneration tower 63 to absorption tower 62. Regeneration cooler 66 further cools amine absorbent A, which has been cooled in regeneration heat exchanger 65, and returns it to absorption tower 62. The amine absorbent A returned to absorption tower 62 is reused for carbon dioxide absorption.

[0041] The carbon dioxide released from amine absorbent A in the regeneration tower 63 is high-purity carbon dioxide with a purity of 99.9% or more and less than 100%. The carbon dioxide from the top of the regeneration tower 63 is transferred via the carbon dioxide transfer path L74 to a carbon dioxide storage facility (not shown) or a transfer vessel (not shown), etc.

[0042] The recovery device 60 is connected to a first power supply path L61 that supplies power from the power generator 50, and a third power supply path L63 that supplies power from another power source (not shown). The power supplied from the first power supply path L61 and the third power supply path L63 is used, for example, to start the electric motors (auxiliary equipment) such as the pump 68 that make up the recovery device 60.

[0043] Furthermore, the recovery device 60 is capable of recovering carbon dioxide from the atmosphere in addition to the carbon dioxide contained in the exhaust gas G from the power generation device 50.

[0044] Each component of the power generation system 10 described above is installed, for example, after an existing nuclear power plant is decommissioned. Furthermore, among the devices constituting the power generation system 10, the power generation device 50 can be newly constructed or obtained by modifying an existing GTCC to use hydrogen as fuel.

[0045] (Instructions for starting the power generation system) Next, the method for starting the power generation system 10 will be explained with reference to the flowchart in Figure 3. First, the high-temperature gas reactor 21 is started up (step S11). In step S11, the first circulator 23 is driven, and the primary heat transfer medium circulates through the first heat transfer medium circulation path L11. Also, the second circulator 32 is driven, and the secondary heat transfer medium circulates through the second heat transfer medium circulation path L12. Then, the secondary heat transfer medium exchanges heat with the primary heat transfer medium in the intermediate heat exchanger 22, and heat from the high-temperature gas reactor 21 is supplied to the secondary heat transfer medium. As a result, the secondary heat transfer medium is heated.

[0046] After the high-temperature gas reactor 21 is started up, steam is generated by the steam generator 31 (step S12). In step S12, the secondary heat transfer medium heated in the intermediate heat exchanger 22 is sent to the first steam generator 31a. The first steam generator 31a heats water with the heat from the secondary heat transfer medium to generate steam. The secondary heat transfer medium that has passed through the first steam generator 31a is then sent to the second steam generator 31b. The second steam generator 31b heats water with the heat from the secondary heat transfer medium to generate steam at a lower temperature than the steam from the first steam generator 31a.

[0047] After step S12, the steam generated in the steam generator 31 is supplied to the hydrogen production unit 40 and the recovery unit 60 (step S13). In step S13, the steam generated in the first steam generator 31a is sent to the hydrogen production unit 40 through the first steam supply path L31. At this time, the hydrogen production unit 40 is heated to a hydrogen production temperature by the steam from the first steam generator 31a and the heating device 42. The steam generated in the second steam generator 31b is sent to the reboiler 64 of the recovery unit 60 through the second steam supply path L32.

[0048] After steam is supplied to the hydrogen production device 40, it is determined whether or not the hydrogen production device 40 has reached the hydrogen production temperature (step S14). If the hydrogen production device 40 has not reached the hydrogen production temperature (step S14; NO), the steam supplied to the hydrogen production device 40 is discharged from the hydrogen production device 40 without being electrolyzed. On the other hand, if the hydrogen production device 40 has reached the hydrogen production temperature (step S14; YES), the power generation device 50 is started and power generation begins (step S15).

[0049] In step S15, fuel such as LNG is supplied to the gas turbine 51 from the fuel passage L51. The gas turbine 51 is driven by the fuel from the fuel passage L51. The rotational force of the gas turbine 51 is transmitted to the generator 52. The generator 52 is driven by the rotational force of the gas turbine 51 and generates electricity.

[0050] After step S15, power from the power generator 50 is supplied to the hydrogen production device 40, and the hydrogen production device 40 begins producing hydrogen (step S16). Also after step S16, power from the power generator 50 is supplied to the recovery device 60, and the recovery device 60 begins recovering carbon dioxide from the exhaust gas G discharged from the power generator 50 (step S17). Steps S16 and S17 may be performed simultaneously, or the order of steps S16 and S17 may be reversed.

[0051] After step S17, hydrogen produced by the hydrogen production unit 40 is supplied to the power generation unit 50, and the gas turbine 51 is driven using the hydrogen produced by the hydrogen production unit 40 as fuel (step S18). In step S18, the proportion of hydrogen from the hydrogen production unit 40 in the fuel of the gas turbine 51 increases, and the proportion of non-hydrogen fuels such as LNG supplied from the fuel path L51 decreases or becomes zero. If the proportion of non-hydrogen fuels becomes zero, the combustion mode of the gas turbine 51 of the power generation unit 50 is switched from co-firing of hydrogen and other fuels to hydrogen-only firing. After completing the above steps, the startup of the power generation system 10 is completed. Even after the startup of the power generation system 10 is complete, if, for example, the supply of hydrogen becomes insufficient, the fuel mode of the gas turbine 51 of the power generation device 50 may be switched from hydrogen-only combustion to co-combustion of hydrogen and other fuels.

[0052] In this embodiment, the hydrogen production device 40 is started after the power generation device 50 is started, but this is not limited to this. The hydrogen production device 40 may be started after it has been heated to a temperature at which it can produce hydrogen, but before the power generation device 50 is started. In this case, the hydrogen production device 40 is started by power from the second power supply path L62 and produces hydrogen. Subsequently, the hydrogen produced by the hydrogen production device 40 is supplied to the gas turbine 51 of the power generation device 50. The gas turbine 51 is driven using hydrogen as fuel, and the generator 52 is driven by the rotational force of the gas turbine 51 to generate electricity. The electricity generated by the power generation device 50 is supplied to the hydrogen production device 40, and the main power supply for the hydrogen production device 40 is switched from external power from the second power supply path L62 to the power supply of the power generation device 50. In this way, the power generation device 50 can generate electricity using only hydrogen as fuel.

[0053] (Effects and Benefits) According to the power generation system 10 and the method for starting the power generation system 10 described above, the following effects can be achieved.

[0054] In this embodiment, the power generation system 10 comprises a high-temperature gas furnace 21, a steam generator 31, a hydrogen production device 40, and a power generation device 50. The steam generator 31 is capable of generating steam using the heat of the high-temperature gas furnace 21. The hydrogen production device 40 is capable of producing hydrogen using the steam generated by the steam generator 31. The power generation device 50 has a gas turbine 51 and a generator 52. The gas turbine 51 is capable of being driven by the hydrogen produced by the hydrogen production device 40. The generator 52 generates electricity using the rotational force of the gas turbine 51. Such a power generation device 50 is capable of supplying power to the hydrogen production device 40.

[0055] As a result, the power generation system 10 can produce hydrogen using the heat from the high-temperature gas reactor 21 and generate electricity using that hydrogen. Therefore, carbon dioxide emissions are suppressed during hydrogen production and power generation. Furthermore, the power generation system 10 can supply the electricity generated by the power generation device 50 to the hydrogen production device 40. This reduces the amount of external power supplied to the hydrogen production device 40, and consequently, also suppresses carbon dioxide emissions associated with the power generation of external electricity. Thus, according to this embodiment, carbon dioxide emissions can be reduced. Therefore, the power generation system 10 can contribute to achieving carbon neutrality.

[0056] In this embodiment, the hydrogen production apparatus 40 is a high-temperature solid electrolyte type steam electrolysis apparatus (SOEC) that produces hydrogen by electrolyzing the steam generated by the steam generator 31.

[0057] As a result, the power generation system 10 can produce a large amount of hydrogen, thereby improving power generation efficiency. In addition, the electrolyte layer 43 constituting the hydrogen production device 40 (SOEC) is stably supplied with more steam than is required for the electrolysis of the SOEC by the first steam generator 31. As a result, the electrolyte layer 43 is always supplied with steam, preventing a shortage of steam and thus preventing the electrolyte layer 43 from being electrolyzed by the hydrogen production device 40 itself.

[0058] In this embodiment, the power generation system 10 includes a recovery device 60 capable of recovering carbon dioxide from exhaust gas G generated by the power generation device 50 by adsorbing it onto an adsorbent. The recovery device 60 uses the heat of steam generated by the steam generator 31 to separate the recovered carbon dioxide from the adsorbent.

[0059] This eliminates the need to separately prepare a heat source necessary to release the captured carbon dioxide, making it possible to improve the overall energy efficiency of the power generation system 10. For example, a large amount of steam is required to operate the reboiler 64 of the recovery device 60 (GSS) as described above. If the reboiler 64 of the recovery device 60 were to use steam generated by the waste heat recovery boiler 54, the reboiler 64 would use a large amount of steam, significantly reducing the power generation efficiency of the power generation steam turbine 55. This would lead to an increase in power generation costs and a decrease in the profitability of the power generation system 10. In contrast, the reboiler 64 of this embodiment uses the heat of steam generated by the steam generator 31. Therefore, process steam extracted from the waste heat recovery boiler 54 to the reboiler 64 is unnecessary. As a result, most of the steam from the waste heat recovery boiler 54 can be used by the power generation steam turbine 55, suppressing increases in power generation costs and decreases in the profitability of the power plant. Furthermore, since the operation between the power generation device 50 (GTCC) and the recovery device 60 (GSS) is simplified, it becomes possible to use existing data such as the load change rate and frequency response of the GTCC and apply existing GTCC operating techniques as they are.

[0060] In this embodiment, the power generation device 50 is capable of supplying power to the recovery device 60.

[0061] This allows the power generation system 10 to secure the power necessary for operating the recovery device 60 within the grid. Therefore, the overall energy efficiency of the power generation system 10 can be improved.

[0062] In this embodiment, the two steam generators 31 include a first steam generator 31a and a second steam generator 31b. The first steam generator 31a supplies steam to the hydrogen production apparatus 40. The second steam generator 31b supplies steam to the recovery apparatus 60. The first steam generator 31a and the second steam generator 31b are connected in series by a second heat transfer medium circulation path L12. The second steam generator 31b is installed downstream of the first steam generator 31a in the direction of secondary heat transfer medium flow. The second steam generator 31b is supplied with the secondary heat transfer medium that has passed through the first steam generator 31a.

[0063] The hydrogen production apparatus 40 requires steam in a high-temperature range suitable for electrolysis. On the other hand, the recovery apparatus 60 uses steam as a heat source when separating carbon dioxide, which has been recovered from exhaust gas G by adsorption onto amine absorbent A, from amine absorbent A. However, it is preferable that the temperature of the steam used in this case is lower than that of the steam used in the hydrogen production apparatus 40.

[0064] According to the above configuration, the first steam generator 31a can be supplied with a secondary heat transfer medium in the high-temperature range heated by the intermediate heat exchanger 22. Therefore, the first steam generator 31a can produce steam at a temperature suitable for hydrogen production. In addition, the second steam generator 31b can be supplied with a secondary heat transfer medium whose temperature has decreased after passing through the first steam generator 31a. As a result, the second steam generator 31b can produce steam at a lower temperature than the first steam generator 31a and supply it to the recovery device 60. This allows the recovery device 60 to be provided with steam at a temperature suitable for separating the recovered carbon dioxide. In this way, the heat generation system can utilize the heat of the high-temperature gas reactor 21 in a stepwise cascade manner. Therefore, the thermal efficiency of the power generation system 10 is improved.

[0065] Incidentally, in this embodiment, a small nuclear reactor capable of generating thermal energy of 900°C or higher is used as the high-temperature gas reactor 21. Therefore, it is necessary to find land where the high-temperature gas reactor 21 can be installed, which seems to be a high barrier to introducing the power generation system 10. In contrast, in this embodiment, each component of the power generation system 10 is installed, for example, after an existing nuclear power plant has been decommissioned.

[0066] This eliminates the need to find new land to install the high-temperature gas reactor 21. Therefore, the barriers to introducing the power generation system 10 can be significantly lowered, making it easier to introduce the power generation system 10.

[0067] In this embodiment, the method for starting the power generation system 10 includes the steps of: starting the high-temperature gas reactor 21 (step S11); generating steam with the steam generator 31 after the high-temperature gas reactor 21 has started (step S12); supplying the steam generated by the steam generator 31 to the hydrogen production device 40 (step S13); determining whether the hydrogen production device 40 has reached a temperature at which it can produce hydrogen after the steam has been supplied to the hydrogen production device 40 (step S14); starting the power generation device 50 and starting power generation if the hydrogen production device 40 has reached a temperature at which it can produce hydrogen (step S14; YES) (step S15); supplying power from the power generation device 50 to the hydrogen production device 40 to start hydrogen production in the hydrogen production device 40 (step S16); and supplying the hydrogen produced by the hydrogen production device 40 to the power generation device 50 and driving the gas turbine 51 using the hydrogen produced by the hydrogen production device 40 as fuel (step S18).

[0068] According to this embodiment, when electricity is supplied to the hydrogen production apparatus 40 from the power generation apparatus 50, conditions other than electricity are met for the hydrogen production apparatus 40 to produce hydrogen, such as the hydrogen production temperature and the required supply amount of steam, which is the raw material for hydrogen. Therefore, when electricity is supplied to the hydrogen production apparatus 40 from the power generation apparatus 50, hydrogen is produced immediately and supplied to the gas turbine 51 of the power generation apparatus 50. This makes it possible to start up the power generation system 10 while minimizing the amount of fuel other than hydrogen required to drive the gas turbine 51.

[0069] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure. In the above embodiment, a nuclear reactor was proposed as an example of the high-temperature gas reactor 21, but it is not limited to this. The high-temperature gas reactor 21 can be any heat source that can secure the heat required by the steam generator 31.

[0070] Furthermore, although the above embodiment described a case where both the primary and secondary heat transfer fluids that transfer heat from the high-temperature gas furnace 21 to the steam generator 31 are helium, the embodiment is not limited to this. The primary and secondary heat transfer fluids can be selected as appropriate.

[0071] Furthermore, in the above embodiment, the first steam generator 31a and the second steam generator 31b were assumed to be connected in series by the second heat transfer medium circulation path L12, but this is not the only possible configuration. As shown in Figure 5, the first steam generator 31a and the second steam generator 31b may be connected in parallel by the second heat transfer medium circulation path L12.

[0072] Furthermore, in the above embodiment, the hydrogen production apparatus 40 is described as a high-temperature solid electrolyte type steam electrolysis apparatus (Solid Oxide Electrolysis Cell; SOEC), but it is not limited to this. For example, as shown in Figure 6, the hydrogen production apparatus 40 may be an apparatus that produces turquoise hydrogen using natural gas or methane as raw materials and does not emit carbon dioxide from the reaction. In this case, for example, the hydrogen production apparatus 140 has a reactor 141, a heating unit 142, a catalyst 143, and a pump 144. Raw material gas such as natural gas or methane is supplied to the reactor 141. The heating unit 142 is located inside the reactor 141. The heating unit 142 is a spirally molded tube-shaped device. Steam generated by the first steam generator 31a flows into the heating unit 142. As a result, the heating unit 142 heats and thermally decomposes the raw material gas with the heat of the steam, generating turquoise hydrogen. The catalyst 143 is also located inside the reactor 141. The catalyst 143 promotes the thermal decomposition of the raw material gas. In this way, the hydrogen production apparatus 140 uses steam as a heat source. The steam is cooled and turned into water as it passes through the heating section 142. The water produced in the heating section 142 is discharged from the hydrogen production apparatus 140 by the pump 144 and returned to the first steam generator 31a. In this case, the power supplied to the hydrogen production apparatus 140 from the first power supply path L61 and the second power supply path L62 is used to drive the pump 144 and other motors (auxiliary equipment) such as the pump (not shown) that sends the raw material gas into the reactor 141.

[0073] <Note> The power generation system 10 described in each embodiment can be understood, for example, as follows:

[0074] (1) The power generation system 10 according to the first embodiment comprises a high-temperature gas furnace 21, a steam generator 31 capable of generating steam using the heat of the high-temperature gas furnace 21, hydrogen production devices 40 and 140 capable of producing hydrogen using the steam generated by the steam generator 31, a gas turbine 51 that can be driven by the hydrogen produced by the hydrogen production devices 40 and 140, and a power generation device 50 that has a generator 52 that generates electricity using the rotational force of the gas turbine 51 and can supply power to the hydrogen production devices 40 and 140.

[0075] As a result, the power generation system 10 can produce hydrogen using the heat from the high-temperature gas reactor 21 and generate electricity using that hydrogen. Therefore, carbon dioxide emissions are suppressed during hydrogen production and power generation. Furthermore, the power generation system 10 can supply the electricity generated by the power generation device 50 to the hydrogen production devices 40 and 140. This reduces the amount of external power supplied to the hydrogen production devices 40 and 140, and consequently, the amount of carbon dioxide emissions associated with the power generation of the external power is also suppressed. Thus, according to this embodiment, carbon dioxide emissions can be reduced.

[0076] (2) The power generation system 10 of the second embodiment is the power generation system 10 of (1), wherein the hydrogen production apparatus 40 is a high-temperature solid electrolyte type steam electrolysis apparatus that produces hydrogen by electrolyzing the steam generated in the steam generator 31.

[0077] This allows the power generation system 10 to produce a large amount of hydrogen, thereby improving power generation efficiency.

[0078] (3) The third embodiment of the power generation system 10 is the power generation system 10 of (1) or (2), and includes a recovery device 60 capable of recovering carbon dioxide in the exhaust gas G generated by the power generation device 50 by adsorbing it onto an adsorbent, wherein the recovery device 60 may separate the recovered carbon dioxide from the adsorbent by utilizing the heat of the steam generated by the steam generator 31.

[0079] This eliminates the need to separately prepare a heat source necessary to release the captured carbon dioxide, making it possible to improve the overall energy efficiency of the power generation system 10.

[0080] (4) The fourth embodiment of the power generation system 10 is the power generation system 10 of (3), wherein the power generation device 50 may be capable of supplying power to the recovery device 60.

[0081] This allows the power generation system 10 to secure the power necessary for operating the recovery device 60 within the grid.

[0082] (5) A method for starting the power generation system 10 according to the fifth embodiment is a method for starting the power generation system 10 according to any one of (1) to (4), comprising the steps of starting the high-temperature gas reactor 21, generating steam with the steam generator 31 after the high-temperature gas reactor 21 has been started, supplying the steam generated by the steam generator 31 to the hydrogen production devices 40 and 140, and determining whether the hydrogen production devices 40 and 140 have reached a hydrogen production temperature after the steam has been supplied to the hydrogen production devices 40 and 140. The process includes the steps of: starting the power generator 50 and beginning power generation when the hydrogen production apparatus 40 and 140 reach a hydrogen production temperature; supplying power from the power generator 50 to the hydrogen production apparatus 40 and 140 to cause the hydrogen production apparatus 40 and 140 to begin hydrogen production; and supplying the hydrogen produced by the hydrogen production apparatus 40 and 140 to the power generator 50 to drive the gas turbine 51 using the hydrogen produced by the hydrogen production apparatus 40 and 140 as fuel.

[0083] According to this embodiment, when electricity is supplied to the hydrogen production devices 40 and 140 from the power generation device 50, conditions other than electricity are met for the hydrogen production devices 40 and 140 to produce hydrogen, such as the hydrogen production temperature and the required supply amount of steam, which is the raw material for hydrogen. Therefore, when electricity is supplied to the hydrogen production devices 40 and 140 from the power generation device 50, hydrogen is produced immediately and supplied to the gas turbine 51 of the power generation device 50. [Explanation of Symbols]

[0084] 10 Power generation systems 21 High-temperature gas reactor 22 Intermediate heat exchanger 23 1st circulation machine 31. Steam Generator 31a First steam generator 31b Second steam generator 32 Second circulator 40 Hydrogen production equipment 41 cases 42 Heating device 43 Electrolyte layer 44 Hydrogen electrode layer 45 Oxygen electrode layer 46 Temperature Sensor 50 Power generation equipment 51 Gas Turbine 52 Generators 53 Rotation axis 54. Waste heat recovery boiler 55 Steam turbine for power generation 60 Recovery device 61 Cooling Tower 61a Cooling tower body 61b Pump 61c cooler 62 Absorption Towers 63 Regeneration Tower 64 Reboiler 65 Regeneration heat exchanger 66 Regeneration cooler 67 Pumps 68 pumps 140 Hydrogen production equipment 141 Reactor 142 Heating section 143 Catalyst 144 pumps A Amine Absorbent Solution G exhaust gas L11 First heat transfer medium circulation path L12 Second heat transfer fluid circulation path L21 Water Supply Route L31 First steam supply path L32 Second Steam Supply Path L33 First Water Discharge Route L34 Second Water Discharge Route L41 Hydrogen Emission Route L42 Hydrogen return pathway L51 Fuel Route L52 Exhaust Gas Emission Route L61 First Power Supply Path L62 Second Power Supply Path L63 Third Power Supply Path L71 Exhaust gas transfer path L72 First Absorbent Liquid Transfer Path L73 Second Absorbent Liquid Transfer Path L74 Carbon Dioxide Transfer Route L75 Cooling water circulation path

Claims

1. High-temperature gas reactors, A steam generator capable of generating steam using the heat of the aforementioned high-temperature gas furnace, A hydrogen production apparatus capable of producing hydrogen using the steam generated by the steam generator, A gas turbine capable of being driven by one of the following: combustion of hydrogen produced by the hydrogen production apparatus, combustion of a second fuel that produces carbon dioxide during combustion, or co-combustion of hydrogen produced by the hydrogen production apparatus and the second fuel; and a power generation device having a generator that generates electricity using the rotational force of the gas turbine and capable of supplying power to the hydrogen production apparatus. A recovery device capable of recovering carbon dioxide from exhaust gas generated by the aforementioned power generation device by adsorbing it onto an adsorbent, Equipped with, The recovery device uses the heat of the steam generated by the steam generator to separate the recovered carbon dioxide from the adsorbent. Power generation system.

2. The hydrogen production apparatus is a high-temperature solid electrolyte type steam electrolysis apparatus that produces hydrogen by electrolyzing the steam generated by the steam generator. The power generation system according to claim 1.

3. The power generation device is capable of supplying power to the recovery device. The power generation system according to claim 1 or 2.

4. A method for starting a power generation system according to claim 1 or 2, The steps include starting up the aforementioned high-temperature gas reactor, After the high-temperature gas reactor is started up, the steam generator is used to generate steam. The steps include supplying the steam generated by the steam generator to the hydrogen production apparatus, The steps include: determining whether the hydrogen production apparatus has reached a hydrogen production temperature after supplying steam to the hydrogen production apparatus; The steps include: when the hydrogen production apparatus reaches a hydrogen production temperature, start the power generation apparatus by burning only the second fuel and start generating electricity; The steps include supplying power from the power generation device to the hydrogen production device and causing the hydrogen production device to start producing hydrogen, The steps include supplying the hydrogen produced by the hydrogen production apparatus to the power generation apparatus, and driving the gas turbine by co-firing the hydrogen produced by the hydrogen production apparatus with the second fuel, or by burning only the hydrogen produced by the hydrogen production apparatus, including, How to start the power generation system.

5. A method for starting a power generation system comprising: a high-temperature gas reactor; a steam generator capable of generating steam using the heat of the high-temperature gas reactor; a hydrogen production device capable of producing hydrogen using the steam generated by the steam generator; a gas turbine capable of being driven by one of the following: combustion of only the hydrogen produced by the hydrogen production device; combustion of only a second fuel that produces carbon dioxide during combustion; or co-combustion of the hydrogen produced by the hydrogen production device and the second fuel; and a power generation device that generates electricity using the rotational force of the gas turbine and is capable of supplying power to the hydrogen production device. The steps include starting up the aforementioned high-temperature gas reactor, After the high-temperature gas reactor is started up, the steam generator is used to generate steam. The steps include supplying the steam generated by the steam generator to the hydrogen production apparatus, The steps include: determining whether the hydrogen production apparatus has reached a hydrogen production temperature after supplying steam to the hydrogen production apparatus; The steps include: when the hydrogen production apparatus reaches a hydrogen production temperature, start the power generation apparatus by burning only the second fuel and start generating electricity; The steps include supplying power from the power generation device to the hydrogen production device and causing the hydrogen production device to start producing hydrogen, The steps include supplying the hydrogen produced by the hydrogen production apparatus to the power generation apparatus, and driving the gas turbine by co-firing the hydrogen produced by the hydrogen production apparatus with the second fuel, or by burning only the hydrogen produced by the hydrogen production apparatus, including, How to start the power generation system.

Images