• Journal of Advanced Marine Engineering and Technology
• /
• 제39권10호
• /
• pp.1037-1043
• /
• 2015

In recent years, Floating Liquefied Natural Gas (FLNG) Unit have attracted considerable attention. Generally, liquefied natural gas (LNG) units are produced in onshore liquefaction terminals from gas supplied from onshore gas fields or large-scale offshore gas fields near the coast. However, the development of these gas fields has approached saturation. Large-scale offshore gas fields far from the coast, as well as undeveloped medium- and small-scale offshore gas fields, have recently attracted attention. Among several proposed concepts, the floating LNG plant in the form of the FLNG system was chosen for further evaluation and development, considering worldwide receiving infrastructure. The design of a 2.5 million tonne per annum FLNG unit has been completed with a capacity corresponding to that of modern onshore liquefaction plants. Various simulation tests were performed to evaluate the performance of the electrical power plant, focusing on the efficiency of the electrical system to secure the aspects of plant safety. This design study analyzes the electrical system for the FLNG unit to improve the safety of operation and maintenance in the field.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 A
• /
• pp.431-433
• /
• 2000

The hydroelectric Power plant of the KOWACO have been establishing and operating a full scale electric power facility, doing the largest generation during the flood period of the summer season. When the huge capacity generator is run like the Chung-Ju's hydroelectric Power plant, the generator current per generator flows a great current estimated at 5,900 A. The bus bar of a great current flows in cubicle, owing to the bus bar current Eddy current is created around magnetic substance and a local heating phenomenon occurs due to Joule heat finally. a local heating phenomenon still exists the danger of safety accident due to contact and accompanies losses enough to healing capacity inevitably. this study applies and examines related theory and numerical formula about the heating cause of a great current & enforces technical verification about the method of heating reduction previous managed at the site.

• 한국안전학회지
• /
• 제31권1호
• /
• pp.132-138
• /
• 2016

The purpose of this study was to develop safety competences, a set of behavioral indicators of each competence and measuring methods of behavioral indicators for preventing human error of nuclear power plants(NPPs). The safety competences and behavioral indicators were derived from the five steps consisted of derivation of preliminary competence items through literature review, content analysis, interview(FGI, BEI), examination of content validity and decision making of final indicators. The results showed that 13 core safety competences and 35 behavior indicators were derived finally. In addition, the methods of measuring safety competences or behavioral indicators such as Behaviorally Anchored Rating Scale (BARS), Behavior Observation Scale (BOS) were developed and suggested.

• 비파괴검사학회지
• /
• 제32권5호
• /
• pp.545-550
• /
• 2012

원자력발전소 증기발생기 세관은 방사성물질이 외부로 누출되지 않도록 압력경계 역할을 하는 주요부품이다. 설비 운전기간이 증가함에 따라 이차측에서 유입된 슬러지가 증기발생기 2차측 유체 흐름을 따라 상부로 이동하면서 유체비등과 난류에 의해 세관 외면에 스케일이 부착되어 세관열화, 유로홈 막힘 및 열전달을 감소시키는 파울링을 유발하는 원인으로 작용한다. 따라서, 원전 운영자는 세관 외면에 쌓인 스케일의 두께를 확인하여 일정시점이 되면 화학세정 등의 정비를 수행한다. 본 논문에서는 보빈코일 와전류신호를 이용하여 세관 외면에 부착된 스케일 두께를 정량적으로 평가하는 기술을 개발하고자 스케일 시험편을 제작하여 스케일 두께와 와전류신호 진폭 간의 상관관계를 분석하였고, 이를 바탕으로 스케일의 두께를 정량적으로 평가하는 기법과 대량의 와전류 데이터를 평가할 수 있는 프로그램을 개발하였다.

• KEPCO Journal on Electric Power and Energy
• /
• 제2권1호
• /
• pp.109-113
• /
• 2016

Techno-economic evaluation of Non-Capture $CO_2$ Utilization (NCCU) technology for the production of high-value-added products using greenhouse gas ($CO_2$) was performed. The general scheme of NCCU process is composed of $CO_2$ carbonation and brine electrolysis process. Through a carbonation reaction with sodium hydroxide that is generated from brine electrolysis and $CO_2$ of the flue gas, it is possible to get high-value-added products such as sodium bicarbonate, sodium hydroxide, hydrogen & chloride and also to reduce the $CO_2$ emission simultaneously. For the techno-economic study on NCCU technology, continuous operation of bench-scale facility which could treat $2kgCO_2/day$ was performed. and based on the key performance data evaluated, the economic evaluation analysis targeted on the commercial chemical plant, which could treat 6 tons $CO_2$ per day, was performed using the net present value (NPV) metrics. The results showed that the net profit obtained during the whole plant operation was about 7,890 mKRW (million Korean Won) on NPV metrics and annual $CO_2$ reduction was estimated as about $2,000tCO_2$. Also it was found that the energy consumption of brine electrolysis is one of the key factors which affect the plant operation cost (ex. electricity consumption) and the net profit of the plant. Based on these results, it could be deduced that NCCU technology of this study could be one of the cost-effective $CO_2$ utilization technology options.

• Structural Engineering and Mechanics
• /
• 제50권1호
• /
• pp.89-103
• /
• 2014

According to experimental studies made so far, design formula of shear characteristics suggested by ISO 22762 and JEAG 4614, representative design code for Lead Rubber Bearing(LRB) shows dependence caused by changes in compressive stress. Especially, in the case of atypical special structure, such as a nuclear power structure, placement of seismic isolation bearing is more limited compared to that of existing structures and design compressive stress is various in sizes. As a result, there is a difference between design factor and real behavior with regards to shear characteristics of base isolation device, depending on compressive stress. In this study, a full-scale low hardness device of LRB, representative base isolation device was manufactured, analyzed, and then evaluated through an experiment on shear characteristics related to various compressive stresses. With design compressive stress of the full-scale LRB (13MPa) being a basis, changes in shear characteristics were analyzed for compressive stress of 5 MPa, 10 MPa, 13 MPa, 15 MPa, and 20 MPa based on characteristics test specified by ISO 22762:2010 and based on the test result, a regression analysis was made to offer an empirical formula. With application of proposed design formula which reflected the existing design formula and empirical formula, trend of horizontal characteristics was analyzed.

• 한국항행학회논문지
• /
• 제28권3호
• /
• pp.348-355
• /
• 2024

원전해체 시 대용량 처분시스템을 구동하거나 운영 중 제어봉 구동장치 제어시스템과 같은 대규모 측정전류를 요하는 중요설비를 측정 및 테스트하기 위해서는 측정 매체로서 안정적으로 전류를 공급할 수 있는 전류원이 필요하다. 그러나, 흔히 말하는 전원공급기는 전압원으로서 전압만을 내기 때문에 측정부하에 관계없이 일정한 전류를 공급할 수 있는 전류원 역할을 하지 못한다. 전류원은 전압원과 달리 제품을 만들기가 쉽지 않다. 원전 부품의 전류-전압 변환시험과 같은 건전성을 평가하기 위해서는 정상전류치보다 몇십배 훨씬 큰 수십 mA나 암페어 수준의 전류를 인가하여 테스트를 수행해야 하기 때문에 암페어(ampere) 단위의 전류를 공급할 수 있는 전류원이 필수적이다. 따라서 본 개발품에서는 이러한 필요에 의하여 입력이 전압으로 나타나는 전압원을 이용하여 측정대상에 원하는 전류를 일정하게 공급할 수 있는 전압제어으로서 대용량 전류를 공급할 수 있는 직류전압제어 대전류원을 개발하였다. 개발된 제품의의 신뢰성을 확인하기 위하여 원전에서 사용되는 실제의 데이터값을 적용하여 테스트하였으며, 그 결과를 분석하여 선택회로의 정당성을 입증하였다.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 2004년도 학술발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
• /
• pp.7-12
• /
• 2004

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.939-944
• /
• 2001

For the application of simultaneous $DeSO_{2}\;&\;DeNO_{x}$ equipment using non-thermal plasma process to the industrial and power plants, the many types of plasma device and process were studied. The e-beam and pulsed plasma corona discharge process are outstanding for the study to apply commercial large-scale plant from among these. In this paper, non-thermal plasma of technical trends and the characteristics of system developed by Doosan heavy industries & construction Co., Ltd. are explained. We have researched pulsed plasma corona discharge process since 1994. At the basis of reasonable results for the pilot plant, we constructed the demonstration plant at a domestic coal-fired power plant in 1999, as the previous step for commercial use. In near future, enough information about designs and costs of commercial-size system will be obtained.

• 한국수소및신에너지학회논문집
• /
• 제30권6호
• /
• pp.490-498
• /
• 2019

The intermittent electric power supply of renewable energy can have extremely negative effect on power grid, so long-term and large-scale storage for energy released from renewable energy source is required for ensuring a stable supply of electric power. Power to gas which can convert and store the surplus electric power as hydrogen through water electrolysis is being actively studied in response to increasing supply of renewable energy. In this paper, we proposed the novel concept of hydrogen liquefaction process combined with pre-cooling process using the liquid air. It is that hydrogen converted from surplus electric power of renewable energy was liquefied through the hydrogen liquefaction process and vaporization heat of liquid hydrogen was conversely recovered to liquid air from ambient air. Moreover, Comparisons of specific energy consumption (kWh/kg) saved for using the liquid air pre-cooling was quantitatively conducted through the performance analysis. Consequently, about 12% of specific energy consumption of hydrogen liquefaction process was reduced with introducing liquid air for pre-cooling and optimal design point of helium Brayton cycle was identified by sensitivity analysis on change of compression/expansion ratio.