• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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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.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.18-24
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• 2012

This study simulated the operation of a steam injected gas turbine combined heat and power (CHP) system. A full off-design analysis was carried out to examine the change in the turbine blade temperature caused by steam injection. The prediction of turbine blade temperature was performed for the operating modes suggested in the previous study where the limitation of compressor surge margin reduction was analyzed in the steam injected gas turbine. It was found that both the fully injected and partially injected operations suggested in the previous study would cause the blade temperature to exceed that of the pure CHP operation and the under-firing operation would provide too low blade temperature. An optimal operation was proposed where both the turbine inlet temperature and the injection amount were modulated to keep both the reference turbine blade temperature and the minimum compressor surge margin. The modulation was intended to maintain a stable compressor operation and turbine life. It was shown that the optimal operation would provide a larger power output than the under-firing operation and a higher efficiency than the original partially injected operation.

• Journal of Hydrogen and New Energy
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• v.28 no.5
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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.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3224-3229
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• 2007

This study aims to analyse the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. The steam is generated by recovering heat from the exhaust gas. Two system configurations, with difference being the operating pressure of the SOFC, are examined and effects of steam injection on performances of the two systems are compared. Two representative gas turbine pressure ratios are simulated and a wide range of both the fuel cell temperature and the turbine inlet temperature is examined. Without steam injection, the pressurized system generally exhibits better system efficiency than the ambient pressure system. Steam injection increases system power capacity for all design cases. However, its effect on system efficiency varies much depending on design conditions. The pressurized system hardly takes advantage of the steam injection in terms of the system efficiency. On the other hand, steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. A higher pressure ratio provides a better chance of efficiency increase due to steam injection.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.86-89
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• 2001

Present study deals with performance analysis and experimental investigation of an inert gas generator (IGG) which can be used as effective means to suppress fire. The IGG uses a turbo-jet engine to generate inert gas for fire extinguishing. It is generally known that a less degree of oxygen content in the product of combustion will increase the effectiveness of fire extinguishing. An inert gas generator system with water injection has advantages of suffocating and cooling effects that are very Important factors for fire extinguishing. Some aspects of influencing parameters, such as, air excess coefficient, compressor pressure ratio, air temperature before combustion chamber, gas temperature after combustion chamber, mass flow rate of water injection etc. on the performance of IGG system are investigated.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.56-56
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• 2012

본 연구는 가정용 및 산업용 유해가스제거용 필터여재의 제조에 관한 것으로 핫멜트(hot-melt) 분사 시스템에 의한 다층구조의 부직포와 활성탄 등의 흡착물질로 구성되는 샌드위치 복합시트 및 필터여 재의 제조에 사용되는 구성재료의 최적화에 관한 연구이다. 스프레이 본딩 시스템에 의한 공정은 종래의 유해가스제거용 필터 미디어의 제조하는 방법인 활성탄과 바인더 역할을 하는 핫멜트 수지를 혼합하여 부직포 원단에 도포하여 활성탄을 부착시키는 공정에 비해 도포되는 핫멜트 수지의 양이 감소에 의한 생산비절감과 충분한 활성탄 도포에 의한 기능성 향상 등에 의해 유해가스 포집율을 높일 수 있으며 공정 이후 스프레이에 의해 도포된 핫멜트수지의 자연건조 방식에 의한, 열원이 불필요하며, 에너지가 절감되며, 속도 향상에 의한 생산성 향상, 분진발생 최소화로 인한 제조현장의 환경개선이 가능할 것으로 사료된다. 1차적으로 본 연구의 필터제조의 최적화를 위해서 스프레이 본딩시스템에 효율적으로 사용가능한 다양한 수지를 검토하였으며, 기존 외산 캐빈필터여재의 미세구조 및 성능특성, 다양한 활성탄의 흡착성능검토, 사용 가능한 여재의 특성분석을 통해 다층구조의 필터 여재에 사용 가능한 구성재료의 최적화에 중심을 두었다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.13-20
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• 2011

In this paper, we proposed a system to raise gas safety management by using the wireless communication module and intelligent gas safety appliances. Our designed systems configure a micom-gas meter, an automatic extinguisher, sensors, and a wallpad. A micom-gas-meter monitors gas flow, gas pressure, and earthquake. An automatic fire extinguisher checks gas(combustible) leaks and temperature of $100^{\circ}C$ and $130^{\circ}C$. Sensors measure smoke and CO gas. In our novel system, a micom-gas meter cut off inner valve with warnings, an automatic fire extinguisher cut off middle valve and spray extinguishing materials, and sensors generate signals for smoke and CO when occurring gas risk. Gas safety appliances and sensors takes safety measures, and transmit those signal to a wallpad. The wallpad again transmit signal like events to a control server. Users can connect web pages for gas safety through B-ISDN and control and manage them. We hereby devised scenarios for gas safety and risk management, and demonstrated their effectiveness through experiments.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.128-135
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• 2012

In this paper, we proposed a system and a scenario to raise efficiency of gas safety management by developing wireless ZigBee communication modules, smart-home gas safety appliances and the system suitable for gas safety. Our designed system consists of a micom gas meter, an automatic extinguisher, sensors, and a wall-pad. A micom-gas-meter monitors gas flow, gas pressure, and earthquake. An automatic fire extinguisher checks combustible gas leaks and temperature of $100^{\circ}C$(cut off) and $130^{\circ}C$(fire). Sensors measure smoke and CO gas. In our novel system, a micom-gas meter cut off inner valve with warnings, an automatic fire extinguisher cut off middle valve and spray extinguishing materials, and sensors generate signals when detecting smoke and CO and then take a next action. Gas safety appliances and sensors automatically takes measures, and transmit those information to a wall-pad. The wall-pad again transmits real time information to server. Users can check and manage gas safety situations by connecting BcN server through web or mobile application. We hereby devised scenarios for gas safety and risk management based on the smart, and demonstrated their efficiency through test applied to filed.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3090-3095
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• 2008

In this study, variable compression ratio system(VCRS) was applied on the heavy-duty CNG engine and the characteristics of power and emission was investigated according to the increasing of compression ratio. As compression ratio increasing, the increasing of thermal efficiency in direct injection is three times higher than that in port injection. The emission of HC and CO in direct injection is reduced about 14.2%, 17.7% but NOx is increased because of increasing temperature in cylinder.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.27-27
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• 1998

연구소기내에서 원활한 연소를 위하여 액체의 균일하고 완전한 미소분열 문제는 매우 중요한 연구분야라 할 수 있으며, 특히 항공기용 가스터빈 연소기에 사용되는 분사 시스템의 설계시에는 단순한 미소분열 문제뿐 아니라 시동성 향상, 화염의 안정화, 공해물질의 저감 등은 물론 압력 차가 작고 유량범위가 넓으며 공기를 이용한 미립화(Atomization)의 효율이 낮은 영역, 즉, 시동(Start-up) 및 플레임 아웃(Flame-out)근처의 영역에서도 효율적인 미립화가 이루어지도록 고려되어져야 한다.