• Plant Journal
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• v.14 no.4
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• pp.39-47
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• 2018

In this research, when the output of the standard coal-fired thermal power plant operating continuously at the rated output of 500 MW is changed to operate at 300 to 500 MW, the amount of sulfur oxide produced and the amount of sulfur oxide in the absorption tower of desulfurization equipment and proposed an extra liquid to gas ratio improvement inversely proportional to the output. In order to calibrate the combustion efficiency at low power, the ratio of sulfur oxides relative to the amount of combustion gas is increased as the excess air ratio is increased. When the concentration of sulfur oxide at the inlet of the desulfurization absorber was changed from 300 to 500 ppm along with the output fluctuation. The liquid to gas ratio of limestone slurry and combustion gas was changed from 10.99 to 16.27. Therefore, if the concentration of sulfur oxides with output of 300 MW is x, The following correlation equation is recommended for the minimum required flow rate of slurry for the reduction of surplus energy due to the increase of the liquid weight at low load. $y1[m^3/sec]=0.11x+3.74$

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.70-75
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• 2014

TMR(triple modular redundant) digital excitation system with simulator is developed for tuning optimal control parameters during commissioning test and coping with system faults rapidly. A new system which mocks up virtual generator, turbine, grid can simulate as if excitation system is connected to a real generator system by setting four switches. The maintenance crew using the simulator is able to test perfectly the phase controller rectifiers, field breaker, sequence relays as well as TMR controller of the excitation system. Commissioning and performance results about the excitation system with simulator is discussed. The trial product was installed and operated at a 500MW thermal power plant after the commissioning test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.2012-2015
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• 2010

In this paper, the mathematical models of the superheater and the desuperheater are derived based on the fundamental laws of physics, mass and energy balance. The parameters of the models are developed for the 500[MW] thermal power plant using the actual data. The simulated model outputs are well matched with the actual ones. It is expected that the proposed models are useful for the temperature controller design of the thermal power plant.

• Plant Journal
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• v.15 no.4
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• pp.30-35
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• 2019

To meet both increasing social demand for reduction of fine dust and the strengthened air pollutant emission standards, this paper indicated performance enhancement of FGD with structural constraints in 500 MW coal fired thermal power plant's. Through modifying internal facilities for flue gases to make swirl in the absorption tower, it made turbulence and increased the efficiency of material transfer, the reaction area and time with the limestone slurry. Therefore, it could reduce dust and enhance the performance of collecting the SO₂. As a result, desulfurization efficiency was improved from 91.61% to 98.43% and dust removal efficiency was improved from 77.4% to 87.08%. Emission density is 7.85 ppm of SO₂ and 4.67 mg/㎥ of dust. This is a level that satisfies emission limit of 25 ppm of SO₂ and 5 mg/㎥ of dust which are the air pollutant emission standards of 2023. The performance enhancement method of this study is expected to be effectively applied to other coal-fired power plants with similar constraints.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.127-131
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• 2017

The present paper describes the slagging field data obtained with the one-dimensional process model for the 500 MW tangentially coal fired boiler in Korea. To obtain slagging field data in terms of thermal resistances [$m^2{\cdot}^{\circ}C/kW$], a number of plant data were collected and analyzed with the one-dimensional modelling software at 500 MW full load. The slagging field data for the primary superheater were obtained for six coal blends, and compared with two TMA (Thermo-Mechanical analyzer) slagging indices and the numerical slagging index, along with the conventional slagging indices which were modified with the ash loading. The advanced two TMA indices for six blended coals give a good slagging tendency when comparing them with the slagging field data, while the modified conventional slagging indices give a relatively poor agreement.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.1
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• pp.38-43
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• 2012

For safe and stable operations of power plants, it is essential to monitor closely crucial measurement values related to power plant trips. In this paper, an intelligent power plant operating state monitoring technique enabling the operating crew member to monitor conveniently the status of the important measurement values and to perceive almost instantly the significance of the implications of those measurement values is developed. The proposed technique is called a "POST(Plant Operating State Tracking) Chart" technique and provides the foundations in developing an intelligent and integrated power plant operating state monitoring support system called the "P-OASIS"(Plant Operation Assessment and Support Intelligent System). The P-OASIS is applied to a thermal power plant of 500[MW] capacity and exhibited impressive performances.

• Plant Journal
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• v.14 no.3
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• pp.35-41
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• 2018

Considering the recent government policy toward North Korea and situation of power facilities in North Korea, it will be necessary to prepare for the consumption of the anthracite coal from Korea in coal-fired power plants. In this study, the anthracite co-fired tests in 500 MW thermal power plants were conducted with varying the main operation conditions, such as anthracite injection position in the boiler, coal fineness and combustion air flow, to investigate the effects on the generation of unburned carbon. It was confirmed that the generation of unburned carbon was remarkably reduced when the anthracite coal was injected into the boiler low burner with a relatively long residence time in the main combustion region, and that the increase of the coal fineness proportional to the combustion reaction surface area also reduces the generation of unburned carbon. An increase in the combustion air flow, which increase the combustion reactivity, also contributes to the reduction of unburned carbon. It is possible to maintain the unburned carbon generation below 5 % of the ash recycling quality by controlling the above operating conditions for the given mixing rate of anthracite, and the priority of changing the operating conditions within the test range is the highest for anthracite coal injection position.

• Resources Recycling
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• v.13 no.5
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• pp.51-56
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• 2004

Economic benefits of the dry bottom ash handling system over the wet bottom ash handling system in a new 500MW${\times}$2units pulverized coal thermal power plant in Korea were evaluated. The higher initial capital cost in the dry bottom ash handling system was estimated. However, this higher initial capital costs would be compensated with reductions of the operating cost mainly due to the recycling of bottom ash. Economic analysis showed that the payback period of 4.9 years and the internal rate of return at 21.1% were expected for the additional initial capital cost of the dry bottom ash handling system.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3259-3263
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• 2007

This paper describes the proceedings of creating countermeasures after analysis and maintenance be able to conduct operation safely in a power plant. in order to operate the power plant in a stable and reliable way, the best condition of the govemor system can be maintained through the response characteristic analysis of the control device for the pitch blade control hydraulic actuator. The fan pitch blade control hydraulic actuator of a 500MW large-scale boiler is frequently operated under normal operation conditions. Common problems or malfunctions of the pitch blade control hydraulic actuators leads to the decline of boiler thermal efficiency and unexpected power plant trip. The inlet and outlet gas can be controlled by using the fan pitch blade control hydraulic actuator in order to regulate the internal pressure of the furnace and control the frequency in the power plant facility which utilizes soft coals as a power source.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.224-232
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• 2009

Power plant start-up is a complicate process involving hundreds of operations that should be performed either automatically or manually. Several major operations should be proceeded in parallel and each major operation is again broken down into detailed operations that must be carried out in a strict sequence. Even though most of the operations are automated, still substantial portions of the operations are carried out manually and the operational status should be monitored by the crew members, which are quite stressful tasks to be performed in real time. In this paper, a data structure called an Event Sequence Monitoring Graph(ESMG) is proposed for monitoring a sequence of events involved in the power plant start-up process. The ESMG is currently being applied to a thermal power plant with a rated output of 500MW. An application example is shown with the boiler feed water pump system start-up process, which exhibits a good potential for future applications.