• 상하수도학회지
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• 제31권6호
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• pp.599-609
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• 2017

Desalination plants have been recently constructed in many parts of the world due to water scarcity caused by population growth, industrialization and climate change. Most seawater desalination plants are designed with a submarine pipeline for intake and discharge. Submarine pipelines are installed directly on the bottom of the water body if the bottom is sandy and flat. Intake is located on a low-energy shoreline with minimal exposure to beach erosion, heavy storms, typhoons, tsunamis, or strong underwater currents. Typically, HDPE (High Density Polyethylene) pipes are used in such a configuration. Submarine pipelines cause many problems when they are not properly designed; HDPE pipelines can be floated or exposed to strong currents and wind or tidal action. This study examines the optimal design method for the trench depth of pipeline, analysis of on-bottom stability and dilution of the concentrate based on the desalination plant conducted at the Pacific coast of Peru, Chilca. As a result of this study, the submarine pipeline should be trenched at least below 1.8 m. The same direction of pipeline with the main wind is a key factor to achieve economic stability. The concentrate should be discharged as much as high position to yield high dilution rate.

• 상하수도학회지
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• 제27권6호
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• pp.771-778
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• 2013

Gas hydrate (GH) process is a new desalination technology, where GH is a non- stoichiometric crystalline inclusion compounds formed by water and a number of gas molecules. Seawater GH is produced in a low temperature and a high pressure condition and they are separated from the concentrated seawater. The drawback of the GH process so far is that salt contents contained in its product does not meet the fresh water quality standard. This means that the GH process is not a standalone process for seawater desalination and it needs the help of other desalting process like reverse osmosis (RO). The objective of this study is to investigate the effect of GH process on energy saving for RO process in seawater desalination. The GH product water quality data, which were obtained from a literature, were used as input data for RO process simulation. The simulation results show that the energy saving effect by the GH process is in a range of 68 % to 81 %, which increases as the salt removal efficiency of the GH process increases. Boron (B) and total dissolved solids (TDS) concentrations of the final product of the hybrid process of GH and RO were also investigated through the RO process simulation to find relavant salt rejection efficiency of the GH process. In conclusion, the salt rejection efficiency of the GH process should exceed at least 78% in order to meet the product water quality standards and to increase the energy saving effect.

• 멤브레인
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• 제20권3호
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• pp.185-196
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• 2010

현재 우리나라가 세계최고 수준을 보유한 해수담수화기술과 해외 플랜트 수주확대를 위한 정부정책의 필요성에 따라 지속적인 해수담수화 시장 선점을 위한 새로운 핵심기술개발이 중요해지는 시점이다. 본 연구에서는 그 중요성이 부각되고 있는 물산업의 동향, 해수담수화기술의 개요 및 시장현황을 고찰하고, 국가 R&D지원 정책방향 및 기술개발지원현황 자료를 분석하였다. 그 결과 다음과 같은 시사점을 얻을 수 있었다. 기업의 담수플랜트 운전경험 축적을 바탕으로 신뢰성을 확보할 수 있도록 제도적 장치가 필요하며, 원천기술확보를 위한 전략적 R&D지원이 이루어져야 한다. 또한, 담수화 플랜트에 소요되는 핵심기자재에 대한 국산화가 선행되어야 할 것이다.

• 멤브레인
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• 제25권4호
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• pp.301-309
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• 2015

최근 해수담수화 기술에 관한 관심이 증가하면서 해수 전처리 기술의 중요성이 날로 증가하고 있다. 해수담수화 기술은 미래 수처리 핵심기술로 자리매김하고 있고 이를 위한 전처리 기술의 올바른 선택과 운영은 향후 해수담수화 기술의 효율향상과 공정 최적화를 위해 중요하게 고려되어야 할 것이다. 해수담수화 전처리 기술의 목적은 주로 해수에 존재하는 입자성 물질, 콜로이드성 물질, 유기물질, 무기물질 그리고 미생물 오염물질 등의 처리를 통해 후단 담수화 기술의 효율성을 향상시키기 위함이나 전처리 기술 대상 처리물질의 범위는 매우 다양하여 맞춤형 전처리 기술의 적절한 적용이 필요하다. 해수담수화에서 올바른 전처리 기술의 적용은 후단 담수화 시설의 높은 처리효율 및 문제점을 최소화시킴과 동시에 해수의 큰 수질변동과 기후적인 그리고 지역적인 영향 등에 즉각적으로 대처할 수 있으므로 전처리 기술의 운영전략은 미래 해수담수화 기술의 성공여부를 결정짓기 위해 매우 중요하게 다루어져야 한다. 또한 최근에 많은 관심을 가지고 있는 해수 미세조류의 번성은 담수화 전처리 기술의 선정에 있어서 잠재적인 장애가 되고 있어 이에 대한 올바른 이해도 반드시 필요하다. 본 총설에서는 해수담수화 전처리 기술에 관한 그동안의 연구동향을 분석하고 해수담수화 전처리 기술의 선택 및 운전 최적화 달성을 위한 향후 도전과제들을 제시하고자 한다.

• 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.

• Membrane and Water Treatment
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• 제2권3호
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• pp.147-158
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• 2011

Membrane distillation process was used for desalination of hot (333 K) geothermal water, which was applied in the plant producing heating water. The investigated water contained 120 g salts/$dm^3$, mainly NaCl. The mineral composition was studied using an ion chromatography method. The obtained rejection of solutes was closed to 100%, but the small amounts of $NH_3$ also diffused through the membrane together with water vapour. However, the composition of obtained distillate allowed to use it as a makeup water in the heating water system. The geothermal water under study was concentrated from 120 to 286 g NaCl/$dm^3$. This increase in the solution concentration caused the permeate flux decline by a 10-20%. The geothermal water contained sulphates, which was subjected to two-fold concentration to achieve the concentration 2.4-2.6 g $SO{_4}{^{2-}}/dm^3$ and the sulphates then crystallized in the form of calcium sulphate. As a results, an intensive membranes scaling and the permeate flux decline was observed. The XRD analysis indicated that beside the gypsum also the NaCl crystallites were deposited on the membrane surfaces. The fresh geothermal water dissolved the mixed $CaSO_4$ and NaCl deposit from the membrane surface. This property can be utilized for self-cleaning of MD modules. Using a batch feeding of MD installation, the concentration of geothermal water was carried out over 800 h, without significant performance losses.

• Journal of Advanced Marine Engineering and Technology
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• 제38권9호
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• pp.1094-1100
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• 2014

오폐수처리, 해수담수화 및 식품산업의 경우 증발과정은 필수공정이며, 이는 기본적으로 용액으로부터 용매인 순수한 물성분을 추출하여 점차 용액의 농도를 증가시키는 방식이다. 농축을 위한 방식은 전기투석, 증발식, 막방식 등의 다양한 방법이 사용되고 있으나, 본 연구에서는 여러 산업분야에서 적용되고 있는 증발식을 대상으로 운전방식에 따른 가열열원의 소모량을 이론적으로 분석하고, 이에 근거하여 다단증발식 해수담수화설비의 운전특성을 파악하였다. 본 연구의 결과에 따르면 시스템에서 이용할 수 있는 전체 온도차, 즉 인입해수의 온도와 1단 증발부로 유입되는 해수온도와의 차를 기준으로 증발단의 수를 증가시킬수록 에너지효율이 상승함을 알 수 있었다.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• 제41권3호
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• pp.182-190
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• 2017

모든 액체는 소량의 기체성분들이 녹아있으며, 액체에 용해되는 기체의 양은 액체에 작용하는 주위압력에 기여하는 각 기체성분의 분압에 비례한다는 헨리의 법칙을 따른다. 따라서 다단증발식 해수담수화설비의 경우, 각 증발단의 운전온도와 압력은 다르며, 이 운전조건에 비례하여 해수에 용해되어 있던 기체들이 증발과정에서 방출되는데 주성분은 불응축기체인 이산화탄소, 질소, 산소 및 아르곤이다. 대류열전달의 입장에서는 불응축기체는 증발증기를 응축시키는 냉각기의 성능을 저하시키는 주요한 원인이기 때문에 증발과정에서 방출되는 불응축기체의 평가는 증발식 해수담수화설비에서 중요한 설계인자 중의 한가지이다. 증발식 해수담수화공정의 경우, 대부분의 증발기는 진공압력으로 유지되기 때문에 진공유지장치의 설계를 위해서는 증발과정에서 해수로부터 방출되는 불응축기체의 방출량을 평가하는 것이 매우 중요다. 본 연구는 불응축기체의 방출량을 정량적으로 계산하기 위해 수행하였으며, 연구결과에 따르면 불응축가스의 방출량은 후단으로 갈수록 감소하며, 담수생산량에 비례함을 알 수 있었다.

• 한국물환경학회지
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• 제27권2호
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• pp.178-187
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• 2011

National water supply, water resources available, the ratio of water supply to total water resources, and the ratio of water supply to available water resources were investigated to find global seawater desalination plant market for 163 nations. Water resources available per capita from 2007 to 2016, population in water scarcity region from 2011 to 2016, and the ratio of water scarcity population to total population were also analyzed for the countries. Annual percentage increase in total municipal drinking water capital expenditure and Annual percentage increase in total industrial water market were analyzed to predict the amount of water supply by use. 76 countries are suffering from water scarcity and 60 countries among the countries have coastal regions. Forty countries were selected by considering the considerable amount and highly increasing trend of water demand by use. Most countries show increasing trend of industrial water and 82 countries have more than 4% annual increasing rate for domestic water expense from 2008 to 2016 among 163 countries. Among the 76 water scarcity countries 16 countries were finally selected by considering expense prediction by use. Middle-east, east asia, pacific ocean, and west europe regions include most selected countries.