• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.77-80
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• 1996

우리나라에서 피크부하용으로 사용하는 복합발전이 하계시에서 외기온도가 상승함에 따라 실제로는 정격출력을 내지 못하고 있다. 따라서 본 연구에서는 연료(LNG)의 냉열을 이용하여 가스터빈의 연소용공기를 냉각시킬 경우, 복합발전 시스템의 성능변화를 분석하기 위하여 시뮬레이션을 수행하였다. 그 결과 LNG의 냉열을 이용하여 연소용공기를 원하는 온도까지 냉각시킬 수 있음을 확인할 수 있었다. 또한 연소기로 연료를 투입하기전에 설계온도까지 예열시키는 열교환기를 통해 배기가스에 함유된 현열을 더욱 많이 회수하면서, 가스터빈 투입연료의 온도를 상승시킬 수 있어, 시스템효율이 더욱 상승함을 알 수 있었다. 결론적으로 외기온도가 변하는 경우에, 본 시스템의 도입을 위해서는 경제성분석과 더불어 열교환기 시스템의 최적합성이 추후 진행되어야 할 것이며, 이를 통해 최적의 발전시스템을 구성할 수 있으리라 생각된다.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.878-884
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• 2001

IGCC(Integrated Gasification Combined Cycle) power plant are becoming more attractive because of fuel flexibility and low emission. In this study, performances are evaluated when the low caloric value syngas fuels producted in gasification process is used a gas turbine originally designed naturel gas fuel. Using GateCycle computational thermal analysis model, performances of GE 7FA gas turbine are predicted for using four types of syngas. Also, off design performance is presented for firing syngas fuel in the gas turbine.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.316-319
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• 2008

A computational analysis has been conducted on the compressible flow in the turbine exhaust nozzle of the gas generator cycle liquid rocket engine. The commercial CFD code Fluent has been used. Four nozzle designs have been compared to select the turbine exhaust nozzle concept. Three candidates with single nozzle have comparable performance. The model with bifurcated nozzles shows significant performance loss. However it will be better in the view of balanced thrust distribution because of its symmetric geometry.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.12
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• pp.1625-1634
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• 2000

Verification of measurements is required for precise evaluation of turbine cycle performance in nuclear power plant. We assumed that initial acceptance data and design data of the plant could provide correlation information between performance data. The data can be used as sample sets for the correct estimation model of measurement value. The modeling was done practically by using regression model based on plant design data, plant acceptance data and verified plant performance data of domestic nuclear power plant. We can construct more robust performance analysis system for an operation nuclear power plant with this validation scheme.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.107-112
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• 2010

A gas turbine consists of an upstream compressor and a downstream turbine with a combustion chamber, and also the compressor and the turbine are generally coupled using a single shaft. Large scale gas turbine compressor is designed as multi-stage axial flow and the blade is fan-type which is thick and wide. Recently radial cracking happens occasionally at the compressor blade tip of large scale gas turbine. So, FEM was performed on the compressor blade and vibration modes and dynamic stresses were analyzed. According to the analysis, 9th natural frequency mode of the blade, which is 2 strip mode, is near the vane passing frequency by the vane located at the upstream of the blade.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.26-31
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• 2017

In the present study, 20 kW turbine for OTEC with a ejector and a motive pump is designed and performance prediction is implemented by means of CFD. The meridional analysis for initial geometry and CFD for detail design are used to design the turbine. This turbine has about 90.9% efficiency and 28.47 kW power at 15,000 rpm and pressure ratio of 1.53. Homogeneous mixture model is used because two phase flow can be occurred in the turbine. Performance evaluation is carried out and then results are presented by plotting of power, mass flow rate and efficiency as varying pressure ratio and rotational speed.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.377-378
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• 2015

본 논문에서는 유기랭킨 사이클(organic rankine cycle: ORC) 발전 시스템에서 터빈과 발전기의 속도를 추정하는 방법을 제안한다. 다이오드 정류기에 의해 왜곡된 발전기 3상 단자 전압은 PLL 기법을 이용한 속도추정의 성능을 저하시키므로, 정상분 추출과 맥동성분 제거를 위한 상태관측기와 주파수 가변형 PR 제어기를 동기좌표계 PLL 기법에 적용하여 발전기의 속도를 추정한다. 제안하는 터빈과 발전기의 속도추정 방법은 실험 결과를 통해 그 성능을 검증한다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.73-76
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• 2006

본 연구에서는 독일 율리히 연구소에서 도입된 면적 200mm*200mm의 연료극 지지체 평판형 SOFC 셀 및 금속 분리판 40장을 적층하여 5kW급 SOFC 스택을 제작하고 연속운전을 수행하여 운전특성을 분석했다. 본 연구를 통해 도입된 5kW급 SOFC 스택은 외국에서 시도된 적이 없는 평판형 SOFC스택의 가압운전을 시도해 보는 것으로서, 스택의 임계압력 특성을 확인하고, 이를 바탕으로 가스터빈-연료전지 하이브리드 시스템에서의 SOFC 스택 가압 운전기술을 확보하는 것이다 이러한 목적을 위해 본 연구에서는 상압형 5kW급 SOFC 스택 운전시스템에 대한 구성과 설계, 전반적인 운전 특성평가 (40셀 스택 운전 열 사이클 시험 연료 전환 $(H_2{\rightarrow}pre-reformed\;gas)$, 1200시간 연속운전 등)가 이뤄졌다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.123-127
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• 2005

LRE(liquid rocket engine) performance design code with several modules for each engine component has been developed for a preliminary design purpose. Thrust chamber, non-cryogenic centrifugal pump, single stage axial impulse turbine, gas generator and exhaust pipe for extra thrust have been considered. For simplicity, pump exit pressures are fixed, which eliminates pressure balancing problem between thrust chamber and turbopump unit. In this paper, calculated performance parameters with system flow charts and the design methodologies for each component are briefly presented and the results are compared with tile real engine specification.

• The KSFM Journal of Fluid Machinery
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• v.16 no.3
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• pp.10-17
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• 2013

The organic Rankine cycle has been widely used to convert the renewable energy such as the solar energy, the geothermal energy, or the waste energy etc., to the electric power. Some previous studies focused to find what kind of refrigerant would be a best working fluid for the organic Rankine cycle. In this study, R245fa was chosen to the working fluid, and the cycle analysis was conducted for the output power of 30kW or less. In addition, properties (temperature, pressure, entropy, and enthalpy etc.) of the working fluid on the cycle were predicted when the turbine output power was controlled by adjusting the mass flowrate. The configuration of the turbine was a radial-type and the supersonic nozzles were applied as the stator. So, the turbine was operated in partial admission. The turbine efficiency and the optimum velocity ratio were considered in the cycle analysis for the low partial admission rate. The computed results show that the system efficiency is affected by the partial admission rate more than the temperature of the evaporator.