• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1201-1204
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• 2004

This paper suggests a DCS (Distributed Control System) model for steam temperature system of the thermal power plant. The model calculated within sectional range is linear. In order to calculate mathematical models, the system is partitioned into two or three sectors according to its thermal conditions, that is, saturated water/steam and superheating state. It is divided into three sections; water supply, steam generation and steam heating loop. The steam heating loop is called 'superheater' or steam temperature system. Water spray supply is the control input. A first order linear model is extracted. For linear approach, sectional linearization is achieved. Modeling methodology is a decomposition-synthetic technique. Superheater is composed of several tube-blocks. For this block, linear input-output model is to be calculated. Each tiny model has its transfer function. By expanding these block models to total system, synthetic DCS linear models are derived. Control instrument include/exclude models are also considered. The resultant models include thermal combustion conditions, and applicable to practical plant engineering field.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.311-318
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• 2011

Small-scale reactors have recently attracted attention as a potential power generation source for the future. The Regional Energy Research Institute for Next Generation is currently developing a small-scale reactor called Regional Energy rX 10 MVA (REX-10). The current paper deals with a power system to be used with small-scale reactors for multi-purpose regional energy systems. This small nuclear system can supply electric and thermal energy like a co-generation system. The electrical model of the REX-10 has been developed as a part of the SCADA system. REX-10's dynamic and electromagnetic performance on the power system is analyzed. Simulations are carried out on a test system based on Ulleung Island's power system to validate REX-10 availability on a power system. RSCAD/RTDS and PSS/E software tools are used for the simulation.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.369.1-369.1
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• 2003

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.5 no.1
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• pp.1-6
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• 2009

In this study, an ORC (Organic Rankine Cycle) is investigated for a low-temperature geothermal power generation by a simulation method. A steady-state simulation model is developed to analyze cycle's performance. The model contains a turbine, a pump, an expansion valve and heat exchangers. The turbine and pump are modelled by an isentropic efficiency. Simulations were carried out for the given heat source and sink inlet temperatures, and given flow rate that is based on the typical power plant thermal-capacitance-rate ratio. HFC-245fa is considered as a working fluid of the cycle. Simulation results, at the given secondary working fluids conditions, show that even though the power can be presented by both the evaporating temperature and the turbine inlet superheat, it depends on the evaporating temperature primarily.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.205-210
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• 2012

For environmental reasons and because of our limited energy resources, high-efficiency power generation technology will be necessary in the future. Ultra-supercritical (USC) power generation technology is the key to managing the greenhouse gas problems and energy resource problems discussed in the Kyoto Protocol to the United Nations Framework Convention on Climate Change. Other countries and manufacturers are trying to build commercial power plants. In this paper, an efficient method of achieving near-zero emission operation of a high-efficiency fossil power plant using USC power generation is discussed. Development of USC power generation in Korea has been supported by the Korean government in two phases: Phase I was USC key technology development from 2002 to 2008, and Phase II is USC development and technology optimization from 2010 to 2017.

• Journal of the Korean Society of Combustion
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• v.18 no.3
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• pp.1-8
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• 2013

Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants have been performed to establish criteria for optimization of power plants. The concept of efficiency, in terms of the difference in energy levels of electricity and heat, was introduced. The efficiency of power and heat generation by power plants with other purposes was estimated, and power generation costs were figured out for various types of combined heat and power plants(i.e., fired and unfired, condensing and non-condensing modes, single or double pressure HRSG).

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.312-317
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• 1998

Reliable maintenance scheduling of main equipments is a crucial problem in thermal power stations in order to skirt overall losses of power generation resulted from severe failures of the equipments. A reasonable method was proposed to determine the maintenance scheduling of whole pump system in thermal power stations in order to reduce the maintenance cost by keeping the present avail-ability of the pump system throughout the operation. The dimensional reduction method was used to solve problems encountered due to few data which involved many operational factors in failure rate of pumps. The problem of bandlimited nature of data with time was solved by extrapolating future failures from presently available actual data with an aid of Weibull distribution. The results of the analysis identified the most suitable maintenance intervals of each pump type accordingly and hence reduce the cost of unnecessary maintenance with an acceptable range in the overall system availability.

• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.55-61
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• 2007

This paper describes the procedure and calculation results of basic design and transient variation of performance of 1 MWe large scale solar thermal power plant (STPP) by using the commercial software of THERMOFLEX and TRNSYS, respectively. In order to simulate the transient variation of STPP, the results of basic design are necessary. The design standard of the STPP is 1 MWe generation with solar only at high DNI condition and then 0.6 MWe output power for 1 hour using stored energy when the DNI becomes lower unable to operate normally. The results of basic design show the important design data of flow rates, water/steam conditions at each equipments and the estimated efficiency of STPP. In addition, dynamic simulation results of STPP are predicted and plotted for one year and three different days weather data of Daejeon.

• Progress in Superconductivity and Cryogenics
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• v.20 no.2
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• pp.6-10
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• 2018

Removal of iron oxide scale from feed-water in thermal power plant can improve power generation efficiency. We have proposed a novel scale removal system utilizing High Gradient Magnetic Separation (HGMS). This system can be applied to high temperature and pressure area. We have conducted the lab-scale model experiments using ${\varphi}50mm$ filters and it demonstrated high removal efficiency in HGMS, but scale-up of the system is required toward practical use. In this study, we conducted a large scale mock-up HGMS experiment. We used the superconducting solenoidal magnet with ${\varphi}400mm$ bore and demonstrated that our HGMS system can achieve sufficient scale removal capacity that is required to introduce into both off-line and on-line system.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.1
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• pp.22-29
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• 2020

In nuclear power plants, there is a risk of thermal fatigue in equipment and piping affecting system soundness because the temperature change of the system accompanies in every operation and shutdown. Therefore, in order to prevent the excess of the fatigue limit during the lifetime of plants, the fatigue limit of each piping material is determined in the designing stage. However, there are many cases where equipment or piping is locally subjected to thermal fatigue that is not considered in the design, resulting in damage to the equipment and piping, and failure during operation. Currently, local thermal fatigue generation mechanisms that are not taken into account in the design stage are gradually being identified. In this paper, the effects of the fluid temperature fluctuations on the piping soundness due to the mixing of hot and cold water, one of the local thermal fatigue generating mechanisms, were evaluated.