• 한국유체기계학회 논문집
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• 제15권6호
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• pp.39-45
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• 2012

This paper describes the outcome of the design of a 200 kW class micro gas turbine and the sensitivity of its performance (efficiency and power) to the variations in major design parameters. The reference design parameters were set up based on the best available component technologies. The resulting net electricity generation efficiency of the micro gas turbine package was found to be competitive to those of other systems in the market. The sensitivities of power and efficiency to the variations in compressor and turbine efficiencies, pressure ratio, turbine inlet temperature, recuperator effectiveness, secondary air ratio, pressure loss ratios of both the cold and hot sides of the recuperator were estimated. Based on the sensitivity data, a simplified method to predict the variation in system performance responding to the combinations of small changes in all design parameters were set up and validated.

• 한국유체기계학회 논문집
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• 제14권2호
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• pp.41-46
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• 2011

This study investigated the changes in performance and operating characteristics of an F-class gas turbine according to the change of working fluid from air to carbon dioxide. The revised gas turbine is the topping cycle of the semi-closed oxy-fuel combustion combined cycle. With the same turbine inlet temperature, the $CO_2$ gas turbine is expected to produce about 85% more power. The main contributor is the greater compressor mass flow and the added oxygen flow for the combustion. Compressor pressure ratio increases about 50%. However, the gas turbine efficiency reduces about 10 %. Modulation of inlet guide vane to reduce the compressor inlet mass flow, the major purpose of which is to reduce the compressor inlet Mach number, was also performed.

• 대한기계학회논문집B
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• 제21권8호
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• pp.996-1008
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• 1997

This paper describes a methodology and results for the analysis of a small steam injected gas turbine cogeneration system. A performance analysis program for the gas turbine engine is utilized with modifications required for the model of steam injection and the heat recovery steam generator (HRSG). The object of simulation is a simple cycle gas turbine engine under development which adopts a centrifugal compressor. The analysis is based on the off-design operation of the gas turbine and the compressor performance map is utilized. Analyses are carried out with the injection ratio as the main parameter. The effect of steam injection on the power and efficiency of gas turbine and cogeneration capacity is investigated. Also presented is the variation in the main operating parameters inside the HRSG. Remarkable reduction in NOx generation by steam injection is confirmed. In addition, it is observed that for the 100% power operation the temperature of the cooled first nozzle blade decreases by 100.deg. C at full steam injection, which seems to have a favorable effect on the engine life time.

• 한국산업융합학회 논문집
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• 제13권1호
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• pp.31-39
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• 2010

An exergy analysis is carried out for the regenerative gas turbine cycle which has a potential of enhanced thermal efficiency and specific power owing to the more possible water injection than that of inlet fogging under the ambient conditions. Using the analysis model in the view of the second law of thermodynamics, the effects of pressure ratio, water injection ratio and ambient temperature are investigated on the performance of the system such as exergetic efficiency, heat recovery ratio of recuperator, exergy destruction or loss ratios, and on the optimal conditions for maximum exergy efficiency. The results of computation for the typical cases show that the regenerative gas turbine system with afterfogging can make a notable enhancement of exergy efficiency.

• 에너지공학
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• 제18권2호
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• pp.93-100
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• 2009

습식압축으로 압축소요동력을 줄이고 재생기로 배기가스 에너지를 회수함으로써 열효율을 향상시킬 수 있는 습식압축 재생 브레이튼 사이클에 대하여 엑서지 해석을 수행하였다. 해석모델을 통하여 시스템의 엑서지 효율과 요소별 엑서지 파괴비 및 배기가스로 인한 엑서지 손실비에 미치는 압력비와 물분사율의 영향을 조사하였다. 전형적인 운전조건에 대한 계산 결과 습식압축 재생 가스터빈 사이클에 의하여 엑서지 효율을 상당히 향상시킬 수 있음을 확인하였다. 물 분사 효과는 배기가스의 엑서지 손실의 감소와 출력 동력의 증가로 나타난다.

• 대한기계학회논문집B
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• 제34권4호
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• pp.443-448
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• 2010

가스발생기 사이클 액체로켓엔진에서 추진제의 공급압력 변화에 대한 성능 즉, 연소압, 터빈 파워, 엔진 혼합비, 가스발생기 연소가스의 온도 변화를 제시하였다. 로켓엔진의 주요 13개 시스템 레벨 변수를 이용하여 엔진 성능을 수치적으로 계산한다. 산화제 공급압이 증가하면 연소압과 터빈 파워는 증가하며 연료 공급압이 증가하면 연소압과 터빈 파워가 감소한다. 연료 유량 증가에 따라 감소된 가스 발생기의 혼합비는 연소가스 온도를 감소시키며 터빈 구동매질로서의 연소가스 물성을 저하시킨다. 연료 유량 증가에 따라 감소된 터빈 파워는 엔진 추력에 직접 영향을 미치는 주연소기의 연소압을 감소 시킨다.

• 한국추진공학회지
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• 제14권1호
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• pp.29-39
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• 2010

증기분사 재생 가스터빈 시스템의 성능을 해석하고 최적 운전조건을 분석하였다. 해석모델을 통해 압력비, 증기분사율, 주위온도나 터빈입구온도 등의 설계변수들이 시스템의 열효율, 연료소모율, 비동력등 성능에 미치는 영향을 최적 운전조건에서 분석하였다. 해석결과들은 증기분사가 재생 가스터빈시스템의 열효율과 비동력을 대폭 향상시킬 수 있음을 보여주었다.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.570-576
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• 2017

Gas turbine system with steam injection has shown outstanding advantages such as high specific power and NOx reduction. In the present work, a comparative exergetic analysis was carried out for Steam Injected Gas Turbine (STIG), Regenerative Steam Injected Gas Turbine (RSTIG), and Regenerative After Fogging Gas Turbine (RAF). Effects of pressure ratio, steam injection ratio and steam injection method on the system performance was theoretically investigated. The results showed that the order of the highest exergy efficiency is RSTIG, RAF, and STIG for low pressure ratios but STIG, RSTIG, and RAF for high pressure ratios. In each arrangement, the combustion chamber has the highest exergy destruction and the compressor has the second one.

• 대한기계학회논문집B
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• 제26권11호
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• pp.1605-1612
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• 2002

Thermodynamic performance analysis has been carried out for a hybrid electric power generation system combining a gas turbine and a solid oxide fuel cell and operating at over-atmospheric pressure. Performance characteristics with respect to main design parameters such as maximum temperature and pressure ratio are examined in detail. Effects of other important design parameters are investigated including fuel cell internal parameters such as fuel utilization factor, steam/carbon ratio and current density, and system parameters such as recuperator efficiency and compressor inlet temperature.

• 한국유체기계학회 논문집
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• 제9권6호
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• pp.35-44
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• 2006

Operation conditions of a reheat cycle gas turbine for a combined cycle power plant was analyzed. Based on measured performance parameters of the gas turbine, a performance analysis program predicted component characteristic parameters such as compressor air flow, compressor efficiency, efficiencies of both the high and low pressure turbines, and coolant flows. The predicted air flow and its variation with the inlet guide vane setting were sufficiently accurate. The compressor running characteristic in terms of the relations between air flow, pressure ratio and efficiency was presented. The variations of the efficiencies of both the high and low pressure turbines were also presented. Almost constant flow functions of both turbines were predicted. The current methodology and obtained data can be utilized for performance diagnosis.