• 환경위생공학
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• 제13권2호
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• pp.26-33
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• 1998

It has been referred as a problem that heat source/sink is distance from heat demand area in using unused energy. To solve the distance problem in using unused energy, the water from city water system like tap water, rain water, waste water used as unused energy. To survey the potential of the water of city water system, it is developed that the calculation method of the potential using unit method. The amount of theoretical unused energy and energy saving in the Osaka City, Japan were estimated by using that method.

• 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.

• 상하수도학회지
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• 제28권3호
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.178-184
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• 2022

Renewable energy sources based on solar radiation, wind energy, geothermal energy, and biomass energy have now reached the level of industrial application. A new way to generate electricity using low-potential heat is to install a hydro-steam turbine. In hydro-steam turbines, hot water is supplied directly to turbine rotor nozzles without prior separation into steam and water in separators, which significantly increases the efficiency of hot water energy use. Such turbines are suggested to be used as autonomous energy sources in geothermal heating systems, heating water boilers and cooling systems of chemical reactors, metallurgical furnaces, etc. The authors conclude that the installation of hydro-steam turbines in heating plants and process boiler plants can also be effective if the used exhaust steam-water mixture at the turbine outlet is used to heat the network water or as return water.

• 신재생에너지
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• 제20권1호
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• pp.110-115
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• 2024

Global sustainable energy needs and carbon neutrality goals make hydrogen a key future energy source. South Korea and Japan lead with proactive hydrogen policies, including South Korea's Hydrogen Law and Japan's strategy updates aiming for a hydrogen-centric society by 2050. A notable advance is the solar thermal chemical water-splitting cycle for green hydrogen production, spotlighted by Korea Institute of Energy Research (KIER) and Niigata University's joint initiative. This method uses solar energy to split water into hydrogen and oxygen, offering a carbon-neutral hydrogen production route. The study focuses on international collaboration in solar energy for thermochemical water-splitting and E-fuel production, highlighting breakthroughs in catalyst and reactor design to enhance solar thermal technology's commercial viability for sustainable fuel production. Collaborations, like ARENA in Australia, target global carbon emission reduction and energy system sustainability, contributing to a cleaner, sustainable energy future.

• 한국수자원학회논문집
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• 제56권9호
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• pp.587-602
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• 2023

기후변화, 인구증가 및 경제발전으로 도시물순환시스템 내 용수 수요량과 물 이용에 필요한 에너지는 지속적으로 증가하고 있다. 따라서 도시물순환시스템을 효율적으로 관리하기 위해 물 부문만을 고려하는 전통적인 방식을 벗어나 물과 에너지 부문 간 상승효과와 상충관계를 고려하는 넥서스 접근법이 주목받기 시작하였다. 이러한 넥서스 방법론을 적용하여 도시물순환시스템이 에너지 집약적인 시스템임을 증명하고, 에너지 원단위로 표현되는 물-에너지 효율 관계를 분석하며, 기후(장기 기후변동, 가뭄, 유형), 지리적 특징(표고차, 평지비, 위치), 시스템 특징(총급수량, 인구, 인구밀도, 관로연장) 및 운영관리 현황(상수관망 수압, 누수율, 물절약)이 미치는 영향을 규명하고자 하는 연구들이 수행되어왔다. 그러나 이를 통해 도시물순환시스템 관리자에게 정책 및 제도의 방향을 제시할 수 있으나 구체적인 정책을 수립하고 시행하는 데 한계가 있었다. 본 연구에서는 기존에 제시된 문헌 조사를 통해 시스템 및 공정별 에너지 원단위 매트릭스 구축하고, 물-에너지 넥서스 모델을 활용하여 도시여건, 외부영향 및 운영관리수준이 시스템에 미치는 영향을 정량화하였으며, 관리자가 벤치마킹할 수 있는 물-에너지 사용효율 기준을 제시하였다. 이를 활용하여 도시물순환시스템 관리자는 시스템의 효율적인 운영관리를 위한 전략과 실행계획을 도출할 수 있으며, 계획의 시행 후 적합성 및 타당성에 대한 평가가 가능할 것이다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.451-456
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• 2012

This study was carried out to evaluate thermal performance of the renewable hybrid heat supply system with solar thermal system and wood pellet boiler for Zero Carbon Green home of apartment houses. The hybrid heat supply system was set up at Korea Institute Energy Research in 2011. The system was comprised of the wood pellet boiler unit with heat capacity designed as 20,000 kacal/hr, a evacuated tubular solar collector 3.74 $m^2$ of aperture area at the $20^{\circ}$ install angle, a 0.3 $m^3$ hot water storage tank, a 0.15 $m^3$ hot water storage tank for space heating. Thermal performance tests for one-house of apartment house were carried out by hot water load and heating load in winter season through the hybrid heat supply system. As a result, hot water energy supplied by the hybrid heat supply system was 11kWh in a day. Solar thermal energy portion was 2.99kWh which is 27% of the total hot water energy supply. wood pellet boiler supply portion was 8.017kWh which is 73% of the total hot water energy supply.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.168-176
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• 1998

A simulation study was conducted to use city-water which is thermally regulated by unused energy as a heat source for urban dwellings. This study utilized multiple heat pump system using the city-water as a heat source and suggested a method of reducing the heat load of hot water supply. The simulation was done to calculate the energy savings at a dwelling for a year. The relation between the controlled temperature of city-water. and electric energy in all seasons was also investigated. Furthermore, it has been found that the controlled water system can lead to considerable energy savings and decrease environmental load such as sensible waste heat which otherwise would form heat islands.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1402-1403
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• 2011

Photovoltaic solar energy policy in the keynote of the world in the development of new technologies in terms of renewable energy sources has been a great interest. Solar energy is the energy density, low light intensity, temperature, and a lot of areas affected by the difference, the effective use difficult. For the installation of photovoltaic solar power systems to develop farmland or forest land resulting from deforestation has become such a problem. In this paper, a way to resolve these issues as part of the development of the reservoir water through the efficient use of land and water resources through the eco-friendly energy production, water quality improvement, the cooling effect of solar modules, solar water system has the advantage of was installed. Terrestrial solar systems installed under the same conditions and solar radiation, power, module temperature, ambient temperature and analyzed. Through this award to demonstrate the effectiveness of the solar system is.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.209-214
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• 2006

In this study, application of groundwater thermal energy by use of riverbank filtration(RBF) system is reviewed and checked as an energy resources. Also, the cooling and heating system using RBF was developed in Chang-Won Waterwork site to examine the feasibility in real operation of the system. We estimates the roughly overall energy obtained from RBF system if the system is used in cooling and heating. The water temperature and room temperature have been monitored to evaluate the efficiency of the system and the preliminary results show that the geothermal energy obtained by RBF could be adopted in cooling and heating energy source efficiently.