KR-20260067162-A - Combined carbon-free power generation system and its control method

Abstract

The present invention relates to a carbon-free combined cycle power generation system comprising: an ammonia storage tank; an ammonia decomposition device that decomposes ammonia supplied from the ammonia storage tank into hydrogen and nitrogen; a gas turbine power generation unit that receives ammonia from the ammonia storage tank and hydrogen supplied from the ammonia decomposition device for combustion; an exhaust gas utilization unit that produces steam using the exhaust gas of the gas turbine power generation unit; and a control device that controls the supply of ammonia and hydrogen to the gas turbine power generation unit, wherein the control device controls the supply of ammonia and hydrogen in conjunction with load fluctuations of the gas turbine power generation unit. According to the present invention, carbon-free fuel is utilized in the gas turbine combined cycle power generation, and can be linked according to gas turbine load fluctuations.

Inventors

• 김규일
• 이욱륜

Assignees

• 한국전력공사

Dates

Publication Date

20260512

Application Date

20241105

Claims (20)

1. Ammonia storage tank; An ammonia decomposition device that decomposes ammonia supplied from the above ammonia storage tank into hydrogen and nitrogen; A gas turbine power generation unit that receives ammonia from the ammonia storage tank and receives hydrogen from the ammonia decomposition device to combust; An exhaust gas utilization unit that produces steam using the exhaust gas of the above-mentioned gas turbine power generation unit; and It includes a control device for controlling the supply of ammonia and hydrogen to the above gas turbine power generation unit, and The above control device is characterized by controlling the supply of ammonia and hydrogen in conjunction with load fluctuations of the above gas turbine power generation unit. Combined cycle carbon-free power generation system.
2. In claim 1, The above ammonia decomposition device is characterized by using a nickel-based (Ni) or ruthenium-based (Ru) catalyst to decompose ammonia at a reaction temperature of 350℃ to 750℃. Combined cycle carbon-free power generation system.
3. In claim 1, A hydrogen buffer tank further comprising a hydrogen buffer tank that receives and stores hydrogen from the ammonia decomposition device. Combined cycle carbon-free power generation system.
4. In claim 3, The above control device is characterized by controlling the supply of hydrogen from the ammonia decomposition device or the supply of hydrogen from the hydrogen buffer tank in conjunction with load fluctuations of the gas turbine power generation unit. Combined cycle carbon-free power generation system.
5. In claim 4, Characterized by the ratio of hydrogen to ammonia supplied to the above gas turbine power generation unit being 30±5% : ammonia 70±5%, Combined cycle carbon-free power generation system.
6. In claim 4, The above control device is characterized by controlling the supply of hydrogen from the ammonia decomposition device and the hydrogen buffer tank to the gas turbine power generation unit during rated operation of the gas turbine power generation unit. Combined cycle carbon-free power generation system.
7. In claim 6, The above control device is characterized by not supplying hydrogen generated from the ammonia decomposition device to the hydrogen buffer tank during rated operation of the gas turbine power generation unit. Combined cycle carbon-free power generation system.
8. In claim 4, The above control device controls the supply of hydrogen from the ammonia decomposition device to the gas turbine power generation unit during low-load operation of the gas turbine power generation unit, and Characterized by supplying the remaining hydrogen generated from the above ammonia decomposition device to the above hydrogen buffer tank for storage. Combined cycle carbon-free power generation system.
9. In claim 4, The above control device controls the supply of hydrogen generated from the ammonia decomposition device to the hydrogen buffer tank when the operation of the above gas turbine power generation unit is stopped, and Characterized by prioritizing the supply of hydrogen stored in the hydrogen buffer tank to the gas turbine power generation unit upon restart of the gas turbine power generation unit. Combined cycle carbon-free power generation system.
10. In claim 4, Characterized by supplying waste heat generated in the exhaust gas utilization unit to the ammonia decomposition device. Combined cycle carbon-free power generation system.
11. In claim 4, A further comprising an ammonia preheating unit provided between the ammonia storage tank and the gas turbine power generation unit, which preheats ammonia by receiving waste heat generated from the exhaust gas utilization unit. Combined cycle carbon-free power generation system.
12. In claim 4, A hydrogen preheating unit further comprising a unit configured between the ammonia decomposition device and the gas turbine power generation unit or between the hydrogen buffer tank and the gas turbine power generation unit, which preheats hydrogen by receiving waste heat generated from the exhaust gas utilization unit. Combined cycle carbon-free power generation system.
13. A method for controlling a carbon-free combined cycle power generation system of claim 4, A step of supplying ammonia from the ammonia storage tank to the gas turbine power generation unit; The method includes the step of supplying hydrogen from the ammonia decomposition device or the hydrogen buffer tank to the gas turbine power generation unit. The step of supplying hydrogen is characterized by controlling the hydrogen supply in conjunction with load fluctuations of the gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.
14. In claim 13, The step of supplying the hydrogen above is, Characterized by supplying hydrogen from the ammonia decomposition device and the hydrogen buffer tank to the gas turbine power generation unit during rated operation of the gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.
15. In claim 14, The step of supplying the hydrogen above is, Characterized by not supplying hydrogen generated from the ammonia decomposition device to the hydrogen buffer tank during rated operation of the above gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.
16. In claim 13, The step of supplying the hydrogen above is, When the above gas turbine power generation unit is in low-load operation, hydrogen is supplied from the above ammonia decomposition device to the above gas turbine power generation unit, and Characterized by supplying the remaining hydrogen from the ammonia decomposition device to the gas turbine power generation unit to the hydrogen buffer tank for storage. Control method for a carbon-free combined cycle power generation system.
17. In claim 13, The step of supplying the above hydrogen is, When the above gas turbine power generation unit is shut down, hydrogen generated from the above ammonia decomposition device is supplied to the above hydrogen buffer tank, and Characterized by prioritizing the supply of hydrogen stored in the hydrogen buffer tank to the gas turbine power generation unit upon restart of the gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.
18. In claim 13, A step in which the above gas turbine power generation unit receives and burns ammonia and hydrogen; A step in which the exhaust gas utilization unit produces steam using the exhaust gas of the gas turbine power generation unit; and A method further comprising the step of supplying waste heat generated in the exhaust gas utilization unit to the ammonia decomposition device. Control method for a carbon-free combined cycle power generation system.
19. In claim 13, The method further includes the step of supplying waste heat generated in the exhaust gas utilization unit to an ammonia preheating unit provided between the ammonia storage tank and the gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.
20. In claim 13, The method further includes the step of supplying waste heat generated in the exhaust gas utilization unit to a hydrogen preheating unit provided between the ammonia decomposition device and the gas turbine power generation unit or between the hydrogen buffer tank and the gas turbine power generation unit. Control method for a carbon-free combined cycle power generation system.

Description

Combined carbon-free power generation system and its control method The present invention relates to a carbon-free combined cycle power generation system comprising a gas turbine and a steam turbine and a method for controlling the same. As shown in Fig. 1, the power generation system of a combined cycle power plant that primarily uses LNG as fuel consists of primary power generation through a gas turbine via fuel combustion and secondary power generation through a steam turbine using high-temperature steam produced by utilizing the heat from the exhaust gas after combustion. The gas turbine is composed of a compressor, a combustor, and a turbine. Atmospheric air is compressed to high pressure through the compressor, and the gas turbine is driven using the high-temperature gas heat generated during the combustion process with fuel in the combustor. The exhaust gas that drives the gas turbine flows into a heat recovery steam generator (HRSG), where low-temperature, low-pressure feedwater flowing through the internal feedwater pipes is converted into high-temperature, high-pressure steam to drive the steam turbine. Currently, in accordance with the allocation of Nationally Determined Contributions (NDCs), power generation methods utilizing clean fuels that do not emit greenhouse gases are gaining prominence in the power generation sector. Research projects and demonstration initiatives for co-firing carbon-free fuels (such as hydrogen and ammonia) at existing large-scale power plants are actively underway. Furthermore, the working draft of the government's recently released 11th Basic Plan for Electricity Planning reflects future carbon-free power generation volumes and proportions, and its importance is growing. In accordance with the recently promoted policies to expand the supply of renewable energy, renewable energy sources such as solar and wind power are expected to increase rapidly. Since renewable energy sources are non-centralized dispatch generators that do not receive separate dispatch instructions, and are variable energy resources characterized by significant instantaneous fluctuations in output and high uncertainty, there is a need for separate generation resources capable of providing flexibility to the power grid. Currently, combined cycle power plants are being utilized as a key resource to supply flexibility to the power grid by leveraging the characteristics of gas turbines, such as short start-stop times and fast load response speeds. When implementing co-firing or full combustion of carbon-free fuels in gas turbine combined cycle power plants—which serve as such flexibility resources—it is necessary to smoothly supply the required amount of carbon-free fuel in response to gas turbine load fluctuations. This requires separate carbon-free fuel supply facilities and control devices; however, existing power generation systems lack such equipment, which limits their application. Carbon-free power generation is a national task reflected in the Basic Plan for Electricity Planning, and considering the characteristics of Korea's power grid, it is absolutely essential to implement carbon-free power generation utilizing flexibility resources such as gas turbines. The matters described in the background technology above are intended to aid in understanding the background of the invention and may include matters that are not prior art already known to those skilled in the art to which this technology belongs. Figure 1 illustrates a conventional combined cycle gas turbine power generation system. FIG. 2 illustrates a carbon-free combined cycle power generation system according to a first embodiment of the present invention. Figure 3 shows the fuel supply method according to load fluctuations. FIG. 4 illustrates a carbon-free combined cycle power generation system according to a second embodiment of the present invention. FIG. 5 illustrates a carbon-free combined cycle power generation system according to a third embodiment of the present invention. In order to fully understand the present invention, the operational advantages of the present invention, and the objectives achieved by the implementation of the present invention, reference must be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described therein. In describing preferred embodiments of the present invention, known technologies or repetitive descriptions that may unnecessarily obscure the essence of the invention will be shortened or omitted. FIG. 2 illustrates a carbon-free combined cycle power generation system according to a first embodiment of the present invention, and FIG. 3 illustrates a fuel supply method according to load fluctuations. Hereinafter, a carbon-free combined cycle power generation system according to a first embodiment of the present invention and a control method thereof will be described with reference to FIG. 1 and FIG. 2. The present invention is a carbo