• Proceedings of the KIEE Conference
• /
• 2004.11b
• /
• pp.138-142
• /
• 2004

Recently over dropped frequencies of power system were recorded when power system was unbalanced between generation and demand. Therefore load following characteristic analysis of thermal and combined cycle power plant generators is necessary for low frequency condition analysis of power system. Frequency simulator supplies simulated frequency to the online generator for prescribed goal. This simulator needs to minimize effects to power system and requires stability first. This paper introduces design and manufacturing case of frequency simulator for load following characteristic analysis of generators.

• Journal of Energy Engineering
• /
• v.19 no.2
• /
• pp.136-142
• /
• 2010

Combustion reactivity and thermal behavior of two imported coals used as a pulverized fuel of commercially thermal power plant were investigated by thermogravimetric analysis (TGA) and large scale test furnace of 200 kg/hr. TGA results showed that combustion efficiency of high moisture coal has lower than reference coal due to the slow combustion completion rate although it has the low ignition temperature, and activation energies of high moisture coal with 79 kJ/mol for overall combustion was higher than reference coal of 53 kJ/mol. Test furnace results ascertained that flame of black band of high moisture coal during the combustion in boiler broke out compared to reference coal and then it becomes to unburned carbon due to the less reactivity and combustion rate. But, Blending combustion of high moisture coal with design coal of high sulfur are available because sulfur content of high moisture coal was too low to generate the low SOx content in flue gas from boiler during the combustion. The ash analysis results show that it was not expected to be associated with slagging and fouling in pulverized coal fired systems due to the low alkali metal content of $Na_2O$ and $K_2O$ compared to bituminous coal.

• Journal of the Korea Society for Simulation
• /
• v.29 no.3
• /
• pp.9-18
• /
• 2020

The development of a large-scale thermal power plant control simulator consists of water/steam systems, air/combustion systems, pulverizer systems and turbine/generator systems. Modeling is possible for all systems except mechanical turbines/generators. Currently, there have been attempts to develop neural network simulators for some systems of a boiler, but the development of simulator for the whole system has never been completed. In particular, autoTuning, one of the key technology developments of all power generation companies, is a technology that can be achieved only when modeling for all systems with high accuracy is completed. The simulation results show accuracy of 95 to 99% or more of the actual boiler system, so if the field PID controller is fitted to this simulator, it will be available for fault diagnosis or auto-tuning.

• Journal of Environmental Impact Assessment
• /
• v.27 no.3
• /
• pp.322-333
• /
• 2018

This study was carried out to measure atmospheric environmental improvement effect and estimate its social benefit of thermal power plants through Environmental Impact Assessment (EIA) for quantitative analysis about operational performances of EIA. In this study, 'EIA outcome' is defined as whether or not the system is implemented, therefore, environmental standard to be followed by each project and consultation contents were compared. In total 60 cases of thermal power plant construction projects that have been consulted over the past 10 years since 2010, major air pollutants have been significantly reduced after the implementation of EIA. The $PM_{10}$ reduced annual 3,745 tons, $NO_2$ by 74,569 tons, and $SO_2$ by 37,647 tons, which were estimated at approximately 240 billion won~5 trillion 967 billion won per year for social benefit. This means the total cost of power plant operations will be cut to 7 trillion 192 billion won~178 trillion 994 billion won over a 30-year period. The reduced amount of air pollutants emitted by energy generation facilities across the country is worth 50%, and its economic value is larger than the annual Current Health Expenditure in Korea. This is meant by the fact that all projects are subject to uniform criteria under the existing relevant regulation, but that each project plans are optimized according to the characteristics of target areas and projects through the process of EIA.

• Journal of Power System Engineering
• /
• v.17 no.3
• /
• pp.23-27
• /
• 2013

In this research paper, we study on how to decrease the high vibration of turbine hood casings which are main facilities of power generation industry. Cause of Standard coal-fired power 500MW facilities turbine hoods' high vibration is that Natural frequency of hood casing designed in near domain frequency, when they are making hoods. We investigate to reduce high vibration at hood casing. We use FEM method to found how to avoid resonance, and test to confirm that our FEM result. We Finally attach minium mass plate at hood casing to avoid resonance and high vibration reduce lower $100{\mu}m$.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.1
• /
• pp.9-18
• /
• 2012

Annual power consumption of our country is positioned in the upper percentile in the world, and because the proportion of fossil power generation is high, which ranks the 10th $CO_2$ emission country. In this regard, government has established and is implementing the National Energy Basic Plan to realize to get out of fossilization in energy supply while focusing on securing the technology for renewable energy as well as its commercialization in order to reduce greenhouse gas. Resource recovery technology for deep seawater thermal energy which is one of renewable energies is newly getting attention domestically as well as in overseas for securing resources and environmental improvement as a core technology for multilateral use of marine resources for low carbon and green growth. Economic feasibility analysis was conducted for the research and development as follows on the use of ocean thermal energy conversion and seawater air conditioning. First, in the case of power generation using deep seawater and warm discharge water from ocean thermal energy conversion plant of 1MW level, it is judged that the economic feasibility is insufficient but the feasibility will be significantly improved if we consider not only power generation but also drinking water and certified emission reduction by developing the power plant to the size for commercialization. Second, the economic feasibility for the use of deep seawater as air conditioning for the power plant of 1,000RT level turned out to be very good. Especially, when we consider certified emission reduction, it will be possible to secure sufficient economic feasibility. When we use it in connection with ocean thermal energy conversion, water conversion and agricultural and fishery use, it is judged that economic ripple effect will be significant and therefore it will be necessary to conduct research and development for early commercialization, distribution and diffusion of deep seawater energy.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.372-378
• /
• 2012

This study was carried out in order to determine the optimum length of a roll type PE pipe heat exchanger employed in the water-to-water heat pump system using the waste heat of the heated effluent flowed out from thermal power generation plants as a heat source. And the heat pump system of 30 RT for an experimental test was designed and manufactured. And also PE pipes were employed to recover the waste heat from the heated effluent. The inside diameter of PE pipe heat exchanger was 20 mm, the thickness was 2 mm and the diameter of a roll was 1,000 mm. And from the results of this study, we found that the optimum length of PE pipe heat exchanger was 75 m per the heat pump capacity of 1.0 RT (3.51 kW) and then the heating COP of heat pump system was 3.8.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.1
• /
• pp.54-61
• /
• 2008

Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increases the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition.

• Nuclear Engineering and Technology
• /
• v.32 no.4
• /
• pp.379-394
• /
• 2000

As an in-vessel retention (IVR) design concept in coping with a severe accident in the nuclear power plant during which time a considerable amount of core material may melt, external cooling of the reactor vessel has been suggested to protect the lower head from overheating due to relocated material from the core. The efficiency of the ex-vessel management may be estimated by the thermal margin defined as the ratio of the critical heat flux (CHF）to the actual heat flux from the reactor vessel. Principal factors affecting the thermal margin calculation are the amount of heat to be transferred downward from the molten pool, variation of heat flux with the angular position, and the amount of removable heat by external cooling In this paper a thorough literature survey is made and relevant models and correlations are critically reviewed and applied in terms of their capabilities and uncertainties in estimating the thermal margin to potential failure of the vessel on account of the CHF Results of the thermal margin calculation are statistically treated and the associated uncertainties are quantitatively evaluated to shed light on the issues requiring further attention and study in the near term. Our results indicated a higher thermal margin at the bottom than at the top of the vessel accounting for the natural convection within the hemispherical molten debris pool in the lower plenum. The information obtained from this study will serve as the backbone in identifying the maximum heat removal capability and limitations of the IVR technology called the Cerium Attack Syndrome Immunization Structures (COASISO) being developed for next generation reactors.

• Korean Journal of Materials Research
• /
• v.10 no.2
• /
• pp.138-143
• /
• 2000

화력발전설비의 주요 손상 요인 중의 하나인 응력부식 균열 성장에 대한 확률론적 잔존 수명평가에 대하여 연구하였으며, 손상해석 및 수명평가에 확률해석 기법을 도입한 확률론적 수명평가 프로그램을 개발하였다. 확률론적 수명평가는 재료물성치, 형상, 하중조건, 운전조건 등과 같은 불확실성과 변동 가능성을 고려하여 해석을 수행하며, 일정 시간 운전후 구조물의 손상이 일어날 확률을 예측하는 것이다. 응력부식 균열 성장에 대한 확률론적 잔존 수명평가 연구를 통하여 확률론적 수명평가 기술의 기반을 구축하였으며, 다른 손상기구에 대한 확률론적 수명평가를 수행하여 발전설비에 발생하는 모든 손상에 대하여 확률론적 수명평가가 가능하도록 확대할 계획이다.