• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.111-112
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• 2011

지구환경문제에 대응하기 위한 탄소배출량 저감 기술 개발과 같은 대응기술 개발이 시급한 가운데 수 해양 공간에 대한 수요의 증가로 플로팅 건축물에 대한 관심 또한 증가하고 있다. 이에 본 연구에서는 플로팅 건축물 주변에 존재하는 신재생에너지 중 해수 열 이용을 위한 수중 열교환기의 성능을 FLUENT를 이용하여 예측 분석하였다.

• Environmental engineer
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• s.323
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• pp.86-95
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• 2013

본 발명은 해수의 담수화 장치에 관한 것으로, 해수를 증기와 온수로 변환하도록 태양열을 이용하여 상기 해수를 가열하는 가열기와, 상기 가열기에 의해 변환된 상기 증기와 상기 온수를 분리하는 분리기를 포함하며, 상기 가열기는, 오목한 곡면을 갖는 반원통 형상으로 마련되고, 상기 반원통 형상의 길이방향을 따라 위치하는 다수의 초점을 향하여 내면으로 조사된 태양광을 반사하는 반사렌즈 및 상기 반사렌즈에 의해 반사된 상기 태양광의 열 에너지에 의해 상기 해수를 가열하도록, 상기 반사렌즈의 초점이 위치하는 길이방향의 지점을 따라 상기 해수가 흐를 수 있도록 형성되는 유로관을 포함하는 것을 특징으로 한다.

• Economic and Environmental Geology
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• v.50 no.4
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• pp.267-276
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• 2017

Seawater intrusion into coastal fractured rock aquifer, resulting in groundwater contamination, is of serious concern in coastal areas of Jeolla Namdo, Korea, which heavily depends on groundwater resources. Time series analysis and forecasting were carried out to analyze and predict EC which is a major indicator of seawater intrusion. Two time series models of autoregressive integrated moving average (ARIMA) and seasonal autoregressive integrated moving average (SARIMA) were tested for suggesting appropriate time series model. Time series data of EC measured over one year showed a increasing trend with short periodic fluctuations, due to tidal effect and pumping, which indicated that EC time series data tended to be non-stationary. SARIMA model was found better fitted to observed EC than any other time series model. Time series analysis and modeling was found to be a useful tool to analyze EC at coastal fractured rock aquifer subject to seawater intrusion.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.6
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• pp.422-432
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• 2013

A System Identification method to develop parametric models linking free surface elevation and wave pressure is presented and two models are built allowing for either wave pressure or free surface elevation simulation. Linear, time invariant model structures with static nonlinearities are assumed and solutions are sought in a form of autoregressive model with extra input (ARX). An arbitrary chosen free-surface elevation and wave pressure dataset is used for estimation of the models, which are subsequently verified against datasets with similar pressure gauge depth but different free-surface elevation spectra due to different meteorological conditions. It is shown that free-surface simulation using System Identification methods can perform better than traditional linear transfer function derived from linear wave theory (LTF), while wave pressure simulation quality using presented methods is generally similar to that obtained with corrected LTF.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.8
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• pp.511-519
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• 2017

In this study, we have performed tests to improve the productivity of hybrid solar stills, which can be operated by solar thermal energy and/or waste heat of exhaust gas from electrical generators. The experimental apparatus is a hybrid solar still with a $1m{\times}2m$ collecting area, which consists of a conventional simple solar still and a vertical multi-effect diffusion(MED) section. The experiments were conducted under various operating conditions, with two identical hybrid solar stills, using solar radiation as the energy source. The results of the tests showed that the yield of the hybrid solar still depends on the various operating conditions. Insulation at the side glasses and a lower basin seawater level increased the productivity of the hybrid solar still. Reflecting fins with less than 47% reflectivity unexpectedly decreased the total productivity. However, the various feeding flow rate of the seawater into MED part did not show clear effects on productivity in the tested range.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.3
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• pp.236-247
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• 2011

This study investigates sea level (SL) rise due to global warming in the Northwestern Pacific (NWP) and Seas around the Korean peninsula (KP) using outputs of IPCC AR4 climate models. Particularly, components of the SL rise induced by a local steric effect, which was not considered in most climate models, were computed using model-projected 3-dimensional temperature and salinity data. Analysis of the SL data shows that the ratio of the SL rise in the NWP and KP was about two times higher than that in global mean and particularly the ratio in the Kuroshio extension region was the highest. The SL rises over 100 years estimated from MPI_ECHAM5 and GFDL_CM2.1 model by A1B scenario considering the thermosteric effect were 24 cm and 28 cm for the NWP and 27 cm and 31 cm for the Seas around the KP, respectively. Statistical analysis reveals that these SL rises are caused by the weakening of the Siberian High in winter as well as variations of pressure system in the NWP and by the resultant change of water temperature. It also found that the highest SL rise in the Kuroshio extension region of the NWP was connected with the large increase of water temperature in this area.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.43 no.4
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• pp.26-33
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• 2014

• Nuclear industry
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• v.23 no.6 s.244
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• pp.72-75
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• 2003

원자력 발전 과정에서 발생되는 열에너지를 해수 담수화의 공정에 활용하고자 하는 노력이 지속적으로 전개되고 있다. 가까운 미래에 전 세계적으로 물 부족 현상이 심화될 것으로 전망되고 있으며 기존의 지표수 혹은 지하수를 이용한 식수 및 산업 용수의 공급은 멀지 않아 한계에 부딪칠 것으로 예상하고 있다. 본 논문에서는 해수 담수화 기술의 기본적 특성을 살펴보고 열 공급원으로서 고려되고 있는 다양한 담수 기술에 대한 경제성 전망을 중심으로 정리하였다.

• 한국해양학회지
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• v.24 no.1
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• pp.29-38
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• 1989

It has been believed that the circulation in the Japan Sea involves separation of current from the Korean coast and formation of a cold cyclonic gyre in the north. To explain this, a simple quasi-geostrophic linear model is considered. The model is basically of an inflow-outflow system. The local forcings, wind and air-sea heat exchange together with damping (both mechanical and thermal), are imposed upon. The results show that only the buoyancy damping due to perturbations from local thermal adjustment can cause the separation and the gyre. Various types of circulation patterns are possible depending on the intensity of the thermal forcing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.341-345
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• 2021

Known to improve resistance to chloride ingress, blast furnace slag is a widely used supplementary cementitious material. However, a detailed characterization of cements blended with slag exposed to seawater remains unavailable. This study employs thermodynamic modeling as a toolkit for assessing the long-term phase evolution of slag cement in seawater. The modeling result shows that slag incorporation leads to the formation of phases that are less prone to structural alteration in seawater. Formation of more ettringite is expected to induce expansion in both plain and blended cements, while brucite is unstable in the blended systems. Despite this, the porosity is expected to increase in the blended cements, and aluminate hydrates with a higher chloride binding capacity are more abundant in the blended cements. The results suggest that the use of slag in concrete improves the durability performance of concrete in marine environments.