• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.250-255
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• 2009

This study was analyzed the long term performance of the demonstration system for solar energy desalination in Jeju. we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as $2m^3$ a $120m^2$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. Through the operation during about 3 years, In a clear day more than $400W/m^2$, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to March, 2009 for 3 years, solar irradiance daily averaged was measured $370W/m^2$, the daily fresh water yield showed that can be produced about 330liter.

• 한국유체기계학회 논문집
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• 제16권1호
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• pp.61-65
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• 2013

Water is an integral part of energy production because it is used directly in many power generation systems such as hydroelectric power plants and thermoelectric power plants. Water is also used extensively in energy-resource extraction, oil, natural gas, and alternative fuels refining and processing. Recently, osmotic power systems using seawater and freshwater has been also investigated to produce electricity in a sustainable way. This study focused on the use of RO and PRO for the mutual conversion of water and energy. This system allows the production of water from seawater if there is not enough water. It can also generate electricity from salinity gradient of brine water and fresh water if there is not enough energy. To demonstrate the feasibility of this technology, a set of laboratory-scale experiments were carried out using a specially-designed RO/PRO system. The efficiency of energy conversion was theoretically estimated based on the results from the experiments. The results indicated that water and energy could be easily converted using a single device. Nevertheless, a lack of optimum membrane for this purpose was identified as a major barrier for practical application.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.172-177
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• 2008

This study was carry out evaluation of long-term performance for the decentralized desalination system with the solar thermal system and the photovoltaic power system. First operating demonstration system was set up in Cheju in 2006. These system comprises the desalination unit with designed daily fresh water capacity of $2m^3$ and is supplied by a $120m^2$ evacuated tubular solar collector, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation supply the electricity for hydraulic pumps to move the working fluids. In a clear day more than 400W/$m^2$, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to October, 2008 for 2 years, solar irradiance daily averaged was measured 370W/$m^2$, the daily fresh water yield showed that can be produced about 330liter.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.11-17
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• 2012

The Waikato River is New Zealand's longest River, though relatively small on international scales. It drains the central North Island and has New Zealand's largest lake (Lake Taupo) at its headwaters. The upper reaches have sustained flows fed by large aquifers which are recharged by rainfall events providing relatively constant river flows, whereas the lower reaches respond more directly to rainfall events having more peaky flows after rainfall and extreme low flows during dry periods. Consumptive allocation from the river is relatively low with only about 3% of the mean annual flow being allocated. However, more than seven times the river's flow is allocated for non-consumptive purposes before discharging to the Tasman Sea. The majority of this non-consumptive allocation is for hydro power generation and as cooling water at both thermal and geothermal power stations which produce up to 25% of New Zealand's electricity. The upper half of the river has been heavily modified with the construction of eight dams for power generation. This has resulted in a succession of cascading dams replacing the previously uncontrolled river. The Waikato River also provides drinking water for Auckland City (NZ's largest city) and Hamilton City (NZ's 4th largest city). In recent years there has also been considerable growth in water requirements for pasture irrigation to support the intensification of dairy farming in the catchment. Operators of the power stations are concerned that any further consumptive allocation will further reduce their ability to generate electricity. The Waikato Regional Council, who is charged with managing the river and allocation of water, has recently set new rules for managing the conflicting allocation demands on the Waikato River. This has resulted in an end to further allocation of water where it results in a loss of water for electricity generation from renewable resources (fresh water and geothermal water). The exception to this is the prioritisation of water for municipal supplies ahead of other consumptive uses such as industries and irrigators.

• 청정기술
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• 제20권4호
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• pp.449-456
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• 2014

기후변화로 인한 국지적인 이상가뭄 빈발 및 물수지 관련 불확실성 증가 등으로 각국에서는 사용가능한 담수량 확보, 즉 물안보 문제가 크게 대두되고 있다. 사용가능한 담수량 중 상당부분이 전력을 생산하는 발전 분야에도 사용되기 때문에 그 중요성이 점차 증대하고 있다. 신재생에너지원인 태양광발전은 설비제조, 설치 및 운전의 전 과정(life cycle)에서 수자원을 소비하지만 전통적인 에너지원인 화력발전이나 원자력발전에 비하면 상대적으로 수자원을 적게 사용한다는 장점이 있다. 본 연구에서는 태양광시스템의 원료채취부터 운영발전까지 물 사용량을 알아보기 위해 전 과정의 물 발자국을 측정하여 그 결과를 분석했다. 물 발자국 산정결과 태양광시스템의 전체 물 발자국은 $0.989m^3/MWh$이며, 폴리실리콘과 태양전지 공정에서 물 발자국이 높게 나타났다. 폴리실리콘 공정은 에너지 다소비 공정이기 때문에 냉각수 사용량이 많았고 태양전지 공정에서는 고효율 결정질 실리콘 세척을 위한 탈 이온수(deionized water) 사용량이 많았기 때문에 물 발자국이 높은 것으로 보인다. 태양광발전은 기존 에너지원보다 물 사용량이 적은 발전원임을 확인할 수 있었으며, 에너지 분야의 물 사용량을 절감할 수 있는 가치를 가지고 있음을 알 수 있다. 향후 에너지정책 결정에 있어서 신재생에너지의 부가적인 가치로서 물 발자국 개념의 도입이 중요하다.

• 한국물환경학회지
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• 제37권6호
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• pp.442-448
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• 2021

Seawater desalination is a technology through which salt and other constituents are removed from seawater to produce fresh water. While a significant amount of fresh water is produced, the desalination process is limited by the generation of concentrated brine with a higher salinity than seawater; this imposes environmental and economic problems. In this study, characteristics of seawater from three different locations in South Korea were analyzed to evaluate the feasibility of crystallization to seawater desalination. Organic and inorganic substances participating in crystal formation during concentration were identified. Then, prediction and economic feasibility analysis were conducted on the actual water flux and obtainable salt resources (i.e. Na2SO4) using membrane distillation and energy-saving crystallizer based on multi-stage flash (MSF-Cr). The seawater showed a rather low salinity (29.9~34.4 g/L) and different composition ratios depending on the location. At high concentrations, it was possible to observe the participation of dissolved organic matter and various ionic substances in crystalization. When crystallized, materials capable of forming various crystals are expected. However, it seems that different salt concentrations should be considered for each location. When the model developed using the Aspen Plus modular was applied in Korean seawater conditions, relatively high economic feasibility was confirmed in the MSF-Cr. The results of this study will help solve the environmental and economic problems of concentrated brine from seawater desalination.

• 한국태양에너지학회 논문집
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• 제34권2호
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• pp.73-81
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• 2014

Ocean thermal energy conversion(OTEC) is a power generation method that utilizes temperature difference between the warm surface seawater and cold deep sea water of ocean. As potential sources of clean-energy supply, Ocean thermal energy conversion(OTEC) power plants' viability has been investigated. Therefore, this paper evaluated the thermodynamic performance of solar-OTEC convergence system for the production with electric power and desalinated water. The comparison analysis of solar-OTEC convergence system performance was carried out as the fluid temperature, saturated temperature difference and pressure of flash evaporator under equivalent conditions. As a results, maximum system efficiency, electric power and fresh water output show at 40, 10, 2.5 kPa of the flash evaporator pressure, respectively. And their respective enhancement ratios were approximately 6.1, 18, 8.6 times higher than that of the base open OTEC system. Also, performance of solar-OTEC system is the highest in the flash evaporator pressure of 10 kPa.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.282-283
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• 2002

Corbicula (Corbiculina) papyracea (Heude) is fresh water clam which lives on the sands and muds, its size was about 3~25 mm with yellow gray color. Shell width of the clam is thin and smooth and growth lines are marvelous and inside of shell colored pink or pink with red. And the clam reproduces itself through virgin generation (Park et al., 1989), ovoviviparous (Kwon et al., 2001) method. There are reports about Corbicula by Kim and Yoo (2000), Kwon et al. (1987), and Lee et al. (1985) but there aren't many report about C. (C.) papyracea. The aim of this work is to present the dynamics of D.(C.) papyracea from Chungpyeong.

• Advances in concrete construction
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• 제8권3호
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• pp.199-206
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• 2019

High performance sandcretes (HPS) are new concretes characterized by particles having a diameter less than 5 mm, as well as very high mechanical strength and durability. This work consists in finding solutions to make sandcretes with good physico-mechanical and durability properties for this new generation of micro-concrete. However, upgrading ordinary sandcrete into high performance sandcrete (HPS) requires a thorough study of formulation parameters (equivalent water/binder ratio, type of cement and its dosage, kind and amount of super plasticizer, and gravel/sand ratio). This research study concerns the formulation, characterization and durability, in a sulphate environment, of a high performance sandcrete (HPS), made from local materials. The obtained results show that the rheological properties of fresh concrete and mechanical strength differ with the mineralogy, density and grain size distribution of sands and silica fume used.

• 현장농수산연구지
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• 제4권1호
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• pp.39-44
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• 2002

This paper was studied on a strategy in rice production under New round system of WTO(World Trade Organization) in Korea. Under enactment of New round system in WTO rice will be opened at the world market and thus rice growers will compete with this marketing system. In this regard, rice industry in Korea would be "a theory of rice triangle" such as high quality, low cost, and environmental friendly system. High quality rice would be obtained through a cultivar, cultivation technology, and quality control(QC) to compete against oversea's dealer. Lower cost in rice production should be concentrated into rapid decrease in rural population and into introducing for young generation. Rice cultivation has been played major role in this peninsula in terms of a preservation of water resource, fresh air and prevention of soil erosion.