• 전기전자학회논문지
• /
• 제23권2호
• /
• pp.675-680
• /
• 2019

석탄화력발전소는 저부하에서 효율 향상을 위해 변압운전으로, 고부하에서는 정압으로 운전하는 복합변압운전 방식으로 운전하고 있으며, 복합변압운전에는 2밸브 및 3밸브 전개모드로 구분되어 운영되고 있다. 각 발전소는 제작사 권고에 따라 터빈제어밸브 모드를 선택하여 운전하고 있으나 최적의 변압운전 부하범위로 운전되고 있지 않고, 각 발전소별 부하범위 또한 상이하게 구성 되어있다. 최적의 변압운전 부하범위로 설정되지 않으면 터빈밸브 교축 손실 발생에 따른 고압터빈 내부효율 저하가 발생되어 플랜트 효율이 저하된다. 이러한 문제점을 개선하기 위해 본 논문에서는 터빈제어밸브 모드별 최적의 변압운전 부하 범위를 개선하기 위해 각 부하별 열 성능 분석 방법을 통해 최적의 부하범위를 선정하고자 한다.

• 시스템엔지니어링학술지
• /
• 제17권1호
• /
• pp.76-84
• /
• 2021

Radioactive waste generated from nuclear power plant decommissioning shall be strictly managed so that radioactive materials above the allowable limit are not leaked into the environment. Radioactive wastes shall be classified and treated for management based on characteristics such as the type of waste, physicochemical properties, nuclide concentration and radioactivity. Waste characterization report shall be prepared and submitted to the disposal facility operator to ensure that the treated waste is suitable for disposal. The disposal facility operator shall review the waste Characterization report and visit the nuclear power plant decommissioning site to ensure that the wastes are processed step by step according to the plan. The waste Characterization report may be used as input data to evaluate disposal facility safety. Domestic and foreign data are collected and reviewed to confirm the entire processes from waste generation to delivery. This paper proposes the method to prepare the waste Characterization report which contains data and information on waste characteristics, treatment facilities & method and packaging method & container.

• Corrosion Science and Technology
• /
• 제4권4호
• /
• pp.140-146
• /
• 2005

Fossil fired power plant produces the electric energy by using a thermal energy by the combustion of fossil fuels as like oil, gas and coal. The exhausted flue gas by the combustion of oil etc. contains usually many contaminated species, and especially sulfur-content has been controlled strictly and then FGD (Flue Gas Desulfurization) facility should be installed in every fossil fired power plant. To minimize the content of contaminations in final exhaust gas, high corrosive environment including sulfuric acid (it was formed during the process which $SO_2$ gas combined with $Mg(OH)_2$ solution) can be formed in cooling zone of FGD facility and severe corrosion damage is reported in this zone. These conditions are formed when duct materials are immersed in fluid that flows on the duct floors or when exhausted gas is condensed into thin layered medium and contacts with materials of the duct walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of those ducts. The frequent shut down and repairing works of the FGD systems also demand costs and low efficiencies of those facilities. In general, high corrosion resistant materials have been used to solve this problem. However, corrosion problems have severely occurred in a cooling zone even though high corrosion resistant materials were used. In this work, a new technology has been proposed to solve the corrosion problem in the cooling zone of FGD facility. This electrochemical protection system contains cathodic protection method and protection by coating film, and remote monitoring-control system.

• 한국전자파학회논문지
• /
• 제22권12호
• /
• pp.1155-1164
• /
• 2011

본 논문에서는 국내 최초로 개발되는 함상용 중거리 레이더에 사용되는 능동 위상 배열 안테나의 송신 빔 특성을 근접 전계 시험으로 측정하는 방안에 대하여 제시하였다. 측정하고자 하는 능동 위상 배열 안테나는 고출력 송신 빔을 펄스 형태로 방사하기 때문에 저출력의 연속적인 파형을 사용하는 일반적인 근접 전계 시험 시설에서는 측정하기 어렵다. 그래서 본 논문에서는 고출력 송신 시에도 견딜 수 있도록 설계된 근접 전계 시험 시설과 펄스 모드 측정을 지원하는 Agilent사의 PNA-X 네트웍 분석기를 이용한 근접 전계 시험으로 펄스 형태의 고출력 송신 빔을 방사하는 능동 위상 배열 안테나를 측정하는 방안에 대하여 제시하였고, 실제 개발된 능동 위상 배열 안테나의 고출력 송신 빔 패턴을 근접 전계 시험으로 측정하였다. 또한, 능동 위상 배열 안테나의 송신 특성인 EIRP(Effective Isotropic Radiated Power)를 측정하였고, 수학적인 계산을 통해 예측한 EIRP 값과 비교한 결과 0.1 dB의 오차 내에서 동일함을 확인하였다.

• 한국기후변화학회지
• /
• 제8권1호
• /
• pp.21-30
• /
• 2017

Recently, There has been much discussed about unused space. This space can be used in a variety of ways. Utilizing it as a facility, craft shop, and utilizing renewable energy generation facilities. Especially, in terms of climate change should be supplied renewable energy. Renewable energy needs to be developed in terms of responding to climate change, and the recent Paris agreement is also emphasizing the importance of renewable energy. In particular, renewable energy needs to be widely disseminated. And renewable energy is limited space. In this regard, idle land can provide opportunities for securing new renewable energy generation facilities. The introduction of new and renewable energy facilities in idle space can enhance the self-sufficiency rate of the local community, which is significant in terms of responding to climate. In this study, to investigate the possibility of utilizing a unused space for a photovoltaic power generation facility, we investigated the amount of electricity which could be generated through photovoltaic power generation, and the economic effects, using a RETScreen model. The results showed that 9,738 MWh of power can be generated and that $4,540tCO_2eqcan$ be saved. Regarding the economic effect, the net present value of the facility was shown to be 2,247,389,020 KRW. As the net present value was shown to be positive, we believe that the installation of a photovoltaic power generation facility in an unused space would have a positive economic effect. We found the net present value following the fluctuation of the SMP price to be positive, though there was some variation. However, as the economic efficiency was shown to be low because the net present value in relation to the maintenance costs was negative, we believe that maintenance costs must be taken fully into account when evaluating economic efficiency. In particular, as subsidies can be used to cover maintenance costs which must be factored into photovoltaic power generation, we believe that photovoltaic power generation can have an economic effect. Because spaces not currently in use can have a positive economic effect as renewable energy power generation facilities, and can also contribute to the reduction of greenhouse gas emissions, unused spaces are thought to greatly help local governments to cope with climate change as well as reinforcing their related capabilities. We believe our study will help local governments with decisions relating to unused real estate utilization in the future.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
• /
• pp.103-106
• /
• 2002

This paper has studied a remote AMR(Automatic Meter Reading) system using the power line and the telephone line as a communication media and the digital power meter. In the developed system, because we have used the power line and telephone, the facility is very easy and then its cost is not expensive. The system includes following elements: a digital power meter, an indoor communication system using a power line modem and a telephone line interface system for sending data to the utility company.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2003년도 가을 학술논문집
• /
• pp.411-420
• /
• 2003

원자력발전소 운전과 함께 국내 원전에서 계속 발생, 저장하고 있는 사용후핵연료를 안전하고도 효율적으로 관리하기 위하여 차세대관리 종합공정을 개발하고 있으며, 이를 실증하기 위한 시설을 설계 중에 있다. 이 실증시설은 조사재시험시설에 마련된 예비 핫셀을 차세대관리 종합공정의 특성을 고려하여 개조하여 사용할 예정이다. 이 연구에서는 실증시설에 대한 기존 시설 및 부대시설의 개조방안 등 기본 건축구조 설계에 대한 기준과 설계내용을 제시하였으며, 건축구조물의 안전성을 입증하기 위한 해석을 수행하고 그 결과를 제시하였다. 본 연구결과는 차세대관리 종합공정 실증시선의 상세설계를 위한 자료로 사용될 것이며, 시설의 인허가를 위한 자료로 활용될 것이다.

• 방사성폐기물학회지
• /
• 제6권4호
• /
• pp.369-385
• /
• 2008

부지감시 및 조사의 목적은 운영 전, 운영중 및 폐쇄 후 단계에서 변화가 예상되는 주요 부지특성을 지속적으로 감시함으로써 방사성폐기물처분장의 성능평가 및 설계에 필요한 기초자료를 제공하는 것이다. 부지감시의 단계별 주요내용은 다음과 같다. 운영전 단계에는 부지의 적합성 평가 및 처분장 건설과 운영에 필요한 주요 부지특성을 감시하며, 운영 중 단계에는 안전하고 효율적인 운영과 환경에 미치는 영향을 판단하기 위하여 주변지역을 포함하여 주요 부지특성을 감시한다. 폐쇄 후 단계에는 처분장의 방사성 물질로 인한 영향을 사전에 예방하고, 처분장의 장기적 안전성을 위하여 필요한 주요 부지특성 항목을 감시한다.

• 한국시스템다이내믹스연구
• /
• 제2권2호
• /
• pp.25-40
• /
• 2001

This paper describes the forecast of power plant construction in a competitive korean electricity market. In Korea, KEPCO (Korea Electric Power Corporation, fully controlled by government) was responsible for from the production of the electricity to the sale of electricity to customer. However, the generation part is separated from KEPCO and six generation companies were established for whole sale competition from April 1st, 2001. The generation companies consist of five fossil power companies and one nuclear power company in Korea at present time. Fossil power companies are scheduled to be sold to private companies including foreign investors. Nuclear power company is owned and controlled by government. The competition in generation market will start from 2003. ISO (Independence System Operator will purchase the electricity from the power exchange market. The market price is determined by the SMP(System Marginal Price) which is decided by the balance between demand and supply of electricity in power exchange market. Under this uncertain circumstance, the energy policy planners such as government are interested to the construction of the power plant in the future. These interests are accelerated due to the recent shortage of electricity supply in California. In the competitive market, investors are no longer interested in the investment for the capital intensive, long lead time generating technologies such as nuclear and coal plants. Large unclear and coal plants were no longer the top choices. Instead, investors in the competitive market are interested in smaller, more efficient, cheaper, cleaner technologies such as CCGT(Combined Cycle Gas Turbine). Electricity is treated as commodity in the competitive market. The investors behavior in the commodity market shows that the new investment decision is made when the market price exceeds the sum of capital cost and variable cost of the new facility and the existing facility utilization depends on the marginal cost of the facility. This investors behavior can be applied to the new investments for the power plant. Under these postulations, there is the potential for power plant construction to appear in waves causing alternating periods of over and under supply of electricity like commodity production or real estate production. A computer model was developed to sturdy the possibility that construction will appear in waves of boom and bust in Korean electricity market. This model was constructed using System Dynamics method pioneered by Forrester(MIT, 1961) and explained in recent text by Sternman (Business Dynamics, MIT, 2000) and the recent work by Andrew Ford(Energy Policy, 1999). This model was designed based on the Energy Policy results(Ford, 1999) with parameters for loads and resources in Korea. This Korea Market Model was developed and tested in a small scale project to demonstrate the usefulness of the System Dynamics approach. Korea electricity market is isolated and not allowed to import electricity from outsides. In this model, the base load such as unclear and large coal power plant are assumed to be user specified investment and only CCGT is selected for new investment by investors in the market. This model may be used to learn if government investment in new unclear plants could compensate for the unstable actions of private developers. This model can be used to test the policy focused on the role of unclear investments over time. This model also can be used to test whether the future power plant construction can meet the government targets for the mix of generating resources and to test whether to maintain stable price in the spot market.

• Nuclear Engineering and Technology
• /
• 제36권3호
• /
• pp.203-209
• /
• 2004

In-phantom neutron flux distribution is measured at the HANARO BNCT irradiation facility. The measurements are performed with Au foil and wires. The thermal neutron flux and Cd ratio obtained at the HANARO BNCT facility are $1.19{\times}10^9\;n/cm^{2}s$ and 152, respectively, at 24 MW reactor power. The measured in-phantom neutron flux has a maximum value at a depth of 3 mm in the phantom and then decreases rapidly. The maximum flux is about $25\%$ larger than that of the phantom surface, and the measured value at a depth of 22 mm in the phantom is about a half of the maximum value. In addition, the neutron beam is limited well within the aperture of the neutron collimator. The two-dimensional in-phantom neutron flux distribution is determined. Significant neutron irradiation is observed within 20 mm from the phantom surface. The measured neutron flux distribution can be utilized in irradiation planning for a patient.