• Journal of Korea Water Resources Association
• /
• v.31 no.6
• /
• pp.855-862
• /
• 1998

This paper investigates the impact of the forecast error on performance of a reservoir system for hydropower production. Forecast error is measured as th Root Mean Square Error (RMSE) and parametrically varied within a Generalized Maintenance Of Variance Extension (GMOVE) procedure. A set of transition probabilities are calculated as a function of the RMSE of the GMOVE procedure and then incorporated into a Bayesian Stochastic Dynamic Programming model which derives monthly operating policies and assesses their performance. As a case study, the proposed methodology is applied to the Skagit Hydropower System (SHS) in Washington state. The results show that the system performance is a nonlinear function of RMSE and therefor suggested that continued improvements in the current forecast accuracy correspond to gradually greater increase in performance of the SHS.

• Korean Chemical Engineering Research
• /
• v.46 no.5
• /
• pp.833-844
• /
• 2008

Bio-energy offers the opportunity to lessen fossil fuel consumption. Energy derived from solar, wind, hydroelectric, geothermal, and biomass sources are considered renewable. Because most forms of bio-energy are derive deither directly or indirectly from the sun, there is an abundant supply of renewable energy available, unlike fossil fuels. The use of bio-energy also provides environmental, economic and political benefits. Bio-energy can be produced from a marine source such as biomass provides a $CO_2$ neutral, non-polluting form of energy. In this paper, the potential of marine biomass is increasingly discussed, given the size of the resource in that more than three quarters of the surface of planet earth is covered by water.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.171-171
• /
• 2018

댐 유입량의 구성을 이해하는 것은 직접유출과 기저유출의 특성에 따라 수자원확보, 물 공급, 관개용수, 수력발전, 생태계 서식지, 친수활동 등 계절별 댐 운영을 효율적으로 수행하는데 기여할 수 있다. 또한, 댐은 대부분 유역 상류에 위치해 있어 댐 유입유량에 있어 다른 수리구조물에 의한 영향이 상대적으로 작기 때문에 앞에서 제시한 인위적 영향을 제외한 기저유출분리를 수행 할 수 있다. 이와 관련하여 본 연구의 목적은 1)댐 유입량에 대한 연별, 월별 기저유출을 분석하고; 2) 유역 상 하류에 위치한 댐의 유입량에 대하여 기저유출 기여도를 비교하는 것이다. 두 개의 연계 댐에 대하여 인위적 영향이 적은 상류에 위치한 댐이 하류에 위치한 댐보다 Baseflow Index가 더 작은 결과를 보여주었다. 상류 수자원시설부터 인위적 방류는 하류의 댐 유입량의 Baseflow Index를 과다산정의 원인이 될 수 있다는 것으로 나타났다. 본 연구의 결과는 댐 유입량의 특성을 월별 연별로 분석함으로써 댐의 역할과 기능을 확대하고 효율적 상 하류 댐 연계운영에 기여할 것으로 기대한다.

• Journal of Advanced Navigation Technology
• /
• v.18 no.3
• /
• pp.254-260
• /
• 2014

We studied water level rising of drum versus time in the small hydraulic vertical water turbine system in this paper. The water level rises continuously up to a certain point with the passage of time if the constant incoming water is supplied, while it stops rising and maintains equilibrium state without any more rising because it increases position energy and evatually makes outgoing velocity and outgoing water quantities of runner area. The water level of drum is determined independent of size, height, width, figure of drum or runner configuration. It comes out that the water level is dependent only on the incoming and outgoing water quantities, and the output power has similar behavior. Therefore, desirable water level and output power are not available unless incoming water quantities is abundant. We validate this phenomina through applyng our methodolgies to the real small hydraulic vertical water turbine system under constructing and testing in industrial facilities in Korea.

• Tunnel and Underground Space
• /
• v.9 no.1
• /
• pp.20-26
• /
• 1999

The completion of the Bakun Diversion Tunnel is subsequently to the Main Dam construction. Therefore, the completion date is very important for the Bakun Hydroelectric Project. Generally, the tunnel lining work as a finishing phase of the tunnelling project occupies a important portion as well as an excavation and a support work of the tunnels in respect to the construction cost and period. Internal section of Bakun Diversion Tunnel is designed circular shape to reduce the roughness of the water flow with 12 meters in diameter of total length 4314.6 meters of 3 tunnels. The lining thickness is varied between 500 mm and 700 mm depending on the structural condition. From the original Tender design of the Bakun tunnels, the required quantity of steel bars was 5,985 ton designed by Reinforced Concrete (RC) through the entire tunnel linings. During the detail design stage by the consideration of the rock conditions and various load conditions, we could suggest five kinds of RC lining type including plain concrete lining type. Through the detail design modification, we could reduce the required amount of steel bars to 2,178 ton, as a half of original Bill of Quantity. Finally, this design modification give us the time and cost saving effect to catch up the construction progress in time.

• Journal of the Society of Naval Architects of Korea
• /
• v.59 no.3
• /
• pp.183-191
• /
• 2022

A design method for a propeller type rim-driven axial-flow turbine for a micro-hydropower system is presented. The turbine consists of pre-stator, impeller and post-stator, where the pre-stator plays a role as a guide vane to provide circumferential velocity to the on-coming flow, and the impeller as a rotational power generator by absorbing angular momentum of the flow. BEM(Blade Element Method), which is based on the turbine Euler equation, is employed to design the pre-stator and impeller blades. NACA 66 thickness form and a=0.8 mean camber line, which is widely accepted as a marine propeller blade section, is used for the pre-stator and turbine blade section. A CFD method, derived from the discretization of the RANS equations, is applied for the analysis of the designed turbine system. The design conditions of the turbine is confirmed by the CFD calculation. Turbine characteristic curve is calculated by the CFD method, in order to provide the performance characteristics at off-design operation conditions. The proposed procedures for the design of a propeller type rim-driven axial-flow turbine are established and confirmed by the CFD analysis.

• Journal of Digital Convergence
• /
• v.11 no.10
• /
• pp.287-294
• /
• 2013

This study were proposed for the promotion policy on public confidence in nuclear power recovery schemes. To this end, the existing survey and secondary data review and public distrust of nuclear power plant safety issues were raised. In addition, the meta-analysis data were analyzed by using. Promote public confidence in nuclear power plants recovered three major policy presented. First, the nuclear power plant for the economical / safety communication strategy, short term / long term in terms proposed. Second, strengthen the nuclear power plant reliability and short-term communication strategy / long term in terms proposed. Finally, Korea Hydro & Nuclear Power's long-term image building measures proposed. The results of this study Korea's nuclear power plants to increase confidence in the effect is expected to be presented.

• Information and Communications Magazine
• /
• v.27 no.4
• /
• pp.3-9
• /
• 2010

모든 경제활동이나 일상 생활의 바탕에는 전기에너지가 있다. 전기에너지로 공장을 운영하고 건물의 냉난방을 유지하고 전자기기들을 가동시킨다. 전기에너지는 화석연료나 원자력, 수력 등을 이용하여 발전소를 통해 얻을 수 있는 에너지다. 발전소의 대부분을 차지하고 있는 화석 연료는 최근에 환경오염문제와 자원고갈문제 등으로 인하여 한계점에 도달하였다. 그에 따른 문제가 심각해지면서 전 세계는 저탄소 녹색성장을 목표로 신재생 에너지원의 효율적인 사용을 연구하고 있다. 기존의 전력망으로는 태양광, 태양열, 풍력, 지열 등과 같은 신재생 에너지원을 발전원으로 사용하기에는 기술적 한계가 있다. 따라서 기존의 전력망과 다른 새로운 개념의 전력망이 필요한데, 이것이 스마트그리드이다. 스마트그리드는 환경오염문제, 자원고갈문제, 발전설비의 경제적 문제를 해결해주고 소비자에게 다양한 품질의 전력을 제공하는 소비자 위주의 전력망이 될 예정이다. 본고에서는 미래의 핵심 기술이 될 스마트그리드의 개념과 그 필요성에 대해 알아 보려고 한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.5
• /
• pp.97-107
• /
• 2001

Many power plants in the thermal and hydraulic utilities, the pulp and the paper industry are faced with high maintenance and down time due to the aged excitation system. For the life extension of the aged power plants, the static excitation system of triple module redundancy type had been developed by KEPRI(Korea Electric Power Research Institute). This paper will discuss the design conception and the application results of system which includes the power control devices(thyristors, GTO), power potential transformer(excitation transformer) and triple module redundancy controller(voltage regulator).

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.1315-1318
• /
• 2001

국내외적으로 배기가스 저감 등 환경규제 강화와 환경의식이 향상되면서 원자력, 석탄, 중유 발전 등은 주변지역의 반대에 직면하여 발전소 건설사업 추진이 순조롭지 못한 실정이다. 또한 석유에너지 자원의 고갈과 국제 고유가 시대에 따라 대체에너지의 개발에 세계 각국이 심혈을 기울이고 있다. 그러나 우리나라의 경우 대규모 수력 발전소 입지를 찾는데는 한계가 있으며, 대부분 개발가능 지점이 15m이하 저낙차의 특징을 갖고 있다. 종래에는 소하천을 가로막아 소수력을 개발하는 것이 주종을 이루었으나, 최근에는 공사비 과다로 인한 경제성 불투명과 각종 주변 지역의 민원으로 개발이 어려워 광역상수도, 하수처리장, 농업용 저수지, 다목적댐 하류 조정지댐 등에 저낙차 유휴에너지를 다각적으로 이용하는 방안이 연구 개발되고 있다. 본 연구에서는 저낙차를 이용한 소수력 발전의 최적설계와 경제성 평가 기법 등을 실 적용한 사례를 중심으로 논하고자 한다.