Combined power generation system with ammonia decomposition device installed outside heat recovery steam generator, and method for driving same

Abstract

A combined power generation system with an ammonia decomposition device installed outside a heat recovery steam generator according to an embodiment of the present invention comprises: a gas turbine generator; a heat recovery steam generator which produces steam by using exhaust gas discharged from the gas turbine generator; and a steam turbine generator that generates power by using steam discharged from the heat recovery steam generator, wherein the ammonia decomposition device is disposed outside the heat recovery steam generator, the ammonia decomposition device generates a reaction gas including hydrogen, nitrogen, and unreacted ammonia by thermally decomposing ammonia supplied from an ammonia tank, the gas turbine generator generates power by using hydrogen, produced from the reaction gas, as fuel, and the exhaust gas discharged from the gas turbine generator is supplied to the heat recovery steam generator and used as an energy source for the ammonia decomposition device.

Description

A combined power generation system in which an ammonia decomposition device is installed outside an array recovery boiler and a method for driving the combined power generation system

[0001] The present invention relates to a combined power generation system in which an ammonia decomposition device is installed outside a waste heat recovery boiler and a method for driving the combined power generation system, and more particularly, to a combined power generation system in which heat energy of exhaust gas discharged from a gas turbine generator is supplied to a waste heat recovery boiler and utilized for ammonia decomposition in an ammonia decomposition device outside the waste heat recovery boiler.

[0002] Combined cycle power generation combines two types of thermal cycles to improve thermal efficiency. Because combined cycle power generation maximizes the chemical energy of fuels to produce electricity, it boasts significantly higher thermal efficiency than other power generation technologies. A representative combined cycle power plant is one that combines a gas turbine cycle and a steam turbine cycle to operate as a single power plant.

[0003] As a primary power generation, a gas turbine is operated to produce primary electricity. However, since the exhaust gas temperature from the gas turbine is high, exceeding 500℃, a heat recovery steam generator (HRSG) is used as a means to recover the heat of this exhaust gas. In other words, it is a plant that passes the high-temperature exhaust gas generated from the gas turbine through the HRSG to create high-temperature, high-pressure steam, and uses this steam to operate a steam turbine as a secondary power generation to produce secondary electricity. Since the high-temperature gas is used to generate electricity once in the gas cycle and then again in the steam cycle, it produces electricity twice in total, so it has the advantage of high thermal efficiency.

[0004] Recently, a power generation technology has been introduced that uses ammonia decomposition to generate hydrogen and then combust it to power a gas turbine. Ammonia, a compound combining hydrogen and nitrogen, offers the advantage of utilizing existing transportation and storage infrastructure. However, its combustion rate is significantly lower than that of liquefied natural gas (LNG), at around 20%, and its calorific value is only 50%, limiting its utility as a power generation fuel. To address this issue, instead of burning ammonia directly, ammonia is decomposed into hydrogen and nitrogen gases using an ammonia decomposition device, which is then combusted to drive a gas turbine.

[0005] However, the technology disclosed to date has adopted a method in which the ammonia decomposition process and turbine power generation process are separated into separate processes and operated separately. That is, the ammonia decomposition facility and the power generation facility (gas turbine and steam turbine) are installed separately. In the ammonia decomposition facility, gaseous ammonia is decomposed to generate a reaction gas containing hydrogen, nitrogen, and unreacted ammonia, and the generated reaction gas is supplied to the power generation facility through a pipeline. In the power generation facility, the gas turbine generates electricity using the reaction gas, and the exhaust gas at the rear end of the gas turbine is converted into steam in a waste heat recovery boiler and then supplied to the steam turbine to operate the steam turbine. In this conventional technology, the thermal energy of the exhaust gas at the rear end of the gas turbine was recovered solely through the steam turbine.

[0006] However, these conventional composite plants require a separate heat source to supply the thermal energy required for ammonia decomposition, which must then be supplied to the ammonia decomposition facility. This additional heat source not only requires installation space within the power plant, but also requires additional energy to operate the plant, resulting in low power generation efficiency.

[0007] In addition, in a structure where the exhaust gas residual heat at the rear end of the gas turbine is recovered only from the steam turbine, there is an arrangement in which it is inevitably discarded into the atmosphere, and the problem of low energy recovery efficiency has also been raised.

[0008] Meanwhile, concerns were raised about the stability of the structure in which the reactor for ammonia decomposition was integrated into the array recovery boiler, and problems were also raised in that improvements (revamping), such as adding catalysts or replacing reactors, were not easy.

[0009] The present invention was created to solve the above-described problem, and the purpose of the present invention is to use the heat energy of exhaust gas discharged from a gas turbine generator as heat energy required for the operation of an ammonia decomposition device, thereby integrating the ammonia decomposition process and the gas turbine power generation process into a single system and increasing the energy recovery efficiency of the exhaust gas of the gas turbine generator.

[0010] According to one embodiment of the present invention for achieving the above-described object, a combined cycle power generation system in which an ammonia decomposition device is installed outside a waste heat recovery boiler comprises: a gas turbine generator; a waste heat recovery boiler that produces steam using exhaust gas discharged from the gas turbine generator; and a steam turbine generator that generates power using steam discharged from the waste heat recovery boiler; wherein an ammonia decomposition device is disposed outside the waste heat recovery boiler, and the ammonia decomposition device thermally decomposes ammonia supplied from an ammonia tank to generate a reaction gas containing hydrogen, nitrogen, and unreacted ammonia, and the gas turbine generator generates power using hydrogen produced from the reaction gas generated from the ammonia decomposition device as fuel, and the exhaust gas discharged from the gas turbine generator is supplied to the waste heat recovery boiler and used as an energy source for the ammonia decomposition device.

[0011] In addition, the heat recovery boiler further includes an evaporator and an internal heat exchanger, and liquid ammonia supplied from the ammonia tank flows into the heat recovery boiler through a preheater and a cooler, and the liquid ammonia flowing into the heat recovery boiler is vaporized in the evaporator, and the vaporized ammonia is preheated while passing through the internal heat exchanger inside the heat recovery boiler and the external heat exchanger outside the heat recovery boiler, and then can flow into the inlet of an ammonia decomposition device arranged outside the heat recovery boiler through an ammonia supply line.

[0012] Additionally, the reaction gas discharged from the outlet of the ammonia decomposition device may be configured to pass through the external heat exchanger via an ammonia discharge line.

[0013] Additionally, the ammonia decomposition device may include a plurality of reactors connected to each other via connecting lines.

[0014] In addition, the plurality of reactors are connected in series with each other, and one ammonia connection line connecting the two reactors has one end connected to the upstream reactor and the other end connected to the downstream reactor, and a part of the section between the one end and the other end is extended so as to be disposed inside the heat recovery boiler, so as to be able to exchange heat with the heat recovery boiler.

[0015] In addition, the vaporized ammonia is preheated while passing through a heat exchanger outside the heat recovery boiler, and then flows into the first reactor of the ammonia decomposition device through an ammonia supply line. However, the ammonia supply line is configured so that a part of the line passes through the inside of the heat recovery boiler, so that heat can be absorbed from the heat recovery boiler.

[0016] In addition, the vaporized ammonia is preheated while passing through a heat exchanger outside the heat recovery boiler, and then flows into the first reactor of the ammonia decomposition device through an ammonia supply line. However, the ammonia supply line may be configured to flow directly into the first reactor without passing through the inside of the heat recovery boiler.

[0017] Additionally, the ammonia decomposition device may include at least three reactors.

[0018] Additionally, the ammonia decomposition device may include 8 to 12 reactors.

[0019] In addition, the combined power generation system includes an absorption tower and a distillation tower, and the reaction gas is cooled in the ammonia preheater and then introduced into the absorption tower, hydrogen and nitrogen are discharged from the upper portion of the absorption tower, and water and ammonia are discharged from the lower portion of the absorption tower, and the discharged hydrogen and nitrogen can be supplied to a gas turbine generator.

[0020] In addition, the gas turbine generator generates power using gas including hydrogen and nitrogen as fuel, and the high-temperature exhaust gas discharged from the gas turbine generator can be introduced into the heat recovery boiler to supply heat energy to the internal space of the heat recovery boiler.

[0021] In addition, the above-described heat recovery boiler includes a high-pressure steam generator and a low-pressure steam generator, and each steam generator includes an evaporator and a superheater, and the exhaust gas flowing into the above-described heat recovery boiler exchanges heat with the ammonia supply line and the ammonia connection line, and then, upon contact with the above-described high-pressure steam generator and the low-pressure steam generator, generates high-pressure and low-pressure steam, and the high-pressure steam and low-pressure steam generated in the above-described heat recovery boiler can be supplied to the above-described steam turbine generator through a steam supply pipe.

[0022] Meanwhile, a driving method of a combined cycle power generation system in which an ammonia decomposition device according to one embodiment of the present invention is installed outside a waste heat recovery boiler comprises: a first step of generating power using a gas turbine generator; a second step of supplying exhaust gas discharged from the gas turbine generator to the waste heat recovery boiler; a third step of generating steam using the exhaust gas in the waste heat recovery boiler; and a fourth step of generating power using the steam in a steam turbine generator; wherein the second step comprises: a step of transferring heat energy required for an ammonia decomposition reaction to the ammonia supply line and the ammonia connection line while heat-exchanging the exhaust gas with an ammonia supply line and an ammonia connection line inside the waste heat recovery boiler; a step of allowing a plurality of ammonia reactors of the ammonia decomposition device installed outside the waste heat recovery boiler to thermally decompose ammonia supplied from an ammonia tank using the heat energy to generate a reaction gas containing hydrogen, nitrogen, and unreacted ammonia; and a step of supplying the generated hydrogen and nitrogen to the gas turbine generator to generate power using the gas turbine generator.

[0023] In addition, the third step may include a step of introducing exhaust gas passing through the ammonia supply line and the ammonia connection line into a high-pressure steam generator and a low-pressure steam generator to generate high-pressure steam and low-pressure steam.

[0024] In addition, in the second step, the exhaust gas is allowed to primarily contact the ammonia supply line and the ammonia connection line inside the array recovery boiler to supply the heat energy required for the ammonia decomposition reaction to the ammonia supply line and the ammonia connection line, and in the third step, the heat energy is supplied to the ammonia supply line and the ammonia connection line in the second step, and the remaining exhaust gas is allowed to secondarily contact the high-pressure steam generator and the low-pressure steam generator to generate high-pressure and low-pressure steam.

[0025] According to one embodiment of the present invention, in addition to the existing heat source applied to the ammonia decomposition device for ammonia decomposition, the heat energy of the exhaust gas of the gas turbine generator is used as the heat source of the ammonia decomposition device, so that there is an advantage in that the total energy required to drive both the ammonia decomposition process and the turbine power generation process can be reduced.

[0026] In addition, the exhaust gas exhaust heat of the gas turbine generator is supplied to the exhaust heat recovery boiler, but is primarily used to supply heat energy for ammonia decomposition, and the remaining exhaust heat is used to generate steam turbine power, and additionally, exhaust heat is recovered from the ammonia evaporator and heat exchanger, so there is an advantage of improving the exhaust heat recovery rate of the exhaust gas.

[0027] As a result, it provides the advantage of being able to operate a single combined power generation system in which the ammonia decomposition process and the turbine power generation process are linked with low operating costs and high heat recovery rate.

[0028] FIG. 1 is a simplified schematic diagram of a combined cycle power generation system in which an ammonia decomposition device according to one embodiment of the present invention is installed outside a heat recovery steam generator (HRSG).

[0029] Figure 2 is a schematic diagram illustrating Figure 1 in more detail.

[0030] FIG. 3a is a conceptual diagram illustrating a process in which an ammonia decomposition process is performed in an array recovery boiler and an ammonia decomposition device according to one embodiment of the present invention.

[0031] Figure 3b is experimental data to explain the ammonia slip reduction efficiency in the case of the reactor configuration according to Figure 3a.

[0032] FIG. 4a is a conceptual diagram illustrating a process in which an ammonia decomposition process is performed in an array recovery boiler and an ammonia decomposition device according to another embodiment of the present invention.

[0033] Figure 4b is experimental data for explaining the ammonia slip reduction efficiency in the case of the reactor configuration according to Figure 4a.

[0034] FIG. 5 is a simplified schematic diagram of a combined cycle power generation system in which an ammonia decomposition device according to another embodiment of the present invention is installed outside a heat recovery steam generator (HRSG).

[0035] Figure 6 is a schematic diagram illustrating Figure 5 in more detail.

[0036] FIG. 7 and FIG. 8 illustrate a process flow for explaining a driving method of a combined power generation system according to one embodiment of the present invention.

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. These embodiments are provided to more fully explain the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the following embodiments. Rather, these embodiments are provided to further faithfully and completely explain the present disclosure and to fully convey the spirit of the present invention to those skilled in the art.

[0038] In addition, in the drawings below, the thickness and size of each layer are exaggerated for convenience and clarity of explanation, and like reference numerals in the drawings represent like elements. As used herein, the term "and / or" includes any one and all combinations of one or more of the listed items. Also, as used herein, the term "connected" means not only when member A and member B are directly connected, but also when member C is interposed between member A and member B, so that member A and member B are indirectly connected. The terminology used herein is used to describe specific embodiments and is not intended to limit the present invention. As used herein, the singular forms may include the plural forms unless the context clearly dictates otherwise. Also, as used herein, "comprise" and "include" and / or "comprising" and "including" specify the presence of mentioned features, numbers, steps, operations, members, elements, and / or groups thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, members, elements, and / or groups thereof.

[0039] Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers, and / or portions, it is to be understood that these elements, components, regions, layers, and / or portions are not limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another. Accordingly, a first element, component, region, layer, or portion described below may refer to a second element, component, region, layer, or portion without departing from the teachings of the present invention.

[0040] Spatial terms such as "beneath," "below," "lower," "above," and "upper" may be used to facilitate understanding of one element or feature depicted in the drawings relative to another element or feature. These spatial terms are provided to facilitate understanding of the present invention in various processing or use states and are not intended to limit the present invention. For example, if an element or feature in a drawing is flipped, an element or feature described as "beneath" or "below" becomes "above" or "above." Therefore, "beneath" is a concept encompassing "top" or "below."

[0041]

[0042] FIG. 1 is a simplified block diagram of a combined cycle power generation system in which an ammonia decomposition device is installed outside a heat recovery steam generator (HRSG) according to an embodiment of the present invention, FIG. 2 is a block diagram illustrating FIG. 1 in more detail, FIG. 3a is a block diagram conceptually illustrating a process in which an ammonia decomposition process is performed in a heat recovery boiler and an ammonia decomposition device according to an embodiment of the present invention, FIG. 4a is a block diagram conceptually illustrating a process in which an ammonia decomposition process is performed in a heat recovery boiler and an ammonia decomposition device according to another embodiment of the present invention, FIG. 5 is a simplified block diagram of a combined cycle power generation system in which an ammonia decomposition device is installed outside a heat recovery steam generator (HRSG) according to another embodiment of the present invention, FIG. 6 is a block diagram illustrating FIG. 5 in more detail, and FIGS. 7 and 8 illustrate process flows for explaining a method for driving a combined cycle power generation system according to an embodiment of the present invention. Hereinafter, with reference to these drawings, a combined cycle power generation system (1000) in which an ammonia decomposition device (1400) according to an embodiment of the present invention is installed outside a heat recovery boiler (1300) will be described.

[0043]

[0044] The combined power generation system (1000) of the present invention comprises a gas turbine generator (1100), a waste heat recovery boiler (1300) that produces steam using exhaust gas discharged from the gas turbine generator (1100), and a steam turbine generator (1200) that generates power using steam discharged from the waste heat recovery boiler (1300).

[0045]

[0046] A gas turbine generator (1100) is a facility that generates primary power by operating a gas turbine using energy generated by combusting fuel, and as illustrated in FIG. 2, includes a compressor, a combustor, a gas turbine, and a generator. The compressor of the gas turbine generator (1100) compresses air and then transmits it to the combustor, and the combustor mixes the compressed air with hydrogen and nitrogen gases and then combusts them to generate high-temperature, high-pressure combustion gas. This combustion gas flows into the gas turbine and rotates a rotor installed in the turbine. At this time, hydrogen and nitrogen of the reaction gas generated in the ammonia decomposition device (1400) are used as fuel for operating the gas turbine generator (1100). A detailed description of this will be provided later.

[0047] Meanwhile, the heat recovery boiler (1300) (HRSG) is connected to the gas turbine through an exhaust gas duct and recovers heat from the exhaust gas discharged from the gas turbine generator (1100) to produce steam. That is, the high-temperature exhaust gas discharged from the gas turbine generator (1100) flows into the heat recovery boiler (1300), and the introduced exhaust gas flows from the inlet to the outlet of the heat recovery boiler (1300) to produce steam.

[0048] The heat recovery boiler (1300) may include a high-pressure steam generator and a low-pressure steam generator, and generates high-pressure and low-pressure steam by sequentially contacting the high-pressure steam generator and the low-pressure steam generator. Each steam generator includes a superheater and an evaporator, and the exhaust gas flowing into the heat recovery boiler (1300) exchanges heat with an ammonia supply line (1410) and an ammonia connection line (1420), and then the residual heat of the exhaust gas sequentially passes through a superheater (not shown) and an evaporator (not shown) of the high-pressure steam generator to generate high-pressure steam, and then sequentially passes through a superheater and an evaporator of the low-pressure steam generator to generate low-pressure steam.

[0049] The low-pressure steam generator has a low-pressure drum (not shown) near the outer wall of the waste heat recovery boiler (1300), and has a superheater (not shown) and an evaporator (not shown) inside the waste heat recovery boiler (1300). Water is supplied to the low-pressure steam generator from a second economizer (not shown). The water supplied from the second economizer flows into the evaporator through the low-pressure drum, and is heated by exhaust gas inside the evaporator to generate saturated steam. The superheater introduces the steam, superheats the steam by the exhaust gas, and discharges the superheated steam. Meanwhile, a portion of the water supplied from the second economizer is supplied to the first economizer (not shown). The high-pressure steam generator has a high-pressure drum (not shown) near the outer wall of the waste heat recovery boiler (1300), and has a superheater and an evaporator inside the waste heat recovery boiler (1300). Water supplied from the first economizer enters the evaporator through a high-pressure drum, where it is heated by exhaust gas within the evaporator, generating saturated steam. The superheater introduces this steam, superheats the steam through the exhaust gas, and discharges the superheated steam. The high-pressure and low-pressure steam generated in each steam generator are supplied to the steam turbine generator (1200) through a steam supply pipe.

[0050] Meanwhile, the steam turbine generator (1200) is connected to the exhaust heat recovery boiler (1300) and generates secondary power using steam discharged from the exhaust heat recovery boiler (1300). The steam generated in the exhaust heat recovery boiler (1300) is transferred to the steam turbine through a steam supply pipe, and the steam turbine uses the steam to rotate blades and transfer rotational energy to the generator. The steam turbine is connected to a condenser, and the condenser condenses the steam discharged from the steam turbine.

[0051]

[0052] Meanwhile, the heat recovery boiler (1300) of the present invention may include an evaporator (1330) (Ammonia Evaporator) and an internal heat exchanger (1320) (Cracked Gas Exchanger, Ammonia Exchanger) inside the boiler body. Low-temperature liquid ammonia stored in the ammonia tank (110) is transferred through a pump and introduced into an ammonia pre-heater (Liquid Ammonia Pre-Heater; 200), and in the pre-heater (200), the liquid ammonia is heated without a phase change. The heated ammonia is supplied to the heat recovery boiler (1300) (HRSG). Liquid ammonia is vaporized in an evaporator (1330) (Fig. 2) inside a heat recovery boiler (1300), and the vaporized ammonia is preheated while passing through an internal heat exchanger (1320) (Fig. 2), and then flows into an external heat exchanger (1340) installed outside the HRSG and is preheated to the input temperature of the ammonia decomposition device (1400). The preheated ammonia flows into the ammonia decomposition device (1400). At this time, the evaporator may be referred to as an ammonia evaporator, the internal heat exchanger may be referred to as an ammonia heat exchanger, and the external heat exchanger may be referred to as a reaction gas heat recovery heat exchanger.

[0053] Meanwhile, the ammonia decomposition device (1400) is placed outside the waste heat recovery boiler (1300). The ammonia decomposition device (1400) thermally decomposes ammonia supplied to the reaction device from the ammonia tank (110) using a catalyst including a metal such as ruthenium, thereby generating a reaction gas containing hydrogen, nitrogen, and unreacted ammonia. The generated reaction gas is discharged to the outside of the ammonia decomposition device (1400). At this time, thermal energy needs to be supplied to the ammonia decomposition device (1400) for the catalytic thermal decomposition reaction of the reactor, and in the present invention, the exhaust gas discharged from the gas turbine generator (1100) is supplied to the waste heat recovery boiler (1300) and used as an energy source for the ammonia decomposition device (1400).

[0054] More specifically, referring to FIG. 1, high-temperature exhaust gas discharged from a gas turbine generator (1100) flows into a waste heat recovery boiler (1300) and flows from the inlet to the outlet of the waste heat recovery boiler (1300). As the high-temperature exhaust gas of the gas turbine flows into the waste heat recovery boiler (1300), the waste heat recovery boiler (1300) forms a high-temperature environment, and the heat energy is used as an energy source for the ammonia decomposition device (1400). Thereafter, as the residual heat flows to the outlet, it sequentially contacts the high-pressure steam generator and the low-pressure steam generator.

[0055] The ammonia decomposition device (1400) is a device that decomposes ammonia to generate a reaction gas. As described above, the ammonia decomposition device (1400) is placed outside the exhaust heat recovery boiler (1300). Ammonia passing through the exhaust heat recovery boiler (1300) is supplied to the ammonia decomposition device (1400) outside the exhaust heat recovery boiler (1300) through an ammonia transfer line. According to the present invention, a part of the ammonia transfer line (including an ammonia connection line (1420), preferably an ammonia supply line (1410)) is configured to pass through the inside of the exhaust heat recovery boiler (1300), thereby allowing heat energy inside the exhaust heat recovery boiler (1300) due to the inflow of high-temperature exhaust gas discharged from the gas turbine generator (1100) to be transferred to the ammonia decomposition device (1400) through the transfer line.

[0056] Specifically, liquid ammonia passes through an evaporator (1330) and an internal heat exchanger (1320) inside an array recovery boiler (1300), and then is preheated while passing through an external heat exchanger (1340), and then is introduced into the inlet of an ammonia decomposition device (1400) through an ammonia supply line (1410). Meanwhile, the introduced ammonia is thermally decomposed while passing through the ammonia decomposition device (1400) to generate a reaction gas, and the reaction gas is discharged to the outlet of the ammonia decomposition device (1400) and then passes through the ammonia discharge line (1430) to the aforementioned external heat exchanger (1340).

[0057] At this time, the ammonia decomposition device (1400) is configured to include a plurality of reactors that are connected to each other via an ammonia connection line (1420). The plurality of reactors can be arranged in series with each other, and two adjacent reactors are connected to each other so as to be communicatively connected via an ammonia connection line (1420).

[0058] The ammonia decomposition device (1400) is composed of the first to Nth reactors, and FIG. 2 illustrates a configuration composed of five reactors (1411, 1412, 1413, 1414, 1415) of the first reactor (1411) to the fifth reactor (1415), as an example. The first reactor (1411) is connected to an external heat exchanger (1340) via an ammonia supply line (1410), the first reactor (1411) and the second reactor (1412) are connected to each other via one ammonia connection line (1420), and the second and third reactors, the third and fourth reactors, and the fourth and fifth reactors are also each connected to each other via one ammonia connection line (1420). And, the fifth reactor is connected to the external heat exchanger (1340) again by the ammonia discharge line (1430). However, the number of reactors is not limited, and preferably, the ammonia decomposition device (1400) may include 8 to 12 reactors from the viewpoint of securing ammonia slip and conversion rate. Specifically, ammonia slippage refers to the discharge of unreacted ammonia resulting from the incomplete decomposition reaction of ammonia when ammonia at high temperature and high pressure passes through the catalyst bed and undergoes a decomposition reaction. Ammonia slip causes corrosion of components or the discharge of undesirable particulate matter into the atmosphere. In particular, the more ammonia slip, the more energy is required for the process for separating ammonia, so it is necessary to reduce ammonia slip in terms of power generation efficiency and the efficiency of the separation process. Referring to FIG. 3b, it can be confirmed that the ammonia (NH3) slip is reduced to approximately 12% after passing through at least the 8th reactor (1418), and the conversion rate (CON[%]) at this time is 77.9%. In this regard, in order to secure a conversion rate of approximately 75% or higher, the reactor may be configured to include at least 8 reactors, preferably 8 to 12 reactors.

[0059] As described above, liquid ammonia passes through the external heat exchanger (1340) of the heat recovery boiler (1300) and then flows into the inlet of the ammonia decomposition device (1400), i.e., the first reactor (1411), through the ammonia supply line (1410). Each reactor is filled with a catalyst such as ruthenium, and a thermal decomposition reaction using the catalyst occurs, generating a reaction gas containing hydrogen, nitrogen, and unreacted ammonia as a result. The generated reaction gas flows into the second reactor, and generates a reaction gas through the same catalytic thermal decomposition reaction. This process continues up to the Nth reactor, and the reaction gas discharged from the Nth reactor is discharged to the outside of the ammonia decomposition device (1400). Then, it passes through the external heat exchanger (1340) through the ammonia discharge line (1430). Each reactor needs to be controlled to a reaction temperature for the catalytic thermal decomposition reaction. In the present invention, exhaust gas discharged from a gas turbine generator (1100) is supplied to a waste heat recovery boiler (1300) to provide a heat source to the waste heat recovery boiler, and this heat source is used as an energy source for controlling the reaction temperature of an ammonia decomposition device (1400). As described above, the ammonia decomposition device (1400) is arranged outside the waste heat recovery boiler (1300), and thus, in order to receive heat from the waste heat recovery boiler (1300), a part of an ammonia transfer line (including an ammonia connection line (1420), preferably an ammonia supply line (1410)) is configured so that its path passes through the inside of the waste heat recovery boiler (1300).

[0060] More specifically, referring to FIG. 3a, ammonia vaporized inside the heat recovery boiler (1300) passes through an external heat exchanger (1340) and then flows into the first reactor (1411) through an ammonia supply line (1410). At this time, a part of the ammonia supply line (1410) is configured to pass through the inside of the heat recovery boiler (1300). Accordingly, the ammonia supply line (1410) absorbs heat from the heat recovery boiler (1300) (endothermic reaction), and can be adjusted to a reaction temperature required for the thermal decomposition reaction of the first reactor (1411).

[0061] Meanwhile, the reaction gas generated in the first reactor (1411) flows into the second reactor (1412) through the ammonia connection line (1420). One end of the ammonia connection line (1420) is connected to the upstream reactor, i.e., the first reactor (1411), and the other end is connected to the downstream reactor, i.e., the second reactor (1412). At this time, a part of the section between one end and the other end of the ammonia connection line (1420) is extended so as to be placed inside the heat recovery boiler (1300). Accordingly, the ammonia connection line (1420) absorbs heat (endothermic reaction) from the heat recovery boiler (1300), so that the reaction temperature can be adjusted to the temperature required for the thermal decomposition reaction of the second reactor (1412). In addition, the reaction gas generated in the second reactor (1412) is introduced into the third reactor (1413) through the ammonia connection line (1420), and a part of the ammonia connection line (1420) is configured to pass through the heat recovery boiler (1300), thereby supplying the heat energy required for the thermal decomposition reaction of the third reactor (1413). Similarly, in the third to fifth reactors, a part of the ammonia connection line (1420) is configured to pass through the heat recovery boiler (1300), thereby transmitting the heat energy required for the downstream reactor. Since the ammonia decomposition reaction is an endothermic reaction, the unreacted gas among the reaction gases output from each reactor decreases in temperature, is re-introduced into the heat recovery boiler, is preheated to the reaction temperature, and is then re-introduced into the reactor to perform the decomposition reaction, thereby repeating a continuous process.

[0062] The exhaust gas of the turbine generator (1100) is introduced into the heat recovery boiler (1300) at a high temperature (over 500°C) to transfer heat energy. By configuring a part of the ammonia supply line (1410) and the ammonia connection line (1420) to be exposed inside the heat recovery boiler (1300), heat exchange with the aforementioned heat energy, i.e., heat absorption, is achieved, thereby preheating to the reaction temperature of the reactor so that the thermal decomposition reaction by the catalyst can be promoted in each reactor.

[0063] According to one embodiment of the present invention, a ruthenium catalyst (Ru) is used as the catalyst charged into the reactor. While commonly used nickel catalysts require an operating temperature of 600°C or higher, ruthenium catalysts can produce hydrogen at a lower operating temperature of 500°C or higher. Therefore, in one embodiment of the present invention, by using a ruthenium catalyst, thermal decomposition can be easily achieved through the exhaust gas flowing into the boiler.

[0064] Meanwhile, the ammonia decomposition device (1400) according to the present invention has multiple reactors arranged outside the exhaust heat recovery boiler (1300), and each reactor individually receives heat energy from the exhaust heat recovery boiler (1300) through an ammonia connection line (1420) to perform a catalytic thermal decomposition reaction. By applying multiple reactors, the ammonia decomposition reaction can be divided into the number of reactors and performed in stages.

[0065] More specifically, by arranging a plurality of reactors in series outside the exhaust heat recovery boiler (1300), the catalytic thermal decomposition reaction can be performed in stages. At this time, since the reactors exist individually, the catalyst loading amount can be independently set for each reactor. In addition, since a plurality of ammonia connection lines (1420) for introducing ammonia into each reactor are provided, and each ammonia connection line (1420) is configured to pass through the exhaust heat recovery boiler (1300), the heat energy required for the catalytic thermal decomposition reaction of the reactor can be controlled to be absorbed according to the reaction temperature of the reactor. The ammonia thermal decomposition reaction within the reactor is affected by the loading amount of the catalyst within the reactor and the reaction temperature. By setting the catalyst loading amount appropriate for the level of heat energy that can be absorbed from the exhaust heat recovery boiler (1300) for each reactor, the optimal catalyst amount with good catalytic efficiency can be calculated and applied. Accordingly, the catalytic efficiency can be increased.

[0066] Additionally, electric heaters can be installed between each reactor to further control the reaction temperature of the reactors. For example, electric heaters can be installed upstream of the first reactor (1411) and upstream of the Nth reactor. This provides additional thermal energy to the first reactor and the Nth reactor, thereby increasing the reaction efficiency and, accordingly, the operability and conversion rate of the ammonia decomposition device.

[0067] According to the present invention, a part of the ammonia transfer line is arranged to pass through the inside of the exhaust gas recovery boiler (1300), so that the heat source by the exhaust gas can be provided to the ammonia decomposition device (1400). According to this configuration, the heat energy of the exhaust gas is recovered and used as ammonia decomposition heat, so there is no need to provide a separate heat source to provide the heat energy required for thermal decomposition, and there is no need to additionally arrange a separate line to transfer the heat energy from the exhaust gas recovery boiler (1300) to the ammonia decomposition device (1400). Therefore, not only can the energy recovery rate be increased, but there is also an advantage in that the structure can be designed in a simplified manner.

[0068] Figure 3b is experimental data illustrating the ammonia slip reduction efficiency for the reactor configuration according to Figure 3a. Referring to this, the ammonia decomposition device is configured to include a total of ten reactors, from reactors 1 to 10. From these experimental data, it can be confirmed that when the ammonia decomposition device is configured with ten reactors, a slip ratio of 2.0% can be achieved at a catalyst amount of 17,300 kg.

[0069]

[0070] Meanwhile, referring to FIG. 4a, ammonia vaporized inside the heat recovery boiler (1300) passes through an external heat exchanger (1340) and then flows into the first reactor through an ammonia supply line (1410). At this time, it is also possible to additionally place a zero reactor (1401) in front of the first reactor (1411) and configure it so that ammonia flows directly from the ammonia supply line (1410) into the zero reactor (1401). At this time, the ammonia supply line (1410) is directly connected to the zero reactor (1401) without passing through the inside of the heat recovery boiler (1300).

[0071] As described above, the reaction gas generated in the ammonia decomposition device (1400) is discharged through the ammonia discharge line (1430) from the outlet of the ammonia decomposition device (1400), i.e., the outlet of the Nth reactor, and at this time, the reaction gas is configured to pass through an external heat exchanger (1340). The external heat exchanger (1340) is referred to as a reaction gas heat recovery heat exchanger. Accordingly, a portion of the heat energy of the reaction gas generated while passing through the Nth reactor can be recovered in the external heat exchanger (1340), and the temperature of the gaseous ammonia passing through the external heat exchanger (1340) increases through heat exchange with the recovered heat energy. Through this, the reaction temperature of the 0th reactor (1401) can be controlled. Accordingly, in the case of the present embodiment, since the ammonia supply line (1410) does not pass through the inside of the heat recovery boiler (1300), it cannot absorb heat from the heat recovery boiler (1300), but it can absorb heat of the reaction gas through the external heat exchanger (1340), thereby supplying the heat energy required for the thermal decomposition reaction of the 0th reactor (1401).

[0072] Figure 4b is experimental data illustrating the ammonia slip reduction efficiency for the reactor configuration according to Figure 4a. Referring to this, the ammonia decomposition device is configured to include a total of 11 reactors, with a 0th reactor added to the 1st to 10th reactors. From these experimental data, it can be confirmed that when the ammonia decomposition device is configured with 11 reactors, a slip rate of 1.58% can be achieved.

[0073]

[0074] Meanwhile, in the embodiment illustrated in FIGS. 1 and 2, the reaction gas discharged through the ammonia discharge line (1430) may be configured to sequentially pass through an additional external heat exchanger (150) and a preheater (200) after passing through an external heat exchanger (1340). The reaction gas passing through the preheater (200) is fed into an absorption tower (400). In the absorption tower (400), unreacted ammonia is recovered, and hydrogen and nitrogen, excluding unreacted ammonia, come out of the absorption tower (400), pass through the external heat exchanger (150) again, and are fed into a gas turbine generator (1100). At this time, a portion of the hydrogen and nitrogen in the path fed into the gas turbine generator (1100) is branched off and fed into a waste heat recovery boiler (1300).

[0075]

[0076] Meanwhile, the combined power generation system (1000) according to the present invention includes an absorption tower (400) and a distillation tower (500). The reaction gas generated in the ammonia decomposition device (1400) is discharged to the outside of the ammonia decomposition device (1400), and the reaction gas generated in the ammonia decomposition device (1400) contains hydrogen and nitrogen, which are the main reactants, and ammonia, which is the unreacted product. The discharged reaction gas is cooled in an ammonia preheater (200) to separate the unreacted products, and then fed into the ammonia absorption tower (400).

[0077] In the absorption tower (400), unreacted ammonia remaining in the reaction gas is separated and absorbed, and accordingly, gas including hydrogen and nitrogen is discharged from the top of the absorption tower (400), and separated and absorbed ammonia is discharged together with water from the bottom of the absorption tower (400). The mixture of water and ammonia discharged from the absorption tower (400) is cooled in the heat exchanger (330) and then fed into the distillation tower (500). Heat is supplied to the distillation tower (500) through a distillation tower reheater, and as the mixture passes through the distillation tower (500), ammonia is discharged and recovered from the top of the distillation tower (500), and water is recovered from the bottom of the distillation tower (500). For reference, the water recovered from the bottom can be cooled in the heat exchanger (330) and then fed back into the ammonia absorption tower (400), and can undergo a process of being separated into water and ammonia while circulating through the absorption tower (400) and the distillation tower (500). Meanwhile, the gas containing hydrogen and nitrogen discharged from the top of the absorption tower (400) can be reheated while passing through the heat exchanger (150) and then supplied to the gas turbine generator (1100).

[0078] Here, as described above, the reaction gas generated while passing through the ammonia decomposition device (1400) is configured to be cooled in the ammonia preheater (200) and then fed into the absorption tower (400). Water is fed into the top of the absorption tower (400), and ammonia in the reaction gas is absorbed by the water and discharged to the bottom of the absorption tower (400). By lowering the temperature of the reaction gas, the separation performance within the absorption tower (400) can be improved. In addition, the mixture of water and ammonia discharged to the bottom of the absorption tower (400) is fed into the distillation tower (500), and as described above, ammonia is discharged and recovered from the top of the distillation tower (500), and water is recovered to the bottom of the distillation tower (500). At this time, the water recovered to the bottom is configured to be cooled in the heat exchanger (330) of FIG. 2 and then fed back into the absorption tower (400). Since the cooled water is sprayed downward inside the absorption tower (400), the temperature of the reaction gas is lowered, and thus, the water and ammonia separation performance of the absorption tower (400) can be improved. Furthermore, according to the present invention, since the reaction gas is introduced into the absorption tower (400) at a high pressure, the absorption tower (400) and the distillation tower (500) can be operated at a high pressure equal to or lower than that of the reaction gas, and thus, the ammonia separation performance in the absorption tower (400) can be improved, and high-purity ammonia separation in the distillation tower (500) becomes easy.

[0079] In the ammonia decomposition device (1400), a catalyst is placed in the region through which ammonia passes. As described above, the system of the present invention can apply a catalyst having a low operating temperature, for example, a ruthenium catalyst. Since such a catalyst has a higher ammonia decomposition efficiency than existing general catalysts (for example, a nickel catalyst), the ammonia decomposition device (1400) can be operated even under high-pressure conditions that are unfavorable to the ammonia decomposition reaction. Therefore, the ammonia decomposition device (1400) is operated at high pressure, and the reaction gas is introduced into the absorption tower (400) at high pressure. Since the absorption tower (400) and the distillation tower (500) are operated at high pressure, the volume of the reaction gas present in the absorption tower (400) and the distillation tower (500) is small, so there is an advantage in that the equipment size of the absorption tower (400) and the distillation tower (500) can be reduced. In general, when operating by injecting high-pressure reaction gas into the reaction device (1310), it is disadvantageous in terms of ammonia decomposition reaction efficiency, but in the present invention, by applying a ruthenium catalyst with better activity than a nickel catalyst to the ammonia decomposition reaction, the decomposition reactivity can be maintained well.

[0080] Meanwhile, the gas turbine generator (1100) generates power using gas containing hydrogen and nitrogen as fuel, and the high-temperature exhaust gas discharged from the gas turbine generator (1100) flows into the waste heat recovery boiler (1300) and supplies heat energy to the internal space of the waste heat recovery boiler (1300). Accordingly, the heat energy required for the ammonia decomposition reaction is supplied to the ammonia decomposition device (1400) while exchanging heat with the ammonia transfer line passing through the interior of the waste heat recovery boiler (1300).

[0081] In other words, the exhaust heat of the exhaust gas discharged from the gas turbine generator (1100) is used as heat energy required for ammonia decomposition. The gas turbine of the gas turbine generator (1100) provides the exhaust gas to the heat recovery boiler (1300) (HRSG) through the exhaust gas duct, and the heat recovery boiler (1300) is subjected to high temperature conditions. In addition, the ammonia transfer line is configured to pass through the inside of the heat recovery boiler (1300) (HRSG), so that heat exchange between the ammonia and the exhaust gas can be achieved by contacting the high-temperature exhaust gas supplied to the heat recovery boiler (1300), and the heat energy can be transferred to the reactor of the ammonia decomposition device (1400), thereby controlling the reaction temperature of the reactor. For reference, in order to secure the conversion rate of the ammonia decomposition reaction, the reaction temperature can also be controlled through a duct burner inside the heat recovery boiler (1300). In addition, the reaction temperature can be controlled by installing an electric heater between the reactors.

[0082]

[0083] According to the combined power generation facility of the present invention configured as described above, a gas turbine generator (1100) generates electricity by using hydrogen produced from a reaction gas generated in an ammonia decomposition device (1400) as fuel, and exhaust gas discharged from the gas turbine generator (1100) is supplied to a waste heat recovery boiler (1300), and is used as a heat source for ammonia decomposition in the ammonia decomposition device (1400) by heat exchange with an ammonia transfer line configured to pass through the inside of the waste heat recovery boiler (1300). In addition, the residual heat of the exhaust gas generates steam while passing through a high-pressure steam generator and a low-pressure steam generator inside the waste heat recovery boiler (1300), and the generated steam is introduced into a steam turbine generator (1200), and the steam turbine operates using the steam to generate electricity.

[0084]

[0085] Meanwhile, FIGS. 5 and 6 illustrate a combined cycle power generation system in which an ammonia decomposition device according to another embodiment of the present invention is installed outside a heat recovery steam generator (HRSG). The embodiment illustrated in FIGS. 5 and 6 differs from the embodiment illustrated in FIGS. 1 and 2 in that an additional external heat exchanger (150) is not provided. The reaction gas discharged through the ammonia discharge line (1430) passes through the external heat exchanger (1340) and is then fed into a preheater (200), and no additional external heat exchanger (150) is provided. The reaction gas passing through the preheater (200) is fed into an absorption tower (400), and unreacted ammonia is filtered out while the reaction gas passes through the absorption tower (400) and the distillation tower (500), and the gas containing hydrogen and nitrogen, excluding this, is fed into a gas turbine generator (1100).

[0086]

[0087] Meanwhile, Fig. 7 illustrates a process flow for explaining a driving method of a combined power generation system (1000) according to one embodiment of the present invention. Hereinafter, a driving method of a combined power generation system (1000) in which an ammonia decomposition device (1400) according to the present invention is installed outside a heat recovery boiler (1300) will be described.

[0088] A driving method of a combined power generation system (1000) according to the present invention includes a first step (S1) of generating power using a gas turbine generator (1100), a second step (S2) of supplying exhaust gas discharged from the gas turbine generator (1100) to a waste heat recovery boiler (1300), a third step (S3) of generating steam using the exhaust gas in the waste heat recovery boiler (1300), and a fourth step (S4) of generating power using the steam in a steam turbine generator (1200).

[0089] Stage 1 (S1) is the stage where the gas turbine generator (1100) generates the first electric power. In this stage, the gas containing hydrogen and nitrogen, as described above, is supplied as fuel to the gas turbine generator (1100). The supplied gas is mixed with compressed air in a combustor, combusted, and then fed into the gas turbine. The high-pressure combustion gas from the combusted gas is supplied to the turbine, rotating the rotor to generate electric power.

[0090] Next, the second step (S2) is a step of supplying exhaust gas discharged from a gas turbine generator (1100) to a heat recovery boiler (1300), and in this step, a portion of the heat of the exhaust gas is recovered and used for ammonia decomposition.

[0091] Specifically, the second step (S2) includes a step (S21) of supplying heat energy required for an ammonia decomposition reaction to an ammonia decomposition device (1400) through the ammonia supply line (1410) and the ammonia connection line (1420) by exchanging heat with the exhaust gas with the ammonia supply line (1410) and the ammonia connection line (1420) inside the exhaust heat recovery boiler (1300), a step (S22) of allowing multiple ammonia reactors of an ammonia decomposition device (1400) arranged outside the exhaust heat recovery boiler (1300) to thermally decompose ammonia supplied from an ammonia tank (110) using the thermal energy to generate a reaction gas containing hydrogen, nitrogen, and unreacted ammonia, and a step (S23) of supplying the generated hydrogen and nitrogen to a gas turbine generator (1100) to generate power using the gas turbine generator (1100).

[0092] The gas turbine of the gas turbine generator (1100) is connected to the heat recovery boiler (1300) (HRSG) through an exhaust gas duct, and an ammonia transfer line is installed inside the heat recovery boiler (1300) (HRSG).

[0093] Accordingly, the process of supplying exhaust gas to the ammonia decomposition device (1400) in step S21 means a process in which high-temperature exhaust gas supplied to the exhaust gas recovery boiler (1300) through the exhaust gas duct comes into primary contact with the ammonia transfer line, thereby heat exchange occurs between the ammonia in the ammonia transfer line and the exhaust gas in the exhaust gas recovery boiler (1300), thereby supplying the heat energy required for the ammonia decomposition reaction to the ammonia decomposition device (1400) through the ammonia transfer line. In addition, step S22 means a process in which the heat energy of the exhaust gas is used as a heat source to decompose ammonia and generate a reaction gas.

[0094] And, in step S23, the gas containing hydrogen and nitrogen among the reaction gases is supplied to the gas turbine generator (1100). For this purpose, the reaction gas discharged outside the ammonia decomposition device (1400) in step S22 passes through the absorption tower (400) and the distillation tower (500), and unreacted ammonia is filtered out, and the gas containing hydrogen and nitrogen excluding this is introduced into the gas turbine. The removal of ammonia through the absorption tower (400) and the distillation tower (500) is the same as described above, so a duplicate description is omitted.

[0095] As a result of performing the second stage (S2), the exhaust gas array is recovered and used for ammonia decomposition, and hydrogen and nitrogen among the generated reaction gases are combusted in a combustor to drive a gas turbine, resulting in the production of first power.

[0096] Next, the third step (S3) is a steam generation process, in which the exhaust gas passing through the ammonia supply line (1410) and the ammonia connection line (1420) is introduced into the high-pressure steam generator and the low-pressure steam generator, thereby generating high-pressure steam and low-pressure steam. The third step is a process in which the heat energy required for the ammonia decomposition reaction is supplied to the ammonia supply line (1410) and the ammonia connection line (1420) by first contacting the ammonia supply line (1410) and the ammonia connection line (1420) inside the heat recovery boiler (1300) in the second step, and the remaining exhaust gas is secondarily contacted with the high-pressure steam generator and the low-pressure steam generator, thereby generating high-pressure and low-pressure steam.

[0097] As a result of performing the third step (S3), the remaining heat energy, excluding the heat used for ammonia decomposition in the high-temperature exhaust gas, passes through the steam generator of the HRSG to generate steam and operate the aforementioned steam turbine, resulting in the production of secondary power.

[0098]

[0099] According to one embodiment of the present invention, an ammonia decomposition device (1400) is configured as an adiabatic reactor type outside an array recovery boiler (1300), and is configured to include 8 to 11 reactors depending on the embodiment.

[0100] This configuration offers the advantage of improved stability, as the catalyst-filled reactor is installed outside the array recovery boiler (1300). In contrast, the standalone case operates in a high-temperature environment by filling the catalyst in 192 tubes inside the heater, posing a risk of catalyst damage and material deformation.

[0101] Additionally, when the ammonia decomposition device (1400) is installed outside the HRSG, it is easy to add catalyst or replace the reactor, and it has the advantage of being able to flexibly respond to catalyst performance in unexpected situations. In contrast, the standalone case has the problem that it is not easy to flexibly respond or improve because the reactor tube filled with the catalyst is installed inside the heater.

[0102] Furthermore, since ammonia decomposition is an endothermic reaction, configuring the reactors in series outside the HRSG can maximize heat recovery efficiency and conversion rate. In particular, multi-stage reactors allow for optimized catalyst loading up to the conversion inflection point, minimizing catalyst usage.

[0103] Meanwhile, by placing an electric heater at the first reactor front end or the last reactor front end, there is an advantage in that the ease of operation and conversion rate can be additionally secured.

[0104]

[0105] The above description is only one embodiment for implementing a combined power generation system in which an ammonia decomposition device according to the present invention is installed outside a heat recovery boiler, and the present invention is not limited to the above-described embodiment, and it will be understood that the technical spirit of the present invention encompasses a range in which various modifications can be implemented by anyone having ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention as claimed in the following claims.

[0106] Description of the symbol

[0107] 1000: Combined Cycle Power System

[0108] 1100: Gas turbine generator

[0109] 1300: Array recovery boiler

[0110] 1330: Evaporator

[0111] 1320: Internal heat exchanger

[0112] 1200: Steam turbine generator

[0113] 1400: Ammonia decomposition unit

[0114] 110: Ammonia tank

[0115] 200: Preheater

[0116] 110: Ammonia tank

[0117] 1340: External heat exchanger

[0118] 400: Absorption tower

[0119] 500: Distillation tower

[0120] 1410: Ammonia supply line

[0121] 1420: Ammonia connection line

[0122] 1430: Ammonia discharge line

[0123] 1411, 1132, 1413, 1414, 1415: Reactors

Claims

1. Gas turbine generator; A heat recovery boiler that produces steam using exhaust gas discharged from a gas turbine generator; and A steam turbine generator that generates electricity using steam discharged from an array recovery boiler; Including, An ammonia decomposition device is placed outside the above array recovery boiler, The above ammonia decomposition device thermally decomposes ammonia supplied from an ammonia tank to produce a reaction gas containing hydrogen, nitrogen, and unreacted ammonia. The above gas turbine generator generates power using hydrogen produced from the reaction gas generated in the ammonia decomposition device as fuel, The exhaust gas discharged from the gas turbine generator is supplied to the heat recovery boiler and is used as an energy source for the ammonia decomposition device. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

2. In paragraph 1, The above array recovery boiler further includes an evaporator, Liquid ammonia supplied from the ammonia tank is introduced into the heat recovery boiler through a preheater and a cooler, and the liquid ammonia introduced into the heat recovery boiler is vaporized in the evaporator, and the vaporized ammonia is preheated while passing through an external heat exchanger outside the heat recovery boiler, and then is introduced into the inlet of an ammonia decomposition device placed outside the heat recovery boiler through an ammonia supply line. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

3. In paragraph 2, The reaction gas discharged from the outlet of the above ammonia decomposition device is configured to pass through the external heat exchanger via the ammonia discharge line. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

4. In paragraph 3, The ammonia decomposition device comprises a plurality of reactors connected to each other through a connecting line. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

5. In paragraph 4, The above multiple reactors are connected in series with each other, One ammonia connecting line connecting the two reactors is connected at one end to the upstream reactor and at the other end to the downstream reactor, and a portion of the line between the one end and the other end is extended so as to be disposed inside the heat recovery boiler, thereby exchanging heat with the heat recovery boiler. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

6. In paragraph 5, The above vaporized ammonia is preheated while passing through a heat exchanger outside the heat recovery boiler, and then flows into the first reactor of the ammonia decomposition device through an ammonia supply line. The above ammonia supply line is configured so that a part of the line passes through the inside of the heat recovery boiler, thereby absorbing heat from the heat recovery boiler. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

7. In paragraph 5, The above vaporized ammonia is preheated while passing through a heat exchanger outside the heat recovery boiler, and then flows into the first reactor of the ammonia decomposition device through an ammonia supply line. The above ammonia supply line is configured to flow directly into the first reactor without passing through the inside of the array recovery boiler. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

8. In paragraph 4, The above ammonia decomposition device comprises at least three reactors, A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

9. In paragraph 4, The above ammonia decomposition device comprises 8 to 11 reactors, A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

10. In paragraph 1, The above combined power generation system includes an absorption tower and a distillation tower, The above reaction gas is cooled in the ammonia preheater and then flows into the absorption tower. Hydrogen and nitrogen are discharged from the top of the absorption tower, and water and ammonia are discharged from the bottom of the absorption tower, and the discharged hydrogen and nitrogen are supplied to a gas turbine generator. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

11. In paragraph 1, The above gas turbine generator generates power using gas containing hydrogen and nitrogen as fuel, The high temperature exhaust gas discharged from the gas turbine generator is introduced into the heat recovery boiler and supplies heat energy to the space inside the heat recovery boiler. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

12. In paragraph 6, The above array recovery boiler includes a high-pressure steam generator and a low-pressure steam generator, and each steam generator includes an evaporator and a superheater. The exhaust gas flowing into the above-mentioned array recovery boiler exchanges heat with the ammonia supply line and the ammonia connection line, and then generates high-pressure and low-pressure steam by contacting the high-pressure steam generator and the low-pressure steam generator. High-pressure steam and low-pressure steam generated in the array recovery boiler are supplied to the steam turbine generator through a steam supply pipe. A combined cycle power generation system in which the ammonia decomposition unit is installed outside the array recovery boiler.

13. A driving method of a combined power generation system in which an ammonia decomposition device according to paragraph 1 is installed outside the array recovery boiler, The first stage of generating gas turbine generators; A second stage of supplying exhaust gas discharged from a gas turbine generator to a heat recovery boiler; A third step of generating steam using the exhaust gas from the above array recovery boiler; and A fourth stage of generating power using the steam in a steam turbine generator; Including, The second step above is, A step of transferring heat energy required for ammonia decomposition reaction to the ammonia supply line and the ammonia connection line while exchanging heat with the exhaust gas and the ammonia supply line and the ammonia connection line inside the array recovery boiler; A step in which a plurality of ammonia reactors of an ammonia decomposition device arranged externally of the above-mentioned array recovery boiler thermally decompose ammonia supplied from an ammonia tank using the thermal energy to generate a reaction gas containing hydrogen, nitrogen, and unreacted ammonia; and A step of supplying the generated hydrogen and nitrogen to a gas turbine generator to generate power through the gas turbine generator; characterized by including, Method of driving a combined cycle power generation system.

14. In paragraph 13, The third step above is, A step of generating high-pressure steam and low-pressure steam by introducing exhaust gas passing through the ammonia supply line and the ammonia connection line into a high-pressure steam generator and a low-pressure steam generator; characterized by including, Method of driving a combined cycle power generation system.

15. In paragraph 14, In the second step, the exhaust gas is brought into primary contact with the ammonia supply line and the ammonia connection line inside the array recovery boiler to supply the heat energy required for the ammonia decomposition reaction to the ammonia supply line and the ammonia connection line, The third step is to supply heat energy to the ammonia supply line and the ammonia connection line in the second step and to allow the remaining exhaust gas to come into secondary contact with the high-pressure steam generator and the low-pressure steam generator to generate high-pressure and low-pressure steam. Method of driving a combined cycle power generation system.

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