• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.91-97
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• 2012

In this study, cost analysis of electrokinetic (EK) restoration process for desalination of saline agricultural land was performed for field application based on a pilot scale field application. For reasonable cost analysis, EK process was classified into three major parts: system design, installation and operation. Cost of system installation consists of materials and installation for electrode/electric wire, power supply and data monitoring, drainage system, etc. Operation cost was calculated based on electrical consumption and water charges for EK process. Total cost for EK process was 2,943,013 won for $1000m^2$ in greenhouse area. Cost for system installation was 2,553,786 won, that is, 87% of total cost, while cost for system operation was 389,229 won, that is, 13% of total cost.

• 공업화학
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• 제34권4호
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• pp.331-346
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• 2023

탄소중립 달성을 위해 에너지 효율적이고 전기화된 사회에 직접 이용될 수 있는 친환경 공정이 주목받고 있다. 다량의 에너지를 소모하는 기존의 열 및 압력 기반의 담수화 기술에서도 이는 예외가 아니기에, 최근 차세대 전기화학 기반 담수화 기술들의 성장이 두드러진다. 대표적으로 에너지 저장 장치의 구동 원리를 기반으로 하는 전기화학적 이온 분리(electrochemical ion separation, EIONS) 기술이 있으며, 여기에는 축전식 탈염(CDI) 기술과 배터리 담수화 시스템(BD)가 포함된다. EIONS 기술에는 시스템 성능 향상을 위해 CDI와 BD를 기본으로 한 다양한 응용 시스템들이 개발되어 왔는데, 이러한 결과물들의 의미와 독창성을 배경지식 없이 한눈에 파악하기 매우 어렵다. 따라서 우리는 이 리뷰 논문에서 EIONS 연구에서의 지난 몇 년간의 기술적 진보와 시스템 개별 특성을 각 시스템의 구동원리, 연구 배경, 장단점을 중심으로 명확하고 구체적으로 설명하고자 한다. 아울러, EIONS의 미래 발전과 연구 방향을 설명하며 리뷰 논문을 마무리하겠다. 이 논문을 통해 EIONS 연구를 막 시작하는 연구자들이 EIONS의 연구 동향을 보다 쉽게 파악할 수 있을 것이다.

• 상하수도학회지
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• 제22권3호
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• pp.337-342
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• 2008

A population growth and industry advances are increasing the demand for water while improving the quality of life. By turning seawater into freshwater it is an alternative for the water shortage problem. The study analyzes the orders and makes suggestions on the outlook of an enterprise that can supply desalination plants both inside and outside the country. It compares the production capacity of enterprises in the desalination industry who deal with the thermal and RO methods. We compare 7 enterprises in the thermal method which includes Doosan Heavy Industries, and the top 10 enterprises in the RO method which includes General Electric Corp. Now that the markets in the Middle East have opened and markets in other regions are gradually growing, demand for water will grow especially in developing countries that are in the process of industrialization. Also, the market share of thermal method desalination has been falling, gradually, because too much energy is spent during the process. On the other hand, the market share of the RO method will rise from 37% in 2005 to 57% in 2015. Recently, the desalination market shows that changing from thermal method to RO method is the trend in the Middle East. Growth and demand in other regions are growing at the same pace as the Middle East. Due to this trend, if the RO system, which is highly effective and uses less energy, were to be continuously developed it would be possible to supply water using sea water and would be a viable alternative water resource.

• 상하수도학회지
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• 제30권6호
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• pp.635-643
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• 2016

Gas hydrate (GH)-based desalination process have a potential as a novel unit desalination process. GHs are nonstoichiometric crystalline inclusion compounds formed at low temperature and a high pressure condition by water and a number of guest gas molecules. After formation, pure GHs are separated from the remaining concentrated seawater and they are dissociated into guest gas and pure water in a low temperature and a high pressure condition. The condition of GH formation is different depending on the type of guest gas. This is the reason why the guest gas is a key to success of GH desalination process. The salt rejection of GH based desalination process appeared 60.5-93%, post treatment process is needed to finally meet the product water quality. This study adopted reverse osmosis (RO) as a post treatment. However, the test about gas rejection by RO process have to be performed because the guest gas will be dissolved in a GH product (RO feed). In this research, removal potential of dissolved gas by RO process is performed using lab-scale RO system and GC/MS analysis. The relation between RO membrane characteristics and gas removal rate were analyzed based on the GC/MS measurement.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.27-33
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• 2007

In this research, to develop the practical application system of fresh water generation system with plate-type fresh water generator using low pressure evaporation method is the main object, and to do that, this study used the evacuated solar collector with operating range of about $50-85^{\circ}C$ as thermal energy source and solar photovoltaic as electric energy source. To achieve that object, this study set up the demo-plant, then estimated and analyzed the usefulness, the safety, and the reliability through pre-tests during short time ahead of the long-time operation. This study showed that the pumps, which are including sea water supply, ejector, hot water supply, and fresh water pumps, were operated one after another. And, the fresh water yield was closely related with the solar irradiance and lower supply temperature of hot water was revealed more reasonable for the solar energy desalination system. That is due to the insufficient area than the solar collector area being required that was estimated through the performance tests of the fresh water generator.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.137-143
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• 2010

In this study, the ejector design was modeled using Fluent 6.3 of FVM(Finite Volume Method) CFD(Computational Fluid Dynamics) techniques to resolve the flow dynamics in the ejector. A vacuum system with the ejector has been widely used because of its simple construction and easy maintenance. Ejector is the main part of the desalination system, of which designs determine the efficiency of system. The effects of the ejector was investigated geometry and the operating conditions in the hydraulic characteristics. The ejector consists mainly of a nozzle, suction chamber, mixing tube(throat), diffuser and draft tube. Liquid is supplied to the ejector nozzle, the fast liquid jet produced by the nozzle entrains and the non condensable gas was sucked into the mixing tube. In the present study, the multiphase CFD modeling was carried out to determine the hydrodynamic characteristics of seawater-air ejector. Two-dimensional geometry was considered with the quadrilateral-mashing scheme. The gas suction rate increases with increasing Motive flow circulating rate.

• 상하수도학회지
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• 제30권4호
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• pp.459-469
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• 2016

Gas hydrate desalination process is based on a liquid to solid (Gas Hydrate, GH) phase change followed by a physical process to separate the GH from the remaining salty water. The GH based desalination process show 60.5-90% of salt rejection, post treatment like reverse osmosis (RO) process is needed to finally meet the product water quality. In this study, the energy consumption of the GH and RO hybrid system was investigated. The energy consumption of the GH process is based on the cooling and heating of seawater and the heat of GH formation reaction while RO energy consumption is calculated using the product of pressure and flow rate of high pressure pumps used in the process. The relation between minimum energy consumption of RO process and RO recovery depending on GH salt rejection, and (2) energy consumption of electric based GH process can be calculated from the simulation. As a result, energy consumption of GH-RO hybrid system and conventional seawater RO process (with/without enregy recovery device) is compared. Since the energy consumption of GH process is too high, other solution used seawater heat and heat exchanger instead of electric energy is suggested.

• Nuclear Engineering and Technology
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• 제47권3호
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• pp.293-305
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• 2015

In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 $MW_{th}$ and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

• 동력기계공학회지
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• 제16권3호
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• pp.5-9
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• 2012

Novel mechanisms for Energy Recovery Devices are proposed to diminish the pressure loss in the high-pressure reverse-osmosis system. In the beginning, the state-of-the-art in the design of Energy Recovery Devices is reviewed and the features of each model are investigated. The direct-coupled axial piston pump(APP) and axial piston motor(APM) showed 39% energy recovery at operating pressure of reverse osmosis desalination systems, 60 bar. Meanwhile, the developed PM2D model, in which APM pistons are arranged parallel to those of APP, is more compact and showed higher efficiency in a preliminary test. Loss-reduction mechanisms employing rod piston and double raw valve port are additionally proposed to enhance the efficiency and durability of the device.

• 한국물환경학회지
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• 제20권5호
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• pp.447-451
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• 2004

The various pretreatment processes were evaluated to remove organic pollutants of weathered oil contaminated seawater(WOCS) for reverse osmosis desalination process, Biodegradation, coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration were used to evaluate the potential of organic pollutants removal in WOCS. Dissolved Organic Carbon(DOC) was almost not removed by biodegradation in WOCS. DOC was removed by 25% and 10% with the addition of $FeCl_3$ and PAC in WOCS, respectively. The removal efficiency using ultrafiltration(WOCS 500) was about 20% of DOC and 40% of $E_{260}$, respectively. In AOP application of WOCS, the removal of organic materials was improved up to 60% by the combination of $UV/O_3$ compared to UV process. However, 98% of DOC in woes could be removed by granular activated carbon filtration. It is revealed that activated carbon filtration is the best process for the pretratment of DOC removal.