• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1223-1227
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• 2013

If the factory test efficiency and field operation efficiency of water turbine are different from each other, issues for efficiency warranty can be raised. So, This paper shows the result for comparative analysis of field operating efficiency vs plant testing efficiency of the water turbine generator installed in agricultural reservoir. The efficiency of the induction generator is analyzed by the change of rotational speed with the parameter obtained by test, the efficiency of water turbine is calculated by the change of head with the design flow. Efficiency deviation of induction generator is lower but the variation of developed power is pretty high near the rated speed and the efficiency variation of water turbine is high by the fluctuation of head for constant flow. It was found that factory test efficiency and total efficiency of water turbine generator calculated according to the rotational speed are very close.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.748-756
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• 2005

The Purpose of this writing is a presentation of small turbine efficiency measuring method, applicable new technology, and several analysis result for real turbine. Measurement methods of hydraulic efficiency written in here are extracted from small turbine applicable international code(IEC, ASME). It includes brief synopsis of 'Current meter method' and 4 other methods and ASFM as a new small turbine applicable technology. And several analysis of test result are for recently performed domestic small turbine result in korea. Through this presentation of extracted code, I hope that it make other small turbine concerner be familiar to perform an efficiency test. for small turbine. And, some analysis of that, make other to feel the importance of efficiency test.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.7
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• pp.1052-1059
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• 2009

The effects of varying the inlet flow angle on the output power of a Francis hydraulic turbine were studied numerically and the result was compared to the experimental results conducted at Korea Institute of Energy Research to determine the brake power of the turbine for each set of operating conditions. The loss of mechanical power of the model turbine was determined by comparing the numerical and experimental results, and thus the turbine efficiency or energy conversion efficiency of the model turbine could be estimated. From the result, it was found that the maximum brake efficiency of the turbine is approximately 46% at an induced angle of 35 degrees. The maximum indicated mechanical efficiency of the turbine is approximately 93% at an induced angle of 25~30 degrees.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.7
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• pp.750-757
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• 2005

The objective of this study is an understanding of the effect of inlet flow angle on the output power performance of a Francis hydraulic turbine, An optimum induced angle at the inlet of the turbine is one of the most important design parameters to have the best performance of the turbine at a given operating condition, In general. rotating speed of the turbine is varied with the change of water mass flowrate in a volute, The induced angle of the inlet water should be properly adjusted to the operating condition to have maximum energy conversion efficiency of the turbine, In this study. a numerical simulation was conducted to have detail understanding of the flow phenomenon in the flow path and output power of the model Francis turbine. The indicated power produced by the model turbine at a given operating condition was found numerically and compared to the brake power of the turbine measured by experiment at KIER. From comparison of two results, turbine efficiency or energy conversion efficiency of the model turbine was estimated. From the study, it was found that the rotating power of the turbine linearly increased with the rotating speed. It means that the higher volume flow rate supplied. the bigger torque on the turbine shaft generated. The maximum brake efficiency of the turbine is around 46$\%$ at 35 degree of induced angle. The difference between numerical and experimental output of the model turbine is defined as mechanical efficiency. The maximum mechanical efficiency of the turbine is around 93$\%$ at 25$\∼$30 degree of induced angle.

• The KSFM Journal of Fluid Machinery
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• v.17 no.4
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• pp.30-39
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• 2014

The cross flow turbine is economical because of its simple structure. For remote rural region, there are needs for a more simple structure and very low head cross flow turbines. However, in this kind of locations, the water from upstream always flows into the turbine with some other materials such as sand and pebble. These materials will be damage to the runner blade and shorten the turbine lifespan. Therefore, there is a need to develop a new type of cross flow turbine for the remote rural region where there is availability of abundant resources. The new design of the cross flow turbine has an inlet open duct, without guide vane and nozzle to simplify the structure. However, the turbine with inlet open duct and very low head shows relatively low efficiency. Therefore, the purpose of this study is to optimize the shape of the turbine inlet to improve the efficiency, and investigate the internal flow of a very low head cross flow turbine. There are two steps to optimize the turbine inlet shape. Firstly, by changing the turbine open angle along with changing the turbine inlet open duct bottom line (IODBL) location to investigate the internal flow. Secondly, keeping the turbine IODBL location at the maximum efficiency achieved at the first step, and changing the turbine IODBL angle to improve the performance. The result shows that there is a 7.4% of efficiency improvement by optimizing turbine IODBL location (open angle), and there is 0.3% of efficiency improvement by optimizing the turbine IODBL angle.

• The KSFM Journal of Fluid Machinery
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• v.4 no.4 s.13
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• pp.28-36
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• 2001

Performance analysis is conducted on an axial-type turbine which is used for fire extinction by injecting water or steam into the turbine. Loss models developed by Hacker and Okapuu are applied for predicting the performance of turbine. Pressure loss generated through a turbine is converted to the thermal efficiency, and thermal and gas properties are calculated within a turbine passage. Total-to-total efficiency, total-to-static efficiency, static temperature at the exit of turbine, output power, flow coefficient, blade loading coefficient, and expansion ratio are predicted with changing the amount of injected steam and the rotational speed. The 74 kW class gas turbine developed at KIMM is chosen for performance analysis. The 74 kW class turbine consists of 1 stage like a current developing gas turbine for fire extinction. Water or steam is injected at the end of combustor, and results show that efficiency and output power are dependent on the temperature of injected water or steam and the static temperature at the exit is decreased.

• 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 Advanced Culture Technology
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• v.3 no.2
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• pp.58-66
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• 2015

This paper aims to compare the use of Centrifugal Turbine and Tesla Turbine in an application of Organic Rankine Cycle (ORC) Machine using Isopentane as working fluid expanding. The working fluid has boiling point below boiling water and works in low-temperature sources between $80-120^{\circ}C$ which can be produced from waste heat, solar-thermal energy and geothermal energy etc. The experiment on ORC machine reveals that the suitability of high pressure pump for working fluid has result on the efficiency of work. In addition, Thermodynamics theory on P-h diagram also presented the effect of heat sources' temperature and flow rate on any work. Thus, the study and design on ORC machine has to concern mainly on pressure pump, flow rate and optimized temperature. Result experiment and calculate ORC Machine using centrifugal Turbine efficiency better than Tesla turbine 30% but Tesla Turbine is cheaper and easily structure. Further study on the machine can be developed throughout the county due to its low cost and efficiency.

• The KSFM Journal of Fluid Machinery
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• v.17 no.4
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• pp.19-29
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• 2014

In addition to the development of micro hydro turbine, the challenge in micro hydro turbine design as sustainable hydro devices is focused on the optimization of turbine runner blade which have decisive effect on the turbine performance to reach higher efficiency. A multi-objective optimization method to optimize the performance of runner blade of propeller turbine for micro turbine has been studied. For the initial design of planar blade cascade, singularity distribution method and the combination of the Bezier curve parametric technology is used. A non-dominated sorting genetic algorithm II(NSGA II) is developed based on the multi-objective optimization design method. The comparision with model test show that the blade charachteristics is optimized by NSGA-II has a good efficiency and load distribution. From model test and scale up calculation, the maximum prototype efficiency of the runner blade reaches as high as 90.87%.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.4
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• pp.377-385
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• 2015

This paper presents a thermodynamic performance analysis of regenerative organic Rankine cycle (ORC) using turbine bleeding to utilize low-grade finite thermal energy. Refrigerant R245fa was selected as the working fluid. Special attention is paid to the effects of the turbine bleeding pressure and the turbine bleed fraction on the thermodynamic performance of the system such as net power production and thermal efficiency. Results show that the thermal efficiency has an optimum value with respect to the turbine bleeding pressure and the net power production is lower than the basic ORC while the thermal efficiency is higher.