• Membrane and Water Treatment
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• 제4권4호
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• pp.237-249
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• 2013

Ultra-pure water (UPW), a highly treated water free of colloidal material and of a conductivity less than 0.06 ${\mu}S$, is an essential component required by modern industry. One of the methods for UPW production is the electrodialysis-ion exchange (ED/IE) system, in which the electrodialysis (ED) process is used as a preliminary demineralization step. The IE step can be replaced with electrodeionization (EDI) to decrease the volume of post-regeneration lyes. In this paper, the electrodialysis process carried out to relatively low diluate conductivity was investigated and the costs of UPW production were calculated. The optimal value of desalination degree by ED in the ED/IE and ED/EDI systems was estimated. UPW unit costs for integrated ED/IE and ED/EDI systems were compared to simple ion exchange and other methods for UPW production (RO-IE, RO-EDI). The minimal UPW unit costs in ED/EDI integrated system were estimated as $0.37/$m^3$ for feed TDS 600 mg/L and $0.36/$m^3$ for feed TDS 400 mg/L at 64 $m^3/h$ capacity, which was lower than in the comparable ED/IE integrated system ($0.42-0.44/$m^3$). The presented results suggest that an ED/EDI integrated system may be economically viable.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1250-1259
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• 2001

This study was experimentally performed to investigate sea water freezing behavior along parallel cooled plate with bubbly flow The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-plate temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

• 한국소음진동공학회논문집
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• 제19권11호
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• pp.1103-1109
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• 2009

In this paper, the control of a membrane used in reverse osmosis desalination plant by using immune algorithm(IA) is addressed. The proposed algorithm IA of auto tuning method can find optimal gains and compared with conventional Ziegler-Nichols tuning method. The results of computer simulation represent that the proposed IA shows a good control performances better than Ziegler-Nichols tuning method.

• 한국막학회:학술대회논문집
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• 한국막학회 2008년도 춘계 총회 및 학술발표회
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• pp.210-213
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• 2008

• 대한기계학회논문집B
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• 제32권12호
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• pp.931-937
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• 2008

A high motive pressure thermal vapor compressor(TVC) for a commercial multi-effect desalination(MED) plant is designed to have a high entraining performance and its robustness is also considered in the respect of operating stability at the abrupt change of the operating pressures like the motive and suction steam pressure which can be easily fluctuated by the external disturbance. The TVC having a good entraining performance of more than entrainment ratio 6.0 is designed through the iterative CFD analysis for the various primary nozzle diameter, mixing tube diameter and mixing tube length. And then for a couple of TVC having a similar entrainment ratio, the changes of the entrainment ratio are checked along the motive and suction pressure change. The system stability is diagnosed through the analyzing the changing pattern of the entrainment ratio.

• 대한토목학회논문집
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• 제42권3호
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• pp.351-357
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• 2022

본 연구에서는 하수재이용과 해수담수화를 동시에 진행할 수 있는 규모 1,000 m³/d의 FO-RO 융합공정과 동일한 규모의 기존 SWRO 공정의 탄소배출량을 계산하여 비교 분석하였다. FO-RO 융합공정은 FO 공정을 도입하여 RO 공정 원수를 희석시킬 수 있기 때문에 RO 공정의 요구 압력이 감소되고 이는 곧 에너지소비량 감소로 이어진다. 에너지소비량에 따른 탄소배출량은 FO-RO 융합공정이 SWRO 공정보다 -0.73 kgCO₂(coal로 전력생산 시) 낮으며, FO 공정 추가 건설로 인해 발생되는 탄소배출량은 +0.16 kgCO₂로 계산되어 FO-RO 융합공정의 총 탄소 배출량이 더 낮은 것으로 나타났다. 하지만, Coal나 oil과 같은 화석연료로 전력을 생산하지 않고, 전력생산 시 탄소배출량이 적은 nuclear나 solar 등으로 사용하면 FO-RO 융합공정의 총 탄소배출량이 SWRO 공정보다 더 높은 것으로 나타났다. 즉, 탄소배출량 관점에서는 전력생산 시 필요 재료(예: coal, oil, nuclear, solar 등)에 따라 친환경적인 공정 판단 여부가 결정되므로 FO-RO 융합공정 도입 필요성을 좌우하는 핵심 요소라고 할 수 있다.

• 설비공학논문집
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• 제28권11호
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• Journal of Radiation Protection and Research
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• 제26권3호
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• pp.225-229
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• 2001

In Korea, an advanced reactor system of 330MWt power called SMART (System integrated Modular Advanced ReacTor) is being developed by KAERI to supply energy for seawater desalination as well as electricity generation. A shielding design of the SMART core with 49 CEDM is established by a two-dimensional discrete ordinates radiation transport analyses. The DORT two-dimensional discrete ordinates transport code is used to evaluate the SMART shielding designs. Three axial regions represent the SMART reactor assembly, each of which is modeled in the R-Z geometry. The BUGLE-96 library is used in the analyses, which consists of 47 neutron and 20 gamma energy groups. The results indicate that the maximum neutron fluence at the bottom of reactor vessel is $5.89 {\times} 10^{17}\;n/cm^2$ and that on the radial surface of reactor vessel is $4.49 {\times} 10^[16}\;n/cm^2$. These results meet the requirement, $1.0 {\times} 10^{20}\;n/cm^2$, in 10 CFR 50.61 and the integrity of SMART reactor vessel during the lifetime of the reactor is confirmed.

• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.23-31
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• 2014

This study was accomplished to get the foundation design data of VMD(Vacuum Membrane Distillation) system for Solar Thermal VMD plant. VMD experiment was designed to evaluate thermal performance of VMD using PVDF(polyvinylidene fluoride) hollow fiber hydrophobic membranes. The total membrane surface area in a VMD module is $5.3m^2$. Experimental equipments to evaluate VMD system consists of various parts such as VMD module, heat exchanger, heater, storage tank, pump, flow meter, micro filter. The experimental conditions to evaluate VMD module were salt concentration, temperature, flow rate of feed sea water. Salt concentration of feed water were used by aqueous NaCl solutions of 25g/l, 35g/l and 45g/l concentration. As a result, increase in permeate flux of VMD module is due to the increasing feed water temperature and feed water flow rate. Also, decrease in permeate flux of VMD module is due to increasing salinity of feed water. VMD module required about 590 kWh/day of heating energy to produce $1m^3/day$ of fresh water.

• 적정기술학회지
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• 제7권2호
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• pp.136-143
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• 2021

키리바시를 포함한 태평양 도서국가들은 기후 변화, 지하수 오염 및 식생 변화로 인한 해수면 상승 및 해안 침식으로 인해 생활 공간의 감소 뿐만 아니라 필수 자원 부족으로 고통받고 있다. 이러한 문제를 해결하기 위한 글로벌 활동은 SDGs 이행을 위한 UN의 노력으로 진행되고 있다. 태평양 도서 국가들이 풍부한 해양 자원을 이용하여 기후 변화에 대응하고 적응할 수 있도록 모색해 왔다. 즉, 해수 플랜트는 이러한 태평양 도서 국가에서 SDG # 14를 기반으로 SDG #2, #6 및 #7을 달성하는 데 도움을 줄 수 있다. 선박해양플랜트연구소(KRISO)는 2016년에 설립한 지속가능 해수이용 아카데미(SSUA)를 통해 키리바시 SSUA협회를 결성하고, 해양수산부(MOF)의 해양수산 ODA사업으로 키리바시에 해수플랜트를 지원하였다. 키리바시 SSUA협회는 해수 및 태양에너지를 이용하는 해수플랜트를 이용하여, 2018년부터 2020년까지 지역 사회에 식수와 채소를 공급하는 공익사업을 하고 있다. 역량강화 과정을 통해 키리바시 SSUA협회는 기술 이전을 받았고, 지역사회에 수경재배 시스템의 설치, 모종과 비료 보급, 재배관리 기술지도 및 모니터링을 실시하였다. 협회는 3년 동안 140여 가구에 수경재배 시스템(일부는 태양광발전 패널 제공)을 보급하고, 다양한 채소를 재배하여 자가 소비 또는 판매하게 하였다. 또한, 태양광발전 연계 해수담수화 시스템을 설치하여 식수를 공급하도록 하고 있다. 만족도 조사를 통해 대부분의 수혜 가구가 만족하였고, 주변 지역 및 도서로 보급확산을 희망하고 있음을 알 수 있었다. 따라서, 키리바시 SSUA협회는 공동체 이용 및 관리 체계화를 지원하는 자활사업을 추진할 계획이며, 이러한 활동은 태평양 도서국가들의 SDGs 달성을 지원하기 위한 ODA 프로그램으로 확산될 수 있을 것이다.