• Journal of Power System Engineering
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• v.9 no.3
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• pp.39-43
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• 2005

Among many other alternative energy resources, small scale hydropower has been brought into attention as a reliable source of energy today, which had been relatively neglected since 1960s. Present low head of Francis turbines and small scale hydroturbines, however, have limitations in the minimum required head and flow rate for efficient operation. This study attempts to develope the Francis turbine which is expected to run efficiently even in very low head and small flow rate, so that the limitations on the conventional small scale hydropower could alleviated and competition with other alternative energy sources in the changable design conditions could attained. The Francis turbine of a new concept was designed based on changable design conditions, hydrodynamics and theory of power transmission. The result of the study shows that two stages runner is more efficient, cheaper in construction, faster responding, and easier maintaining than single stage runner of Francis turbine

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.205.2-205.2
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• 2011

Micro hydraulic turbines take a growing interest because of its small and simple structure as well as high possibility of applying to micro and small hydropower resources. The differential pressure exiting within the city water pipelines can be used efficiently to generate electricity like the energy generated through gravitational potential energy in dams. In order to reduce water pressure at the inlet of water cleaning centers, pressure reducing valves are used widely. Therefore, pressure energy is wasted. Instead of using the pressure reduction valve, a micro counter-rotating hydraulic turbine can be replaced to get energy caused by the large differential pressure found in the city water pipelines. In this study, in order to acquire design data of counter-rotating tubular type micro-turbine, output power, head, and efficiency characteristics due to the diffuser.

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

• Magazine of RCR
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• v.12 no.1
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• pp.39-43
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• 2017

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.207.2-207.2
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• 2011

소수력자원의 개발을 위해서는 소수력발전입지에 대한 설계변수의 분석이 매우 중요하다. 설계변수는 해당유역의 강우사상과 밀접한 관계가 있으므로 이에 대한 정량적인 분석이 요구된다. 본 연구에서는 수계별 소수력발전입지에 대하여 설계변수의 특성을 분석하였다. 분석결과, 금강수계, 남한강수계 및 섬진강수계는 유역면적이 증가하여도 비가용량의 변화가 크지않지만, 낙동강수계와 북한강수계는 유역면적의 크기에 관계없이 비가용량의 변화가 크게 나타났다. 또한 비출력량의 경우에도 비가용량과 유사하게 금강수계, 남한강수계 및 섬진강수계는 유역면적이 증가하여도 비출력량의 변화가 크지않지만, 낙동강수계와 북한강수계는 유역면적의 크기에 관계없이 비출력량의 변화가 크게 나타났다. 이러한 현상은 우리나라의 연강수량이 남부지방이 중부지방에 비하여 많기 때문으로 판단된다. 낙동강수계는 하도가 남북으로 길기 때문에 소수력발전입지의 위치에 따라 비가용량의 크기의 변화가 크고, 북한강수계도 이와 비슷한 경향을 갖는다. 반면에 금강수계, 남한강수계 및 섬진강수계는 하도가 동서방향으로 길기 때문이다. 또한 연간가동율의 경우에는 모든 수계에 대하여 변화가 크지 않았고, 유역면적의 변화에 대해서도 큰 변화가 없었다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1070_1071
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• 2009

Recently, small hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. Therefore, a cross-flow hydraulic turbine is proposed for small hydropower development in this study. The turbine‘s simple structure and high possibility of applying to the sites of relatively low effective head and large flow rate can be advantages for the introduction of the small hydropower development. The purpose of this study is not only to investigate the effects of air layer in the turbine chamber on the performance and internal flow of the cross-flow turbine, but also to suggest a newly developed air supply method. CFD analysis for the performance and internal flow of the turbine is conducted by an unsteady state calculation using a two-phase flow model in order to embody the air layer effect on the turbine performance effectively. The result shows that air layer effect on the performance of the turbine is considerable. The air layer located in the turbine runner passage plays the role of preventing a shock loss in the runner axis and suppressing a recirculation flow in the runner. The location of air suction hole on the chamber wall is very important factor for the performance improvement. Moreover, the ratio between air from suction pipe and water from turbine inlet is also significant factor of the turbine performance.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.281-289
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• 1999

Small-scale hydropower projects at existing agricultural reservoirs can contribute to produce electric energy by maximizing the use of releases from the reservoirs. The irrigation water duration, the reservoir hydropower simulation, and the nonlinear programming model are employed to estimate potential hydroelectric energy at an existing reservoir. The nonlinear programming model consists of finding a maximum hydroelectric energy subject to irrigation water demand constraints. The sample reservoir given a set of inflow and irrigation water is considered. The optimal solutions by the optimization model yield the most hydroelectric energy for the analysis period in the three methods. Consequently, the nonlinear programming model uses the most water for hydropower generation with respect to the total inflow of the sample reservoir. It is also found that additional storage by increasing the normal water level of the sample reservoir does not significantly increase the annual hydroelectric energy for the given reservoir. It is expected that the optimization model and the proposed procedure for estimating potential hydroelectric energy can be applied to evaluate feasibility analysis for small scale hydropower additions at existing agricultural dams.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.192.1-192.1
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• 2010

Micro hydraulic turbines take a growing interest because of its small and simple structure as well as high possibility of applying to micro and small hydropower resources. The differential pressure exiting within the city water pipelines can be used efficiently to generate electricity like the energy generated through gravitational potential energy in dams. In order to reduce water pressure at the inlet of water cleaning centers, pressure reducing valves are used widely. Therefore, pressure energy is wasted. Instead of using the pressure reduction valve, a micro counter-rotating hydraulic turbine can be replaced to get energy caused by the large differential pressure found in the city water pipelines. In this paper, detail studies have been carried out to acquire basic design data of micro counter-rotating hydraulic turbine, output power, head, and efficiency characteristics on various number of runner vane. Moreover, the influences of pressure, tangential and axial velocity distributions on turbine performance are also investigated.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1029-1038
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• 2009

Recently, it is expected that small hydropower (SHP) could potentially provide sufficient amounts of alternative energy in Korea where there is an abundance of potential sites and where social efforts are being made to reduce the emissions of green house gases. In the past, the resources survey for SHP development has been carried out using onsite surveys and paper maps, which incurred a great deal of time and cost. Furthermore, the tools for decision making such as determining development priorities or evaluating feasibility have been considered only economic aspect and focused on the performance characteristics of power generation. However, as the concept of sustainable development has been being advanced in recent years, especially focused on human-social, environmental and ecological in addition to economical sector; the consideration of these multiple criteria has become essential for sustainable SHP development. This study aims to propose the spatial multi-criteria decision making (MCDM) methodology for determining priorities among a number of locations on the planning stage of SHP development using AHP and GIS. The proposed methodology is applied for determining development priorities among the SHP locations in Cho River basin and this study presents the detailed spatial information data and the results of development priorities. As a fundamental work, this study will be beneficial to the future activation of SHP development and will help the decision making in evaluating the feasibility of SHP development.