• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3241-3246
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• 2007

Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed with hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of the syngas to the performance of a gas turbine in a combined cycle power plant. For this purpose, a commercial gas turbine is selected and its performance characteristics are analyzed with three different fuels, i.e., natural gas ($CH_4$), syngas and hydrogen. It is found that different heating values of those fuels and chemical compositions in their combustion gases are the causes in the different performance characteristics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1664_1665
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• 2009

Many years ago, most of thermal power plants built in this country were of subcritical pressure, of medium or small size, of constant pressure operations and of drum type steam generators with circulation type boilers. But, nowadays almost all of them were of high efficiency, of supercritical pressure, of big capacity, of sliding pressure operations, and of once through type steam generator. It has such advantage as the reduction of startup duration, but it control system and operation method are very complicated. It has a big difference in operation method of turbine and boiler. The feedforward control needs to be introduced to prevent such problems as thermal shock during the transit from normal operation into bypass operation. This paper introduces the turbine control and turbine bypass control during startup of thermal power plants.

• 전기학회논문지
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• 제58권6호
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• pp.1130-1137
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• 2009

This paper describes a scaled model development of PMSG wind power system using wind turbine simulator and matrix converter. The wind turbine simulator, which consists of an induction motor with vector drive, calculates the output torque of a specific wind turbine using simulation software and sends the torque signal to the vector drive after scaling down the calculated value. The operational feasibility of interconnected PMSG system with matrix converter was verified by computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was conformed by experimental works with a laboratory scaled-model of wind power system. The simulation and experimental results confirm that matrix converter can be effectively applied for the PMSG wind power system.

• International Journal of Ocean System Engineering
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• 제3권4호
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• pp.164-168
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• 2013

Tidal-current power is now recognized as a clean power resource. The turbine blade is the fundamental component of a tidal current power turbine. The kinetic energy available within a tidal current can be converted into rotational power by turbine blades. While in service, turbine blades are generally subjected to cyclic fatigue loading due to their rotation and the rotor-tower interaction. Predicting the fatigue life under a hydrodynamic fatigue load is very important to prevent blade failure while in service. To predict the fatigue life, hydrodynamic load data should be acquired. In this study, the vibration characteristics were analyzed based on three-dimensional unsteady simulations to obtain the cyclic fatigue load. Our results can be applied to the fatigue design of horizontal-axis tidal turbines.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.354-360
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• 2001

Hybrid energy system of fuel cell and gas turbine is discussed as the system to be used in the distributed power generation. Discussion is first directed to the distributed power generation system which is expected to be more popularly introduced both in urban and isolated areas. In the next some characteristic features of fuel cell and micro gas turbine are shortly described. In the last discussion is turn to the fuel cell and micro gas turbine hybrid system. In particular, performance characteristics of a representative SOFC/MGT hybrid system are investigated through the concept design at various power capacity levels.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2314-2316
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• 2001

The steam gererator which produces thermal energy from coal or gas is a very important device in power plants, including the turbine driving synchronous generator which transforms kinetic energy into electrical energy. The turbine and the generator are driven by many kinds of media according to the types of which power plants are classified into steam turbine generator, gas turbine generator, water turbine generator and so on. This paper introduces the overspeed protection as well as the various speed and load control methods of some types of turbines.

• 대한안전경영과학회지
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• 제25권3호
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• pp.1-7
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• 2023

As the capacity of renewable power generation facilities rapidly increases, the variability of electric power system and gas turbine power generation is also increasing. Therefore, problems may occur that require urgent repair while the gas turbine rotor is stopped. When the gas turbine rotor turning is stopped and then restarted, if the turning period is not appropriate, severe vibration may occur due to rotor bending. As a result of the experiment, it was confirmed that normal operation is possible when the gap data measured at the start of rotor turning after maintenance work is similar to the existing value. And the vibration value at the start of rotor turning was lower as the rotor temperature was lower or the stop period was shorter.

• Wind and Structures
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• 제19권2호
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• pp.199-217
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• 2014

Reported experimental and computational fluid dynamic (CFD) studies have demonstrated significant power augmentation of diffuser shrouded horizontal axis micro wind turbine compared to bare turbine. These studies also found the degree of augmentation is strongly dependent on the shape and geometry of the diffuser such as length and expansion angle. However study flow field over the rotor blades in shrouded turbine has not received much attention. In this paper, CFD simulations of an experimental diffuser shrouded micro wind turbine have been carried out with the aim to understand the mechanisms underpinning the power augmentation phenomenon. The simulations provide insight of the flow field over the blades of bare wind turbine and of shrouded one elucidating the augmentation mechanisms. From the analysis, sub-atmospheric back pressure leading to velocity augmentation at the inlet of diffuser and lowering the static pressure on blade suction sides have been identified as th dominant mechanisms driving the power augmentation. And effective augmentation was achieved for ${\lambda}$ above certain value. For the case turbine it is ${\lambda}$ greater than ${\approx}2$.

• Journal of Advanced Marine Engineering and Technology
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• 제32권5호
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• pp.698-706
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• 2008

Performance improvement of Small hydro turbine is a very important subject to solve in the stage of introduction and development of the turbine. Cross-flow hydro turbine should be also studied more in detail for the turbine performance in order to extend the sites of application. In order to improve the turbine performance, the effect of the turbine shape on the turbine performance should be examined. Therefore, the effect of runner blade number on the turbine performance is investigated by use of a commercial CFD code. The results show that runner blade number gives remarkable effect on the efficiency and output power of the turbine. Pressure on the surface of the runner blade changes considerably by the blade number at Stage 1, but relatively small change of velocity distribution occurs in the flow passage.

• 전기학회논문지
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• 제64권12호
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• pp.1718-1723
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• 2015

The diameter of the rotor of 2MW wind turbine is being developed by a number of companies with more than 80m, reliability and economic efficiency of the wind power generator has been improved. The need for large-scale wind turbine with excellent economy has been attracting attention because the new orders and the location of the wind turbine market has reached a limit. Technology development for enlargement of wind turbine is possible not only the improvement of energy efficiency but also reduce the construction costs per unit capacity. However, mechanical gearboxes used in wind generators have problems of wear, damage, need for lubrication oil and maintenance. Therefore, we want to configure the gearbox of a large-scale wind turbine using a magnetic gear in order to solve these problems of mechanical gearbox.