• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1478-1479
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• 2006

AE(Acoustic Emission) 검출기법을 이용한 새로운 방식의 변압기 on-line 진단 장비의 개발을 소개한다. 금번에 개발된 변압기 진단 장비(AMiD)는 다년간에 걸친 프로젝트 수행과 실 현장측정 결과를 토대로 축적된 경험과 기술력을 바탕으로 설계, 제작되었다. 본 장비는 국내 전력용 변압기의 운전 환경에 적합하며, 각 변압기의 운전 환경과 운전 조건에 따라 유동적으로 적용될 수 있다. 본문에서는 장비의 기본적인 사양 및 기술적 특징에 대해서 설명한다.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.254-256
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• 2010

본 논문에서는 대용량 연료전지 시스템용 용융탄산염 연료전지 (Molten Carbonate Fuel Cell, MCFC)의 동특성 해석을 한다. MCFC 시스템 정상 운전 시 출력변화에 따른 전력변화율, 장시간 운전 시 출력의 변화, 운전 중단 시 예열 온도 측면에 관한 해석을 수행하고, 해석한 결과는 MATLAB Simulink를 통해 타당성을 검증한다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.106-111
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• 1996

600MWe급 상업용 가압경수로의 무붕산운전 가능성을 핵설계 측면에서 검토하였다. 기본 원자로 핵연료 형태는 AP600 기준으로 무붕산 노심이 가능하도록 핵연료 농축도, BP 재질/갯수/위치/농도, 제어봉의 재질/위치/갯수등의 설계 변수등을 변화시켰다. 핵연료 농축도는 1.95w/o, 2.9w/o, 3.5w/o를 사용하였으며, BP의 갯수는 8에서 24개까지 사용하였으며, 재질은 Gd$_2$O$_3$, 농도는 축방향 출력분포를 평탄화 시키기 위하여 10w/o-14w/o를 사용하였다. 제어봉 설계에서 재질은 경제적이며, 제어봉가가 큰 B$_4$C를 사용하였으며, 반응도 제어에는 weak 제어봉을 사용하여 출력분포에 대한 영향을 최소화 하도록 설계하였다. 또한 출력분포제어에는 독립적으로 작동되는 고반응도가의 제어봉을 설정하여 노심 상부에서 동작하게 함으로써 반응도에 미치는 영향이 적도록 설계하였다. 설계 결과 아직 안전성 확보 여부에 대한 연구가 수행되지 않은 상태이나 주기초에서 주기말까지 잉여반응도를 1% 미만으로 유지하고, 축방향 BP zoning이 이루어지면 현재의 상업용 원자로에도 무붕산 운전이 가능할 것으로 판단된다. 또한 주기초 A.O.가 -14%, 제어봉의 삽입과 인출에 따른 국부 첨두치가 2.16으로 나타나 안전성 확보에도 큰 어려움은 없을 것으로 생각된다.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.193-193
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• 1999

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.589-597
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• 2010

Strengthening the regulation standard of biological nutrient in wastewater treatment plant(WWTP), the necessity of repair of WWTP which is operated in conventional activated sludge process to advanced nutrient removal treatment is increased. However, in full-scale wastewater treatment system, it is not easy to fine the optimized operational condition of the advanced nutrient removal treatment through experiment due to the complex response of various influent conditions and operational conditions. Therefore, in this study, an upgrading design of conventional activated sludge process to advanced nutrient removal process using the modeling and simulation method based on activated sludge model(ASMs) is executed. And a design optimization of advanced treatment process using the response surface method(RSM) is carried out for statistical and systematic approach. In addition, for the operational optimization of full-scale WWTP, a correct analysis about kinetic variables of wastewater treatment is necessary. In this study, through partial least square(PLS) analysis which is one of the multivariable statistical analysis methods, a correlation between the kinetic variables of wastewater treatment system is comprehended, and the most effective variables to the advanced treatment operation result is deducted. Through this study, the methodology for upgrading design and operational optimization of advanced treatment process is provided, and an efficient repair of WWTP to advanced treatment can be expected reducing the design time and costs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.44-54
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• 2018

Stress and fatigue of the distributor, an equipment of the high-pressure evaporator for the HRSG, were evaluated according to ASME Boiler & Pressure Vessel Code Section VIII Division 2. First, from the results of the piping system analysis model, reaction forces of the tubes connected to the distributor were derived and used as the nozzle load applied to the detailed analysis model of the distributor afterward. Next, the detailed model to analyze the distributor was constructed, the distributor being statically analyzed for the design condition with the steam pressure and the nozzle load. As a result, the maximum stress occurred at the bore of the horizontal nozzle, and the primary membrane stress at the shell and nozzle was found to be less than the allowable. Next, for the transient operating conditions given for the distributor, thermal analysis was performed and the structural analysis was carried out with the steam pressure, nozzle load, and thermal load. Under the transient conditions, the maximum stress occurred at the vertical downcomer nozzle, and of which fatigue life was evaluated. As a result, the cumulative usage factor was less than the allowable and hence the distributor was found to be safe from fatigue failure.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.150-155
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• 2015

Recently, LNG receiving terminals have been widely constructed and expanded for an increase in LNG demand. Selection of the storage tank for send-out and estimation of send-out flow rate have significant influence to process operation and economics. In this study, a send-out flow rate of each storage tank is optimized in order to minimize the total BOG generation rate. Considering a size and characteristic of each storage tanks, BOG flow rates are estimated using a dynamic simulation with varying liquid levels in the tanks. The regression model is developed fitting BOG flow rates and tank liquid levels, which are boil off rate model to predict BOG flow rates with particular level data. The objective function and constraints including required total send-out flow rate and level limit in the tanks are formulated to optimize a send-out flow rate of each tank. This method for optimization of send-out operation is applied to the Incheon LNG receiving terminal considering two scenarios for various liquid levels and maximum and minimum required send-out flow rates. For maximum required send-out flow rate, this method achieves BOG reduction of 9% comparing with assumed conventional operation.

• Clean Technology
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• v.23 no.2
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• pp.163-171
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• 2017

Currently, researches on recycling and reuse of waste energetic materials have recently gained a great attention from advanced countries due to ever tightening environmental regulations. In this study, as a part of a recycling technology, the experiments and dynamic simulation of simulated moving bed (SMB) process were performed to efficiently separate TNT and RDX from their mixture, which are main components of ammunition. In order to determine the operation zone of SMB process, the retention times of TNT and RDX were measured using HPLC at different flow rates and the adsorption equilibrium of each component was obtained by using a moment method. According to the adsorption equilibrium and the triangle theory of SMB process, four operation points were determined and separation experiments were carried out by the SMB process using the solvent consisting of acetonitrile and water. Two different mixing ratios (6:4 and 1:1) of acetonitrile and water were chosen for the experiment due to the great impact of mixing ratio of the solvent on separation. The performance of SMB process was evaluated by purity, recovery, productivity and solvent consumption. Pure TNT and RDX were successfully obtained from the SMB process and the dynamic simulation for the SMB process agreed well with the experimental results. Therefore, the dynamic model could be applied for predicting the dynamic behavior of the SMB process and designing a large scale SMB process.

• Korean Journal of Culture and Social Issue
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• v.8 no.1
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• pp.17-40
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• 2002

The purpose of this study is to investigate the differences in the traffic environments and driving behaviors in 5 regions of Korea. Data were collected through the survey research from 1387 passenger car drivers in 14 locations in Korea. The main findings of this research are as followings: First of all, There were significant differences in traffic environment factors(road topography, construction, road & safety facilities, pedestrian behaviors, surrounding drivers) among 5 regional areas. When we examined drivers factors, there were significant differences among 5 metropolitan areas on wearing seat belt, most of constructions related to drink driving, speed-limit violation. There were many differences in driving habits, intentions, behaviors including wearing seat belt, driving after drinking according to metropolitan area, and also in case of speed-limit violation and careless driving behavior. These results suggested that there are many differences in traffic environments and driver's behaviors among regional areas. These result suggests that traffic safety policy and practice should be prepared based upon the peculiarities of regional area. We discussed these resulte in terms of the regional traffic policy and the suggestions for future studies were added.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.671-688
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• 1998

본 논문은 작업그룹의 과업을 수행하는 인지적 과정을 분석하는 방안을 제시한다. 먼저, 그룹의 인지현상을 연구하는 분산인지이론을 검토하고, 기존의 개인 과업 분석 방법론중의 하나인 GOMS를 확장하여 그룹에 적용할 수 있는 분산형 GOMS 방법론을 제안한다. 제안한 분산형 GOMS 방법론을 작업그룹의 실제 사례인 원자력 발전소의 주 제어실 운전반의 한 과업에 시험적으로 적용하여 분석해 본 결과를 제시한다. 각 구성원의 업무 수행 시간, 의사소통시간, 최대인지 부하등을 기초로 작업그룹의 업무 수행시간과 인지 부하의 ？형도를 계산하여 그룹의 과업에 대해 분석하였다.