• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.902-909
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• 2012

This study is aimed to develop a new type of micro cross-flow hydro turbine which has very simple structure and relatively high efficiency. Micro eco cross-flow hydro turbine (ECFT) is proposed to apply in the ranges of very low and middle specific speeds in order to extend the operational range of the turbine. In order to not only obtain a basic data for a new design method of ECFT but also improve the turbine efficiency, experiments and CFD analysis on the performance and internal flow characteristics of the turbine model are conducted. According to the present study results, anti-recirculation block (ARB) and relatively wide turbine width with high flow rate improve the turbine efficiency.

• International Journal of Fluid Machinery and Systems
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• v.8 no.4
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• pp.294-303
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• 2015

The present study is conducted to identify a better design and optimal number of Francis runner blades for sediment laden high head micro hydropower site, Tara Khola in the Baglung district of Nepal. The runner is designed with in-house code and Computational Fluid Dynamics (CFD) analysis is performed to evaluate the performance with three configurations; 11, 13 and 17 numbers of runner blades. The three sets of runners were also investigated for the sediment erosion tendency. The runner with 13 blades shows better performance at design as well as in variable discharge conditions. 96.2% efficiency is obtained from the runner with 13 blades at the design point, and the runners with 17 and 11 blades have 88.25% and 76.63% efficiencies respectively. Further, the runner with 13 blades has better manufacturability than the runner with 17 blades as it has long and highly curved blade with small gaps between the blades, but it comes with 65% more erosion tendency than in the runner with 17 blades.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.534-535
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• 2006

This study attempts to develope the micro-turbine generators 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 be alleviated and competition with other alternative energy sources in the changable design conditions could be attained. The micro turbine generator of a new concept was designed based on changable design conditions, hydrodynamics and theory of power transmission.

• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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• pp.17-23
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• 2013

Recently so much attention has been focused on renewable energy and, since its sources to exploit are already almost saturated in the country, the practical alternative to this situation could be a micro-turbine which uses the low head and low flow. From a point of view of local micro-turbine design capacity and manufacturing technology, the problems such as the accumulation of technical skills, the expansion of related industries, the national policy expansion and the turbine efficiency to improve are still vulnerable and it's true that there are also negative views about the economic feasibility, the technicity and the operation management of the micro-turbine. However, if the improvement can be done in technology of low-head double regulation micro-turbine to generate more outputs and the operation management can be reliably realized, the micro-turbine will be re-evaluated as an appliable source of renewable energy, even the output is small, and by a paradigm shift, it could realize a power generation as an economic and rational system.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.1
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• pp.95-104
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• 2022

Micro hydropower is a readily available renewable energy source that can be harvested utilizing hydrokinetic turbines from shallow water canals, irrigation and industrial channel flows, and run-off river stream flows. These sources generally have low head (<1 m) and low velocity which makes it difficult to harvest energy using conventional turbines. A horizontal-axis screw turbine was designed and numerically tested to extract power from such low-head water sources. The 3-bladed screw-type turbine is placed horizontally perpendicular to the incoming flow, partially submerged in a narrow water channel at no-head condition. The turbine hydraulic performances were studied using Computational Fluid Dynamics models. Turbine design parameters such as the shroud diameter, the hub-to-shroud ratios, and the submerged depths were obtained through a steady-state parametric study. The resulting turbine configuration was then tested by solving the unsteady multiphase free-surface equations mimicking an actual open channel flow scenario. The turbine performance in the shallow channel were studied for various Tip Speed Ratios (TSR). The highest power coefficient was obtained at a TSR of 0.3. The turbine was then scaled-up to test its performance on a real site condition at a head of 0.3 m. The highest power coefficient obtained was 0.18. Several losses were observed in the 3-bladed turbine design and to minimize losses, the number of blades were increased to five. The power coefficient improved by 236% for a 5-bladed screw turbine. The fluid losses were minimized by increasing the blade surface area submerged in water. The turbine performance was increased by 74.4% after dipping the turbine to a bottom wall clearance of 30 cm from 60 cm. The final output of the novel horizontal-axis screw turbine showed a 2.83 kW power output at a power coefficient of 0.63. The turbine is expected to produce 18,744 kWh/year of electricity. The design feasibility test of the turbine showed promising results to harvest energy from small hydropower sources.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1342-1343
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• 2011

댐체를 통해 하류 관개용수로 무효방류되는 수자원을 활용한 초소수력 발전가능성에 관한 고찰을 통해 개발 가능한 신재생 에너지 발굴 및 경제성과 타당성에 대하여 검증해 보고자 한다.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2839-2844
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• 2007

Micro hydraulic power generation of which the output is less or equal to a 100kW is attracting considerable attention. This is because of its small, simple, renewable, and abundant energy resources. By using a small hydropower generator of which main concept is based on using the different water pressure levels in pipe lines, energy which was initially wasted by use of a reducing valve at the end of the pipeline, is collected by turbine in the hydropower generator. A propeller shaped hydroturbine has been used in order to use this renewable pressure energy. In this study, in order to acquire basic design data of tubular type hydraulic turbine, output power, head, efficiency characteristics due to the flow coefficient are examined in detail. Moreover influences of pressure and velocity distributions with the variations of runner vane angle on turbine performance are investigated by using a commercial CFD code.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.408-411
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• 2007

The small hydropower uses hydraulic power to generate electricity, which one of the future energy resources of the power industry. The tubular turbine which uses in the city water pipe lines's differential pressure electricity is produced, this structure is simple, and therefore advantageous. The effects of cavitation that occurs in the turbine is researched, By using CFD we analysed the flow pattern inside the turbine. As a result, we found out to become the performance fall of turbine.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.1-11
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• 2017

Interest in all kinds of renewable energies has been highly increased while the micro-small-hydro power(MSHP) development has shown relatively slowly growth because of the negative public recognition about dam site development. It is, however, announced that the micro-SHP shows higher energy conversion efficiency compared to other renewable energies and does not emit any carbon dioxide. Thus, it is concerned about the development and application of micro-SHP as an alternative energy. In this study, the application for Android was exploited with Eclipse to visualize readily the potential realizable amount of hydropower by micro-SHP. With this application, we can select the region from the map, obtain the design discharge of the selected site was calculated with HEC-HMS, presented by U.S. Army of Corp. and perform the simply economic analysis in sequence. Yeongwol in Gangwon-do Province, Korea was chosen as the target area since historically abundant precipitation was found and it is possible to obtain fundamental data from WAMIS. Results from this study could be expanded the whole region of Korea. Also, the initial investment cost would be reduced if the location for micro-SHP would be determined properly, because this application can help us easily select and examine the potential micro-SHP sites without on-the-spot visit.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.45-56
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• 2015

This paper aims to develop a submerged propeller turbine for micro hydropower plant which allows to sustain high values of efficiency in a broad range of hydrological conditions (H=2~6 m, $Q=0.15{\sim}0.39m^3/s$). The two aspects to be considered in this development are mechanical simplicity and high-efficiency operation. Unlike conventional turbines that have spiral casing and gear box, this is directing driving and no spiral casing. A 10 kW class turbine which has the most high potential of the power generation has been developed. The most important element in the design of turbine is the runner blade. The initial blade is designed using inverse design method and then the runner geometry is modified by classical hydraulic method. The design process is carried out in two steps. First, the blade shape is fix and then other components of submerged propeller turbine are designed. Computational fluid dynamics analyses based on the Navier-Stokes equations have been used to obtain overall performance data for the blade and the full turbine, respectively. The results generated by performance parameters(head, guide vane opening angle and rotational speed) variations are theoretically analysed. The evaluation criteria for the blade and the turbine performances are the pressure distribution and flow's behavior on the runner blades and turbine. The results of simulation reveals an efficiency of 91.5% and power generation of 10.5kW at the best efficiency point at the head of 4m and a discharge of $0.3m^3/s$.