• Journal of Environmental Impact Assessment
• /
• v.19 no.6
• /
• pp.625-631
• /
• 2010

The objective of this work was to investigate how carbon sink and sequestration of vegetation and soil in the development project area can impact the land use plan, in addition to carbon emission capacity of the development project when we conduct environmental impact assessment. Especially, we did this work for a development project of solar power plant which would be constructed in forest area. Through this work, we found that 1) the amount of carbon sink and sequestration largely decreased due to reduction of the green area, 2) in terms of carbon sink and sequestration, conservation of natural green area is better than construction of newly vegetated area, 3) biochar application into soil can become an alternative for increase of carbon sink, and 4) even though a solar power production does hugely reduce carbon emissions and offset the carbon sink and sequestration capacity from the forest, it is necessary to consider the public value of the forest(reduction of heat island, habitat etc.) in siting for development area.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1267-1272
• /
• 2008

OTEC power plants are studied as a viable option for the supply of clean energy. In this paper, the thermodynamic performance of OTEC system was calculated. The results show that the working fluids such as R32 and R125 would be alternatives based upon cutting down the system size, environmental preservation, and conditions without having a severe penalty in efficiency. the initial cost significantly. The regeneration system increase in energy efficiency, and the system can generate electricity when the difference in warm and cold seawater inlet temperatures are greater than $15^{\circ}C$. Also, the system efficiency of OTEC power plant using the condenser effluent from nuclear power plant instead of the surface water increased about 2%.

• Nuclear Engineering and Technology
• /
• v.22 no.4
• /
• pp.371-379
• /
• 1990

The Xenon spatial oscillation may give rise to operational difficulties in a nuclear power plant. In this study, in order to investigate the Xenon instability for a PWR, the frequency-domain technique is adopted by using Generalized Nyquist Criterion, which is more general and suitable for the multi-input/multi-output system. Also linearized modal fluxes are obtained by a modal expansion. This model has been implemented to test the axial Xenon stability of YGN-1 unit against the changes in plant operating parameters ; power level, control rod position, and core average burnup. The results show that the increase of power level and the deeper insertion of control rod have the destabilizing effect, and that the burnup progress makes the core less stable. Also the results show that the overestimation due to modal interaction was found not to be significant.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.520-523
• /
• 2005

국내에서 대체에너지 공급 비율을 보면 청정에너지로 분류할 수 있는 태양열에너지, 태양 광 에너지, 풍력에너지를 모두 합하여 대체에너지의 $10\%$이하이며, 대체에너지 비율의 $90\%$ 이상을 폐기물로부터 얻은 에너지가 차지하고 있는 실정이다. 신재생에너지원에는 여러 종류가 있지만 해양에너지원에 대해 대상을 설정하고 이에 대한 부존량을 살펴보면 진도 주변의 해역에서 조류발전 부존량이 약 362만 kW가 되며, 시화호와 새만금 등지에서의 조력발전 부존량이 650만 kW, 동해안 후포 연안을 비롯한 파력발전 부존량이 20만kW가 되는 것으로 알려져 있다. 이에 따라 해양에너지를 실용화하기 위한 연구가 국내외에서 연구되고 있다. 본 논문은 권선형유도발전기를 갖는 조류발전 시스템을 대상으로 연구한 결과로 권선형유도발전기를 제어하기 위한 전력변환장치 개발과 관련한 내용이다. 신재생에너지원이 발전 단가 측면에서 경제성을 갖기 위해서 발전기 용량은 5MW 급까지 대용량화되어 있는 단계이지만 국내에서는 아직 MW급 이상이 되는 권선형 유도발전기와 권선형 유도발전기를 제어하는 전력변환장치에 대한 연구 실적이 없는 상황이다 이에 본 논문에서는 1MW급의 권선형유도발전기에 대한 개발 사례를 소개하면서 유효전력제어, 역률제어, 계통연계방법, 그리고 운전 속도에 따라 변동되는 회전자측에서의 피상전력 특성 등을 제시하고자 한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.3
• /
• pp.54-60
• /
• 2015

There are 5 purification plants with the adopted advanced water purification treatment process in Korea. Annual operating costs were 8,990 million won including purchase cost of oxygen and power usage charges. We need research to optimize, in the future, when considering the direction of domestic water treatment continues to adopt advanced water treatment process. In this paper, calculate the optimal operating costs by injected the oxygen gas, used power cost. approximately 25% of the operating costs can be reduced when injected the ozone gas is 1.0ppm than 2.0ppm, the necessary amount of oxygen is increased then power is lower. so operating costs are decided according to oxygen costs. On the other hand, high ozone concentration 2.0ppm, the necessary power is increased then amount of oxygen is lower. Therefore, in the case of G purification plant, the controlling factor of the input ozone concentration 2ppm, PID control operation by setting the concentration of over 10Wt% is efficient. The installed capacity is the more little the more better when considering on Ozone injection rate in the process of water treatment.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.1083-1087
• /
• 1997

Every effort is now being exerted in industrialized and developing countries to reduce emission of greenhouse gases from electric power sector. In this paper, we provide supply-side resource mix strategies in the long-term generation expansion planning under the expected greenhouse gas regulations. Under the environmental regulations, we explore the least-cost generation expansion plan of Korea and determine the composition of future resource mixes. Our analysis is performed on the basis of the revised WASP package which can evaluate emission of carbon dioxide from each power plant. The evaluation process of carbon dioxide emissions, which can consider the efficiency and operating conditions of each generator simultaneously, has been incorporated into the probabilistic production cost simulation module of WASP.

• Journal of Welding and Joining
• /
• v.30 no.6
• /
• pp.10-14
• /
• 2012

Recently the low alloy steel plate made with manganese-molybdenum is used widely in steam drum and separator of the new coal-fired power plant boiler. This material is suitable for the vapor storage of high pressure and high temperature. The high temperature creep strength of Mn-Mo alloy is higher than the carbon plate(SA516) that used in the subcritical pressure boiler. It reduces the thickness of the pressure vessel and makes the lightweight possible. Recently in the power plant boiler operation and production process, the damage has happened frequently in the heat affected zone and base material according to the hydrogen crack and delayed crack. This paper describes the research result about the damage case experienced in the boiler steam drum production process and present the optimum manufacture method for the similar damage prevention of recurrence.

• Nuclear Engineering and Technology
• /
• v.33 no.3
• /
• pp.339-348
• /
• 2001

NSSS Control Systems automatically mitigate transient conditions and leads to a stable plant condition without operator actions when a transient occurs during normal power operation. In this paper, the function and performance of NSSS control systems were examined and evaluated by comparing the predicted results with the measured data for the selected events. Loss of a Main Feedwater Pump and Load Rejection to House Load Operation events were selected for the evaluation among the transient tests peformed during the Power Ascension Test (PAT) of UCN unit 4. The overall schematic control actions of NSSS control systems can be evaluated easily through the observation of these two typical events. The selected events were analyzed by the KISPAC computer code[l] which had been used in developing the control logic and determining the control setpoints during the plant design. Additionally, the performance of FWCS during low power operation was evaluated. The result of evaluation showed that the NSSS control systems were designed properly and the performance of the NSSS control systems was excellent and also the computer code had a good prediction capability.

• Journal of Welding and Joining
• /
• v.30 no.2
• /
• pp.16-21
• /
• 2012

• Asian Journal of Atmospheric Environment
• /
• v.12 no.3
• /
• pp.255-273
• /
• 2018

To develop effective emission abatement strategies for eighteen coal-fired power plants located throughout Korea, power plant emission data and TAPM (The Air Pollution Model) were used to quantify the impact of emission reductions on primary $PM_{10}$ concentrations. TAPM was validated for two separate time periods: a high $PM_{10}$ concentration period from April 7 to 12, 2016, and a low $PM_{10}$ concentration period from June 1 to June 6 2016. The validated model was then used to analyze the impacts of five applicable power plant shut-down scenarios. The results showed that shut-down of four power plants located within the Seoul metropolitan area (SMA) would result in up to 18.9% reduction in maximum $PM_{10}$ concentrations, depending on synoptic conditions. A scenario for the shutdown of a single low stack height with highest-emission power plant located nearest to Seoul showed a small impact on averaged $PM_{10}$ concentrations (~1%) and 4.4% ($0.54{\mu}g/m^3$) decrease in maximum concentration. The scenario for four shutdowns for power plants aged more than 30 years within SMA also showed a highest improvement of 6.4% ($0.26{\mu}g/m^3$ in April) in averaged $PM_{10}$ concentrations, and of 18.9% ($2.33{\mu}g/m^3$ in June) in maximum concentration, showing almost linear relationship in and around SMA. Reducing gaseous air pollutant emissions was also found to be significant in controlling high $PM_{10}$ concentrations, indicating the effectiveness of coreduction of power plant emissions together with diesel vehicle emissions in the SMA. In addition, this study is implying that secondary production process generating $PM_{10}$ pollution may be a significant process throughout most regions in Korea, and therefore concurrent abatement of both gas and particle emissions will result in more pronounced improvements in air quality over the urban cities in South Korea.